5. World Geography(www.upscpdf.com)

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 1

THE UNIVERSE AND SOLAR SYSTEM Content: The Universe Origin of the universe The Units of Measuring distances in the Universe GALAXY Our Own Galaxy: The Milky Way STARS Birth and Evolution of a Star Formation of a Protostar Formation of a Star from Protostar Final Stages of a Star̛ s Life Formation of Supernova Star and Neutron Star Black Holes The Solar System Sun Planets Satellites (or Moons) Asteroids Comets Meteors The Shape of the Earth Evidence of the earth’s Sphericity The Earth’s Movement Day and Night The Earth’s Revolution Varying Lengths of Day and Night The Altitude of the Midday Sun www.visionias.in

©Vision IAS

Page 1 of 2

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Seasonal Changes and their Effects on Temperature Dawn and Twilight ECLIPSE Lunar Eclipse Solar Eclipse The Geographical Grid- Latitude and Longitude Latitude Longitude Longitude and Time Standard Time and Time Zones

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

Page 2 of 2

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

The Universe The vast space surrounding us is called universe. It is mostly empty space. The universe includes everything that exists: the most distant stars, planets, satellites, as well as our own earth and all the objects on it. Nobody knows how big the universe is or whether it has any limits. However, it is estimated that the Universe contains 100 billion galaxies, each of which comprises 100 billion stars. The sun which sustains all the life on our planet is only one of the billions and billions of stars that exist in this universe, whereas the planet earth on which we live is only a tiny speck in this vast space called universe. The earth is one of the eight planets, all of which revolve around a central star called sun. The billions stars which exists in the universe are not distributed uniformly in space. These stars occur in the form of clusters (or groups) of billions of stars called galaxies. Thus, in order to study the constitution of this universe we have to first discuss the objects like galaxies, stars, planets and satellites, etc., which are found in the universe.

Origin of the universe The most popular argument regarding the origin of the universe is the Big Bang Theory. It is also called expanding universe hypothesis. Edwin Hubble, in 1920, provided evidence that the universe is expanding. As time passes, galaxies move further and further apart. The distance between the galaxies is found to be increasing and thereby, the universe is considered to be expanding. Here, the expansion of universe means increase in space between the galaxies. However, Scientists believe that though the space between the galaxies is increasing, observations do not support the expansion of galaxies in itself. An alternative to this was Hoyle’s concept of steady state. It considered the universe to be roughly the same at any point of time. It did not have a beginning and did not have an end. However, with greater evidence becoming available about the expanding universe, scientific community at present favours argument of expanding universe.

Stages in Big Bang Theory (i)

(ii)

(iii)

In the beginning, all matter forming the universe existed in one place in the form of a “tiny ball” (singular atom) with an unimaginably small volume, infinite temperature and infinite density. At the Big Bang the “tiny ball” exploded violently. This led to a huge expansion. It is now generally accepted that the event of big bang took place 13.7 billion years before the present. The expansion continues even to the present day. As it grew, some energy was converted into matter. There was particularly rapid expansion within fractions of a second after the bang. Thereafter, the expansion has slowed down. Within first three minutes from the Big Bang event, the first atom began to form. Within 300,000 years from the Big Bang, temperature dropped to 4,500 K and gave rise to atomic matter. The universe became transparent.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Evidences in support of Big Bang Theory Evidence

Interpretation

The light from other galaxies is red-shifted.

The other galaxies are moving away from us.

The further away the galaxy, the more its light is red-shifted.

The most likely explanation is that the whole universe is expanding. This supports the theory that the start of the universe could have been from a single explosion.

Cosmic Microwave Background

The relatively uniform background radiation is the remains of energy created just after the Big Bang.

According to Nebular Hypothesis the planets were formed out of a cloud of material associated with a youthful sun, which was slowly rotating. The theory was give by German Philosopher Immanuel Kant (Though he did not use word Nebular) and later revised by Mathematician Laplace in 1796. You will learn about Kant in Moral Thinkers (GS Paper IV).

The Units of Measuring distances in the Universe  The extremely vast distances between the various heavenly bodies like the stars and GALAXY planets can be well expressed in terms Astronomical Unit (A.U), Light year, and Parsec. Galaxies are building blocks of the universe. Galaxy is a vast system of billions of stars, which  Astronomical unit is defined as the mean distance from the earth to the sun. One AU is also contains a large8 number of gas clouds mainly of hydrogen gas (where stars are born), and equal to 1.5×10 kilometres. dust, isolated in space from similar system.  Light year is the distance travelled by light in one year. It is equal to 9.46×10¹² kilometres. Classification of galaxies  Parsec: It represents the distance at which the radius of Earth’s orbit subtends an angle Galaxies are usually the basis of equals their shape and3.26 are of three types of one second classified of arc. onOne parsec about light-years or :30.9 trillion kilometres. 1) Spiral 2) Elliptical 3) Irregular Some of the brightest galaxies are elliptical galaxies but spiral galaxies are usually much bigger than others. We live on the outer edge of a spiral type of galaxy called milky way.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Our Own Galaxy: The Milky Way It is a spiral type of galaxy. It is about 100000 light years in diameter and has disk-shaped structure. The Milky Way galaxy is rotating slowly about its centre in the counter-clockwise direction. All the stars (The sun too along with the solar system) rotate about the centre of the Milky Way galaxy. The disc of stars is quite thick at the centre representing a relatively high concentration of the stars at the centre of the galaxy. The sun is far away(~27000 LY) from the centre of the Milky Way galaxy. Since the Milky Way galaxy appears like a river of light in the night sky running from one corner of the sky to the other, it is called ̒Akash Ganga ̓.

      

STARS Stars are the heavenly bodies like the sun that are extremely hot and have light of their own. Stars are made up of vast clouds of hydrogen gas, some helium and dust. In all the stars (including the sun), hydrogen atoms are continuously being converted into helium atoms and a large amount of nuclear energy in the form of heat and light is released during this process. It is this heat and light which makes a star shine. Thus, a star is a hydrogen nuclear energy furnace, so big that it holds together by itself. The stars are classified according to their physical characteristics like size, colour, brightness and temperature. Stars are of three colours: red, white and blue. The colour of a star is determined by its surface temperature. The stars which have comparatively low surface temperature are red, the star having high surface temperature are white whereas those stars which have very high surface temperature are blue on colour. Some of the important example of the stars are: Pole (or Polaris), Sirius, Vega, Capella, Alpha centauri, Beta centauri, Proxima centauri, Spica, Regulus, Pleiades, Aldebaram, Arcturus, Betelgeuse, and of course, the Sun.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

All the stars (except the pole star) appear to move from east to west in the night sky. This can be explained as follows: the earth itself rotates on its axis from west to east. So, when the earth rotates on its axis from west to east, the stars appear to move in the opposite direction, from east to west. Thus, the apparent motion of the stars in the sky is due to the rotation of the earth on its axis. Since we are ourselves on the earth, the earth appears to be stationary to us but the stars appear to be moving in the sky. Thus, it is due to the rotation of earth on its axis that we see the stars changing their positions in the sky as the night progresses.

Birth and Evolution of a Star The raw material for the formation of a star is mainly hydrogen gas and some helium gas. The life cycle of a star begins with the gathering of hydrogen gas and helium gas present in the galaxies to form dense clouds of these gases. The stars are then formed by the gravitational collapse of these over-dense clouds of gases in the galaxy. Let us deal the various stages in the formation of star-

Formation of a Protostar In the beginning, the gases in the galaxies were mainly hydrogen with some helium. However, they were at a very low temperature of about, -173°C. Since the gases were very cold, they formed very dense clouds in the galaxies. In addition, the gas cloud was very large, so the gravitational pull between the various gas molecules was quite large. Due to large gravitational force, the gas cloud started contracting as a whole. Ultimately, the gas were compressed so much that they formed a highly condensed object called a protostar. A protostar looks a like a huge, dark, ball of gas. The formation of protostar is only a stage in the formation of complete star. A protostar does not emit light. The next stage consists in the transformation of this highly condensed object called protostar into a star which emits light. Formation of a Star from Protostar The protostar is a highly dense gaseous mass, which continues to contract further due to tremendous gravitational force. As the protostar begins to contract further, the hydrogen atoms present in gas cloud collide with one another more frequently. These collisions of hydrogen atoms raise the temperature of protostar more and more. The process of contraction of protostar continues for about a million years during which the inner temperature in the protostar increases from a mere, -173°C in the beginning to about 107°C. At this extremely high temperature, nuclear fusion reactions of hydrogen start taking place. In this process, four small hydrogen nuclei fuse to produce a bigger helium nucleus and a tremendous Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

amount of energy is produced in the form of heat and light. The energy produced during the fusion of hydrogen to form helium makes the protostar glow and it becomes a star. This star shines steadily for a very, very long time. Final Stages of a Star̛ s Life In the first part of the final stage of its life, a star enters the red-giant phase where it becomes a red-giant star. After that, depending on its mass, the red-giant star can die out by becoming a white dwarf star, or by exploding as a supernova star, which ultimately ends in the formation of neutron star and black holes. (1)

Red- Giant Phase. Initially, the stars contain mainly hydrogen. With the passage of time, hydrogen gets converted into helium from the centre outwards. Now, when all the hydrogen present in the core of the star gets converted into helium, then the fusion reactions in the core would stop. Therefore, ultimately, the matter in the core of the star would consist only of helium. Due to the stoppage of fusion reactions, the pressure inside the core of the star would diminish, and the core would begin to shrink under its own gravity. In the outer shell or envelope of the star, however, some hydrogen still remains, the fusion reactions would continue to liberate energy but with much reduced intensity. Due to all these changes, the overall equilibrium in the star is upset and in order to readjust it, the star has to expand considerably in its exterior region(outer region). Thus the star becomes very big ( it becomes a giant), and its colour changes to red. At this stage, the star enters the red-giant phase and it is said to become a red-giant star. Our own star, the sun, will ultimately turn into a red-giant star after about 5000 million year from now. The expanding outer shell of the sun will then become so big that it will engulf the inner planets like mercury and Venus, and even the earth. When a star reaches the red-giant phase, then its future depends on its initial mass. Two cases arise: (a) If the initial mass of the star is comparable to that of the sun, then the redgiant star loses its expanding outer shell and its core shrinks to form a white dwarf star which ultimately dies out as a dense lump of matter into the space. (b) If the initial mass of the star is much more than of the sun, then the redgiant star formed from its explodes in the form of a supernova star, and the core of this exploding supernova star can shrink to form a neutron star or black hole.

(2)

Formation of White Dwarf Star: If the mass of red-giant star is similar to that of the sun, the red-giant star would lose its expanding outer shell or envelope because then the comparatively smaller amount of hydrogen fuel present in it will be used up rapidly, and only the core of the red-giant star will gradually shrink into an extremely dense ball of matter due to gravitation. Because of this enormous shrinking of helium core, the temperature of core would rise greatly and start another set of nuclear fusion reactions in which helium is converted into heavier elements like carbon, and an extremely large amount of energy will be released. When the mass of a star is similar to the mass of the sun (which is comparatively a small mass), then all the helium is converted into carbon in a short time and then further fusion reactions stop completely. Now, as the energy being produced inside the star stops, the core of star contracts (shrinks) under its own weight. And it becomes a white dwarf star.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

A great Indian scientist Chandrasekhar made a detailed study of the stars which end their lives by becoming white dwarf stars. Chandrasekhar concluded that the start having a mass less than 1.44 times the solar mass (or sun’s mass) would end up as white dwarf stars. The maximum limit of 1.44 times the solar mass (for a star to end its life as a white dwarf) is known as ‘Chandrasekhar Limit’. If, however, a star has a mass more than 1.44 times the solar mass or sun’s mass, then it will not die out by becoming a white dwarf star. This is because due to greater mass, it will have more nuclear fuel in it, which will not get exhausted in a short time. The stars having mass much more than solar mass (or sun’s mass) led to supernova explosions and end their lives by becoming neutron stars or black holes. This point will become clearer from the following discussion: Formation of Supernova Star and Neutron Star: When a very big star is in the red-giant phase, then being big, its core contains much more helium. This big core made up of helium continues to contract (shrink) under the action of gravity producing higher and higher temperature. At this extremely high temperature, fusion of helium into carbon takes place in the core and lot of energy is produced. Since the star was very big and contained enormous nuclear fuel helium, so a tremendous amount of nuclear energy is produced very rapidly which causes the outer shell (or envelope) of this red-giant star to explode with a brilliant flash like a nuclear bomb. This type of ‘exploding star is called supernova. The energy released in one second of a supernova explosion is equal to the energy released by the sun in about 100 years. This tremendous energy would light up the sky for many days. When a supernova explosion takes place, then clouds of gases in the envelope of red-giant star are liberated into the space and these gases act as raw material for the formation of new stars. The heavy core left behind after the supernova explosion continues to contract and ultimately becomes a neutron star (if mass of star was 1.44 time to 3 times the Sun) or Black Hole (if the mass of star was more than 3 times the sun). A neutron star contains matter in even denser form than found in white dwarf stars. Although a number of white dwarfs have been detected, but no one has yet observed a neutron star. This may be because neutron stars are very faint. A spinning neutron star emits radio waves and is called a pulsar.

Black Holes A black hole is an object with such a strong gravitational field that even light cannot escape from its surface. A black hole may be formed when a massive object (very big object) undergoes uncontrolled contraction (a collapse) because of the inward pull of its own gravity. We will now describe how the black holes are formed from neutron stars after the supernova explosions of big stars. When a supernova explosion of a very massive star takes place, then the gaseous matter present in the outer shell(or envelope) of the star is scattered into space but the core of the star survives during supernova explosion. This heavy core of the supernova star continues to contract (shrink) and becomes a neutron star. The fate of this neutron star depends on its mass. If the neutron star is very heavy, then due to enormous gravitational attraction, it would continue to contract indefinitely. And the vast amount of matter present in a neutron star would be ultimately packed into a mere point object. Such an infinitely dense object is called a black hole. Thus black holes are formed by the indefinite contraction of heavy neutron stars under the action of their own gravity. The neutron stars shrink so much and become so dense that the resulting black holes do not allow anything to escape, not even light, from their surface. This is because the black holes have tremendous gravitational force. Since even light cannot escape from blackholes, therefore, black holes are invisible, they Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

cannot be seen. The presence of a black hole can be felt only by the effect of its gravitational field on its neighbouring objects in the sky. For example, if we see a star moving in a circle with no other visible stars in the centre, then we can conclude that there is a black hole at the centre. And it is the gravitational pull exerted by this black hole which is making the star goes in a circle around it.

Dark matter1 Dark matter is a type of matter hypothesized in astronomy and cosmology to account for a large part of the mass that appears to be missing from the universe. Dark matter cannot be seen directly with telescopes; evidently it neither emits nor absorbs light or other electromagnetic radiation at any significant level. Dark Matter is not exactly balck hole. The composition of the constituents of cold dark matter is currently unknown. It could be group of black holes, dwarfs or some new particle.

The Solar System The solar system consists of the sun, the eight planets and their satellites, and thousands of other smaller heavenly bodies such as asteroids, comets and meteors. The Solar System is at a distance of about 27,000 light years from the centre of the Milky Way galaxy and is about 5 billion years old. The sun is at the centre of the solar system and all these bodies are revolving around it. The gravitational pull of the sun keeps all the solar system and all the planets and other objects revolving round it. Thus, the motion of all members of the solar system is governed mainly by the gravitational force of the sun. The solar system is dominated by the sun. The sun accounts for almost 99.9 percent of the matter in the whole solar system. The sun is also the source of all the energy in the solar system.

Sun The sun is the head of solar family or solar system. Compared with the millions of other stars, the sun is a medium sized star and of average brightness... Though sun is the nearest star to the earth, even then it is at a distance of 150×106kilometres from the earth and light, travelling at a great speed of 300,000 kilometres per second, takes about 8 minutes and 20 seconds to reach us from the sun. However, light takes about 4.3 years to reach us from the next nearest star called proxima centauri. Sun is not a solid body. The sun is a sphere of hot gases. It consists mostly of hydrogen gas.. The nuclear fusion reactions taking place in the centre of the sun( in which hydrogen is converted into helium) produce a tremendous amount of energy in the form of heat and light. It is this energy, which makes the sun shine From the Earth, we see only the surface of the sun. The shining surface of the sun is called photosphere. The surface of the sun (photosphere) appears like a bright disc to us, it is also known as disc of the sun. It is this bright, shining disc of the sun (or photosphere) which radiates energy and acts as a source of energy for us. The temperature at the sun (or the temperature of the bright disc of the sun) is about 6000°C. The temperature at the centre of the sun is about 15 million °C. The outer layer of the sun’s atmosphere made up of thin, hot gases is called corona. The corona is visible only during a total eclipse of the sun. 1

Details of dark matter and dark energy will be discussed in Science and Technology notes.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Planets Planets are solid heavenly bodies which revolve round a star (e.g. the sun) in closed elliptical paths. A planet is made of rock and metal. It has no light of its own. A planet shines because it reflects the light of the sun. since the planets are much nearer than the stars, they appear to be big and do not twinkle at night. The planets move round the sun from west to east, so the relative positions of the planets keep changing day by day. The planets are very small as compared to the sun or other stars. There are 8 major planets including the earth. These planets in the order of increasing distances from the sun are given below1. 2. 3. 4. 5. 6. 7. 8.

Mercury (Budha): it is nearest to the sun. Venus ( Shukra) Earth (Prithvi) Mars (Mangal) Jupiter (Brihaspati): Biggest Planet. Saturn (Shani) Uranus (Arun) Neptune (Varun)

IAU new definition of planet The definition of planet set in 2006 by the International Astronomical Union (IAU) states that, in the Solar System, a planet is a celestial body which:  is in orbit around the Sun,  has sufficient mass to assume hydrostatic equilibrium (a nearly round shape), and  Has "cleared the neighbourhood" around its orbit. For this they become the dominant gravitational body in their orbit in the Solar System. Pluto lacks it. Any object if meet the first two criteria but doesn’t meet the 3rd criteria is considered a dwarf planet. Thus Pluto is a dwarf planet.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Planets and dwarf planets of our solar system (Milky Way) The 8 planets have been divided into two groups. All the planets of a particular group have some common features. The two groups of planets are: 1. Terrestrial Planets 2. Jovian Planets The four nearest planets to the Sun, Mercury, Venus, Earth and Mars, are called terrestrial planets, because their structure is similar to earth. The common features of the terrestrial planets are: 1. 2. 3. 4. 5.

They have a thin, rocky crust. They have a mantle rich in iron and magnesium. They have a core of heavy metals. They have thin atmosphere. They have very few natural satellites (or moons) or no satellites.

They have varied terrain such as volcanoes, canyons, mountains, and craters. The planets which are outside the orbit of Mars are called Jovian planets because their structure is similar to that of Jupiter. The Jovian planets are: Jupiter, Saturn, Uranus, and Neptune. The common features of the Jovian planets are: 1. They are all gaseous bodies (made of gases) 2. They have ring system around them. 3. They have a large number of natural satellites (or moons).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Solar System Fact Sheet Sun

Mass (1024k g) Diameter (k m) Density (kg/ m3) Gravity (m/ s2) Escape Velocity (k m/s) Rotation Period (hou rs) Length of Day (hours) Distance from Sun (106 k m) Perihelion ( 106 km) Aphelion (1 06 km) Orbital Period (day s) Orbital Velocity (k m/s) Orbital Inclination ( degrees) Orbital Eccentricity Axial Tilt (degree s) Mean Temperatur e (C) Surface Pressure (b ars)

1,988 ,500 1,392 ,684 1,408

(For reference only. Do not try to memorise facts.) VE MER NU EAR MO MA JUPIT SATU CURY S TH ON RS ER RN 4.8 5.9 0.0 0.6 0.33 7 7 73 42 1898 568 12, 12, 347 67 142,9 120,5 4879 104 756 5 92 84 36 524 551 334 39 5427 3 4 0 33 1326 687 3.7

Student Notes: URA NUS

NEPT UNE

86.8 102 51,11 49,52 8 8

PLUT O 0.013 1 2390

1271

1638

1830

8.9

9.8

1.6

3.7

23.1

9

8.7

11

0.6

10. 4 583 2.5 280 2

11. 2

2.4

5

59.5

35.5

21.3

23.5

1.1

24. 6 24. 7

9.9

10.7

-17.2

16.1

153.3

24

655 .7 708 .7

9.9

10.7

17.2

16.1

153.3

69.8

108 .2 107 .5 108 .9

149 .6 147 .1 152 .1

0.3 84 0.3 63 0.4 06

22 7.9 20 6.6 24 9.2

88

224 .7

365 .2

27. 3

68 7

4331

10,74 7

47.9

35

29. 8

1

24. 1

13.1

9.7

6.8

5.4

4.7

7

0 0.0 17

5.1 0.0 55

1.9 0.0 94

1.3

2.5

0.8

1.8

17.2

0.205

3.4 0.0 07

0.01

177 .4

23. 4

6.7

25. 2

3.1

26.7

97.8

28.3

122.5

167

464

15

-20

-65

-110

-140

-195

-200

-225

0

92

1

0

0.0 1

Unkn own

Unkn own

Unkn own

Unkn own

0

4.3 1407. 6 4222. 6

57.9 46

23. 9

1433. 2872. 4495. 5 5 1 5870 1352. 2741. 4444. 740.5 6 3 5 4435 1514. 3003. 4545. 7304. 816.6 5 6 7 3 778.6

0.049 0.057

30,58 59,80 90,58 9 0 8

0.046 0.011 0.244

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF Number of Moons Ring System? Global Magnetic Field?

https://t.me/UPSC_PDF

0

0

1

0

2

67

62

27

14

5

No

No

No

No

No

Yes

Yes

Yes

Yes

No

Yes

Unkn No Yes No No Yes Yes Yes Yes own (Source: http://nssdc.gsfc.nasa.gov/planetary/factsheet/)

Satellites (or Moons) A satellite (or moon) is a solid heavenly body that revolves round a planet. The moon revolves round the earth, so moon is a satellite of the earth.. Except Mercury and Venus all other planets of solar system have satellites. The satellites have no light of their own. They shine because they reflect the light of the sun. It should be noted that though we commonly call earth’s natural satellite as moon, the satellites of all other planets can also be called their moons.

Earth’s moon key pointsThe moon is a natural satellite of the earth. Moon revolves round the earth on a definite, regular path- the moon’s orbit. Gravitational attraction of the earth holds the moon in its orbits. The moon is about one-fourth the size of the earth in diameter and weight is about one-eighth that of the earth. Moon has no air or water. Its surface is covered with hard and loose dirt, craters and mountains. On the moon, days are extremely hot and nights are very cold. Because the moon is nearer to the earth, it appears to be much bigger than the stars. The moon has no light of its own, it is light from the sun which is reflected by the moon’s surface.

       

Origin of Moon In 1838, Sir George Darwin suggested that initially, the earth and the moon formed a single rapidly rotating body. The whole mass became a dumb-bell-shaped body and eventually it broke. It was also suggested that the material forming the moon was separated from what we have at present the depression occupied by the Pacific Ocean. However, the present scientists do not accept either of the explanations. It is now generally believed that the formation of moon, as a satellite of the earth, is an outcome of ‘giant impact’ or what is described as “the big splat”. A body of the size of one to three times that of mars collided into the earth sometime shortly after the earth was formed. It blasted a large part of the earth into space. This portion of blasted material then continued to orbit the earth and eventually formed into the present moon about 4.44 billion years ago. Other Objects in the sky: In addition to the stars, planets and satellite, there are three other objects which we can occasionally see in the sky during night. These are asteroids, comets and meteors. We will discuss all of them one by one.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Asteroids Asteroids are very small planets of rock and metal which revolve round the sun mainly between the orbits of mars and Jupiter. Actually, asteroids are a belt of a kind of debris, which somehow failed to assemble into a planet and keep revolving between the orbits of mars and Jupiter. There may be as many as 100,000 asteroids. The biggest asteroid called ‘ceres’ has a diameter of about 800 kilometres whereas the smallest asteroid is as small as pebble. Some experts believe that asteroids are the pieces of a planet that went close to Jupiter and was broken up by its gravitational pull. Others think that they are part of a ring of separate pieces of matter formed at the same time as the planets. Sometimes an asteroid can collide with earth. Though the collision of an asteroid with the earth happens very rarely, even then a careful watch is kept on the motion of asteroids by the astronomers. This is because the collision of an asteroid with the earth can cause a lot of damage to life and property on the earth. In fact, the extinction of dinosaurs the earth which occurred about 65 million years ago, is believed to have been caused by the collisions of some asteroids with the earth. When an asteroid collides with the earth, then a huge crater is formed on the surface of the earth. Many such collisions of the asteroids must have occurred in the past during the entire history of the earth which may have caused craters of different sizes on its surface. However, the natural process of soil erosion like wind and rain, tend to fill up these craters in due course of time. Only a few such craters survived on the surface of the earth so far. The ‘Lonar Lake’ in Maharashtra is one such crater formed by the collision of an asteroid with the earth.

Comets According to new definition, Neptune is the outermost planet of the solar system. However, it’s orbit does not mark the boundary of the solar system. The solar system extends much beyond at the edge of the solar system, there are billions of very small objects called ‘comets’ these comets were formed very early from the same gas cloud from which other members of the collar system were made. These comets are so far off that normally they cannot be seen. They keep on revolving around the Sun, unknown to the world. Sometimes, however, the normal path of a comet is disturbed and the comet starts moving towards the sun. As the comet approaches the sun, it develops a long, glowing tail and becomes visible only when it approaches the sun because the sun’s rays make its gas glow which spreads out to form a tail millions of kilometres long. And it presents a spectacular sight. Thus, a comet is a collection of gas and dust, which appears as a bright ball of light in the sky with a long glowing tail. The tail of a comet always points away from the sun. Comets revolve around the sun like planets. The period of revolution of comets around the sun is, however, very large. For example, Halley’s Comet has a period of about 76 years. Halley's Comet last appeared in the inner Solar System in 1986 and will next appear in mid-2061. Just like asteroids, comets are also of great interest to scientists. This is because they are made of the same material from which the whole solar system was made. The study of the tail of the comets has shown the existence of molecules of carbon, oxygen, hydrogen and nitrogen such as CO, CH4 and HCN on it. Since these simple molecules help to form complex molecules necessary for the origin of life, some scientist have suggested that the seeds of life on the earth were brought by comets from the outer space. Comets do not last forever. Each time a comet passes the sun, it loses some of its gas and ultimately only the dust particles are left in space.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

When these particle enter into the earth’s atmosphere, they burn up due to heat produced by air resistance and produce a shower of meteors or shooting stars.

Meteors Many times we see a streak of light in the sky during night which disappears within seconds. It is called a meteor or shooting star. Meteors are the heavenly bodies from the sky which we see as a bright streak of light that flashes for a moment across the sky. The meteors are also called shooting stars. Some meteors are the dust particles left behind by comets and others are the pieces of asteroid which have collided. When a meteor enters into the atmosphere of earth with high speed, a lot of heat is produced due to the resistance of air. This heat burns the meteor and the burning meteor is seen in the form of a streak of light shooting down the sky, and it falls on the earth in the form of dust. If a meteor is big, a part of it may reach the earth’s surface without being burned up in air. This fragment is called a meteorite. Thus, a meteor which does not burn completely on entering the earth’s atmosphere and lands on earth is known as a meteorite. Meteorites are a sort of stones from the sky. By studying the composition of meteorites we can get valuable information about the nature of the material from which the solar system was formed. It should be noted that the number of meteorites striking the moon’s surface is quite large whereas very few meteorites reach the earth’s surface. This is due to the fact moon has no atmosphere to burn the falling meteorites by producing the frictional heat.

The Shape of the Earth In ancient times, people believed that the shape of the Earth was flat and it had steep edges. Today we know that the Earth is almost spherical. However, it is not a perfect sphere, rather it an oblate spheroid, bulging slightly at the equator and flattened slightly at the poles. The difference between the equatorial diameter and the polar diameter is less than 44 km. The diameter of the Earth is 12,756 km at the equator, whereas it is 12,712 km between the poles. This is due to the centrifugal force caused by the Earth’s rotation around its axis. This difference is insignificant and thus for all practical purposes the Earth is taken as spherical in shape. The view that the Earth is spherical in shape was first forwarded by the famous Greek philosopher, Phagoras, in the sixth century BC. But people did not believe him. Later, Aristotle, Varahamihira, Aryabhata and Copernicus also opined that the Earth is spherical in shape.

Evidence of the earth’s Sphericity There are many ways to prove that earth is spherical. The following are some of them. 1. The Sun and the other planets in the Solar System are all spherical in shape. 2. If the Earth was flat, then all the places on the Earth would have had sunrise and sunset exactly at the same time. 3. If we watch a ship approaching the land, first we see the smoke of the ship (as the entire ship lies below the line of sight) and gradually the entire ship, as it comes up over the horizon. If the Earth was flat, we would have been able to see the whole ship at a time. 4. A circular shadow observed during the lunar eclipse can only be cast by a spherical body. 5. If you look around from any place, whether a mountain, a level plain, or top of a very tall building, the horizon will always appear circular. This is possible only in case of a spherical body. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

6. Magellan’s circumnavigation in 1520 proved that the Earth is spherical in shape. 7. Engineers when driving poles of equal length at regular intervals on the ground have found that they do not give a perfect horizontal level. The centre pole normally projects slightly above the poles at either end because of the curvature of the earth. 8. Nowadays, when you can see the Earth in its true perspective from the outer space, the fact that the shape of the Earth is spherical needs no further proof. Goldilocks zone A habitable zone, also called a Goldilocks zone, is the region around a star where orbiting planets similar to the Earth can support liquid water. It is neither too hot, nor too cold. Scientists hunting for life in the Solar System and around other stars believe liquid water is an important ingredient necessary for life. In September 2010 astronomers using the Keck telescope announced they had found an exoplanet, Gliese 581g2, about three times the size of Earth in the habitable zone of its star. The Earth is a unique planet because it sustains life. Here are some more details: 1. The Earth lies between the orbits of Venus and Mars and the average distance from the Sun is about 148 million km. This gives it the optimum location with reference to the distance from the Sun. It is neither too hot like Venus nor too cold like Mars and the outer planets. The average temperature is about 17°C on the side facing the Sun. 2. The Earth has a favourable environment and presents optimum conditions for the origin, growth and survival of various life forms. If the heat received from the Sun (insolation) increases or decreases by about 10 per cent, then a very large part of the Earth would become unsuitable for living organisms. 3. The rotation of the Earth around its axis, helps in keeping the extremes of temperatures between day and night well within tolerable limits. 4. The presence of adequate quantities of water in the oceans, seas, gulfs, rivers, lakes, etc., is a unique feature of our planet. Water occupies about 71 per cent of the total surface area of the Earth. These water bodies provide Ideal conditions for the origin and evolution of various life forms. The water cycle maintains the continuous flow of water on Earth. 5. The atmosphere acts as a shield and protects our planet from the harmful ultra-violet rays coming from the Sun. The atmosphere also absorbs terrestrial radiation from the Earth’s surface and thus keeps the Earth comparatively warmer during the night time and also during the winter season. 6. The presence of oxygen in the atmosphere has made life possible on Earth, as it is essential for respiration and survival of all living organisms.

Origin of Life on Earth Modern scientists refer to the origin of life as a kind of chemical reaction, which first generated complex organic molecules and assembled them. This assemblage was such that they could duplicate themselves converting inanimate matter into living substance. The record of life that existed on this planet in different periods is found in rocks in the form of fossils. The microscopic structures closely related to the present form of blue algae have been found in geological formations that are much older than these were some 3,000 million years ago. It can be assumed that life began to evolve sometime 3,800 million years ago. The summary of evolution of life from unicellular bacteria to the modern man is given in the Geological Time Scale on last page. 2

UPSC asked question on Gliese 581g

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

The Earth’s Movement In the Solar System, the Earth has a special relationship with the Sun and the Moon. The Earth revolves around the Sun, and the Moon revolves around the Earth. The Earth also rotates on its axis. These motions of the Earth cause days and nights, seasons, tides, eclipses, etc. Day and Night When the earth rotates on its own axis, only one portion of the earth’s surface comes into the rays of the sun and experiences daylight. The other portion which is away from the sun’ rays will be in darkness. As the earth rotates from west to east, every part of the earth’s surface will be brought under the sun at some time or other, a part of the earth’s surface that emerges from darkness into the sun’s rays experiences sunrise. Later, when it is gradually obscures from the sun is in fact, stationary and it is the earth which rotates. The illusion is exactly the same as when we travel in a fast- moving train. The trees and houses around us appear to move and we feel that the train is stationary. The Earth’s Revolution When the earth revolves round the sun, it spins on an elliptical orbit and one complete revolution takes 365⅟4 days or a year. As it is not possible to show a quarter of a day in the calendar, a normal year is taken to be 365 days, and an extra day is added every four years as a Leap Year. The Earth rotates once in about 24 hours with respect to the sun and once every 23 hours 56 minutes and 4 seconds with respect to the stars. This is the reason why the stars rise four minutes early every next day. Earth's rotation is slowing slightly with time; thus, a day was shorter in the past. This is due to the tidal effects the Moon has on Earth's rotation. Atomic clocks show that a modern day is longer by about 1.7 milliseconds than a century ago. Leap seconds are used to synchronise atomic clock. Varying Lengths of Day and Night The axis of the earth is inclined to the plane of the ecliptic (the plane in which the earth orbits round the sun) at an angle of 66⅟2°, giving rise to different seasons and varying lengths of day and night. If the axis were perpendicular to this plane, all parts of the globe would have equal days and night at all times of the year, but we know this is not so. In the hemisphere in winter as we go northwards, the hours of darkness steadily increase. At the Arctic Circle (66⅟2°) the sun never ‘rise’ and there is darkness for the whole day in mid- winter on 22 December. Beyond the Arctic Circle the number of days with complete darkness increases, until we reach the North Pole (90°N) when half the year will have darkness. In the summer (June) conditions are exactly reversed. Daylight increases as we go polewards. At the Arctic Circle, the sun never ‘sets’ at mid-summer (21 June) and there is a complete 24-hour period of continuous daylight. In summer, the region north of the Arctic Circle is popularly referred to as “Land of the MidNight Sun’. At the North Pole, there will be six months of continuous daylight. In the southern hemisphere, the same process takes place, except that the conditions are reversed. When it is summer in the northern hemisphere, the southern conditions will experience winter. Mid- summer at the North Pole will be mid-winter at the South Pole.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

REVOLUTION OF EARTH The Altitude of the Midday Sun In the course of a year, the earth’s revolution round the sun with its axis inclined at 66⅟2 to the plane of the ecliptic changes the apparent altitude of the midday sun. The sun is vertically overhead at the equator on two days each year. These are usually 21 March and 21 September though the date changes because a year is not exactly 365 days. These two days are termed equinoxes meaning ‘ equal nights’ because on these two days all parts of the world have equal days and nights. After the March equinox the sun appears to move north and is vertically overhead at the Tropic of Cancer (23⅟2°N) on about 21 June. This is known as the June or summer solstice when the northern hemisphere will have its longest day and shortest night. By about 22 December, the sun will be overhead at the Tropic of Capricorn (23⅟2°S). This is the winter solstice when the southern hemisphere will have its longest day and shortest night. The Tropics thus marks the limits of the overhead sun, for beyond these, the sun is never overhead at any time of the year. Such regions are marked by distinct seasonal changes- spring, summer, autumn and winter. Beyond the Arctic Circle(66⅟2°N) and the Antarctic Circle (66⅟2°S)where darkness lasts for 6 months and daylight is continuous for the remaining half of the year, it is always cold; for even during the short summer the sun is never high in the sky. Within the tropics, as the midday sun varies very little from its vertical position at noon daily, the four seasons are almost equal all the year round.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Seasonal Changes and their Effects on Temperature Summer is usually associated with much heat and brightness and winter with cold and darkness. Why should this be so? In summer, the sun is higher in the sky than in winter. When the sun is overhead its rays fall almost vertically on the earth, concentrating its heat on a small area; temperature therefore rises and summer are always warm. In winter the oblique rays of the sun, come through the atmosphere less directly and have much of their heat absorbed by atmospheric impurities and water vapour. The sun’s rays fall faintly and spread over a great area. There is thus little heat, and temperatures remain low. In addition, days are longer than nights in summer and more heat is receives over the longer daylight duration. Nights are shorter and less heat is lost. There is a net gain in total heat received and temperature rise in summer. Shorter days and longer nights in winter account for the reverse effects. Dawn and Twilight The brief period between sunrise and full daylight is called dawn and that between sunset and complete darkness is termed twilight. This is caused by the fact that during the period the dawn and twilight the earth receives diffused or refracted light from the sun whilst it is still below the horizon. Since the sun rises and sets in a vertical path at the equator the period during which refracted light is received is short. But in temperate latitudes, the sun rises and sets in an oblique path and the period of refracted light is longer. It is much longer still at the poles, so that the winter darkness is really only twilight most of the time. ECLIPSE An eclipse occurs when the Sun, the Earth and the Moon are in a straight line in the plane of ecliptic. When the Earth obstructs the rays of the Sun from reaching the face of the Moon, the Moon gets eclipsed. When the Moon hides the face of the Sun, then it is an eclipse of the Sun. At anytime the Sun is able to light only half of the Earth’s surface which is facing the Sun. The other half, which is turned away from the Sun is in darkness. Lunar Eclipse A lunar eclipse will occur, only when the Sun, the Earth and the Moon are in a straight line, and the Earth lies between the Sun and the Moon. This is possible on a Full Moon day. But a lunar eclipse does not occur on every Full Moon day, as these three bodies have to be in the plane of ecliptic. a. If the Moon is exactly in the plane of ecliptic, a total lunar eclipse will occur. b. If the Moon is close to the plane of ecliptic, a partial lunar eclipse will occur. c. If the Moon is far above or far below the plane of ecliptic, no eclipse will occur. Solar Eclipse A solar eclipse will occur only when the Sun, the Earth and the Moon are in a straight line, and the Moon lies between the Sun and the Earth. This is possible on a New Moon day. But the solar eclipse does not occur on every New Moon day, as these three bodies have to be in the plane of ecliptic. a) If the Moon is exactly in the plane of ecliptic, a total solar eclipse will occur. b) If the Moon is close to the plane of ecliptic, a partial solar eclipse will occur. c) If the Moon is far above or far below the plane of ecliptic, no eclipse will occur. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The Diamond Ring Effect is a visual phenomenon that occurs during a total solar eclipse. It is seen from earth when standing in the umbra of the moon’s shadow, and occurs as a part of Baily’s Beads. Baily’s Beads are glimmers of the sun’s brilliant surface (the photosphere) which shine as dots of light around the disc of the lunar shadow. When only one “bead” remains, momentarily, the view of the eclipse resembles a diamond ring. The ring is produced as the sun’s less bright corona layer and other upper atmospheric structures remain dimly visible as a solid ring while a dazzling dot of the photosphere shines at the edge.

The Geographical Grid- Latitude and Longitude The earth’s surface is so vast that unless a mathematical method can be used, it is impossible to locate any place on it. For this reason, imaginary lines have been drawn on the globe. One set running east and west, parallel to the equator, are called lines of latitude. The other set runs north and south passing through the poles and are called lines of longitude. The intersection of latitude and longitude pin-points any place on the earth’s surface. For example Delhi is 28°37’N and 77°10’E.

Latitude Latitude is the angular distance of a point on the earth’s surface, measured in degrees from the centre of the earth. It is parallel to a line, the equator, which lies midway between the poles. These lines are therefore called parallels of latitude, and on a globe are actually circles, becoming smaller polewards. The equator represents 0° and the North and South Poles are 90°N and 90°S. Between these points lines of latitude are drawn at intervals of 1°. For precise location on a map, each degree is sub-divided into 60 minutes and each minute into 60 seconds. The most important lines of latitude are the equator, the tropic of Cancer (23⅟2°N.), the tropic of Capricorn (23⅟2°S.), the Arc c Circle (66⅟2°N.) and the Antarc c Circle (66⅟2°S.). As the earth is slightly flattened at the poles, the linear distance of a degree of latitude at the pole is a little longer than that at the equator. For example at the equator (0°) it is 68.704 miles, at 45° it is 60.054 miles and at the poles it is 69.407 miles. The average is taken as 69 miles. This is a useful figure and can be used for calculating distances to any place. Bombay is 18.55°N; it is therefore 18.55*69 or 1280 miles from the equator.

Latitude and Longitude Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Longitude Longitude is an angular distance, measured in degrees along the equator east or west of the Prime (or First) Meridian. On the globe longitude is shown as a series of semi-circles that run from pole to pole passing through the equator. Such lines are also called meridians. Unlike the equator which is centrally placed between the poles, any meridian could have been taken to begin the numbering of longitude. It was finally decided in 1884, by international agreement, to choose as the zero meridian the one which passes through the Royal Astronomical Observatory at Greenwich, near London. This is the Prime Meridian (0°) from which all other meridians radiate eastwards and westwards up to 180°. Since the earth is spherical and has a circumference calculated at 25,000 miles, in liner distance each of the 360 degrees of longitude is 25,000/360 or 69.1 miles. As the parallels of latitude become shorter polewards, so the meridians of longitude, which converge at the poles, enclose a narrower space. The degree of longitude therefore decreases in length. It is longest at the equator where it measures 69.172 miles. At 25° it is 62.73 miles, at 45° it is 49 miles, at 75° 18 miles and at the pole 0 mile. There is so much difference in the length of degrees of longitude outside the tropics, that they are not used for calculating distances as in the case of latitude. But they have one very important function; they determine local time in relation to G.M.T or Greenwich Mean Time, which is sometimes referred to as World Time.

Longitude and Time Local time: Since the Earth makes one complete revolution of 360° in one day or 24 hours, it passes through 15° in one hour or 1° in 4 minutes. The earth rotates from west to east, so every 15° we go eastward, local time is advanced by 1 hour. Conversely, if we go westwards, local time is retarded by 1 hour. We may thus conclude that places east of Greenwich see the dun earlier and gain time, whereas places west of Greenwich see the sun later and lose time. If we know G.M.T., to find local time, we merely have to add or subtract the difference in the number of hours from the given longitude, as illustrated below. A simple memory aid for this will be East-Gain-Add (E.G.A.) and West-Lose-Subtract (W.L.S.). You could coin your own rhymes for the abbreviations. Hence when it is noon, in London (Longitude 0°5W.), the local time for Chennai (80°E.) will be 5 hours 20 minutes ahead of London or 5.20 p.m. but the local time for New York (74°W.) will be 4 hours 56 minutes behind London or 7.04 a.m. Standard Time and Time Zones If each town were to keep the time of its own meridian, there would be much difference in local time between one town and the other. 10 a.m. in Georgetown, Penang would be 10.10 in Kota- Bharu (a difference of 2½° in longitude). In larger countries such as Canada U.S.A., China, India, and Russia the confusion arising from the differences alone would drive the people mad. Travellers going from one end of the country to the other would have to keep their appointments. This is impracticable and very inconvenient. To avoid all these difficulties, a system of standard time is observed by all countries. Most countries adopt their standard time from the central meridian of their countries. The Indian Government has accepted the meridian of 82.5° east for the standard time which is 5hrs. 30 minutes ahead of Greenwich Mean Time. The whole world has in fact been divided into 24 Standard Time Zones, each of which differs from the next by 15° in longitude or one hour in Time. Most countries adhere to this division but due to the peculiar shapes and locations of some countries, reasonable deviations from the Standard Time Zones cannot be avoided.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Larger countries like U.S.A. (9), Canada (6) and Russia (9) which have a great east-west stretch have adopted 9, 6 and 9 time zones respectively for practical purposes.

Daylight saving time (DST) is a change in the standard time with the purpose of getting better use of the daylight. Typically, clocks are adjusted forward one hour near the start of spring and are adjusted backward in the autumn. Although it has only been used in the past hundred years, the idea of DST was first conceived many years before.

Geological Time Scale The earth is believed to be 4.5 billion years old. The 4.5 billion year long history of the earth is divided into four era - Pre-Cambrian, Palaeozoic, Mesozoic and Calnozoic. Pre-Cambrian has been the longest era in the earth’s history and it continued from the origin of earth to about 600 million year ago from today. The eras are divided into periods, and the periods are divided in to epochs. A brief account of the geological history of the earth is given in the following table.

Eons

Era

Period Quaternary Tertiary

Cainozoic (From 65 million years to the present times)

Mesozoic 65 - 245 Million Mammals

Epoch Holocene Pleistocene Pliocene Miocene Oligocene Eocene Palaeocene

Cretaceous Jurassic Triassic

Age/Years Before Present

Life/ Major Events

0 - 10,000 10,000 - 2 million 2 - 5 million 5 - 24 million 24 - 37 Ma 37 - 58 Million 57 - 65 Million

Modern Man Homo Sapiens Early Human Ancestor Ape: Flowering Plants and Trees, Anthropoid Ape Rabbits and Hare Small Mammals : Rats – Mice

65 - 144 Million 144 - 208 Million 208 - 245 Million

Extinction of Dinosaurs Age of Dinosaurs Frogs and turtles

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF Palaeozoic 245 - 570 Million

Proterozoic Archean Hadean

Origin of Stars Supernova Big Bang

Permian Carboniferous Devonian Silurian Ordovician Cambrian

Pre- Cambrian 570 Million - 4,800 Million

5,000 13,700 Million

https://t.me/UPSC_PDF

245 - 286 Million 286 - 360 Million 360 - 408 Million 408 - 438 Million 438 - 505 Million 505 - 570 Million

Reptile dominate-replace amphibians First Reptiles: Vertebrates: Coal beds Amphibians, First trace of life on land: Plants, First Fish No terrestrial Life: Marine Invertebrate

570 - 2,500 Million 2,500 - 3,800 Million 3,800 - 4,800 Million

Soft-bodied arthropods Blue green Algae: Unicellular bacteria Oceans and Continents form – Ocean and Atmosphere are rich in Carbon dioxide

5,000 Million 12,000 Million 13,700 Million

Origin of the sun Origin of the universe

Questions 1. Gliese 581g (UPSC 2011/2 Marks) 2. What does the solar system consists of? Discuss the motion of the entire solar system as a whole and also the motion of most of the bodies forming the solar system. (UPSC 2003/ 15 Marks) 3. What is the difference between a comet and a meteor? (UPSC 1997/3 Marks) 4. Why does a lunar eclipse occur only on a full moon? (UPSC 1996/3 Marks) 5. What is a leap second? (UPSC 1992/3 Marks) 6. What is ‘Chandrashekhar limit’? (UPSC 1985/3 Marks) 7. Astronomers have, of late, been discussing ‘black hole.’ What is a ‘black hole’?(UPSC 1979/3 Marks) 8. What is the ‘diamond ring effect’ observed during a total solar eclipse? How is it caused?(UPSC 1979/3 Marks)

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 2

INTERIOR OF EARTH Introduction Sources of Information Direct Sources Indirect Sources 1)

Temperature

2)

Density

3)

Pressure

4)

Gravitation force

5)

Magnetic surveys

6)

Meteorites

7)

The Moon

8)

Earthquake Waves

Structure of the Earth’s Interior The Crust The Mantle The Core Crust and Mantle vs. Lithosphere and Asthenospher

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Introduction Human life is largely influenced by the physiography of the region. Therefore, it is necessary that one gets acquainted with the forces that influence landscape development. Also to understand why the earth shakes or how a tsunami wave is generated, it is necessary that we know certain details of the interior of the earth.

Sources of Information Most of the information about the Earth’s interior is based on inferences drawn from different sources – both direct and indirect.

Direct Sources Our knowledge about the structure and interior of the earth from direct observation is very limited. No instrument has been invented so far which can see through the interior of the earth directly. The deepest depth of an oil well drilled so far is 8 kilometers. The deepest mine of the world is Robinson Deep in South Africa. Its depth is less than 4 kilometer. Besides mining, scientists have taken up a number of projects to penetrate deeper depths to explore the conditions in the crustal portions. Scientists world over are working on two major projects such as “Deep Ocean Drilling Project” and “Integrated Ocean Drilling Project”. The deepest drill at Kola, in Arctic Ocean, has so far reached a depth of 12 km. This and many deep drilling projects have provided large volume of information through the analysis of materials collected at different depths. Volcanoes are yet another major source of direct information – they tell us about the composition and characteristics of the materials found inside the Earth. However, it is difficult to ascertain the depth of the source of such material.

Indirect Sources The centre of the earth downward is 6,371 kilometers away from the surface of the earth. In comparison to this distance the depth of a deep well or a mine is insignificant. It is therefore, necessary to take help of indirect scientific evidences to know about the interior of the earth. These sources include temperature, pressure and density of earth, behaviour of seismic waves (the waves generated by Earthquakes), Meteors, the Moon etc. These sources may be classified into three groups (a) Artificial sources such as temperature, pressure and density. (b) Evidences from the theories of origin of earth (c) Natural Sources e.g. volcanic eruption, earthquakes, meteors and seismology. 1) Temperature Temperature goes on increasing with the increase in depth inside the earth. This is clearly proved while going down a mine or deep wells. The volcanic eruptions or hot water springs also confirm this fact that temperature increasing towards the interior of the earth. On an average, Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

there is a rise of 1oC temperature for every 32 meters of depth. This rapid increase in temperature continues to great depth there after the temperature increases slowly.

Fig 1: Temperature profile of the inner Earth The main reasons for the increase in heat and temperature in the interior of the earth are the following: i. Radioactive disintegration within rocks which liberates heat ii. Internal and external forces (gravitational pull, weight of overlying rocks etc.) iii. Chemical reactions It is tempting to think that under the conditions of this enormous temperature in the interior of the earth nothing can be found in solid state. Under such conditions all existing rocks should be either in liquid or gaseous state. But it is not so. Along with the increase in temperature with depth, pressure too increases in the interior of the earth. This pressure is lacs of times more than the pressure exercised by atmospheric layers on the surface of the water in oceans. For this reason due to enormous pressure, liquid state rocks of the core have the properties of solids. It is possible that these rocks might be in plastic state. It is why these rocks have elasticity. Due to the pressure of overlying layers on the earth’s interior these rocks do look solid upto 2900 kilometers’ depth. Sometimes due to lessening of overlying pressure, the rocks in the interior melt down and the fluid comes to the surface or is in the process of finding its way to the surface of the earth. A volcanic eruption is one such example. 2) Density In accordance with the Newton’s laws of gravity the earth’s density has been calculated to be 5.5 (gms per cubic centimeter). However, it is surprising that the rocks near the surface of the earth have an average density of 2.7 only (gms per cubic centimeter). This density is less than half the average density of the earth as a whole. From this, it is clear that the density too increases with the increase in depth. The earth’s internal part is composed of very dense

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

rocks; their density must be in the range of 8-10 (gms per cubic centimeter). The density of the central part of the core is still more. Higher density could be due to heavy metals like Nichel and Iron at the centre as well as due to pressure of overlying layers. 3) Pressure Just like temperature and density and pressure too increase with increase in depth inside the earth. Some earth scientists believe that due to the weight of the overlying layers the pressure goes on increasing with depth and others think that materials of the interior of the earth are heavier since birth of the earth. The happenings due to change in pressure inside the earth affect the physical features on the surface of the earth. 4) Gravitation force The gravitation force (g) is not the same at different latitudes on the surface. It is greater near the poles and less at the equator. This is because of the distance from the centre at the equator being greater than that at the poles. The gravity values also differ according to the mass of material. The uneven distribution of mass of material within the earth influences this value. The reading of the gravity at different places is influenced by many other factors. These readings differ from the expected values. Such a difference is called gravity anomaly. Gravity anomalies give us information about the distribution of mass of the material in the crust of the earth. Gravity anomalies also inform us about the distribution of molten material in the crust of the earth. 5) Magnetic surveys The earth also acts like a huge magnet. The rapid spinning of earth creates electric currents in its centre (molten outer core) that creates a magnetic field around the earth. The magnetic field is strongest at the magnetic north and south poles. The magnetic north and south poles do not coincide with geographic north and south poles. In fact, the earth’s magnetic field keeps on changing. Magnetic surveys provide information about the distribution of magnetic materials in the crustal portion, and thus, provide information about the distribution of materials in this part. 6) Meteorites The space debris, while entering the atmospheric layers of earth are burnt due to the friction of air. Only the heavier objects whose outer layers have been burnt fall to the earth. Man has discovered many such meteorites and after examining them obtained evidences about the interior of the earth. The meteorites which have been examined are of two types: (i) Rock; and (ii) Metals. The metallic meteorites chiefly contain heavy materials like iron and nickel. The meteorites too have originated during the formation of solar system. It is, therefore, very much in order to believe that both the meteorites and the earth are made of similar materials. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

7) The Moon The first information about the earth’s interior had been obtained through the study of the moon. There are several ways of determining the moon’s orbit around earth. Among these one of the important factors is earth’s mass. Remember, there is close relationship between the mass and earth’s gravitation. The movements of the moon and its distance from earth provide the basis for determining the mass of the earth by earth scientists. 8) Evidence from Theories The earth was mostly in a volatile state during its primordial stage. Due to gradual increase in density the temperature inside has increased. As a result the material inside started getting separated depending on their densities. This allowed heavier materials (like iron) to sink towards the centre of the earth and the lighter ones to move towards the surface. With passage of time it cooled further and solidified and condensed into a smaller size. This later led to the development of the outer surface in the form of a crust. During the formation of the moon, due to the giant impact, the earth was further heated up. It is through the process of differentiation that the earth forming material got separated into different layers. Starting from the surface to the central parts, we have layers like the crust, mantle, outer core and inner core. From the crust to the core, the density of the material increases. We shall discuss in detail the properties of each of this layer in the next chapter. 9) Earthquake Waves Earthquakes1 are caused by the movements in the interior of the earth. These movements cause waves inside the earth just as waves are generated on the surface of water in a lake when a stone is thrown into it. Incidentally, majority of the earthquakes originate in the upper mantle. The earthquake waves are measured on the seismograph. The study of earthquake waves helps earth-scientists to get a lot of information about the types of rocks and layered composition in the interior of the earth. Earthquake waves are basically of two types — body waves and surface waves. Body waves are generated due to the release of energy at the focus(origin of earthquake) and move in all directions travelling through the body of the earth. Hence, the name body waves. The body waves interact with the surface rocks and generate new set of waves called surface waves. These waves move along the surface. The velocity of waves changes as they travel through materials with different densities. The denser the material, the higher is the velocity. Their direction also changes as they reflect or refract when coming across materials with different densities. There are two types of body waves: P-waves and S-waves. Important surface waves are Rayleigh waves and L-waves (named after A. E. H. Love). 1

Note: Earthquakes, Richter scale, epicenter, hypocenter etc. will be discussed in another chapter.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Body Waves Surface Waves ‘S’- Waves’ or Secondary ‘P’- Waves’ or Primary waves L-waves waves I. These are ‘Longitudinal I. These are transverse I. These are transverse Waves’. waves. waves. II. Under their influence II. Under their impact II. Their propagation is particles are displaced in particles swing side by limited to the surface of backward-forward the earth only. side (shear waves). III. Their velocity through direction. (compression III. Their velocity is lower solid particles or rocks is than the primary waves. waves.) about 3.5 kilometers IV. These waves cannot pass III. Their velocity is the per second. through liquids. They fastest. IV. They cause the greatest travel through solids IV. Their average velocity is damage and destruction only. 6-15 kilometers per of property during the second. earthquake. V. Different densities of rocks have different velocities. VI. They can travel through all mediums – solids, liquids and gases.

Fig 2: Particle motion in seismic waves

Fig 3: Arrival time of seismic waves

Fig4: Shadow Zones

Fig 5: Earthquake

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Structure of the Earth’s Interior The earthquake waves undergo changes at definite intervals during their propagation through the interior of the earth. They also undergo the action of reflection and refraction. Places on earth where seismic waves are not recorded are called “shadow zones”. S-waves are not recorded beyond 103o angular distance from focus which indicate that outer core of earth is in molten or semi-molten in which S-waves cannot propagate. As P-waves are not recorded between angular distances of 103o to 142o, it indicates that the core has different density, state and composition. From the analysis of the behavior of these waves it is clear that the interior of the earth has a layered structure of different densities. With the help of earthquake waves, we can get the information about the exact location of the layers, their depth, thickness and other physical and chemical properties. Based on the passage of these waves through different types of rocks and their behavior we can conclude that the earth’s interior has three main layers. These three layers are: (i) Crust, (ii) Mantle and (iii) Core. This arrangement can be compared to that of a boiled egg.

Fig 6

The Crust: It is the earth’s uppermost layer. Crust is solid, rigid and very thin compared with the other two. Like the shell of an egg, the Earth's crust is brittle and can break. The thickness of the crust is not same everywhere. Oceanic crust is thinner as compared to the continental crust. The mean thickness of oceanic crust is 5 km whereas that of the continental is around 30 km. The continental crust is thicker in the areas of major mountain systems. It is as much as 70 km thick in the Himalayan region.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Its two main parts are: i. The uppermost thin layer– It is composed of such rocks which contain a large proportion of silica and aluminum. It is called SIAL (SI = Silica, AL = Aluminum). The continents are mostly composed of sial. It average density is 2.7 and thickness is of about 28 kilometers. ii. The lower layer of the crust is made of comparatively heavier rocks. Silica and magnesium are the major constituents in it. This part is therefore, known as SIMA (SI – Silicon, MA = Magnesium). The oceanic floor is also made of this rock strata. Its average thickness is 6-7 kilometers and density of about 3.0. The thickness of SIAL and SIMA put together does not exceed 70 kilometers. Its volume is 1% of the total volume of the earth. In comparison to 6378 km radius of the earth, the thickness of 70 kilometers is insignificant. However, this cannot be over looked. This shallow crust is the ground of the nature’s wonderful activities.

Fig 7: Earth Crust

The Mantle: Its thickness is about 2900 Km. It volume is 83% of the whole earth. Near the lower limit of the crust the velocity of P-waves increases from about 6.4 kilometers per second to 8 km per second. This change in velocity of P-waves indicates the surface discontinuity between the crust and the mantle. It is popularly known as Moho or the Mohorovicic discontinuity (after the name of its discoverer). The mantle is made up of dense and heavy materials such as oxygen, iron and magnesium. The average density of the materials in the mantle varies between 3.5 g per cubic cm and 5.5 g per cubic cm. The temperature of this layer ranges between 900°C and 2200° C. The temperature is quite high and the hot rocks form magma in this layer. The pressure of the overlying layers, keeps the lower part of the crust and the upper part of the mantle in an almost solid state. If cracks appear in the crust, the pressure is released and the molten matter from inside the Earth tries to reach the surface through volcanic eruptions. The upper portion of the mantle is called asthenosphere. The word astheno means weak. It is considered to be extending upto 400 km. It is the main source of magma that finds its way to the surface during volcanic eruptions.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The mantle plays an important role in all the happenings in the interior of the earth. It also gives rise to Convection Currents. These currents supply energy for happenings like continental drift, earthquake, volcanoes, etc.

Fig 8: The Discontinuities

The Core: It extends from 2900 Km depth upto the centre of the earth (6378 km). It is the interior most part of the earth. It begins from Gutenberg Discontinuity. The mantle is demarcated from the core by Gutenberg Discontinuity. The core is divided into two parts: (i) The Outer Core, (ii) The Inner Core. The outer core is possibly in wholly liquid or semi-liquid state. The transverse or S-waves of earthquakes, seem to disappear at the Gutenberg Discontinuity. The outer core extends from the depth of 2900 km, upto 5150 km. It has an average density of 10. The inner core is believed to be solid. It extends from the depth of 5150 km upto the centre of the earth (6378 km). The velocity of P waves increases at the boundary of outer and inner core. Its density is between 12-13. To volume of the entire core is 16% of earth as a whole. The mass of the core is 32% of the earth’s mass. The major part of the core is made up of heavy metals like iron and nickel. This zone is therefore known as Nife (Ni = Nickel, Fe = Ferrous). It is also known as Barysphere (which means heavy metallic rocks). Table 3.1 Name of the Layer A. Crust 1. Upper SIAL 2. Lower SIMA

B. Mantle 3. upper mantle (From Moho to 410 km) 4. transition zone (410– 660 km),

Chemical Composition Crustal material contains lighter elements like Si, O, Al, Ca, K, Na, etc... Feldspars (Anorthite, Albite, Orthoclase) are common minerals in the crust (CaAL2Si2O8, NaALSi3O8, KALSi3O8). is made up of Si and O, like the crust, but it contains more Fe and Mg. Thus, Olivine (Fe2SiO4-Mg2SiO4) and pyroxene (MgSiO3-FeSiO3)

Depth 5-70 Km.

Density

Physical Property Solid State

2.75 – 2.90

35-2900 km. 3.4-5.6

Some properties of solid, some plastic. Near the melting point their behavior is like

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF 5. lower mantle (660– 2891 km) C. Metallic Core of Barysphere 6. Outer Metallic Core 7. Inner Metallic Core

www.UPSCPDF.com

are abundant in the mantle

https://t.me/UPSC_PDF

solids heavy

NIFE (Nickel + Ferrous or Iron) Barysphere (Heavy Metallic rocks)

2900 – 5150 km

5.10 – 13.00

5150 – 6378 km

Liquid or in plastic state Rigid because of tremendous overlying pressure

Crust and Mantle vs. Lithosphere and Asthenosphere Lithosphere, asthenosphere, and mesosphere represent changes in the mechanical properties of the Earth. Crust, Mantle and Core refer to changes in the chemical composition of the Earth. The lithosphere (litho: rock; sphere: layer) is the strong, upper 100 km of the Earth. The lithosphere is the tectonic plate (we talk about it in plate tectonics). The asthenosphere (asthenos: weak) is the weak and easily deformed layer of the Earth that acts as a “lubricant” for the tectonic plates to slide over. The asthenosphere extends from 100 km depth to 660 km beneath the Earth's surface. Beneath the asthenosphere is the mesosphere, another strong layer.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

N

Student Notes:

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 3

G.S. PAPER I – GEOGRAPHY

CONTINENT DRIFT, SEAFLOOR SPREADING, ENDOGENIC AND EXOGENIC FORCES AND BASICS OF PLATE TECTONICS, SOME IDEAS ABOUT SUPERCONTINENTS ETC. 1. Supercontinents a. Supercontinent Cycle b. Pangaea 2. Continental drift a. About continent drift b. Continent drift theory of Alfred Wegener i. Explaining theory with appropriate diagrams ii. Evidences in support of the theory iii. Forces for drifting iv. Criticism of Wegener’s theory 3. Post-drift studies a. Convection current theory by Arthur Holmes b. Mapping of Ocean floor c. Seafloor spreading by Hess 4. Plate tectonics a. Major and Minor plates b. Movement of plates i. Movement of the Indian plate c. Types of boundaries d. Forces for the plate movement e. Objections to plate tectonic theory 5. Endogenic and Exogenic forces a. Geomorphic processes and agents b. Endogenic processes i. Diastrophism ii. Volcanism c. Exogenic processes i. Weathering ii. Mass movement iii. Erosion and deposition Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

EARTH OF THE DISTANT PAST WAS A VERY DIFFERENT PLANET THAN THE ONE WE KNOW TODAY 1. SUPERCONTINENT If you could travel through time to arrive at the Earth of a billion years ago, you would have a hard time navigating. A strange giant continent and a single planetary ocean would replace the familiar continents and oceans of today’s world. A supercontinent is the assembly of most or all the Earth’s continental blocks to form a single large landmass. There is no unanimity among tectonicists on a single definition of supercontinent. Hoffman (1999) used the term “supercontinent” to mean “a clustering of nearly all continents”. According to this definition, Pangaea is a supercontinent while Gondwana is not. There are other scholars who consider Gondwanaland a supercontinent of pre-Cambrian period. In the past, there existed many supercontinents at different time. The positions of continents have been accurately determined back to the early Jurassic period. However, beyond 200 million years, continental positions are much less certain. Following is the list of supercontinents. Supercontinent name Ur (Vaalbara) Kenorland Proto Pangaea-Paleopangaea Columbia Rodinia Pannotia Pangaea

Age ~3.6-2.8 Billion years ago ~2.7-2.1 Billion years ago ~2.7-0.6 Billion years ago ~1.8-1.5 Billion years ago ~1.25-0.75 Billion years ago ~600 Million years ago ~300 Million years ago

Table 1 – Supercontinents through geologic history 1.1. SUPERCONTINENT CYCLE Supercontinent does not last forever. A supercontinent cycle is the breakup of one supercontinent and the development of another. Pangaea , last supercontinent, was formed by the continental fragments dispersed during the breakup of Pannotia during the latter half of the Paleozoic Era (figure 1).

(a) Pannotia split

(b) Assembled Pangaea 200 million years ago

Figure 1 - Supercontinents Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

1.2. PANGAEA Like its predecessor Pannotia, the giant continent of Pangaea also became victim to the Earth’s internal heat. According to Alfred Wegener, Pangaea which was surrounded on all sides by extensive water mass called Panthalasa, began to split around 200 million years ago. Pangaea broke into two large continental masses Laurasia and Gondwanaland forming the northern and southern components respectively. Subsequently, Laurasia and Gondwanaland continued to break into various smaller continents that exist today. 2. CONTINENTAL DRIFT Abraham Ortelius, a Dutch map maker, was the first one to propose the possibility of the two Americas, Europe and Africa to be once joined together as early as 1596. Antonio Snider drew a map showing the three continents together in 1858, but this was so much opposed to the scientific view then prevailing that nobody took notice of it. In 1910, F.B. Taylor of America invoked the hypothesis of horizontal displacement of continents or continental drift with a view to explaining the distribution of mountain ranges. 2.1. CONTINENTAL DRIFT THEORY OF ALFRED WEGENER It was Alfred Wegener – a German meteorologist - who put forth a comprehensive argument in the form of “the continental drift theory” in 1912. Wegener was a climatologist who wanted to explain the change of climates in the geological past. There are several geological evidences to show that there have been important and large scale changes in the climates of the world in the geological past. He came to the conclusion that either the climatic zones have moved or if they have not, then there has been movement of the landmasses. The distribution of Climatic belts of the world is governed primarily by the Sun. It, therefore, appear to be more probable that the landmasses have changed their position. According to Wegener, all the continents formed a single continental mass, a mega ocean surrounded by the same. The super continent was named PANGAEA, a Greek word which meant all earth. The mega-ocean was called PANTHALASSA, meaning all water as shown in figure 1a. Wegner also imagined that in the carboniferous period the South pole was near the South African coast and the north pole lay in the Pacific ocean. Wegener argued that, around 200 million years ago, the Pangaea began to split. The initial two blocks – Gondwanaland and Laurasia – started drifting away and in between a shallow sea emerged by filling up the water from Panthalasa. It was known as Tethys Sea. The present shape and relative position of the continents is the result of fragmentation of Pangaea by rifting and the drifting apart of the broken parts (figure 2). He called this drifting away of continents as Polflucht or the flight from the poles. He took help of theory of Isostasy in which the continental blocks, made of SIAL, are floating over the ocean floor, made of SIMA.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 2 – Pangaea 2.1.1.EVIDENCES IN SUPPORT OF THE THEORY A variety of evidences were offered in support of the continental drift theory. These are summarized as:a. The matching of continents (“jig-Saw-fit”) – The shorelines of Africa and South America facing each other have a remarkable and unmistakable match. It may be noted that map produced using a computer programme to find the best fit of the Atlantic margin was presented by Bullard in 1964. It proved to be quite perfect. The match was tried at 1,000 fathom line instead of the present shoreline. b. Rocks of Same Age Across the Oceans - The belt of ancient rocks of 2,000 million years from Brazil coast matches with those from western Africa. The earliest marine deposits along the coastline of South America and Africa are of the Jurassic age. This suggests that the ocean did not exist prior to that time. Similarly, Appalachian mountains of North America which come right up to the coast and then continue their trend across the North Atlantic Ocean in the old Hercynian fold mountains of South-West Ireland, Wales and Central Europe. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

c. Tillite - It is the sedimentary rock formed out of deposits of glaciers. The Gondawana system of sediments from India is known to have its counter parts in six different landmasses of the Southern Hemisphere. At the base the system has thick tillite indicating extensive and prolonged glaciation. Counter parts of this succession are found in Africa, Falkland Island, Madagascar, Antarctica and Australia besides India. It clearly demonstrates that these landmasses had remarkably similar histories. d. Placer Deposits - The occurrence of rich placer deposits of gold in the Ghana coast and the absolute absence of source rock in the region is an amazing fact. The gold bearing veins are in Brazil and it is obvious that the gold deposits of the Ghana are derived from the Brazil plateau when the two continents lay side by side. e. Distribution of Fossils - The observations that Lemurs occur in India, Madagascar and Africa led some to consider a contiguous landmass “Lemuria” linking these three landmasses. Mesosaurus was a small reptile adapted to shallow brackish water. The skeletons of these are found only in two localities: the Southern Cape province of South Africa and Iraver formations of Brazil. The two localities presently are 4,800 km apart with an ocean in between them. Such presence of identical plants and animals is possible only when they lived on a common landmass. 2.1.2. FORCES FOR DRIFTING Wegener suggested that the movement responsible for the drifting of the continents was caused by pole-fleeing force and tidal force. The polar-fleeing force relates to the rotation of the earth. This was, according to Wegener, the cause for movement of continents towards equator ward. Tidal force – due to the attraction of the Moon and the Sun – was the main reason given by Wegener for the westward movement of the Americas. Wegener believed that these forces would become effective when applied over many million years. 2.1.3. CRITICISM OF WEGENER’S THEORY It is clear that Wegener had amassed an imposing array of evidences in support of his theory and some of this evidence was undeniably convincing. But so much of theory was based on speculation and inadequate evidence that it provoked a lot of criticism and controversy. a) The greatest criticism has been the force of continental drift proposed by him. Tidal force need to be ten thousand million times stronger than at present to move the continents. b) Wegener proposed that Rockies and Andies mountain chain are formed during the westward drift of Americas. But if the SIAL (continents) is floating over SIMA (ocean floor), then the SIMA could not offer so much resistance as to cause folds and build mountain system. c) The jig-saw-fit of the opposing coasts of Atlantic Ocean was not so complete. d) Though there was similarity in the structural and stratigraphical features of the two coasts of the Atlantic, it would not be quite correct to conclude that one was an extension of the other and that they were joined together. 3. POST-DRIFT STUDIES A number of discoveries during the post-war period added new information to geological literature. Most of the evidences for the continental drift theory of Alfred Wegener were collected from the continental areas. New literature collected from the ocean floor mapping provided new dimensions for the study of distribution of oceans and continents.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

3.1. CONVECTION CURRENT THEORY While explaining the processes of mountain building, Arthur Holmes put forward his theory of convection current in 1928-29. According to Holmes, convection currents exist in the mantle portion of

Figure 3 – Convection currents in the mantle portion of the Earth the Earth as shown in figure 3. The cause of the origin of these currents is the presence of radioactive elements which causes thermal differences in the mantle portion. Holmes argued that there exists a system of such currents in the entire mantle portion. This was an attempt to provide an explanation to the issue of force, on the basis of which contemporary scientists discarded the continental drift theory. 3.2. MAPPING OF OCEAN FLOOR Post-war period saw surge in the detailed research of the ocean configuration. It revealed that ocean floor is not just a vast plain but is full of features such as mid-oceanic ridge, trenches, Abyssal plains etc. The mid-oceanic ridges were found to be most active in terms of volcanic eruptions. The age of rocks from Oceanic floor is nowhere more than 200 million years as compared to billions of year sold rocks from continental region and hence, oceanic rocks are much younger than the continental areas. Another interesting fact was that the rocks located equi-distant from the crest were found to have remarkable similarities in terms of their constituents, age, magnetic properties etc. 3.3. SEA FLOOR SPREADING The hypothesis of sea-floor spreading was first put forward by Harry Hess in 1961. Post-drift studies had been able to establish the facts which were not available at the time of Wegener. These may be summarized as:a) The ocean crust rocks are much younger than the continental rocks. The age of rocks in the oceanic crust is nowhere more than 200 million years old compare to continental rocks out of which some are as old as 3,200 million years. b) The sediments on the ocean floor are unexpectedly very thin and thickness of the sediments increases with the distance from the ridge. They were only 6 to 7 km thick, whereas below the continental surfaces this thickness was 30 to 40 kms. c) Mid-oceanic ridge was not found only in Atlantic Ocean, but ridges were present in all the oceans. These ridges contain large scale evidences of faulting and volcanicity and are bringing huge amounts of lava to the surface. d) The rocks equidistant on either sides of the crest of mid-oceanic ridges show remarkable similarities in terms of period of formation, chemical compositions and

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

magnetic properties. Rocks closer to the mid-oceanic ridges are of normal polarity and are the youngest. The age of the rocks increases as one moves away from the crest. On the basis of above facts the realization dawned that the ocean floor possibly is the youngest and most active part of the earth’s surface. In 1961, Harry Hess argued that the ocean floor was mobile and

Figure 4 – Sea-floor spreading constant eruption at the crest of oceanic ridges causes the rupture of the oceanic crust and the new lava wedges into it, pushing the oceanic crust on either side as shown in figure 4. The ocean floor, thus spreads. But this spreading does not cause the shrinking of the other. Hess argued about the sinking of the crust which was spread in the trench system and does it gets consumed. On analysis, it was found that 2 cm/year is adequate for separation of South America from Africa in about 200 million years. 4. PLATE TECTONICS Since the advent of the concept of sea floor spreading, the interest in the problem of distribution of oceans and continents was revived. The hypothesis of plate tectonics is an extended and more comprehensive version of the theory of sea-floor spreading. This is a great unifying concept which “draws sea-floor spreading, continental drift, crustal structures and world pattern of seismic and volcanic activity together as aspects of one coherent picture.” The term plate was first used by Tuzo Wilson in his definition of transform faults in 1965, but the hypothesis of plate tectonics was first outlined by W.J. Morgan in 1967. More or less concurrently but independently D.P. Mackenzie and Parker had arrived at similar conclusions. It first came to be known by the name of New Global Tectonics but after sometime the term Plate Tectonics gained currency. Basic assumptions of plate tectonics are as follows: 1. There is spreading of sea floor and new oceanic crust is being continually created at the active mid-oceanic ridges and destroyed at trenches. 2. The area of the earth’s surface is fixed. It means, the amount of crust consumed almost equals the amount of new crust created. 3. The new crust that is formed becomes part and parcel of a plate.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

4.1. MAJOR AND MINOR PLATES A tectonic plate (also called lithospheric plate) is a massive, irregularly-shaped slab of solid rock. Plates are generally composed of both continental and oceanic lithosphere. This is an important difference between plate tectonics and continental drift theories. The lithosphere includes the crust and the top mantle with its thickness range varying between 5-100 km in oceanic parts and about 200 km in the continental areas. The plates are the inert aseismic regions bounded by narrow mobile belts which are characterized by Seismic and volcanic activity or by orogenic belts. Plates’ configuration is not related to the distribution of land and water. Plates can split or get welded with adjoining plate. The theory of plate tectonics proposes that the earth’s lithosphere is divided into seven major and some minor plates. The major plates are as follows: a) Antarctic plate - Antarctica and the surrounding ocean b) North American plate – North America continent along with Western Atlantic floor separated from the South American plate along the Caribbean islands c) South American plate – South America continent along with western Atlantic floor d) Pacific plate – covers almost entire pacific ocean e) India-Australia-New Zealand plate – Australian continent along with Indian subcontinent and Indian Ocean. f) African plate – Africa continent along with eastern Atlantic floor g) Eurasian plate – Eurasia along with eastern Atlantic floor

Figure 5 – Major and Minor plates of the world Minor plates are small in areas. They are also moving in different directions like major plates. Some important minor plates are listed below: a) Cocos plate – Between Central America and Pacific plate b) Nazca plate – Between South America and Pacific plate Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF c) d) e) f)

https://t.me/UPSC_PDF

Arabian plate – Mostly the Saudi Arabian landmass Philippine plate – Between the Asiatic and Pacific plate Caroline plate – Between the Philippine and Indian plate (North of New Guinea) Fuji plate– North-east of Australia.

4.2. MOVEMENT OF PLATES These tectonic plates float on and travel independently over the asthenosphere, which lies over the mantle. Much of the earth's seismic activities occur at the boundaries of these plates. It is a relatively slow movement, driven by thermal convection currents and other geological activities originating deep within the earth's mantle. Plates have moved horizontally over the asthenosphere as rigid units. The movement of a plate is defined by the position of its pole of rotation and its angle of rotation about the rotation axis; its rate of movement varying with distance from the pole of rotation, being nil at the pole and reaching a maximum at the equator relative to the pole of rotation. The strips of normal and reverse magnetic field that parallel the mid-oceanic ridges help scientists determine the rates of plate movement. These rates vary considerably. The arctic ridge has the slowest rate(less than 2 cm per year), and the East Pacific Rise near Easter Island in the South Pacific has the fastest rate (more than 15 cm per year). The eastern part (Australia) is moving northward at the rate of 5.6 cm per year while the western part (India) is moving only at the rate of 3.7 cm per year due to impediment by Himalayas. This differential movement is resulting in the compression of the plate near its center at Sumatra and a potential division into Indian and Australian Plates. The rate of spreading at the MidAtlantic Ridge near Iceland is relatively slow, about 2 cm per year. 4.2.1.MOVEMENT OF THE INDIAN PLATE The Indian plate includes Peninsular India and the Australian continental portions. India was a large island situated off the Australian coast, in a vast ocean. The Tethys sea separated it from the Asian

Figure 6 – Movement of the Indian Plate Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

continent. India is believed to have started her northward journey about 200 million years ago. India collided with Asia about 40-50 million years ago causing formation of Himalayas. The subduction zone along the Himalayas forms the northern plate boundary in the form of continent— continent convergence. Scientists believe that the process is still continuing and the height of the Himalayas is rising even to this date. 4.3. TYPES OF BOUNDARIES Plate boundaries are very important and significant structural features. Nearly all seismic, volcanic and tectonic activities are confined to the plate margins. Boundaries are very distinct and easy to identify. They are associated with newly formed mountain systems, oceanic ridges and trenches. Plates are moving continuously and have relative direction of movement. Based on the direction of movement three types of plate boundaries can, easily, be identified (figure 7).

Figure 7 – Types of plate boundaries 4.3.1. DIVERGENT BOUNDARIES Where new crust is generated as the plates pull away from each other. The sites where the plates move away from each other are called spreading sites. The best-known example of divergent boundaries is the Mid-Atlantic Ridge. At this, the American Plate(s) is/are separated from the Eurasian and African Plates at rate of around 2 cm per year. 4.3.2.CONVERGENT BOUNDARIES Where the crust is destroyed as one plate dived under another at an angle of approximately 450. The location, where sinking of a plate occurs, is called a subduction zone. There are three ways in which convergence can occur. These are: (i) between an oceanic and continental plate; (ii) between two oceanic plates; and (iii) between two continental plates. 4.3.3.TRANSFORM BOUNDARIES Where the crust is neither produced nor destroyed as the plates slide horizontally past each other. Transform faults are the planes of separation generally perpendicular to the mid-oceanic ridges. As the eruptions do not take all along the entire crest at the same time, there is a differential movement of a portion of the plate away from the axis of the earth. Also, the rotation of the earth has its effect on the separated blocks of the plate portions. 4.4. FORCES FOR THE PLATE MOVEMENT At the time of Wegener, it was believed that the earth was a solid, motionless body. However, sea floor spreading and tectonic plate theories emphasized that both the surface of the earth Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

and the interior are dynamic. Generally, it is accepted that tectonic plates are able to move because of the relative density of oceanic lithosphere and the relative weakness of the asthenosphere. The convection currents (proposed by Arthur Holmes) get diverted or converged on approaching the crust layer. Heat within the earth comes from two main sources: radioactive decay and residual heat. 4.5. OBJECTIONS TO PLATE TECTONICS THEORY Although plate tectonics has been a powerful principle to explain distribution of continents and oceans, there are several problems to which it has not been able to offer a satisfactory solution. (i) (ii) (iii)

(iv)

The length of the spreading ridge is far greater than the subduction zone. Plate tectonics is unable to explain why subduction is limited to the Pacific coasts while spreading is found in all the Oceans. It has failed to provide a satisfactory explanation for mountain building. Mountain ranges such as eastern highlands of Australia etc which cannot be related to plate tectonics. It is not definite that each plate behaves like a unit, and some people have proposed an increase in the number of plates.

5. ENDOGENIC AND EXOGENIC FORCES The earth’s crust is dynamic which has moved and moves vertically and horizontally. It is being continuously subjected to external forces induced basically by sunlight as well as by internal forces caused by events occurring inside the earth. The external forces are known as exogenic forces and the internal forces are known as endogenic forces. The variations in the relief over the earth surface remain as long as the opposing actions of exogenic and endogenic forces continue. The net resultant of these forces shape the landforms across the earth’s surface. We can divide landforms into two basic categories – initial landforms and sequential. The initial landforms are produced by endogenic forces. These initial landforms are modified and shaped by the exogenic forces with simultaneous application of endogenic forces. 5.1. GEOMORPHIC PROCESSES AND AGENTS Geomorphology is the study of nature and origin of landforms. One of the approaches for such study is deductive reasoning which depended largely on the geomorphic processes. The endogenic and exogenic forces causing physical stresses and chemical actions on earth materials and bringing about changes in the configuration of the surface of the earth are known as geomorphic processes. The action of exogenic forces result in wearing down (degradation) of relief and filling up (aggradation) of basins, on the surface of the earth. On the other hand, the endogenic forces continuously elevate or build up parts of the earth’s surface. On the other hand, geomorphic agent is any exogenic element of nature like wind, waves, water, ice, ocean currents, etc. capable of acquiring and transporting earth material. When these elements of nature become mobile due to gradients, they remove the materials and transport them over slopes and deposit them at lower level. A process is a force applied on the earth material affecting the same. An agent is a mobile medium which removes, transports and deposits earth materials. Unless stated separately, geomorphic processes especially exogenic and geomorphic agents are one and the same.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

5.2. ENDOGENIC PROCESSES The energy emanating from within the earth is the main force behind endogenic geomorphic processes. This energy is mostly generated by radioactivity, rotational and tidal friction and primordial heat from the origin of the earth. This energy due to geothermal gradients and heat flow from within induces diastrophism and volcanism in the lithosphere. Due to variations in geothermal gradients and heat flow from within, crustal thickness and strength, the action of endogenic forces are not uniform and hence the tectonically controlled original crustal surface is uneven. Diastrophism and Volcanism are included in endogenic geomorphic processes. These may be summarized as:5.2.1. DIASTROPHISM All processes that move, elevate or build up portions of the earth’s crust come under diastrophism. These forces operate slowly and their effects are visible only after thousands of years. The diastrophic forces include both the vertical and horizontal movements. They include: a. Orogenic processes involve mountain building through severe folding, faulting, thrusting, often as a result of plate tectonics. It includes forces of compression and tension which are tangential to the earth’s surface in contrast to radial forces under epeirogenesis. Under compression forces, sediments within geosynclines are buckled and deformed into long, linear mountain chains (Himalayas). Under the operation of intense tensional forces, the rock strata are fractured. The line along which displacement of the fractured rock strata takes place is called the fault line (Narmada rift valley). b. Epeirogenic processes involve upliftment or depression of the Earth’s crust at a continental scale which moves the crustal rocks enmasse in a vertical or radial direction. It is a continental building process. Epeirogenic movement can be permanent or transient. The movement is caused by a set of forces acting along the Earth radius, such as those contributing to isostasy and faulting. For ex - Epeirogenic movement has caused the southern Rocky Mountain region to be uplifted from 1300 to 2000m in the past. c. Earthquake1 involves a shock or series of shocks due to sudden movement of crustal rocks within the crust or mantle. Earthquakes are generally associated with boundaries of tectonic plates. There are instances where earthquakes have occurred well inside the tectonic plate. The release of energy occurs along the fault. A fault is a sharp break in the crustal rocks. Tendency of rocks to move apart at some point of time overcomes the friction. This causes release of energy and the energy waves in all directions. d. Plate tectonics involves horizontal movements of crustal plates. 5.2.2. VOLCANISM Volcanism includes the movement of molten rock (magma) onto or toward the earth’s surface and also formation of many intrusive and extrusive volcanic forms. The layer below the solid crust is mantle which contains a weaker zone called asthenosphere. It is from this that the molten rock material finds their way to the surface. The material in the upper mantle portion is called magma. The magma is conveyed to the surface essentially along tube-like conduits and the extrusion of lava builds distinctive conical or dome shaped landforms.

1

earthquakes involving local relatively minor movements.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

5.3. EXOGENIC PROCESSES The exogenic processes derive their energy from atmosphere determined by the ultimate energy from the sun and also the gradients created by tectonic factors. They are essentially processes of land destruction.

Figure 8 – Denudational process and their driving forces The basic reason of these processes is development of stresses in the body of the earth materials. It is this stress that breaks rocks and other earth materials. The shear stresses result in angular displacement or slippage. Stress can be produced by gravitation pull, climatic factors – thermal gradients, pressure gradients, amount and intensity of precipitation, humidity etc. The density, type and distribution of vegetation also exert influence on exogenic processes. The exogenic geomorphic processes vary from one climatic region to another. These vary within a climatic region also due to location variation in climatic elements. All the exogenic geomorphic processes are covered under a general term, called denudation which means to strip off. Denudation consists of two kinds of processes – static and mobile. Weathering is a static process while mass movement, erosion and transportation are mobile processes (figure 8).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

5.3.1.WEATHERING Weathering may be described as the mechanical disintegration or chemical decomposition of rocks in situ by different geomorphic agents at or near the surface of the earth. It changes hard massive rock into finer material. It is the first phase in the denudation process which prepares rock materials for transportation by the agents of erosion and mass movement. The main factors responsible for weathering are geological – rock structure, climatic, topographic and vegetative. These factors result into activities such as thermal expansion, exfoliation, rock solutions, salt and ice crystallization etc. There are three types of weathering which are described below in detail. I.

CHEMICAL WEATHERING PROCESS

No rock-forming mineral is absolutely chemically inert; some are more readily altered than others. A variety of chemical actions such as carbonation, hydration, oxidation and reduction act on the rocks to decompose and dissolve them. Water, air (Oxygen and carbon dioxide) along with heat must be present to speed up all chemical reactions. Biological activities such as decomposition of plants and animals increase acidity and other elements in the crust which enhances chemical weathering. Hydration – is a process by which certain types of mineral expand as they take up water and expand, causing additional stresses in the rock due to increase in the volume of mineral itself. For instance, calcium sulphate absorbs water and turns to gypsum. Decomposed products of rock-forming minerals are also subjected to hydration, thereby accelerating the disintegration of the rock. This process of hydration is reversible and continued repetition causes fatigue in the rock which eventually may lead to cracking of overlaying materials and finally disintegration. Oxidation and reduction – oxidation is the addition of oxygen to form oxides or hydroxides while reduction is the reverse of oxidation. Oxidation occurs when mineral has access to atmosphere or oxygenated water. To put it simply, they rust. Red color of iron turns to brown upon oxidation. Solution – few minerals such as rock salt are significantly soluble in water. Such rockforming minerals are easily leached out without leaving any residue in rainy climates and accumulate in dry regions. Minerals like calcium carbonate present in limestones are soluble in water containing carbonic acid. Carbon dioxide produced by decaying organic matter along with soil water greatly aids in this reaction. Carbonation – many minerals are soluble in rainwater, which contains carbon dioxide and acts as a weak carbonic acid. This is particularly important in the decomposition of limestones; the rain water converts the calcium carbonate into calcium bicarbonate, which is soluble and can be taken away in the groundwater.









These weathering process are inter-related. Hydration, oxidation, carbonation etc. go hand-inhand and hasten the weathering process. II.

PHYSICAL WEATHERING PROCESS

Physical weathering is the mechanical disintegration of rock-forming minerals by different geomorphic agents. The main factors responsible for it are (i) temperature change, (ii) the crystallization of water or other crystal growth, (iii) pressure-release mechanism, (iv) mechanical action of plants and animals. These factors act slow but can cause great damage to the rocks because of continued stress or fatigue developed in the rock. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Expansion by unloading – pressure release (unloading) mechanism causes disintegration of rock. It is because of continued erosion by various geomorphic agents. Fractures develop roughly parallel to the surface. This process has been termed exfoliation. Exfoliated sheets may measure thousands of meters. Temperature change and expansion – thermal expansion of rock is the cause of rock cracking and disintegration. If you travel to arid-tropics, it is possible that you may hear sounds like rifle shots which are actually cracking of the rock as they contract. The theory is that rocks are poor conductors of heat. Due to strong diurnal heating, the outer layers of the rock warm up considerably, but do not transmit heat to the inner layers. During night when temperature falls, same layer gets contracted. This should lead to the setting up of stresses in the rock, causing fracturing parallel to the surface Salt weathering – a number of salts such as Sodium Chloride, Calcium sulphate may enter rocks in dissolved form. On drying and crystallization they expand and set up a disruptive effect. Expansion of these salts depends on temperature and their own thermal properties. Force exerted by crystallization is sometimes more than the tensile strength off rocks, thus causes splitting. Areas with alternating wetting and drying conditions favour salt weathering. Frost action and crystal growth – frost action is one of the most important weathering processes in cold climates. When water fills the pores, cracks and crevices in rocks and then freezes, it expands and exerts a bursting pressure. The rocks are fractured, cracked. In this process, rate of freezing is important. Freezing also penetrates to a greater depth when the ground is bare rather than forest covered.









These processes – chemical and mechanical – are not stand alone activities. Different processes acted upon same rock and produced net resultant weathered material together. For instance, both chemical and mechanical weathering processes further weaken the joints, the layers thereby peeling off in sheets. It is probably best to conclude that chemical weathering and pressure release ally with temperature changes to produce rock disintegration. It is likely that hydration process may also be involved when crystallization takes place. Another instance is of hydration where hydration itself is a mechanical effect, but it occurs intimately with hydrolysis in such a manner that it is difficult to draw any hard and fast line here between mechanical and chemical weathering. Actions of plants, human and animal affect both chemical and mechanical weathering. III.

BIOLOGICAL ACTIVITY

It includes the role of plants and animal in promotion of both physical and chemical weathering. Burrowing and wedging by organisms like earthworms, termites, rodents etc., help in exposing the new surfaces to chemical attack and assist in the penetration of moisture and air. Human beings by disturbing vegetation, ploughing and cultivating soils, also help in mixing and creating new contacts between air, water and minerals in the earth materials. Tree roots can occasionally be shown to have forced apart adjacent blocks of rock. Decaying plant and animal matter help in the production of humic, carbonic and other acids which enhance decay and solubility of some elements. 5.3.2.MASS MOVEMENT Mass movement or mass wasting is the term used for the movement of material down a slope under the influence of gravity. Thus it excludes those in which material is carried directly by a transporting medium such as running water, wind or ice. That means mass movement does not come under erosion though there is a shift of materials from one place to another. The Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

movement of mass may range from slow to rapid, affecting shallow to deep columns of materials and include creep, flow, slide and fall. Weathering is not a pre-requisite for mass movement though it aids mass movement. Mass wasting is viewed as a transitional phenomenon between weathering which is defined as occurring in situ and erosion which requires as one element transport by some agent. Mass wasting combines elements of both weathering and erosion. Factors favouring mass movement are: (i) weathering; (ii) rock composition; (iii) texture and structure of material; (iv) slope gradient; (v) extent of lubrication. Several activities precede mass movements. They are : (i) removal of support from below to materials above through natural or artificial means; (ii) increase in gradient and height of slopes; (iii) overloading through addition of materials naturally or by artificial filling; (iv) overloading due to heavy rainfall, saturation and lubrication of slope materials; (v) removal of material or load from over the original slope surfaces; (vi) occurrence of earthquakes, explosions or machinery; (vii) excessive natural seepage; (viii) heavy drawdown of water from lakes, reservoirs and rivers leading to slow outflow of water from under the slopes or river banks; (ix) indiscriminate removal of natural vegetation.

Figure 9 - Relationships among different types of mass movements Heave (heaving up of soils due to frost growth and other causes), flow and slide are the three types of mass movements (figure 9). Mass movements can be grouped under three major classes: Slow movements – the slow downhill movement of debris and soil on moderate slope is described as creep. Depending upon the type of material involved, several types of creep viz., soil creep, talus creep, rock creep, rock-glacier creep etc., can be identified. Leaning fence post, accumulation of earth on the upslope side of stone walls, etc. are example of creep. Also included in this group is solifluction which involves slow downslope flowing soil mass or fine grained rock debris saturated or lubricated with water. This process is quite common in moist temperate areas where surface melting of deeply frozen ground and long continued rain respectively, occur frequently. The permanently frozen ground prevents the downward percolation of water in summer, producing a highly saturated and mobile soil layer. Also, there is absence of deeprooted vegetation to bind the soil. Solifluction can occur on slopes of 30 or less. Rapid movement – these depend on there being sufficient water to saturate comprehensively the soil mass. These movements are mostly prevalent in humid climatic regions and occur over gentle to steep slopes. Earthflow is movement of water-saturated clayey or silty earth materials down hillsides. When slopes are steeper, even the bedrock especially of soft sedimentary rocks like shale or deeply weathered





Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

igneous rock may slide downslope. Another type in this category is mudflow. In the absence of vegetation cover and with heavy rainfall, thick layers of weathered materials get saturated with water and either slowly or rapidly flows down along definite channels. It looks like a stream of mud within a valley. Mudflows occur frequently on the slopes of erupting or recently erupted volcanoes. A third type is the debris avalanche, which is more characteristic of humid regions. Avalanche can be much faster than the mudflow. Landslides – In these, as the velocity does not continually decrease downwards, there must be one or more shear surfaces on which movement takes place. Where the shear surface is approximately planar, the strict meaning of the term slide is appropriate. However, another common type of landslide takes place on arcuate shear planes, and these are called rotational slips. It results into slumping of debris with backward rotation. Most landslides usually occur fairly rapidly, often after excess groundwater following heavy rain has reduced soil strength. Over steep slopes, rock sliding is very fast and destructive.



5.3.3.EROSION AND DEPOSITION The erosion can be defined as “application of the kinetic energy associated with the agent to the surface of the land along which it moves”. Erosion is a term referring to those processes of Denudation which wear away the land surface by the mechanical action of the debris which is being acquired and transported by various agents of erosion. The agents by themselves are also capable of erosion. Abrasion by rock debris carried by these geomorphic agents also aid greatly in erosion. For erosion to occur the agent must be capable of exerting a force on the surface greater than its shear strength. When massive rocks break into smaller fragments through weathering and any other process, erosional geomorphic agents like running water, groundwater, glaciers, wind and waves remove and transport it to other places depending upon the dynamics of each of these agents. Weathering aids erosion but it is not a pre-condition for erosion to take place. Deposition is a consequence of erosion. The erosional agents loose their velocity and hence energy on gentler slopes and the materials carried by them start to settle themselves. The coarser materials get deposited first and finer ones later. Alluvial fans at the foothills, alluvial plains, delta etc. are few examples of deposition landforms.

UPSC Questions 1. What do you understand by the theory of continental drift? Discuss the prominent evidences in its support.(UPSC 2013/5 Marks) 2. Sea-floor spreading. (UPSC 2010/5 Marks)

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com GEOGRAPHY: 4

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com

EARTHQUAKE TSUNAMI AND VOLCANIC ACTIVITY AND ASSOCIATED LANDFORMS Contents: 1. EARTHQUAKES 1.1. 1.2. 1.3. 1.4.

TYPES OF EARTHQUAKES SEISMIC WAVES DEPTH OF EARTHQUAKES MEASUREMENT OF EARTHQUAKES 1.4.1.Magnitude Scale 1.4.2.Intensity Scale 1.4.3.Classification of Earthquakes 1.5. DISTRIBUTION OF EARTHQUAKES 1.5.1.Seismic Belts of the world 1.5.2.Seismic Zones of India 1.6. EFFECTS OF EARTHQUAKES 2. TSUNAMI 2.1. 2.2. 2.3. 2.4.

CAUSES PROPAGATION CONSEQUENCES EARLY WARNING AND MITIGATION

3. VOLCANOES 3.1. VULCANICITY 3.1.1.Causes of Vulcanism 3.2. COMPONENTS OF A VOLCANO 3.2.1.Types of lavas 3.3. TYPES OF VOLCANOES 3.4. VOLCANIC LANDFORMS 3.4.1.Extrusive Landforms 3.4.2.Intrusive Landforms 3.5. DISTRIBUTION OF VOLCANOES 3.6. EFFECTS OF VOLCANIC ERUPTIONS 3.7. GEYSERS 3.8. HOT SPRINGS 3.9. FUMAROLES Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Earthquakes

Student Notes:

An earthquake in simple words is shaking of the earth. It is caused due to release of energy, which generates waves that travel in all directions. The release of energy occurs along a fault. A fault is a sharp break in the crustal rocks. Rocks along a fault tend to move in opposite directions. As the overlying rock strata press them, the friction locks them together. However, their tendency to move apart at some point of time overcomes the friction. As a result, the blocks get deformed and eventually, they slide past one another abruptly. This causes dissipation of energy, and the energy waves travel in all directions. The point where the energy is released is called the focus of an earthquake, alternatively, it is called the hypocentre. The energy waves travelling in different directions reach the surface. The point on the surface, nearest to the focus, is called epicentre. It is the first one to experience the waves. It is a point directly above the focus.

Figure 1: Hypocentre and Epicentre

Types of Earthquakes 1. Tectonic Earthquakes: These are generated due to sliding of rocks along a fault plane. This movement causes imbalance in the crustal rocks which results in earthquakes of varying magnitude, depending upon the nature of dislocation in the rock strata. 2. Volcanic Earthquakes: Volcanic activity is considered to be one of the main causes of earthquakes. In fact, volcanic activity and seismic events are so intimately related to each other that they become cause and effect for each other. Each volcanic eruption is followed by an earthquake and many of the severe earthquakes can cause volcanic eruptions. The explosive violent gases during the process of volcanic activity try to escape upward and hence they push the crustal surface from below with great force. This leads to severe tremors of high magnitude, which depend upon the intensity of volcanic eruptions. 3. Collapse Earthquakes: In areas of intense mining activity, sometimes the roofs of underground mines collapse causing minor tremors. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

4. Explosion Earthquakes: Ground shaking may also occur due to the explosion of chemical or nuclear devices. 5. The earthquakes that occur in the areas of large reservoirs are referred to as reservoir induced earthquakes. Above may also be referred as various causes of earthquakes with one and two being the natural causes of earthquakes while three, four and five represent anthropogenic or man-made causes of earthquakes.

Seismic waves The waves generated by an earthquake are called the 'seismic waves' or ‘earthquake waves’. These are recorded by an instrument called the seismograph or the seismometer. For further understanding of earthquake waves, refer to the portion of the notes on ‘Interior of Earth’.

Depth of Earthquakes Earthquake focus depth is an important factor in shaping the characteristics of the waves and the damage they inflict. The focal depth can be deep (from 300 to 700 km), intermediate (60 to 300 km) or shallow (less than 60 km). Deep focus earthquakes are rarely destructive because the wave amplitude is greatly attenuated by the time it reaches the surface. Shallow focus earthquakes are more common and are extremely damaging because of their close proximity to the surface

Measurement of Earthquakes The earthquake events are scaled either according to the magnitude or intensity of the shock. Magnitude Scale Magnitude is the amount of energy released and is based on the direct measurement of the size of seismic waves. The magnitude scale is known as the Richter Scale. The Richter magnitude scale was developed in 1935 by Charles F. Richter as a mathematical device to compare the size of earthquakes. The magnitude of an earthquake is determined from the logarithm of the amplitude of waves recorded by seismographs. Because of the logarithmic basis of the scale, each whole number increase in magnitude represents a ten fold increase in measured amplitude; as an estimate of energy, each whole number step in the magnitude scale corresponds to the release of about 31 times more energy than the amount associated with the preceding whole number value. Intensity Scale Intensity of an earthquake is measured in terms of its effects on human life. The intensity of an earthquake at a specific location depends on a number of factors. Some of them are:  the total amount of energy released,  the distance from the epicentre,  the types of rocks and the degree of consolidation. The Mercalli intensity scale is a scale used for measuring the intensity of an earthquake. The scale quantifies the effects of an earthquake on the Earth's surface, humans, objects of nature, and man-made structures on a scale of I through XII, with I denoting ‘not felt’, and XII ‘total destruction’. Data is gathered from individuals who have experienced the quake, and an intensity value will be given to their location. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

Characteristic Mercalli Scale The effects caused by Measures earthquake Measuring Observation Tool Quantified from observation of effect on earth’s surface, Calculation human, objects and man-made structures I (not felt) to XII (total destruction) Scale

Consistency

https://t.me/UPSC_PDF

Richter Scale The energy released by the earthquake Seismograph Base-10 logarithmic scale obtained by calculating logarithm of the amplitude of waves.

From 2.0 to 10.0+ (never recorded). A 3.0 earthquake is 10 times stronger than a 2.0 earthquake.

Varies depending on Varies at different distances from the epicentre, distance from but one value is given for the earthquake as a epicentre. whole. Table 1: Comparison between Richter and Mercalli Scale

Classification of Earthquakes Category

Magnitude on Richter Scale

Slight

Upto 4.9

Moderate

5.0 to 6.9

Great

7.0 to 7.9

Very Great

8.0 and more

Table 2: classification of earthquakes based on magnitude

Distribution of Earthquakes Most earthquakes in the world are associated with the following: the zones of young fold mountains, the zones of faulting and fracturing, the zones representing the junctions of continental and oceanic margins, the zones of active volcanoes, and along the different plate boundaries.

    

Seismic Belts of the world The main seismic belts are as under: 1. Circum-Pacific Belt: The Belt includes the coastal margins of North America, South America and East Asia. These are as represent the eastern and western margins of the Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Pacific Ocean respectively, and account for about 65 per cent of the total earthquakes of the world. The western marginal zones are represented by the Rockies and the Andes mountain chains. These are also the zones of convergent plate boundaries where the Pacific oceanic plate is subducted below the American plates. The eastern marginal zones are represented by the island arcs of Kamchatka, Sakhalin, Japan and Philippines. The earthquakes are caused due to collision of the Pacific and the Asiatic plates and the consequent volcanic activity. Japan records about 1500 seismic shocks every year. 2. Mid-Continental Belt: The Mid-Continental Belt includes the Alpine mountains and their off shoots in Europe, Mediterranean Sea, northern Africa, eastern Africa and the Himalayas. The Mid-Continental Belt extends through Sulaiman and Kirthar zones in the west, the Himalayas in the north and Myanmar in the east. This belt represents the weaker zone of Fold Mountains. About 21 per cent of the total seismic events are recorded in this belt. 3. Mid-Atlantic Ridge Belt: The Mid-Atlantic Ridge Belt includes the Mid-Atlantic ridge and several islands near the ridge. It records moderate earthquakes which are caused due to the moving of plates in the opposite directions. Thus the seafloor spreading and the fissure type of volcanic eruptions cause earthquakes of moderate intensity in this region.

Figure 2: Distribution of Earthquake belts Seismic Zones of India The Indian sub-continent is highly prone to multiple natural disasters including earthquakes, which is one of the most destructive natural hazards with the potentiality of inflicting huge loss to lives and property. Earthquakes pose a real threat to India with 59% of its geographical area vulnerable to seismic disturbance of varying intensities including the capital city of the country. The varying geology at different locations in the country implies that the likelihood of damaging earthquakes taking place at different locations is different. Thus, a seismic zone map is required so that buildings and other structures located in different regions can be designed to withstand different level of ground shaking. The current zone map divides India into four zones – II, III, IV and V. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 3: Seismic Zones of India The following table gives the distribution of various regions of the country into various seismic zones: Zone

Damage risk

Region

The entire North-east, including the seven sister states, the Kutch district, parts of Himachal and Jammu & Kashmir, and the Andaman and Nicobar islands. Parts of the Northern belt starting from Jammu and Kashmir to Himachal Pradesh. Also including Delhi and parts of Haryana. The Koyna region of Maharashtra is also in this zone.

Zone V

Very high damage risk zone

Zone IV

High damage risk zone

Zone III

A large part of the country stretching from the North including some parts of Rajasthan to the South Moderate damage risk zone through the Konkan coast, and also the Eastern parts of the country.

Zone II

Low damage risk zone

These two zones are contiguous, covering parts of Karnataka, Andhra Pradesh, Orissa, Madhya Pradesh, and Rajasthan, known as low risk earthquake zones. Table 4: Region falling in various zones of the country

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Effects of Earthquakes

Student Notes:

The direct and indirect effects of an earthquake includes: 1. Deformed Ground Surface: The earthquake tremors and the resultant vibrations, result in the deformation of the ground surface, due to the rise and subsidence of the ground surface and faulting activity. The alluvium filled areas of the flood plains may get fractured at several places. 2. Damage to man-made structures: Man-made structures such as buildings, roads, rails, factories, dams, bridges, etc., get severely damaged. 3. Damage to towns and cities: The towns and cities are the worst affected due to a high density of buildings and population. Under the impact of tremors, large buildings collapse and men and women get buried under the debris. Ground water pipes are damaged and thus water supply is totally disrupted. 4. Loss of human and animal life: The destructive power of an earthquake depends upon the loss it can cause in terms of loss of life arid property. The Bhuj earthquake of India in 2001 (8.1 on the Richter Scale) caused over one lakh human casualties. 5. Devastating fires: The strong vibrations caused by an earthquake can cause fire in houses, mines and factories due to the bursting of gas cylinders, contact with live electric wires, churning of blast furnaces, displacement of other electric and fire related appliances. 6. Landslides: The tremors in hilly and mountainous areas can cause instability of unconsolidated rock materials. This ultimately leads to landslides, which damage settlements and transport systems. 7. Flash floods: Very strong seismic events result in the collapse of dams and cause severe flash floods. Floods are also caused when the debris produced by tremors blocks the flow of water in the rivers. Sometimes the main course of the river is changed due to the blockage. 8. Tsunamis: When the seismic waves travel through sea water, high sea waves are generated, which can cause great loss to life and property, especially in the coastal areas.

Tsunami Tsunami is a Japanese word which means ‘harbour wave’. It is a series of traveling ocean waves of extremely long length generated by disturbances associated primarily with earthquakes occurring below or near the ocean floor. Underwater volcanic eruptions and landslides can also generate tsunamis. Tsunamis are a threat to life and property to anyone living near the ocean. Large tsunamis have been known to rise over 100 feet, while tsunamis 10 to 20 feet high can be very destructive and cause many deaths and injuries.

Causes Tsunamis generally are caused by earthquakes. Not all earthquakes generate tsunamis. To generate tsunamis, earthquakes must occur underneath or near the ocean, be large and create movements in the sea floor. All oceanic regions of the world can experience tsunamis, but in the Pacific Ocean there is a much more frequent occurrence of large, destructive tsunamis because of the many large earthquakes along the margins of the Pacific Ocean.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 4: Generation of Tsunami Other less common causes of earthquakes are submarine landslides, submarine volcanic eruptions and very rarely a large meteorite impact in the ocean.

Propagation In the open ocean a tsunami is less than a few feet high at the surface, but its wave height increases rapidly in shallow water. Tsunamis wave energy extends from the surface to the bottom in the deepest waters. As the tsunami attacks the coastline, the wave energy is compressed into a much shorter distance creating destructive, life-threatening waves. Where the ocean is over 20,000 feet deep, unnoticed tsunami waves can travel at the speed of a commercial jet plane, nearly 600 miles per hour. They can move from one side of the Pacific Ocean to the other in less than a day. This great speed makes it important to be aware of the tsunami as soon as it is generated. Scientists can predict when a tsunami will arrive since the speed of the waves varies with the square root of the water depth. Tsunamis travel much slower in shallower coastal waters where their wave heights begin to increase dramatically.

Figure 5: Rise in Tsunami amplitude near the coast Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Offshore and coastal features can determine the size and impact of tsunami waves. Reefs, bays, entrances to rivers, under sea features and the slop of the beach all help to modify the tsunami as it attacks the coastline. When the tsunami reaches the coast and moves inland, the water level can rise many feet. In extreme cases, water level has risen to more than 50 feet for tsunamis of distant origin and over 100 feet for tsunami waves generated near the earthquake's epicentre.

Consequences The consequences vary from loss of livelihood for fishermen to unknown damages to coral reefs and flora and fauna. It may take years for the coral reefs to get back the balance and mangrove stands and coastal tree plantations get destroyed or severely affected. With so much sea water coming inland, salination is another effect that not only makes the soil less fertile to support vegetation but also increases vulnerability to erosion, the impacts of climate change and food insecurity. For humans, on the other hand, fisheries, housing and infrastructure are the worst affected.

Early Warning and Mitigation Major tsunami warning centres are: 1. Pacific Tsunami Warning Center (PTWC): The Tsunami Warning System (TWS) in the Pacific, comprised of 26 participating international Member States, has the functions of monitoring seismological and tidal stations throughout the Pacific Basin to evaluate potentially tsunami genic earthquakes and disseminating tsunami warning information. The Pacific Tsunami Warning Center is the operational center of the Pacific TWS. Located near Honolulu, Hawaii, PTWC provides tsunami warning information to national authorities in the Pacific Basin. 2. The Alaska Tsunami Warning Center (ATWC): in Palmer, Alaska, serves as the regional Tsunami Warning Center for Alaska, British Columbia, Washington, Oregon, and California. 3. Indian Tsunami Early Warning System (ITEWS): The Indian Tsunami Early Warning System has the responsibility to provide tsunami advisories to Indian Mainland and the Island regions. Acting as one of the Regional Tsunami Advisory service Providers (RTSPs) for the Indian Ocean Region, ITEWS also provide tsunami advisories to the Indian Ocean Rim countries along with Australia and Indonesia. In order to confirm whether the earthquake has actually triggered a tsunami, it is essential to measure the change in water level as near to the fault zone with high accuracy. There are two basic types of sea level gages: coastal tide gages and open ocean buoys. Tide gages are generally located at the land-sea interface, usually in locations somewhat protected from the heavy seas that are occasionally created by storm systems. Tide gages that initially detect tsunami waves provide little advance warning at the actual location of the gage, but can provide coastal residents where the waves have not yet reached an indication that a tsunami does exist, its speed, and its approximate strength. Open ocean tsunami buoy systems equipped with bottom pressure sensors are now a reliable technology that can provide advance warning to coastal areas that will be first impacted by a tsunami, before the waves reach them and near by tide gages. Open Ocean buoys often provide a better forecast of the tsunami strength than tide gages at distant locations. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Apart from technology, we can also use natural barriers to mitigate the effect of tsunamis. Coral reefs act as natural breakwaters, providing a physical barrier that reduces the force of a wave before it reaches the shore, while mangrove forests act as natural shock absorbers, also soaking up destructive wave energy and buffering against coastal erosion.

Volcanoes The word volcano is derived from the name of ‘Vulcano’, a volcanic island in the Aeolian Islands of Italy whose name in turn originates from ‘Vulcan’, the name of a god of fire in Roman mythology. Volcano is a vent or an opening through which heated materials consisting of water, gases, liquid lava and rock fragments are erupted from the highly heated interior to the surface of the Earth. The layer below the solid crust of earth is mantle. It has higher density than that of the crust. The mantle contains a weaker zone called asthenosphere. It is from this that the molten rock materials find their way to the surface. The material in the upper mantle portion is called magma. Once it starts moving towards the crust or it reaches the surface, it is referred to as lava. ‘Volcanology’ or ‘vulcanology’ is the term given to the study of volcanoes, and the scientists who study them are called the ‘volcanologists’ or ‘vulcanologists’.

Vulcanicity Vulcanicity includes all those processes in which molten rock material or magma rises to the crust to solidify as crystalline or semi-crystalline rocks. Some scientists use ‘vulcanism’ as a synonym for vulcanicity. Vulcanicity has two components; one of them operates below the crustal surface and the other above the crust, i.e. the endogenetic mechanism and the exogenous mechanism. The endogenetic mechanism includes the creation of hot and liquid magma and gases in the mantle and the crust, their expansion and upward ascent, their intrusion and cooling and solidification in various forms below the crustal surface. The exogenous mechanism includes the process of the appearance of lava, volcanic dust and ashes, fragmental materials, mud, smoke, etc., in different forms on the earth’s surface. Causes of Vulcanism The mechanism of vulcanism and the volcanic activity are associated with several processes, such as: 1. A gradual increase of temperature with increasing depth at the rate of 1 degree Celsius for every 32 m. 2. Magma is formed due to the lowering of melting point, which in turn is caused by the reduction in pressure of the overlying material. 3. Gases and vapour are formed due to heating of water, which reaches underground through percolation. 4. The ascent of magma forced by vast volume of gases and water vapour. 5. The occurrence of volcanic eruption.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Components of a Volcano The volcanoes of explosive type have a volcanic cone, which is formed when the erupted material accumulates around the vent. The vent is an opening of circular or nearly circular shape at the centre of the cone. The vent is connected to the interior of the earth by a narrow pipe. The volcanic materials erupt through this pipe. A funnel-shaped hollow at the top of the cone is called the crater.

Figure 6: Components of a volcano Types of lavas There are two main types of lavas: 1. Basic Lavas: These are the hottest lavas and are highly fluid. They are dark coloured like basalt, rich in iron and magnesium but poor in silica. They flow quietly and are not very explosive. They affect extensive areas, spreading out as thin sheets over great distances before they solidify. The resultant volcano is gently sloping with a wide diameter and forms a flattened shield or dome. 2. Acid Lavas: These lavas are highly viscous with a high melting point. They are light coloured, of low density and have a high percentage of silica. They flow slowly and seldom travel far before solidifying. The resultant volcano is therefore steep-sided. The rapid cooling of lava in the vent obstructs the flow of the outpouring lava, resulting in loud explosions throwing out many volcanic bombs or pyroclasts. Note: Pyroclasts are any volcanic fragment that was hurled through the air by volcanic activity.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Types of volcanoes There is a wide variation in the mode of volcanic eruption and their periodicity. Accordingly the volcanoes can be classified on the basis of the mode of eruption and their periodicity of eruption. Classification on the basis of mode of eruption: The volcanoes are classified into two groups on the basis of their mode of eruption: 1. Violent or Explosive type: The eruption of violent or explosive type is so rapid that huge quantities of volcanic materials are ejected thousands of metres in the sky. On falling, these materials accumulate around the volcanic vent and form volcanic cones. Such volcanoes are very destructive. They are generally associated with acidic lavas. 2. Effusive or Fissure type: The eruption of the fissure type of volcanoes-occurs along a long fracture, fault or fissure. Magma ejects slowly and the resultant lava spreads on the surface. The speed of the lava flow depends on the nature and volume of magma, slope of the ground and the temperature conditions. Classification on the basis of periodicity of eruption: The volcanoes are divided into three types on the basis of the periodicity of their eruption: 1. Active Volcanoes: Volcanoes are said to be active when they frequently erupt or at least when they have erupted within recent time. Etna and Stromboli are typical examples. 2. Dormant Volcanoes: Volcanoes that have been known to erupt and show signs of possible eruption in future are described as dormant. Mt. Vesuvius is the best example. 3. Extinct Volcanoes: Volcanoes that have not erupted at all in historic times but retain the features of volcanoes are termed extinct. Ship rock in Netherlands is one such example. All volcanoes pass through active, dormant and extinct stages but it is impossible to be thoroughly sure when a volcano has become extinct.

Volcanic Landforms Various landforms are created due to the cooling and solidification of magma (below the Earth's surface) and lava (on the Earth's surface). Some relief features are formed due to the accumulation of volcanic materials. The volcanic landforms are grouped into two broad categories: Extrusive landforms and Intrusive landforms. Extrusive Landforms Extrusive landforms are determined by the nature and composition of the lava. Major extrusive landforms are as under: 1. Cinder or ash cones are formed due to the accumulation of loose particles around the vent. Its size increases due to the continuous accumulation of volcanic material minus lava. The larger particles are arranged near the crater and the finer particles are deposited at the outer margins of the cone. The lava flows are so viscous that they solidify after a short distance. 2. Composite cones are the highest and are formed by the accumulation of various layers of volcanic material. They have alternate layers of lava and fragmented Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

material, wherein lava acts as the cementing material. These are mainly associated with cooler and more viscous lava and the volcanoes associated with them are called composite volcanoes. 3. Shield Volcanoes are built almost entirely of fluid lava flows. They are named for their large size and low profile, resembling a warrior's shield lying on the ground. Barring the basalt flows, the shield volcanoes are the largest of all the volcanoes on the earth. These volcanoes are mostly made up of basalt, a type of lava that is very fluid when erupted. For this reason, these volcanoes are not steep. 4. Craters are depressions formed at the mouth of the volcanic vent, which is usually funnel-shaped. Some volcanoes may have greatly enlarged depressions called calderas. These are the result of violent eruptions accompanied by the subsidence of much of the volcano into the magma beneath. Water may collect in the crater or the caldera forming crater or caldera lakes. 5. Flood Basalt Provinces are formed when volcanoes outpour highly fluid lava that flows for long distances. Some parts of the world are covered by thousands of sq. km of thick basalt lava flows. There can be a series of flows with some flows attaining thickness of more than 50 m. Individual flows may extend for hundreds of km. The Deccan Traps from India, presently covering most of the Maharashtra plateau, are a much larger flood basalt province.

Figure 7: Volcanoes based on extrusive landforms Intrusive Landforms The lava that cools within the crustal portion assumes different forms called intrusive forms. Some of these forms are:

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 8: Various intrusive landforms formed in volcanic regions 1. Batholiths are long, irregular, undulating and dome-shaped features. They are a large body of magmatic material that cools in the deeper depth of the crust and develops in the form of large domes. They appear on the surface only after the denudational processes remove the overlying materials. They cover large areas, and at times, assume depth that may be several km. These are granitic bodies. Batholiths are the cooled portion of magma chambers. 2. Laccoliths are formed due to the intrusion of magma along the bedding planes of horizontal sedimentary rocks. They are usually mushroom or dome shaped. 3. Phacoliths are formed due to the intrusion of acidic magma along the anticlines and synclines in the region of fold mountains. 4. Lapoliths are formed when magma solidifies in shallow basins into a saucer shape. 5. Sills and Sheets are intrusive igneous rocks usually parallel to the bedding planes of sedimentary rocks. Depending on the thickness of deposits, thinner ones are called sheets while thick horizontal deposits are called sills. 6. Dykes are wall-like formation of solidified magma. These are vertical to the bed of sedimentary rocks. The thickness ranges from a few centimetres to several hundred metres, but the length can be several kilometres.

Distribution of Volcanoes The volcanoes are mostly associated with the weaker zones of the Earth's crust which are also zones of seismic activities like the earthquakes. The weaker zones are mostly found in the areas of fold mountains. They are also associated with the meeting zones of oceans and continents, or with the mountain building activity. Most of the world's active volcanoes are associated with the plate boundaries. About 15 per cent of the volcanoes are associated with the divergent plate boundaries and about 80 per cent Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

with the convergent plate boundaries. Some volcanoes are also found in the intra-plate regions. The main volcanic belts are as under: 1. Circum-Pacific Belt: It includes the volcanoes of the eastern and western coastal areas of the Pacific Ocean. This belt is also known as the Ring of Fire of the Pacific Ocean. It begins from Erebus mountains of Antarctica and runs northwards through Andes of South America and Rockies of North America to reach Alaska. From there, it turns eastwards along the coast of Asia to include the volcanoes of Sakhalin and Kamchatka, Japan and Philippines respectively. This belt finally merges with the Mid-continental Belt in Indonesia. Most of the high volcanic cones and volcanic mountains are found in the Circum-Pacific Belt. Cotopaxi in Andes (5896 m) is the highest volcanic mountain in the world. The other famous volcanoes are Fujiyama (Japan), Shasta, Rainier, Mt St Helena (USA). 2. Mid-Continental Belt: It includes the volcanoes of the Alpine mountains and the Mediterranean Sea. The volcanic eruptions are caused due to the convergence and collision of the Eurasian Plates and the African and Indian Plates. Some of the famous volcanoes of the Mediterranean Sea such as the Stromboli, Vesuvius, Etna, etc., are in this belt. This belt is not continuous and has several volcanic free zones such as the Alps and the Himalayas. The important volcanoes in the fault zone of eastern Africa are Kilimanjaro, Meru, Elgon, Rungwe, etc. 3. Mid-Atlantic Belt: It includes the volcanoes along the mid-Atlantic ridge which is the divergent plate zone. They are mainly of the fissure eruption type. Iceland, is the most active volcanic area.

Figure 9: Distribution of volcanoes

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Effects of volcanic eruptions Volcanic eruption causes heavy damage to human life and property. Some of them are as under: Large volumes of hot lava moving at a fast speed can bury man-made buildings, kill people and animals, destroy agricultural farms and pastures, burn and destroy forests. The fall out of large quantities of fragmented materials, dust, ash, smoke, etc., creates health hazards due to poisonous gases emitted during eruption. It also causes acid rain. If the explosive eruption has occurred suddenly, the human beings get no time to escape to safer places. Heavy rains mixed with volcanic dust and ash cause enormous mud-flow on the steep slopes of the cones. Earthquakes caused due to explosive eruptions can generate destructive tsunamis, seismic waves, etc. These can cause loss of life and property in the affected coastal regions. The volcanic eruptions can change the heat balance of the Earth and the atmosphere, causing climatic changes.

  





But there are many positive effects also. Some of them are: Lava can give rise to fertile soils. Most of the precious stones are formed due to volcanic activity. Geysers and springs are tourist attraction and are also important from the medical point of view due to the chemicals dissolved in them. Some crater lakes are source of rivers and often offer scenic attraction for tourists. Most of the volcanic rocks when exposed on the surface are a storehouse of metals and minerals.

   

Geysers Geysers are fountains of hot water and superheated steam that may spout up to a height of 150 feet from the earth beneath. The phenomena are associated with a thermal or volcanic region in which the water below is being heated beyond boiling point. The jet of water is usually emitted with an explosion, and is often triggered by gases seeping out of the heated rocks. Almost all the world’s geysers are confined to three major areas: Iceland, New Zealand and Yellowstone park of U.S.A.

Hot Springs Hot springs or thermal springs are more common, and may be found in any part of the earth where water sinks deep enough beneath the surface to be heated by the interior forces. The water rises to the surface without any explosion. Such springs contain dissolved minerals which have medical value.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Iceland has thousands of hot springs. Hot springs are common in many parts of India, especially in the hilly and mountainous parts. Some of them are in Manikaran (Kulu), Tattapani (Shimla), Jwalamukhi (Kangra), Rajgir (Patna), Sitakund (Munger) and in Yamunotri and Gangotri.

Fumaroles A fumarole is a vent in the Earth's surface which emits gases and water vapour. Sometimes the emission is continuous, but in majority of cases emission occurs after intervals. It is widely believed that gases and water vapour are generated due to cooling and contraction of magma after the eruption. Fumaroles are the last signs of the activeness of a volcano.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com

GEOGRAPHY: 5

MOUNTAIN BUILDING ISLAND FORMATIONS AND HOTSPOTS

Contents: 1. Mountains Types of Mountains

Fold Mountains Block Mountains Volcanic Mountains Residual Mountains 2. Islands Continental Islands Oceanic Islands

3. Hotspots

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Mountains

Student Notes:

Since the dawn of geological time, no less than nine orogenic or mountain building movements have taken place, folding and fracturing the earth's crust. Some of them occurred in PreCambrian times about 600-3,500 million years ago. The three more recent orogenies are the Caledonian, Hercynian and Alpine. The Caledonian about 320million years ago raised the mountains of Scandinavia and Scotland, and is represented in North America. These ancient mountains have been worn down and no longer exhibit the striking forms that they must once have had. In a later period, during the Hercynian earth movements, about 240 million years ago, were formed such ranges as the Ural Mountains, the Pennines and Welsh Highlands in Britain, the Harz Mountains in Germany and the Appalachians in America. These mountains have also been reduced in size by the various sculpturing forces. The last of the major orogenic movements of the earth, the Alpine, occurred about 30 million years ago. Young fold mountain ranges were formed on a gigantic scale. Being the most recently formed, these ranges, such as the Alps, Himalayas, Andes and Rockies are the loftiest and the most imposing. Their peaks are sometimes several miles high.

Types of Mountains Based on their mode of formation, four main types of mountains can be distinguished: Fold Mountains These mountains are the most widespread and also the most important. They are caused by large-scale earth movements, when stresses are set up in the earth's crust. Such stresses may be due to: the increased load of the overlying rocks, flow movements in the mantle, magmatic intrusions into the crust, or the expansion or contraction of some part of the earth.

   

When such stresses are initiated, the rocks are subjected to compressive forces that produce wrinkling or folding along the lines of weakness. As illustrated in Fig.1 and 2, folding effectively shortens the earth's crust, creating from the original level surface a series of 'waves'.

Fig.1 Earth’s crust before folding

Fig.2 Earth’s crust after folding

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The upfolded waves are called anticlines and the troughs or downfolds are called synclines. Due to the complexity of the compressional forces, thefolds may develop much more complicated forms. When the crest of a fold is pushed too far, an overfold is formed (Fig.3). If it is pushed still further, it becomes a recumbent fold. In extreme cases, fractures may occur in the crust, so that the upper part of the recumbent fold slides forward over the lower part along a thrust plane forming an over thrust fold. The over-riding portion of the thrust fold is termed a nappe.

Fig. 3 Types of Folding Since the rock strata have been elevated to great heights, sometimes measurable in miles, fold mountains maybe called mountains of elevation. The fold mountains are also closely associated with volcanic activity. They contain many active volcanoes, especially in the Circum-Pacific fold mountain system. They also contain rich mineral resources such as tin, copper, gold and petroleum.

Characteristics Fold mountains are the youngest mountains on the surface of the Earth. Young folded mountains represent the highest mountains on the earth. They also have the highest mountain summits. Mt. Everest is the most typical example (8848m). Fold mountains have been formed due to the folding of sedimentary rocks formed due to the deposition and consolidation of sediments in water bodies mainly in the oceanic environment. The sedimentary rocks of the fold mountains were deposited in shallow seas. The greater thickness of sediments is possible due to the continuous sedimentation and subsidence. The length of the fold mountains is much more than their width. The east-west extent of the Himalayas is about 2400 km, but their north-south width is only 400 km. Thus the fold mountains must have been formed in long, narrow and shallow seas. Fold mountains are generally arc-shaped, having a concave slope on one side and convex on the other. Fold mountains are found along the margins of the continents facing ocean such as the Andes and the Rockies. If we consider the former Tethys Sea, then the Himalayas are also located along the margins of the continent. Fold mountains are mostly located in two directions. In the north-south direction lie the Rockies and the Andes, while in the west-east direction lie the Himalayas and the Alps.

  





 



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Human activity surrounding fold mountains Winter sports such as skiing in resorts. Climbing and hiking in the summer months. Agriculture - takes place mainly on south facing slopes and includes cereals, sugar beet, vines and fruits. Forestry - coniferous forests for fuel and building. Communications - roads and railways follow valleys. Hydroelectric power (HEP) - steep slopes and glacial melt water are ideal for generating HEP. Hydroelectric accounts for 60 per cent of Switzerland's electricity production.

     

Block Mountains When the earth's crust bends, folding occurs, but when it cracks, faulting takes place. Faulting may be caused by tension or compression, forces which lengthen or shorten the earth's crust, causing a section of it to subside or to rise above the surrounding level. Earth movements generate tensional forces that tend to pull the crust apart (fig. 4), and faults are developed. If the block enclosed by the faults remains as it is or rises, and the land on either side subsides, the upstanding block becomes the horst or block mountain. The faulted edges are very steep, with scarp slopes and the summit is almost level, e.g. the Hunsruck Mountains, the Vosges and Black Forest of the Rhineland. Tension may also cause the central portion to be let down between two adjacent fault blocks forming a graben or rift valley, which will have steep walls. The East African Rift Valley system is 3,000 miles long, stretching from East Africa through the Red Sea to Syria. Compressional forces set up by earth movements may produce a thrust or reverse fault and shorten the crust. A block may be raised or lowered in relation to surrounding areas. Fig.5 illustrates a rift valley formed in this way. In general large-scale block mountains and rift valleys are due to tension rather than compression.

Fig. 4 Block Mountains formed by tensional forces Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Fig.5 Rift Valley formed by compressive forces Volcanic Mountains These are built up from material ejected from fissures in the earth's crust. The materials include molten lava, volcanic bombs, cinders, ashes, dust and liquid mud. They fall around the vent in successive layers, building up a characteristic volcanic cone (Fig. 6). Volcanic mountains are often called mountains of accumulation. They are common in the Circum-Pacific belt and include such volcanic peaks as Mt. Fuji (Japan), Mt. Mayon (Philippines), Mt. Merapi (Sumatra), Mt. Agung (Bali) and Mt. Catopaxi (Ecuador).

Fig. 6 Volcanic Mountains Residual Mountains These are mountains evolved by denudation. Where the general level of the land has been lowered by the agents of denudation some very resistant areas may remain and these form residual mountains, e.g. Mt. Manodnock in U.S.A. Residual mountains may also evolve from Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

plateaux which have been dissected by rivers into hills and valleys like. In these type of mountains, the ridges and peaks are all very similar in height.

Fig. 7 Residual Mountains

Islands An island is a piece of land surrounded on all sides by water. It may occur individually or in a group, in open oceans or seas. Smaller ones of only local significance are found even in lakes and rivers. Generally speaking all islands may be grouped, based on their mode of formation, under the following two broad types.

Continental Islands These islands were formerly part of the mainland and are now detached from the continent. They may be separated by a shallow lagoon or a deep channel. Their separation could be due to subsidence of some part of the land or to arise in sea level, so that the lowland links are submerged by the sea. Their former connection with the neighbouring mainland can be traced from the similar physical structure, flora and fauna that exist on both sides of the channel. In the course of time, modification by men and other natural forces may give rise to different surface features. Continental islands can be further classified as under: 1. Individual Islands: These lie just outside the continent, very much associated with the characteristic features of the mainland of which they were once part. Some of the outstanding examples are New foundland, separated from the mainland by the Strait of Belle Isle; Madagascar, by the Mozambique Channel. 2. Archipelagoes or island groups: These comprise groups of islands of varying sizes and shapes, e.g. the British Isles, the Balearic Islands of the Mediterranean and also those of the Aegean Sea. 3. Festoons or island arcs: The islands form an archipelago in the shape of a loop around the edge or the mainland, marking the continuation of mountain ranges which can be traced on the continent. Most of these island arcs are formed as one oceanic tectonic plate subducts another one and, in most cases, produces magma at a depth below the overriding plate, e.g. Andaman and Nicobar Islands, the East Indies, the Aleutian Islands, RyukyuIs lands, Kurile Islands and other island arcs of the Pacific coasts.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Oceanic Islands These islands are normally small and are located in the midst of oceans. They have no connection with the mainland which may be hundreds or thousands of miles away. They have a flora and fauna unrelated to those of the continents. Due to their remoteness from the major trading centres of the world, most of the oceanic islands are very sparsely populated. Some of them provide useful stops for aeroplanes and ocean steamers that ply between continents across vast stretches of water. Oceanic Islands can be further classified as under: 1. Volcanic islands: Many of the islands in the oceans are in fact the topmost parts of the cones of volcanoes that rise from the ocean bed. Most of them are extinct, but there are also some active ones. The best known volcanic peak of the Pacific Ocean is Mauna Loa in Hawaii Other volcanic islands have emerged from the submarine ridges of the oceans. The volcanic islands are scattered in most of the earth's oceans.  In the Pacific Ocean, they occur in several groups such as Hawaii, the Galapagos Islands (Ecuador) and the South Sea islands.  In the Atlantic are the Azores (Portugal), Ascension, St. Helena1, Madeira (Portugal) and the Canary Islands (Spain).  In the Indian Ocean, there are Mauritius and Reunion (French Island in Indian Ocean).  In the Antarctic Ocean are the South Sandwich Islands and Bouvet Island. 2. Coral islands: Unlike the volcanic islands, the coral islands are very much lower and emerge just above the water surface. These islands, built up by coral animals of various species, are found both near the shores of the mainland and in the midst of oceans. Coral islands include:  Marshall Islands, Gilbert (Kiribati) and Tuvalu (formerly Ellice Islands) of the Pacific.  Bermuda(British Overseas Territory) in the Atlantic. Laccadives and Maldives of the Indian Ocean. Artificial Island An artificial island is a man-made island, created by expanding existing islets, building on existing reefs or making them from scratch, off the coastline. Man has been building such islands for hundreds of years. The Flevopolder in the Netherlands is the largest artificial island in the world. In News (The Hindu June 2012): Israeli politicians are floating an idea to expand their seaside country — artificial islands. Palm Islands The Palm Islands are two artificial islands in Dubai, United Arab Emirates in the shape of palm trees. The islands are the Palm Jumeirah and the Palm Jebel Ali.

1

Saint Helena, Ascension and Tristan da Cunha is a British Overseas Territory in the southern Atlantic Ocean consisting of the island of Saint Helena, Ascension Island and the island group called Tristan da Cunha.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Climate change has hit islands hard with some in danger of disappearing completely as sea levels rise. The world’s first underwater cabinet meeting organised by the Maldivian president on 17 October 2009 was a symbolic cry for help over rising sea levels that threaten the tropical archipelago’s existence

Fig: Palm Islands Importance of Islands Earth’s 175,000 islands are home to more than 600 million inhabitants Islands and their oceans represent one-sixth of earth’s total area Islands support many of the most unique and isolated natural systems including: • more than half the world’s marine biodiversity • 7 of the world’s 10 coral reef hotspots • 10 of the 34 richest areas of biodiversity in the world 64% of recorded extinctions are on islands Over two-thirds of the world’s countries include islands. Island ecosystems provide food, fresh water, wood, fibre, medicines, fuel, tools and other important raw materials, in addition to aesthetic, spiritual, educational and recreational values. In fact, the livelihood and economic stability of the islands depend on its biodiversity.

  

  

Hotspots2 A hot spot is a very hot region deep within the Earth. It is usually responsible for volcanic activity. They may be unanimously hot, and provide a great deal of molten magma. Hot spots do not always create volcanoes that spew rivers of lava. Sometimes, the magma 2

Biodiversity hotspot, a region of significant biodiversity is different thing.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

heats up groundwater under the Earth’s surface, which causes water and steam to erupt like a volcano. These eruptions are called geysers. There are 40 to 50 hot spots around the world, including near the Galapagos Islands (Ecuador) and Iceland. Hot spots can create entire chains of islands, like the U.S. state of Hawaii. Hawaii is on the Pacific plate, an enormous section of the Earth in the Pacific Ocean that is constantly moving, but very, very slowly. Although the plate is always moving, the hot spot underneath it stays still. The hot spot spewed magma that eventually became a chain of islands that rose over the surface of the water. These islands were created one right after the other as the plate moved, almost like an island factory. Scientists use hot spots to track the movement of the Earth’s plates.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 6

ROCKS AND MINERALS

Introduction Rocks Minerals Some Major Minerals and Their Characteristics Major Types of Rocks Igneous Rocks Characteristics of igneous rocks Economic Importance of Igneous Rocks Sedimentary Rocks Characteristics of sedimentary rocks Economic Importance of Sedimentary Rocks Metamorphic Rocks Characteristics of metamorphic rocks Parent Rock and its Metamorphic Changed Form Economic Importance of Metamorphic Rocks Rock Cycle

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Introduction Rocks and minerals make up the Earth’s crust. Crust or the lithosphere is the thin outermost layer of the Earth. The hard resistant materials of the crust are called rocks. But in scientific terms, rocks include not only the hard materials such as granite, sandstone and marble, but also soft and loose materials such as chalk, clay, sand, salt and coal.

Minerals Minerals are those substances which occur naturally in rocks. These are non-living solid substances which have a definite chemical composition. Minerals are often classified as metallic and non metallic. The surface of the metallic minerals is generally slippe and glossy. Gold, copper and lead are metallic minerals. They are melted to obtain metals. The surface of the non metallic minerals is dull. They cannot reflect the sun-rays. Gypsum, quartz and mica are non-metallic minerals. Metals cannot be obtained from these minerals. Rocks and minerals account for about 99 per cent of the materials found in the outer layer of the lithosphere. Some rocks have useful minerals, which provide us with metals and chemicals. Out of about 2000 different minerals, only 12 are known as the rock-forming minerals. Oxygen and silicon account for about 75 per cent of the Earth’s crust by weight. These elements are essential for plant and animal life on the Earth. PHYSICAL CHARACTERISTICS OF MINERALS -Minerals have distinct physical properties that can be used to correctly identify a mineral. These are  Crystal structure: arrangement of atoms inside mineral  Hardness: on the Mohs scale, a ten-point scale running from the softest, talc to the hardest, diamond.  Lustre: appearance in light  Colour  Streak: colour of a mineral when it has been ground to a fine powder. Often tested by rubbing the specimen on an unglazed plate.  Cleavage: how mineral splits along various planes  Fracture: how it breaks against its natural cleavage planes  Specific gravity: density compared with water

Some Major Minerals and Their Characteristics Minerals Feldspar

Composition Common fieldspar silicon and oxygen. Specific fieldspar sodium, potassium, calcium, aluminium .

Importance Used in ceramics and glass making

Other facts Half of the earth’s crust is composed of feldspar

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF Quartz

Prominent components of Sand and Granite and used in Radio and Radar

Hard mineral virtually insoluble in water.

Pyroxene

Pyroxene consists of commonly found in calcium, aluminum, meteorites magnesium, iron and silica.

Pyroxene forms 10 per cent of the earth’s crust.

Amphibole

Aluminum, calcium, silica, iron, magnesium are the major elements of amphiboles. It comprises of potassium, aluminium, magnesium, iron, silica etc

used in asbestos industry Hornblende is another form of amphiboles used in electrical instruments

They form 7 per cent of the earth’s crust

Magnesium, iron and silica are major elements of olivine.

Used in jewellery

Mica

Olivine

Consists of silica.

https://t.me/UPSC_PDF

It forms 4 percent of the earth's crust. It is commonly found igneous and metamorphic rocks. Found in basaltic rocks.

Rocks Rocks are generally a mixture of two or more minerals and do not possess a definite chemical composition.

Major Types of Rocks On the basis of their mode of formation, rocks can be classified into the following three types: 1. Igneous rocks 2. Sedimentary rocks 3. Metamorphic rocks

Igneous Rocks The word igneous is derived from the Latin word ‘ignis’ meaning fire. These rocks are of thermal origin and are associated with volcanic eruptions. These rocks have been formed due to solidification of hot and molten material called magma. It is believed that at the time of its birth the Earth was in a molten state. The igneous rocks were the first to be formed as a result of the solidification of the outer layer of the Earth. Thus, igneous rocks are also known as the primary rocks. They can be divided into two types— intrusive1 igneous rocks and extrusive igneous rocks. Igneous rocks that cool below the surface of the Earth are called intrusive igneous rocks. The rate of cooling is slow inside the Earth. Thus the crystals formed on cooling are large. Two common examples of intrusive rocks are dolerite and granite.

1

Igneous rock bodies will be discussed in chapter on volcanoes.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Igneous rocks that cool on the surface of the Earth are called extrusive igneous rocks. These rocks are also known as volcanic rocks. Due to rapid cooling, the crystals are fine grained such as in basalt. On the basis of their composition the igneous rocks are also classified as acidic Igneous Rocks and Basic igneous rocks. In Acidic Igneous rocks silica content in rocks is more than 65 per cent. These rocks are light colored and have less density. These are also known as ‘Silicic rocks’. Granite and rhyolite are examples of these rocks. In Basic Igneous rocks the silica content is less than 65 per cent. They are composed predominantly of ferromagnesian minerals (rich in iron and magnesium). They are dark coloured and dense. Gabbro and basalt are basic rocks. Characteristics of igneous rocks They are compact and massive and do not possess rounded particles. They do not occur in distinct beds or stratas. They are generally granular and crystalline. They are hard and impermeable. They are less affected by chemical weathering. They do not contain any fossils or traces of animals or plants. Most of the igneous rocks consist of silicate minerals. The valuable minerals such as iron, gold, silver, aluminium, etc., are found in them.

       

Economic Importance of Igneous Rocks I. They are a reservoir of minerals. II. Majority of metallic minerals are found in igneous rocks. III. Economically important minerals are found in these rocks-Magnetic iron, nickel, copper, lead, zinc, chromite, manganese, tin. IV. Rare minerals like gold, diamonds, platinum are also found in these rocks. V. Basalt and granite are used for construction of buildings and roads. VI. The formation of black soils is probably the result of erosion of these rocks. These soils are very much suited to cultivation of cotton and some other crops.

Sedimentary Rocks The word sedimentary has been derived from the Latin word ‘sedimentum’, meaning settling down. Rain, wind, ice, running water, plants and animals constantly break the rocks into fragments of all sizes. These broken rock materials are carried away by wind, ice and running water, and deposited in the depressions. The deposited materials are called sediments, and they give rise to sedimentary rocks. The sediments are generally deposited in horizontal layers or stratas. Thus these rocks are also referred to as stratified rocks. The loose materials are converted into hard and compact rocks such as shale and sandstone. This is due to the pressure exerted from the top or because of cementation. The sedimentary rocks can be formed mechanically (sandstone), chemically (gypsum or salt) or organically (coal, limestone). The sedimentary rocks are most widespread and cover about 75 per cent of the total land area on the earth.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Characteristics of sedimentary rocks They are comparatively softer than the igneous rocks. They are made up of minute particles of various shapes and sizes. They have layers horizontally arranged one above the other. They have been mostly formed under water. They have mud cracks and marks of ripples and waves. They have fossils between the layers. Most of them are permeable and porous. Of all the sedimentary deposits, coal and petroleum are the most important ones. Modern industries depend on the products from the sedimentary rocks.

        

Economic Importance of Sedimentary Rocks It is true that they contain lesser minerals than in the igneous rocks. But iron ore, phosphates, building stones, coal, raw materials for cement and bauxite are obtained from these. Mineral oil and Natural Gas is also obtained from sedimentary rocks. In India there is a possibility of finding oil fields in the sedimentary rock strata of the sub-Himalayan zone, in the delta regions of Ganga, Kaveri, Godavari and Krishna rivers, Rann of Kutch and the Gulf of Khambhat. The mineral oil commonly known as petroleum is formed by the decay of tiny marine organisms (in contrast Coal is formed from dead plant) between to impermeable rocks. Sandstone, limestone are used in construction of buildings. The forts of Agra, Delhi and Fatehpur Sikri are built of red sandstone Fertile Soils: The Indus and Ganga basins are also made of sedimentary rocks. Their alluvial soils are highly fertile.





 

Metamorphic Rocks The word metamorphic means ‘changed form’. The rocks, originating at or near the surface of the Earth are sometimes subjected to tremendous heat and pressure. This can change the original properties of rocks such as their colour, hardness, texture and mineral composition. Such changed rocks are called metamorphic rocks. Both igneous and sedimentary rocks can change into metamorphic rocks. The special feature about the origin and formation of metamorphic rocks is that they remain in their original position and change under the impact of internal and external forces. Metamorphism can be of thermal and dynamic origin. 1. In the case of thermal metamorphism, the original rocks are changed under the influence of high temperature inside the Earth’s crust. For example, limestone is converted into marble, sandstone into quartzite, shale into slate and coal into graphite. 2. In the case of dynamic metamorphism, the original rocks are changed under the influence of pressure at great depths inside the Earth’s crust. For example, granite is converted into gneiss and shale into schist. Characteristics of metamorphic rocks • •  •

They are usually hard. They have a high specific gravity. They may be banded. They do not have void spaces in them.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Parent Rock and its Metamorphic Changed Form

Student Notes: NAME OF THE ROCK

TYPE OF ROCK

NAME OF THE METAMORPHIC ROCK

Limestone

Sedimentary Rock

Marble

Dolomite

Sedimentary Rock

Marble

Sandstone

Sedimentary Rock

Quartzite

Shale

Sedimentary Rock

Slate

Slate

Metamorphic Rock

Phylite/Schist

Coal

Sedimentary Rock

Graphite/Diamond

Granite

Igneous Rock

Gneiss

Phyllite

Metamorphic Rock

Schist

Economic Importance of Metamorphic Rocks 1) Building Construction Materials: Gneiss, quartzite, slate, marble are used as building materials. In India marble is found in Alwar, Ajmer, Jodhpur and Jaipur districts of Rajasthan. The thick sheet of slate is used for laying the surface of billiards table. Slate is found in parts of Riwari (Haryana), Karigra (H.P) and Bihar. 2) Industrial Uses: Graphite is used for making pencils. Its melting point is 3500°C. Therefore pots for melting of metals are made of graphite. Graphite is indispensible for atomic energy power house Quartzite, one of the hardest rocks, used in glass making. 3) Beauty Aids: Steatite is used for making talcum powder and other such beauty aids. 4) Asbestos is fire resistant. 5) Garnet: It is a precious stone. It is used for making abrasives.

Rock Cycle Rock cycle is the intimate relationship and mutual interdependence between the three types of rocks—igneous, sedimentary and metamorphic. The change of one type of rock into another type under different conditions is known as the rock cycle. In the cycle of rock change, the materials of the lithosphere are constantly being formed and transformed in both their physical and mineral composition. The rock cycle has neither a beginning nor an end. There are two environments for the working of a rock cycle, such as: a) a surface environment of low temperature and pressure b) a deep environment of high temperature and pressure. At the surface of the Earth, the igneous rocks are exposed to the agents of weathering and erosion. They are then broken and deposited in basins or depressions. Here the sediments are compressed and cemented into sedimentary rocks. The leftover igneous rocks and the newly created sedimentary rocks are likely to change into metamorphic rocks due to heat and pressure in course of time. The formation of sedimentary rock on the Earth’s surface and its conversion into metamorphic rock takes place within the crust of the Earth. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The sedimentary rocks may be buried again and may melt to form the igneous rocks. In the rock cycle, the matter of the Earth’s crust is not lost. The cycle of rock change has been active since our planet became a solid. The loops in the cycle of rock change are powered by two main sources of energy such as:  the heat inside the Earth, which can melt the existing rocks; and  the solar energy responsible for weathering and erosion, and finally converting them into sedimentary rocks. Throughout the geological period of millions of years, the mineral matter of the Earth has been changing due to the working of the rock cycle.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 7

LANDFORMS AND THEIR EVOLUTION

Contents: 1. Introduction 2. Landform and Landscape 3. Causes: 4. Landforms and Scale: Crustal Orders of Relief 5. Evolution of Landform 6. Landform classification 7. Fluvial Landforms (Latin: Fluvius=River) Action of a river/ stream (1) Erosion (2) Transportation (3) Deposition (i) The Upper Course Waterfalls , Rapids and cataracts Pot Holes (ii) The Middle Course (iii) The Lower Course River Rejuvenation Knick point River Terrace Incised or entrenched meanders Significance of work of River Features Overview Erosional Landforms Depositional Landforms Erosional and Depositional Landforms 8. Coastal landforms Coastal processes: Tides, Current and Waves Sea Waves mechanism Coastal erosion

www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Erosional Features Cliffs and wave-cut-platforms Capes and bays Cave, Arch and Stack Blow holes and Geos Depositional Features Wave-Built Platform or Terrace Beaches Bars , Spits and Tombolo Types of Coasts Coastlines of submergence Coastlines of Emergence 9. Glacial Landforms Action of Glacier The landforms created by glacial erosion Cirque (or Corrie): This is an arm chair shaped hollow found in the side of a mountain Arete Pyramidal Peaks Tarn Bergschrund ‘U’ - shaped Valley Hanging Valley Truncated spurs Paternoster lakes Roche Moutonnee Glacial landforms resulting from deposition Boulder clay or glacial till Outwash deposits Erratics Moraines Outwash plain and Kettles Kames Eskers Drumlins 10. Landform by the Action of Wind Mechanism of wind Action in deserts Erosional Landforms-Wind Ventifacts or Dreikanter Ventifact Rock Pedestals or Mushroom Rocks Yardangs Zeugens Mesas and Buttes Inselbergs

www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Depositional Landforms-wind Loess Fluvial Desert Landforms Wadis Pediments Bahada (Bajada): Playas 11. Karst topography Erosional landform (i) Sink Holes , Swallow Holes, Dolines and Uvalas / valley sink (ii) Lapies (vi) Caves Depositional Landforms Stalactites and Stalagmites 12. Economic significance of karst regions

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in ©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

1. Introduction

Student Notes:

The surface of the earth is very uneven and never perfectly flat. It has highlands and lowlands; slopes of varying types -steep, gentle, long and gradual and some very abrupt features. There are depressions and cracks of different shapes and sizes. There are also large areas of almost flat land. Some are rocky, some sandy while the others are covered with soil and vegetation. These different land features that form a part of the larger landscapes (large tracts of the earth’s surface) are known as landforms. Each landform has a typical physical shape, size and material make up.

2. Landform and Landscape A landscape is the general shape of the land surface. Each landscape has its own geologic structure and topographic relief. Topographic relief is the change of elevation between the highest and the lowest places. Landscapes include a variety of topographic features related to the processes that shaped the land surface. A landform is a single feature of a landscape such as mountain, valley or a river system. Hence, several related landforms together make up landscapes. Topography refers to the elevation and relief of the Earth’s surface. Landforms are the topographic features on the Earth’s surface. Geomorphology is the study of earth surface processes and landforms.

3. Causes: The landforms on the Earth’s surface have been created and developed by two types of forces—the tectonic forces and the gradational forces(weathering etc.). The tectonic forces originate from within the Earth and create irregularities on the surface of the Earth. The gradational forces originate from outside the Earth and work to modify and smoothen the irregularities created by the tectonic forces. The work of these two types of forces develops the relief features or landforms on the surface of the Earth. (Read more from Geomorphic Processes Notes).

4. Landforms and Scale: Crustal Orders of Relief To make a systematic study of the landforms, the geographers have divided the landscape into three orders of relief. 1) The first order of relief includes the continental platforms and the ocean basins. The continental platform is the land above the sea level and the ocean basins are the land below the sea level. 2) The second order of relief includes the mountains, plateaus and plains. In the ocean basins, it includes the continental shelves, continental slopes, abyssal plains, midoceanic ridges, submarine canyons and trenches. 3) The third order of relief includes the mountain peaks, cliffs, hills, spurs, sand dunes, valleys, gorges, caves, beaches, etc.

5. Evolution of Landform Every landform has a beginning. Landforms once formed may change in their shape, size and nature slowly or fast due to continued action of geomorphic processes and agents. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Due to changes in climatic conditions and vertical or horizontal movements of land- masses, either the intensity of processes or the processes themselves might change leading to new modifications in the landforms. Evolution here implies stages of transformation of either a part of the earth’s surface from one landform into another or transformation of individual landforms after they are once formed. That means, each and every landform has a history of development and changes through time. A landmass passes through stages of development somewhat comparable to the stages of life — youth, mature and old age. The evolutionary history of the continually changing surface of the earth is essential to be understood in order to use it effectively without disturbing its balance and diminishing its potential for the future. Geomorphology deals with the reconstruction of the history of the surface of the earth through a study of its forms, the materials of which it is made up of and the processes that shape it.

6. Landform classification1 The genetic landform classification system groups landforms by the dominant set of geomorphic processes responsible for their formation. This includes the following processes and associated landforms: 1. 2. 3. 4. 5. 6. 7. 8. 9.

Tectonic Landforms Extrusive Igneous Landforms Intrusive Igneous Landforms Fluvial Landforms Karst Landforms Aeolian Landforms Coastal Landforms Ocean Floor Topography Glacial Landforms

Within each of these, the resulting landforms are a product of either constructive and destructive processes or a combination of both. Landforms are also influenced by other agents or processes including time, climate, and human activity.

7. Fluvial Landforms (Latin: Fluvius=River) In humid regions, which receive heavy rainfall running water is considered the most important of the geomorphic agents in bringing about the degradation of the land. The landforms either carved out (due to erosion) or built up (due to deposition) by running water are called Fluvial Landforms (both erosional and depositional) and the running waters which shape them are called fluvial process. Fluvial processes involve both the overland flow of water down the slope, and stream flow in which water moves in a channel along a valley bottom.

1

Notes 1: We will discuss only important Landforms here. 2. Too many new terms are introduced in this chapter so do not try to memorise all landforms in first go. 3. Observe the diagram before reading the description. 4. Some landforms are discussed in other notes. 5. Landform are generally not asked in mains but could be asked due to changed syllabus. Moreover, understanding of landforms is needed to understand Indian phyiography correctly. Understanding of Landform also assist us in International relations (Geostrategy, Culture), Economic, Science and Tech. etc. 6. Notes are little bigger due to inclusion of more diagrams)

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Action of a river/ stream The work of a stream includes erosion, transportation and deposition. These activities go on simultaneously in all stream channels. (1) Erosion It is the removal of rock or soil. Stream erosion takes place through four processes – hydraulic action, abrasion, attrition and solution Solution or Corrosion- This is the chemical action of river water. The acids in the water slowly dissolve the bed and the banks. This occurs in streams running through rocks such as chalk and limestone. Abrasion or Corrasion- As the rock particles bounce, scrape and drag along the bottom and sides of the river, they break off additional rock fragments. This form of erosion is called corrasion. This is the mechanical grinding of the rivers against the banks and bed of the river. The erosional mechanism of abrasion operation in two ways (i) Lateral Corrasion: This is sideways erosion which widens the river valley. (ii) Vertical Corrasion: This is the downward erosion which deepens the river valley. Attrition- is the mechanical tear and wear of the erosional tools in themselves. The boulders, cobbles, pebbles etc. while moving with water collide against each other and thus are fragmented into smaller and finer pieces in the transit. Hydraulic Action- involves the breakdown of the rocks of valley sides due to the impact of water currents of channel. In fact, hydraulic action is the mechanical loosening and removal of materials of rock by water alone. No load or material is involved in this process.









(2) Transportation River carries rock particles from one place to another. This activity is known as transportation of load by a river. The load is transported in four ways. Traction -The heavier and larger rock fragments like gravel, pebbles etc. are forced by the flow of river to roll along its bed. These fragments can be seen rolling, slipping, bumping and being dragged. This process is known as traction and the load is called traction load. Saltation-Some of the fragments of the rocks move along the bed of a stream by jumping or bouncing continuously. This process is called saltation. Suspension-The holding-up of small particles like sand, silt and mud by the water as the stream flows is called suspension. Solution-Some parts of rock fragments are dissolved in the river water and are thus transported.



  

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

(3) Deposition When the stream comes down from hills to plain area, its slope becomes gentle. This reduces the energy of the stream. The decrease in energy hampers transportation; as a result part of its load starts settling down. This activity is known as deposition. The larger particles, such as boulders and pebbles, are deposited first and the finest particles of silt are the last to be deposited. Deposition takes place usually in plains and low lying areas. When the river joins a lake or sea, the whole of its load is deposited. 3 (b) Development of a River Valley The erosional and depositional land features produced and modified by the action of running water may be better understood if we note the stages through which a stream passes from its source to its mouth. The source of a river may lie in a mountainous region and the mouth may meet the sea or lake. The whole path followed by a river is called its course or its valley. The course of a river is divided into three sections: i. The upper course or the stage of youth ii. The middle course or the stage of maturity iii. The lower course or the stage of old age.

The Upper, Middle and Lower Courses of River

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

(i) The Upper Course The upper course begins from source of the river in hilly or mountainous areas. The river tumbles down the steep slopes and as a result, its velocity and eroding power are at their maximum. Consequently, valley deepening assumes its greatest importance at this stage. Normally, weathering also plays its part on the new surfaces exposed along the banks of the stream. The weathered rock material is carried into the stream partly through the action of gravity and partly by rain water flowing into the river. Weathering helps in widening a valley at the top giving it a typical ‘V’ shaped cross section. Such valleys are known as ‘V’ shaped valleys.

If the bed rock is hard and resistant, the widening of the valley at its top may not take place and the down cutting process of a vigorous river may lead to the formation of a gorge i.e. a river valley with almost vertical sides. George generally develops between pairs of escarpments or cliffs. In India, deep gorges have been cut by the Brahmaputra and the Indus in the Himalayas. Deep gorges also develop in limestone regions and in rocks lying in dry climates.



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Grand Canyon of the river Colorado in U.S.A.

The Valley of Kaveri river near Hogenekal, Dharmapuri district, Tamilnadu in the form of gorge

interlocking spurs

The narrow and very deep gorge with vertical walls is known as ‘I’ shaped valley or canyon. A canyon is very deep gorge with steep sides running for hundreds of kilometers, e.g. Grand Canyon of the river Colorado in U.S.A. As the river flows through the valley it is forced to swing from side to side around more resistant rock outcrops (spurs). As there is little energy for lateral erosion, the river continues to cut down vertically flowing between spurs of higher land creating interlocking spurs.





Some of the others features that are developed in the upper course of a river include rapids, cataracts, cascades, waterfalls, potholes and plunge-pool. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Waterfalls, Rapids and cataracts Waterfalls develop when a layer of erosion-resistant rock lies across a streams course. The less resistant rock on the downstream side is more easily eroded than the resistant rock. The river bed is thus steepened where the two rocks meet and a waterfall develops. The great force of falling water in a waterfall makes hydraulic action effective at its base. The blocks of rocks are broken into smaller boulders by attrition as they collide against each other. The base is further eroded by abrasion to create deep plunge pools beneath. Rapids are formed due to unequal resistance of hard and soft rocks traversed by a river, the outcrop of a band of hard rock may cause a river to 'jump' or 'fall' downstream. Similar falls of greater dimensions are also referred to as cataracts. These interrupt smooth navigation.

Pot Holes River potholes can be created when larger pieces of load that the river cannot remove by traction are swirled around by eddy currents. An eddy current is where the water turns round on itself. The river is not strong enough here to pull the large boulder (as in the diagram,) the obstruction creates a swirling motion in the water. Eventually, the boulder creates a pothole, by abrasion on the river bed.

(ii) The Middle Course In the middle course, lateral corrasion tends to replace vertical corrasion. Active erosion of the banks widens the ‘V’ shaped valley and result in formation of 'U' shaped valley. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

In middle valley course river often develops a winding course. Even a minor obstacles force a river to swing in loops to go round the obstacles. These loops are called meanders. Meander is not a landform but is only a type of channel pattern. The formation of meanders is due to both deposition and erosion and meanders gradually migrate downstream. The force of the water erodes and undercuts the river bank on the outside of the bend where water flow has most energy due to decreased friction. On the inside of the bend, where the river flow is slower, material is deposited, as there is more friction. Thus river Meanders refer to the bends of longitudinal courses of the rivers.

Fig: Development of a meander. In the middle course the volume of water increases with the confluence of many tributaries and this increases the river’s load. Thus work of the river is predominantly transportation with some deposition. Rivers which sweep down from steep mountain valleys to a comparatively level land drop their-loads of coarse sand and gravels as there is sudden decrease in velocity. The load deposited generally assumes a fan like shape, hence it is called an alluvial fan. Sometimes several fans made by neighbouring streams often unite to form a continuous plain known as a piedmont alluvial plain, so called because it lies at the foot of the mountain.

Figure 7.4 : An alluvial fan deposited by a hill stream on the way to Amarnath, Jammu and Kashmir

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

(iii) The Lower Course In the lower course, the river moving downstream across a broad, level plain is heavy with debris brought down from the upper and middle courses. Vertical corrasion has almost ceased, the lateral corrasion still goes on to erode its banks further. The work of the river is mainly deposition in the lower course. Many tributaries join the river and the volume of water increases, coarse materials are dropped and the fine silt is carried down towards the mouth of the river. Large sheets of material are deposited on the level bed and the river splits into a maze of channels. Such a stream is called a braided stream.

Diagram showing Braided stream In lower course large quantity of sediment is carried by river. During annual floods, these sediments are spread over the low lying adjacent areas. A layer of sediments is thus deposited during each flood gradually building up a fertile flood plain. A raised ridge of coarse material is also formed along each bank of the river due to deposition. Such ridges are called levees. They are high nearer the banks and slope gently away from the river. When rivers shift laterally, a series of natural levees can form. Point bars are also known as meander bars. They are found on the convex side of meanders of large rivers and are sediments deposited in a linear fashion by flowing waters along the bank. They are almost uniform in profile and in width and contain mixed sizes of sediments. Rivers build a series of them depending upon the water flow and supply of sediment. As the rivers build the point bars on the convex side, the bank on the concave side will erode actively and these zones are referred as cut bank.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

In the lower course of the river, meanders become much more pronounced. The outer bank or concave bank is so rapidly eroded that the meander becomes almost a complete circle. A time comes when the river cuts through the narrow neck of the loop. The meander, now cut off from the main stream, takes the form of an oxbow lake. When the curvature of the meander loops is so accentuated due to lateral erosion, the meander loop become almost circular and the two ends of meander loops come closer, consequently, the streams straightness their coarses and meander loops are abandoned to form ox-bow lakes. This lake gradually, turning into swamps disappears in course of time. Numerous such partially or fully filled oxbow lakes are marked at short distance from the present course of river like the Ganga.

Upon entering a lake or a sea, the river deposits all the load at its mouth giving rise to the formation of a delta .Delta is a triangular relief features with its apex pointing up stream and is marked as a fan-shaped area of fine alluvium. Some deltas are extremely large. The GangaBrahmaputra Delta is the largest delta in the world. The following conditions favour the formation of deltas: 1. active vertical and lateral erosion in the upper course of the river to supply large amount of sediments, 2. tideless, sheltered coast; 3. shallow sea, adjoining the delta and 4. no strong current at the river mouth which may wash away the sediments. Due to the obstruction caused by the deposited alluvium, the river discharge its water through several channels which are called distributaries. Some rivers emptying into sea have no deltas but instead they have the shape of a gradually widening mouth cutting deep inland. Such a mouth is called estuary. The formation of estuaries is due to the scouring action of tides and currents. But in most of the cases the original cause is the subsidence of the earth’s crust in the area of the outlet. The two west flowing rivers of India, the Narmada and the Tapi do not form deltas. They form estuaries when they join the Arabian Sea. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

River rejuvenation Rejuvenation occurs when there is either a fall in sea level relative to the level of the land or a rise of the land relative to the sea. This enables a river to renew its capacity to erode as its potential energy is increased. The river adjusts to its new base level, at first in its lower reaches and then progressively inland. In doing so, a number of landforms may be created: knick points, waterfalls and rapids, river terraces and incised meanders. Knick point A knick point is a sudden break or irregularity in the gradient along the long profile of a river. Some knick points are sharply defined, for example waterfalls, whereas others are barely noticeable. Although a number of factors can cause such features to occur, they are most commonly attributed to rejuvenation.

When a river is rejuvenated, adjustment to the new base level starts at the sea and gradually works its way up the river's course. The river gains renewed cutting power (in the form of vertical erosion), which encourages it to adjust its long profile. In this sense the knick point is where the old long profile joins the new. River Terrace A river terrace is remnant of a former floodplain which has been left at a higher level after rejuvenation of the river. Where a river renews its down cutting, it sinks its new channel into the former flood plain leaving the old floodplain above the level of the present river. There terraces are cut back as the new valley is widened by lateral erosion. If renewed rejuvenation takes place, the process is repeated and a new pair of terraces is formed beneath the original ones. The River Thames has created terraces in its lower course by several stages of rejuvenation. Terraces provide useful shelter from floods in a lower-course river valley, and natural route ways for roads and railways. The built-up areas of Oxford and London are mainly located along the terraces of the River Thames. When a terrace is present only on one side of the stream and with none on the other side or one at quite a different elevation on the other side, the terraces are called non-paired terraces. Unpaired terraces are typical in areas of slow uplift of land or where the water column changes are not uniform along both the banks.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Incised or entrenched meanders If a rejuvenated river occupies a valley with well-developed meanders, renewed energy results in them becoming incised or deepened. The nature of the landforms created is largely a result of the rate at which vertical erosion has taken place. When incision is slow and lateral erosion is occurring, an ingrown meander may be produced. The valley becomes asymmetrical, with steep cliffs on the outer bends and more gentle slip-off slopes on the inner bends. With rapid incision, where down cutting or vertical erosion dominates, the valley is more symmetrical, with steep sides and a gorge-like appearance, These are described as entrenched meanders.

Diagram showing incised meander

Significance of work of River All rivers undertake three closely interrelated activities erosion, transportation and deposition. Their work has therefore both advantages and disadvantages from a human point of view. Rapids and waterfalls interrupt the navigability of a river. By depositing large quantities of sediments in the lower course, the river silts up ports preventing large streamers from anchoring close to shores. Thus deltas are not suitable site for large ports. Many rivers flood, bursting leeves and causing damage to life and agricultural activities.

 



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Rivers with steep gorges and waterfalls provide natural sites for the generation of hydro electric power which further support industries through supply of energy. In the regions of insufficient rainfall irrigational canals support livelihood of people like Indira Gandhi canal in Rajasthan. The flood plains of large rivers with their thick mantles of fine silt are some of the richest agricultural areas of the world. Like delta of Ganga accounts for almost all the jute production of world. Fresh water fishing is important along many rivers. The organic matter brought down by the river waters provide valuable food for fishes.

  



Features of Overview

Characteristics

Features

Youthful Stage – Upper course  Vertical and headward erosion  Rough channel bed  High competence, low capacity  Large gradient / slope  High turbulence  Narrow channel  Straight course

Mature Stage – Middle Course  Vertical and Lateral erosion  Wider and deeper channel  Competence decreases, capacity increases

Old Stage –Lower Course

v-shaped valley, waterfalls, rapids, potholes, gorges, braided streams, Interlocking spurs

Meanders, river cliffs, slip off slopes, flood plains,

Levees, deltas, point bars, sand bars, oxbow lakes, meanders, larger flood plain, raised banks

EROSIONAL LANDFORMS

     

Waterfalls Gorges Rapids Potholes V-shaped valleys Interlocking spurs

DEPOSITIONAL LANDFORMS

  

Deltas Levees Braided Rivers

Deposition Lateral erosion High discharge & velocity High capacity, low competence Meandering course Wide flood plain Channel depth & width at maximum  Low gradient/slope       

EROSIONAL AND DEPOSITIONAL LANDFORMS

  

Meanders Oxbow lakes Floodplains

8. Coastal landforms Coastal processes: Tides, Current and Waves Coastal processes are the most dynamic and hence most destructive. The coastline of any place is always affected by the dynamic processes operating on the coasts, such as tides, waves and current. Tides and currents when come in contact with the shore have very little direct impact on the coastline. Instead, Waves are the prime agents of erosion in coastal regions. Waves are the Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

result of transfer of energy from atmosphere to water by the wind moving over the water surface. The size of a wave is dependent upon wind velocity, wind duration and the area or distance over which the wind is traveling.

Anatomy of a wave Sea Waves mechanism Waves are most destructive during storm conditions. They exhibit a chaotic pattern at that time, with smaller waves being superimposed over larger waves. The destruction caused by combined effect of those waves is very huge. When these waves approach shallow areas near the coast, they experience rapid reduction in speed. The result is curling of the crest and eventual breaking of the wave. The zone of breaking of waves is called the surf zone. When a wave breaks, the water from it runs up the beach. This is called the swash. The movement of water back down the beach to the sea is called the backwash.

Surf Zone: Swash and Backwash Coastal landforms are of two types erosional landform and depositional landform.

Coastal erosion Coastal erosion is the wearing away and breaking up of rock along the coast. Sea waves play a prominent role in coastal erosion. The rate of marine erosion depends on the nature of rock, the extent of rock exposure to the sea, the effect of tides and currents, and human interference.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Erosional Features

Student Notes: Cliffs and wave-cut-platforms A rock rising vertically above sea water with steep slope is called cliff. It is formed because maximum impact of the sea waves is observed on the lower part of the coastal rocks and consequently the lower part of the rocks is eroded more rapidly than the upper part. In India a number of sea cliffs are found along the Konkan Coast of India.

Figure No. 3- Cliff As the cliff retreats, a new landform is formed. This is a wave-cut-platform. It is a gentle sloping rock cut flat surface. It is created at the bottom of the cliff face. It is not a smooth platform of rock, rather it consists of ridges and grooves. The basic reason for the formation of a wave-cut-platform is the recession of the cliff. Capes and bays Capes and bays are features of irregular coastline. They are formed where hard rocks like granite and limestone occur in alternating bands with softer rocks like sand and clay. The softer rocks are eroded and converted into inlets, coves and bays. The harder rocks resist erosion and persist as headlands or capes.

 

Figure No. 4- Formation of Headlands and Bays Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Cave, Arch and Stack The processes of erosion by waves particularly hydraulic power and corrosion, convert any vertical line of weakness in rocks into caves. However, the rock needs to be relatively hard or resistant otherwise it will collapse before the cave is formed. If the headland is subjected to erosion from two sides, the caves developing on either sides of the headland join to form a natural arch or sea arch. With time, continued erosion causes the arch to collapse, leaving an isolated vertical column of the rock, known as a stack, in front of the cliff. In due course of time, the stack also gets eroded by the action of waves and it ends up in the form of a stump. Continual erosion by waves in caves led toarch

stack

stump

Figure No. 5-Coastal Erosional Features Blow holes and Geos Hole on the roof of the cave is known as blow hole. When the lines of weakness occur on the roof of a cave, hydraulic action of waves leads to the collapse of joint blocks from the roof and leads to the development of a hole on the roof. The enlargement of blow holes and continued action of waves weakens the cave roof. When the roof collapses, a long narrow inlet, or creek, develops. Such deep and long creeks are called geos

.

Figure No. 6- blow holes Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Depositional Features The sea waves also transport the eroded materials and deposit these at other places. Landforms resulting from deposition include platforms, beaches, bars & tombolos . Wave-Built Platform or Terrace It is a terrace formed by the deposition of sediments derived from the erosion of cliffs or from the continued abrasion of a cliff by the action of waves. Beaches Beaches are the most familiar of all the coastal landforms. They are the main feature of deposition found along the coast. They consist of all the material (sand etc.) built up between the high and low tide mark (High tide is highest level of tide while low tide is lowest level of tide). There are a number of different sources of beach material. Rivers are the main source as fine mud and gravel are deposited at the mouth of a river. Other sources of beach material include constructive waves (bringing material up the beach from the sea) and cliff erosion. Beaches are temporary features. Beaches called shingle beaches contain excessively small pebbles and even cobbles. Marina Beach of Chennai and Kovalam Beach of Thiruvananthapuram are the famous beaches of India.

Beach and related features Bars, Spits and Tombolo- These are ridges of sand, pebbles or mud. Bar is such ridge which has joined two headlands cutting across a bay. (see figure) .Sand bars that obtain a length of hundreds of kilometres are called offshore bars or longshore bars. Offshore bars may enclose a water body to form a lagoon, such as the Chilka Lake and Pulicat Lake in India. (Laggons are referred as Kayals in Kerala). If bars are formed in such a way that one end is linked to land and the other end projects into the sea, they are called spits. A connecting bar that joins two landmasses (mainland to island) is known as a tombolo. (see figure 8)



  

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Depositional Features along the Coast

Types of Coasts Coastlines are divided into two basic types (1) Coastline of Submergence (2) Coastline of Emergence

Coastlines of submergence Coastlines of submergence are formed in Coastal areas which have become lowered below current sea level. The cause is rise in sea level in consequence of ice melting since the last ice age. This group includes Ria, fiord, estuarine, and Dalmatian or Longitudinal coasts. a) Ria Coasts: A ria coast is formed when a non-glaciated highland coast becomes submerged and the valleys filled with sea water. These submerged valleys are often V-shaped. This type of coast is found in north-western Spain and south-western Ireland. b) Fiord (Fjord) Coasts: A fjord is a narrow, high-walled, and very long submerged glacial valley. Fjords are formed when a descending glacier carves a U-shaped valley into the bedrock. When these fjord are submerged fjord coast is formed. c) Dalmatian or Longitudinal Coasts: These coasts are formed when a mountain ridge running parallel to the sea coast is submerged. In this mountain ranges become chains of islands resembling patches on body of Dalmatian dog. d) Estuarine Coast: Estuary/estuarine coasts are coasts where lowland coasts are submerged, flooding river. Their entrances are sand and silt free, Thames of Britain are the example of such type of coasts.

Coastlines of Emergence Uplifted or emergent coasts are coasts where the coast has been raised(due to fall in sea level or a rising of the crust) and the ocean waves now erode a lower level. a) Emerged Upland Coasts: An emerged highland coast is formed when coastal plateau lands are raised above sea level. The chief feature of an emerged upland coast is a raised beach or cliff-line which now found above the present zone of wave action. The Northern part of west coast of India is an example of an emerged upland coast.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Emergent upland coast

b) Emerged Lowland Coasts: An emerged lowland coast is produced by the uplift of part of the neighbouring continental shelf. The chief feature of an emerged lowland coast is spits lagoons, bars, marshes and beaches. The coasts of Kerala and Tamil Nadu are example of an emerged lowland coast.

Emergent lowland coast

9. Glacial Landforms A moving mass of ice and snow is called a glacier. Glaciers are formed when there is net year to year accumulation of snow, that is, when the amount of snow that falls in winter is greater than the amount that melts away in summer. Snow keeps on accumulating in layers one above the other. Its overlying pressure is applied to the underlying snow. It is so great that snow in lower layers becomes granular, hard and compact. The pressure also quickens the melting of some of the snow, which on refreezing starts turning into a granular ice. Again it is the pressure of the overlying layers which makes this solid mass of ice mobile. Thus glacier is formed through the processes of accumulation, compaction and recrystallisation of snow. The movement of glacier is very slow and it moves from a few centimetres to a few metres in a day.

Action of Glacier There are three main types of glacial erosion - plucking, abrasion and freeze thaw.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Plucking is when melt water from a glacier freezes around lumps of cracked and broken rock. When the ice moves downhill, rock is plucked from the back wall. Abrasion is when rock frozen to the base and the back of the glacier scrapes the bed rock. Freeze-thaw is when melt water or rain gets into cracks in the bed rock, usually the back wall. At night the water freezes, expands and causes the crack to get larger. Eventually the rock will break away. Erosional work of glacier Erosion by glaciers is tremendous because of friction caused by sheer weight of the ice. As a glacier moves over the land, it drags rock fragments, gravel and sand along with it. These rock fragments become efficient erosive tools. With their help glacier scrapes and scours the surface rocks with which it comes in contact. This action of glacier leaves behind scratches and grooves on rocks. Glaciers can cause significant damage to even un-weathered rocks and can reduce high mountains into low hills and plains.

The landforms created by glacial erosion Cirque (or Corrie): This is an arm chair shaped hollow found in the side of a mountain Arete - This is a narrow, knife edge ridge separating two corries Pyramidal Peaks - These are formed when three or more corries form in the side of one mountain. Tarn - This is a lake found in a corrie

Cirque, arete and pyramidal peak

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Bergschrund These form when a crevasse or wide crack opens along the headwall of a glacier; most visible in the summer when covering snow is gone.

Figure no.2- Bergschrund ‘U’ - shaped Valley The glacier does not carve a new valley like a river but deepens. Glacier movement widens a preexisting valley by smoothening away the irregularities. In this process the glacier broadens the sides of the valley and form a ‘U’ - shaped valley. Such a valley is relatively straight, has a flat floor and nearly vertical sides. Hanging Valley Just like tributary streams of river, there are tributary glaciers also which join the main glacier after moving over their mountainous path. These tributary glaciers like the main glaciers carve U - shaped valleys. However, they have less volume of ice than the main glaciers and thus their rate of erosion is less rapid. As a result their valleys are smaller and not as deep as that of the main glacier. Due to this difference in deepening; the valley of the tributary glacier is left at a higher level than that of the main glacier. The valley of the tributary glacier just looks like hanging downwards at the point of its confluence with the main valley. This type of a topographical feature is called a hanging valley. This feature is visible when ice has melted in both the valleys. When the ice in the hanging valley melts, a waterfall is formed at the point of confluence of this stream with the main river.

Glacial Erosional Landforms

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Truncated spurs In the process of carving the sides of its valley, a glacier erodes or truncates the lower ends of ridges that extended into the valley. These ridges that have triangular facets produced by glacial erosion at their lower ends are termed as truncated spurs.

Paternoster lakes A series of Tarns lakes, resembling a string of prayer beads, are known as paternoster lakes. Roche Moutonnee A roche moutonnée is a rock hill shaped by the passage of ice to give a smooth up-ice side (stoss side) and a rough, plucked surface on the down-ice side(lee side).

Roche Moutonnee

Glacial landforms resulting from deposition Glaciers carry along their bases the rock fragments they have scraped and plucked from the underlying bedrock. These forms the feature of glaciated lowland. The landforms created by glacial erosion are: Boulder clay or glacial till The unassorted coarse and fine debris dropped by the melting glaciers is called glacial till. Outwash deposits Some amount of rock debris small enough to be carried by such melt-water streams is washed down and deposited. Such glacio- fluvial deposits are called outwash deposits. Unlike till deposits, the outwash deposits are roughly stratified and assorted.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 22

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Erratics When boulders of considerable size are deposited far from their origin, they are known as erratics. They have been transported and deposited by a glacier.

Moraines When glacial ice melts, different types of rock are laid down that have been carried along by the glacier. Piles of these deposits are called moraines. Different types of moraine Terminal moraines are found at the terminus or the furthest (end) point reached by a glacier. Lateral moraines are found deposited along the sides of the glacier. Medial moraines are found at the junction between two glaciers. Ground moraines are disorganised piles of rocks of various shapes, sizes and of differing rock types.

Outwash plain and Kettles-As the moraines are deposited, melting water emerges from the glaciers rapidly in the form of streams. These streams carry loads of suspended materials. As the water moves, it soon loses its velocity and load carrying capacity, and it drops most of its bed load. As a result, a broad surface of stratified drift is formed, which is called an outwash plain. The basins or depressions found between the outwash plains are called Kettles. Kames-Rounded mounds/hills of fluvioglacial deposits are known as Kames.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 23

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Eskers-In glaciated areas sinuous ridges of sand and gravel are known as eskers. They marks the former sites of sub glacial melt water streams. Drumlins Drumlins are elongated hills of glacial deposits. They can be 1 km long and 500 metres wide, often occurring in groups. A group of drumlins is called a drumlin swarm or a basket of eggs. These would have been part of the debris that was carried along and then accumulated under the ancient glacier. The long axis of the drumlin indicates the direction in which the glacier was moving. The drumlin would have been deposited when the glacier became overloaded with sediment. However glaciologists still disagree as to exactly how they were formed.

Glacio-Fluvial Deposits

10. Landform by the Action of Wind (Also called Aeolian=Wind ) Wind is also an important agent of denudation. Wind action is mostly limited to arid and semiarid areas of the world, where the absence of vegetation cover and the presence of extensive desolate rocks, help in erosional, transportation and depositional processes. There is a definite pattern to the location of world deserts. Almost all the deserts are confined within the 15° to 30° north and south latitudinal belts, also known as the trade wind belts.  Aridity is the result of lack of water, which is dependent on the mean annual rainfall.  These areas are affected by cold currents. These cold currents ensure that there is little moisture available to condense and form clouds. The coasts of western North and South America and Africa display such conditions.  Continetiality is also a major reason for the development of arid and semi-arid conditions. Air descending from mountainous areas warms and dries by compression, little rainfall forms and it results in aridity. Central areas of continents are also dry because air moving over landmasses does not absorb large amounts of water vapour. About one-third of the land surface of the world can be classified as arid, semi- arid or dry. The major deserts regions of the world include the Sahara desert, Arabian Desert, Kalahari, Namib, Atacama deserts, Great Australian desert, desert of the south-west U.S.A and Mexico. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 24

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

The combined effect of the erosional activity of wind and water in the arid and semi-arid regions give rise to the following types of surfaces.  Erg (Sandy or True Desert): The erg in the Sahara and Saudi Arabia, and koum in Turkmenistan are the true sandy deserts. They consist of vast, almost horizontal, sand sheets or of regular dune lines, or of an undulating sand sea.  Stony Desert: In a stony desert, horizontal sheets of smoothly angular gravel cover the surface. This is known as the reg in Algeria and serir in Libya and Egypt.  Badland: Badland is any landscape characterised by deep dissection, ravines, gullies, and sharp- edged ridges. The name has been given after the arid area in South Dakota, U.SA.  Hamada or Rocky Desert: It consists of large areas of sand and dust, with patches of bare rock. These bare rocks are perfectly smoothened and polished. This type of deserts in Sahara is known as Hamada.  Mountain Desert: Some deserts are found in the highlands, mountain ranges and the plateau areas. The Ahaggar Mountain and Tibesti mountain of Sahara are examples of these deserts.

Mechanism of wind Action in deserts Attrition: When wind borne particles roll against one another in collision they wear each other so that their sizes are greatly reduced and converted into finer materials. Deflation: The complete blowing away of fine dust, leaving coarse and heavier materials, is known as deflation. As a result of deflation, larger hollows known as blow-outs are formed. Deflation also exposes bedrock to wind abrasion (corrasion). There are numerous blow-outs (deflation hollows) in the valley of the Nile. Abrasion or Corrosion: In the process of abrasion, winds pick up dust and sand and drive them with tremendous force against the rocks. In fact, in the desert and semi-desert areas, winds carry with them enormous quantities of sand, dust and small angular fragments which act as tools of erosion as they strike against the rock surfaces. By this process, the less resistant rocks are eroded and in time completely worn away, while the hard and very resistant rocks are polished and smoothed to a remarkable degree.

Erosional Landforms-Wind Ventifacts or Dreikanter: These are stone that has received one or more highly polished, flattened facets as a result of erosion by windblown sand. The facets are cut in sequence and correlate with the dominant wind direction. As one surface is cut, the stone may become out of balance and may turn to expose another surface to the wind. A ventifact that has been eroded to three curved facets is called a dreikanter.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 25

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Ventifact

Rock Pedestals or Mushroom Rocks: Due to the presence of alternate layers of soft and hard rock and the effect of sand-blasting by winds on these, features with irregular edges are formed. Grooves and hollows are cut into the rock surfaces, carving them into fantastic pillars called rock pedestals.

Formation of yardangs

Formation of zeugen

Yardangs: A yardang is a streamlined hill carved from bedrock or any consolidated or semiconsolidated material by the dual action of wind abrasion, dust and sand, and deflation. Zeugens: Zeugens are also formed by wind abrasion where a surface layer of hard rock is underlain by a layer of soft rock into a ridge and furrow landscape. The ridges are called zeugens which may be as high as 100 feet. Ultimately the are undercut and gradually worn away. Mesas and Buttes: Mesa is a Spanish word meaning table. It is a flat, table-like landmass with a very resistant horizontal top layer and very steep sides. With continued denudation through the ages, mesas are reduced to flat-topped hills called buttes.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 26

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Inselbergs: Inselberg is a German word for Island Mountain, has been widely adopted to describe a steep-sided hill of solid rock, rising abruptly from a plain (level ground). They are made of granite. Inselbergs in arid regions are also called bomhardts.

Depositional Landforms-wind The main depositional landforms of wind are sand dunes and loess. Ripple Marks: Ripple marks are small scale depositional features of sand. This pattern is produced in unconsolidated sediments by the agents of erosion-like wind. Ripples may be either longitudinal or transverse. Sand Dunes: These are mounds or ridges of wind-blown sand. The dunes are generally mobile. There is wide variation in their shape, size and structure. On an average, their height ranges between a few metres to 20 metres, but there are some sand dunes which are more than several hundred metres in height and 5 to 6 km in length. Dunes are most well represented in the erg desert(a broad, flat area of desert). There are many types of sand dunes. The two most important dunes are Barchans and Longitudinal dunes, which are described in detail. Barchans: They are crescent-shaped sand dune produced by the action of wind predominately from one direction. This type of dune possesses two "horns" that face downwind, with the steeper slope known as the slip face, facing away from the wind. They gradually migrate with the wind as a result of erosion on the windward side and deposition on the leeward side.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 27

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Longitudinal Dunes (Seif): Seif is an Arabic word, meaning sword dune. These are long, straight dunes and are parallel to the wind direction. Formed in regions where wind blows from more than one direction in a region with an abundant supply of sand. Loess: Loess is fine-grained material that has been transported and deposited by the wind. The sediments come from glacial outwash plains, where glaciers deposit fine particles of silt and clay, or from desert areas that have little vegetation to anchor small particles. Prevailing wind patterns blowing across these environments can produce thick deposits of loess downwind of the area. In China such yellowish wind borne dust from the Gobi desert is called Hwangtu-the yellow earth

Fluvial Desert Landforms Despite being a dry climate arid and semi-arid regions are also influenced by the action of water. Running water is also an important external agent for landform development in deserts. Though rare, the rainfall is intense in its effect on the lightly vegetated cover region of desert and produce abrupt runoff. This occasional rainfall in the deserts results in flash-floods. Loose gravels, sand and fine dust are swept down the hill sides. They cut deep gullies and ravines forming badland topography. The Chambal present a typical example of badland. Some of the important landforms resulting from fluvial action in deserts are pediments, bajada, and playas. Wadis- In Deserts the water flow during flash flood is so strong that it cuts the ground and carries away the soil material. This results in creation of wide channels called wadis. These remain dry for most of the times.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 28

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Pediments: It is an erosional plain formed at the base of the surrounding mountains scraps. Bahada (Bajada): It is a depositional feature made up of alluvial material laid down by the seasonal streams. These are also known as depositional plains of desert. Playas: A (shallow) playa lake may form in the central basin of a desert from abundant rainfall on rare occasions Due to evaporation and infiltration the water in these lakes are present for only a few days or weeks--the dry flat lake bed that remains is called a playa. These lakes are temporary in nature.

Desert Fluvial Landforms

11. Karst topography In rocks like limestones or dolomites rich in calcium carbonate the surface water as well as groundwater through the chemical process of solution and precipitation develop varieties of landforms. These two processes of solution and precipitation are active in limestones or dolomites occurring either exclusively or interbedded with other rocks. Any limestone or dolomitic region showing typical landforms produced by the action of groundwater through the processes of solution and deposition is called Karst topography .‘Karst’ word comes from the Karst region of Adriatic Sea coast in Croatia (Yugosalvia) where such formations are noticeable. This region is made up of limestone rocks, where underground water is the most active agent of gradation.

Erosional landform (i) Sink Holes , Swallow Holes, Dolines and Uvalas / valley sink A sinkhole is a surface depression or hole in a region of limestone terrain. Sinkholes can range in size from a few feet or meters to over 100 meters (300 feet) deep. A sinkhole can even collapse through the roof of an underground cavern and form what's known as a collapse sinkhole

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 29

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Gradual enlargement of sink holes due to continuous dissolution of limestones result in the coalescence of closely spaced sink holes into one large hole which is called Swallow hole. Further enlargement of swallow holes due to continuous solution result into a larger depression which are called dolines in karst erosion. Uvalas are extensive depression. Larger uvalas have been seen to cover several square kilometers, with a depth of up to 200 metres. They are formed due to coalescence of several dolines due to continuous solution and enlargement of dolines, or due to collapse of upper roof of large cavities formed underground or due to coalescence of various sink holes.

(ii) Lapies It is weathered limestone surface found in karst regions and consisting of etched, fluted, and pitted rock pinnacles separated by deep grooves. This rugged surface is formed by the solution of rock along joints and areas of greater solubility by water containing carbonic and humic acids. (vi) Caves In areas where there are alternating beds of rocks (shales, sandstones, quartzites) with limestones or dolomites in between or in areas where limestones are dense, massive and occurring as thick beds, cave formation is prominent. Water percolates down either through the materials or through cracks and joints and moves horizontally along bedding planes. It is along these bedding planes that the limestone dissolves and long and narrow to wide gaps called caves result. There can be a maze of caves at different elevations depending upon the limestone beds and intervening rocks. Caves normally have an opening through which cave streams are discharged. Caves having openings at both the ends are called tunnels.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 30

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Depositional Landforms

Student Notes: Stalactites and Stalagmites They are the major depositional features formed in the caverns in limestone regions. The water containing limestone in solution, seeps through the roofs of the caverns in the form of a continuous chain of drops. A portion of the water dropping from the ceiling gets evaporated and a small deposit of limestone is left behind on the roof. This process continues and deposit of limestone grows downwards like pillars. These forms are called stalactites. When the remaining portion of the water dropping from the roof of the cavern falls on the floor, a part of it is again evaporated and a small deposit of limestone is left behind. This deposit grows upward from the floor of the cavern. These type of depositional features are called stalagmites. As the process grows, both stalactite and stalagmite often join together to form vertical columns and pillars in the caverns.

12. Economic significance of karst regions Karst regions are often barren. The porosity of the rocks and the absence of surface drainage makes vegetation growth difficult. Therefore, these regions support short turf and poor grasses. However, limestone vegetation in tropical regions is luxuriant because of all the year round rainfall. Lead is the only mineral of importance in karst region. Lead occurs in veins in associations with limestone. In addition to this, Limestone is used as building materials or quarried for the cement industry.



  

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 31

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 8

INDIA: PHYSICAL FORMATION, PHYSIOGRAPHY, DRAINAGE, STRUCTURE AND RELIEF AND BASICS OF SOILS

Contents: 1. INDIA LOCATION 1.1 1.2 1.3 1.4

Indian Standard Time (IST) Size India’s Administrative Division India and the World

2. PHYSICAL FORMATION OF INDIA 2.1 The Peninsular Block 2.2 The Himalayas 2.2.1 Syntaxial Bends of the Himalayas 2.3 Indo-Ganga-Brahmaputra Plain

3. PHYSIOGRAPHY 3.1 Himalayan Mountains 3.1.1 Kashmir or Northwestern Himalayas 3.1.2 Himachal and Uttarakhand Himalayas 3.1.3 Darjiling and Sikkim Himalayas 3.1.4 Arunachal Himalayas 3.1.5 Eastern Hills and Mountains or Purvanchal 3.2 The Northern Plains 3.2.1 The Bhabar Plain 3.2.2 The Tarai Tract 3.2.3 Bhangar Plains 3.2.4 Khadar Plains 3.2.5 The Delta Plains 3.2.6 The Plains of Rajasthan 3.2.7 The Punjab Haryana Plains 3.2.8 The Ganga Plains 3.2.9 The Brahmaputra Plain 3.3 The Peninsular Plateau 3.3.1 The Deccan Plateau 3.3.2 The Central Highlands

www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3.3.3 The North-Eastern Plateau 3.4 The Indian Desert 3.5 The Coastal Plains 3.5.1 Western Coastal Plains 3.5.2 Eastern Coastal Plains 3.6 The Islands 3.6.1 Andaman and Nicobar Islands 3.6.2 Lakshadweep Islands

4. DRAINAGE 4.1 Drainage Pattern 4.2 Drainage System of India 4.3 The Himalayan Drainage System 4.3.1 Landforms of Himalayan Rivers 4.3.2 The Indus System 4.3.3 The Ganga System 4.3.4 The Brahmaputra System 4.4 The Peninsular Drainage System 4.4.1 Evolution of Peninsular Drainage System 4.4.2 River Systems 4.4.3 Easy Floring Rivers 4.4.4 West Flowing Rivers 4.5 Comparison between Himalayan and Peninsular Rivers 4.6 National River Linking Project 4.7 National Waterways

5. SOIL 5.1 Soil Properties 5.2 Soil Horizons 5.3 Soil Forming Factors 5.4 Soil Classification 5.4.1 Soil Classification in India 5.5 Soil Degradation 5.6 Soil Erosion 5.7 Soil Management

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in ©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

INDIA LOCATION India is a vast country lying entirely in the Northern hemisphere. The main land extends between latitudes 8°4'N and 37°6'N and longitudes 68°7'E and 97°25'E (figure 1). The Tropic of Cancer (23° 30'N) divides the country into almost two equal parts (figure 2). The southern part of the country lies within the tropics and the northern part lies in the sub-tropical zone or the warm temperate zone. This location is responsible for large variations in land forms, climate, soil types and natural vegetation in the country. To the south east and south west of the mainland, lie the Andaman and Nicobar islands and the

Figure 1 – India in the world Lakshadweep islands in Bay of Bengal and Arabian Sea respectively. Andaman and Nicobar islands make southern boundary of India Union at 6°45'E in Bay of Bengal. The southernmost point of the India Union “Indira Point” got submerged under the sea water in 2004 during the Tsunami. If you work out the latitudinal and longitudinal extent of India, they are roughly about 30 degrees, whereas the actual distance measured from north to south extremity is 3,214 km, and that from east to west is only 2,933 km (figure 2). Why is it so? This is because the east-west distance between two successive meridians of longitude along the equator is at its maximum 111 km. This, however, goes on decreasing as one moves from the equator to the poles, where it is zero. This is because all the meridians of longitude merge in a single point at the poles both North and South. On the other hand, the north-south distance between any two successive parallels of latitude along any meridian of longitude remains almost uniform, i.e., 111 km.

Indian Standard Time (IST) While the sun rises in the northeastern states about two hours earlier as compared to Jaisalmer, the watches in Dibrugarh, Imphal in the east and Jaisalmer, Bhopal or Chennai in the other parts of India show the same time. Why does this happen? What is Indian Standard Time Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

(IST)? What is the use of standard meridian (figure 2)? Variation of nearly 30degree in longitude causes a time difference of

Figure 2 – India: Extent and Standard Meridian nearly two hours between the easternmost and the westernmost parts of our country. Standard meridian is an imaginary line used for reckoning standard time. For the convenience of all, each country chooses its standard meridian in a multiple of 7°30'. India’s standard meridian passes through 82° 30'E.Time along this Standard Meridian of India passing through Mirzapur (in Uttar Pradesh) is taken as the standard time for the whole country and known as IST with a time offset of UTC + 5:30. There is a continuous demand from northeastern states to have separate time zone. Currently, the single time zone causes problems for them, especially in summers when daybreak comes as early as 4:30am around the summer solstice. A farmer in Assam can start work one hour before her or his counterpart in a state like Gujarat. Tea gardens in Assam have for years set their clocks an hour ahead of the rest of the country.

SIZE The land mass of India has an area of 3.28 million square km. India’s total area accounts for about 2.4 per cent of the total geographical area of the world; whereas it sustains17.5per cent of the world population. India is the seventh largest country of the world. India has a land Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

boundary of about 15,200 km and the total length of the coast line of the mainland including Andaman and Nicobar and Lakshadweep is 7,516.6 km.

Figure 3 – India: Administrative Division India is bounded by the young fold mountains in the northwest, north and north east. South of about 22° north latitude, Indian Landmass begins to taper, and extends towards the Indian Ocean, dividing it into two seas, the Arabian Sea on the west and the Bay of Bengal on its east. The Peninsular shape of India makes climate of southern India differ from that of Northern India. Vast sandy expanse of Marusthal in Rajasthan and marshy great Rann of Kachchh make western boundary of the India.

INDIA’S ADMINISTRATIVE DIVISON India, that is Bharat, is a union of states. India has total twenty-eight1 states and seven Union Territories (Figure 3). New Delhi is the capital of India. Rajasthan is the largest state while Goa is the smallest state in terms of geographical area. The Tropic of Cancer (23° 30'N) passes through Mizoram, Tripura, West Bengal, Jharkhand, Chhattisgarh, Madhya Pradesh, Rajasthan and Gujarat (8 states). Jammu and Kashmir makes northern border while Tamil Nadu makes 1

As of Jan 2013 Telangana is in process.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

southern border. Similarly, Gujarat and Arunachal Pradesh are the western most and eastern most states respectively. Except Madhya Pradesh, Chhattisgarh, Jharkhand, Haryana, all states share international or marine boundary.

INDIA AND THE WORLD The Indian landmass has a central location between the East and the West Asia. India is a southward extension of the Asian Continent. The Trans Indian Ocean routes provide a strategic central location to India. It is India’s eminent position in the Indian Ocean which justifies the naming of an Ocean after it. India is part of Indian sub-continent and shares boundary with every country of this region. Land neighbours of India include Pakistan, Afghanistan, China, Nepal, Bhutan, Myanmar and Bangladesh. Most of our boundary with Pakistan and Bangladesh is almost man-made while boundary with other countries largely form a natural boundary. Sri Lanka and Maldives are the two island countries located in the Indian Ocean, which are our neighbours. Sri Lanka is separated from India by the Gulf of Mannar and Palk Strait.

PHYSICAL FORMATION OF INDIA Earth of the distant past was a very different planet than the one we know today. Over these long years, it has undergone many changes brought about primarily by the endogenic and exogenic forces. We have already studied about the movement of Indian plate which started its northward journey about 200 million years ago. This northward movement of the Indian plate is still continuing and it has significant consequences on the physical environment of the Indian subcontinent. Here, we will study about geological structure of India. The geological regions of India are broadly divided into three parts - (i) The Peninsular Block; (ii) The Himalayas; and (iii) Indo-Ganga-Brahmaputra Plain.

THE PENINSULAR BLOCK The plateau of Peninsular India exhibits a complex system of geological structures. It has some of the oldest rocks of the world from the Precambrian period and the youngest rocks of the Quaternary period. The features of this block have developed over period of time. Since the Cambrian period, the Peninsula has been standing like a rigid block with the exception of some of its western coast which is submerged beneath the sea and some other parts changed due to tectonic activity without affecting the original basement. It has been subject to various vertical movements and block faulting. The rift valleys of the Narmada, relict and residual mountains like the Aravali hills, and block fault like Malda fault in the Eastern India are example of it.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 4 – Peninsular block This region contains all types of rocks - igneous, metamorphic and sedimentary rocks. For instance, limestone, sandstone sedimentary rocks are found in river valleys. Coal belts of Peninsular India were developed during the Gondwana period. The black soil of Deccan is due to outpouring of huge quantity of lava during Cretaceous period. The northern boundary of the Peninsular Block may be taken as an irregular line running from Kutch along the western flank of the Aravali Range near Delhi and then roughly parallel to the Yamuna and the Ganga as far as the Rajmahal Hills and the Ganga delta (figure 4). Apart from these, Rajasthan in the west and the Karbi Anglong and the Meghalaya Plateau in the northeast are also extensions of this block. The northeastern parts are separated by the Malda fault in West Bengal from the Chotanagpur plateau. In Rajasthan, the desert and other desert–like features overlay this block.

THE HIMALAYAS The Himalayas are geologically young, weak and flexible and structurally fold mountains unlike the rigid and stable Peninsular Block. The disintegration of Pangaea, about 200 million years ago, led to the formation of a long Tethys sea between the Lauretian Shield and Gondwanaland. This sea was occupying the region of Himalayas called geosyncline. About 6530 million years ago, the Indian plate came very close to the Eurasian plate and started subducting under it (figure 5). This caused lateral compression due to which the sediments of the Tethys were squeezed and folded into three parallel ranges of the Himalayas. Since the northward movement of the Indian plate is still continuing, these mountains are still subjected

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

to endogenic forces apart from exogenic forces. It is said that the height of the Himalayan peaks is still increasing.

Figure 5 – Plate tectonics and evolution of Himalayas The Himalayas consist of four litho tectonic mountain ranges, namely (i) the Trans-Himalaya; (ii) the Greater Himalaya; (iii) the Lesser Himalaya; and (iv) the Shiwalik. The first phase of uplift produced the ranges of Trans Himalayas around 65 million years ago. Subsequent uplift led to formation of Greater Himalayas, Lesser Himalayas and Shiwalik mountain ranges.

SYNTAXIAL BENDS OF THE HIMALAYAS The structures and trends of the Himalaya change sharply at both ends of the range, defining bends called "syntaxes." It develops along the edges of two colliding plates near the zone of active collision. The western syntaxial bend is near Nanga Parbat where the Indus has cut deep gorge. The geological formations here take sharp hair-pin bends as if they were bent around pivotal points obstructing them. There is a similar hair-pin bend in Arunachal Pradesh where the mountains take a sharp bend from the eastern to southern direction after crossing the Brahmaputra river.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 6 – Himalaya’s syntaxes at NP (Nanga Parbat) and NB (Namcha Barwa)

INDO-GANGA-BRAHMAPUTRA PLAIN The third geological division of India comprises the plains which lie to the south of Shiwalik formed by the river system Indus, the Ganga and the Brahmaputra. Originally, it was a geosynclinal depression which attained its maximum development during the third phase of the Himalayan mountain formation approximately about 64 million years ago. It is an aggradational plain formed by the alluvial deposits of rivers originating in Himalayas in north and the Peninsular plateau in South. Since then, it has been gradually filled by the sediments brought by the Himalayan and Peninsular rivers. Average depth of alluvial deposits in these plains ranges from 1,000-2,000 m. Some geologists are of the opinion that Great plains are a remnant of the Tethys Sea. After the upheaval of Shiwalik, the remaining part of the Tethys was left as a large trough. Because the Himalayas were rising during that period, rivers experienced rejuvenation and greater quantity of eroded material which increased the thickness of alluvium in this trough (figure 7).

Figure 7 – The great plains of India

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Table 1 – Geological Time Scale of India

PHYSIOGRAPHY ‘Physiography’ deals with the study of the surface features and landforms of the earth. It is the outcome of structure, process and the stage of development. There are significant variations among the different regions of India in terms of their geological structure. The relief and physiography of India has been greatly influenced by the geological and geomorphological processes active in the Indian subcontinent. The land of India is characterized by great diversity in its physical features. The north has a vast expanse of rugged topography consisting of a series of mountain ranges with varied peaks, beautiful valleys and deep gorges. The south consists of stable table land with highly dissected plateaus, denuded rocks and developed

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

series of scarps. In between these two lies the vast north Indian plain. Based on these macro variations, India can be divided into the six physiographic divisions as shown in figure 8.

Figure 8 – Physiographic division of India

HIMALAYAN MOUNTAINS The North and Northeastern Mountains consist of the Himalayas and the Northeastern Hills. The Himalayas represent the loftiest and one of the most rugged mountain barriers of the world. The altitudinal variations are greater in the eastern half than those in the western half. They are steeper at their southern side as compared to northern side. They are separated from the plains by the Himalayan Front Fault (HFF).Himalayas are not only the physical barrier, they are also a climatic, drainage and cultural divide. The general orientation of these ranges is from northwest to the southeast direction in the northwestern part of India. Himalayas in the Darjiling and Sikkim regions lie in an east west direction, while in Arunachal Pradesh they are from southwest to the northwest direction. In Nagaland, Manipur and Mizoram, they are in the north south direction. They form an arc, which covers a distance of about 2,400 Km. Its width varies from 400 Km in Kashmir to 150 Km in Arunachal Pradesh. Longitudinal division of Himalayas include – Trans-Himalayas, the Greater Himalayas, the Lesser Himalayas and the Shiwaliks (Figure 9). The trans-Himalayas are about 40km wide and contain Tethys sediments which are underlain by ‘Tertiary granite’. Trans-Himalayas in clue Karakoram, Ladakh and Zaskar Mountain ranges in India. The Greater Himalayas rise abruptly like a wall. They are 25 km wide with an average height above 6100m. Almost all the lofty peaks of the Himalayas Mt. Everest, Kanchenjunga, Nanga-Parbat lies in this zone. This mountain range has very few gaps mainly provided by the antecedent rivers, otherwise it is the most continuous range in the Himalayan system. The width of lesser Himalayas is about 80 km with an average height of 1300 – 4600 m. This region is subjected to extensive erosion due to heavy rainfall, deforestation and urbanization. The Shiwalik extend over a width of 10-50 Km and have an altitude varying between 900 and 1100 metres. These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 9 – Himalayas and Northeastern Hills located farther north. Shiwalik are absent beyond Nepal. Landforms like gorges, V-shaped valleys, rapids, waterfalls etc. are indicative of youthful stage of Himalayas. Cross sectional view of Himalayan system is given below (figure 10).

Figure 10 - Cross sectional view of Himalayan system Besides the longitudinal divisions, the Himalayas have been divided on the basis of regions from west to east. These divisions have been generally demarcated by river valleys. On the basis of relief, alignment of ranges and other geomorphologic features, the Himalayas can be divided into the five sub-divisions as shown in figure 11.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 11 – Himalayan – Longitudinal Divisions KASHMIR OR NORTHWESTERN HIMALAYAS Sprawling over an area of about 350,000 sq km, the range stretches about 700km in length and 500 km in width. This division is lying between Indus and Ravi rivers. With an average height of 3000m, it has the largest number of glaciers in India such as Baltoro, Siachen glaciers. Kashmir Himalayas comprise a series of ranges such as the Karakoram, Ladakh, Zaskar and Pir Panjal. The northeastern part of the Kashmir Himalayas, Ladakh, is a cold desert, which lies between the Greater Himalayas and the Karakoram ranges. It is one of the loftiest inhabited regions of the world. Between the Great Himalayas and the Pir Panjal range, lies the world famous valley of Kashmir and the famous Dal Lake. A special feature of Kashmir valley is Karewas formation which is thick deposits of glacial clay and other materials embedded with moraines and useful for saffron cultivation. The southernmost part of this region consists of longitudinal valleys known as ‘duns’ such as Jammu duns and Pathankot duns etc. Some of the important passes of the region are Zoji La on the Great Himalayas, Banihal on the Pir Panjal, Photu La on the Zaskar and Khardung La on the Ladakh range. Important fresh lakes such as Dal and Wular and salt water lakes such as Pangong Tso and Tso Moriri are also in this region. Some famous places of pilgrimage such as Vaishno Devi, Amarnath Cave, Charar -e-Sharif, etc. are also located here. Srinagar, capital city of the state of Jammu and Kashmir is located on the banks of Jhelum river. HIMACHAL AND UTTRAKHAND HIMALAYAS Stretching over Himachal Pradesh, it occupies an area of about 83,000 sqkm. All the three ranges – the Greater, the Lesser (which is locally known as Dhaoladhar in Himachal Pradesh and Nagtibha in Uttaranchal) and the Shiwalik Himalayas – are well represented in this region. This division lies between Ravi and Kali rivers. It is drained by two major river systems of India, i.e. the Indus and the Ganga. Tributaries of the Indus include the river Ravi, the Beas and the Satluj, and the tributaries of Ganga flowing through this region include the Yamuna and the Ghaghara. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The northernmost part of the Himachal Himalayas is an extension of the Ladakh cold desert. Gangotri, Milam and Pindar are the main glaciers of Uttarakhand. The northern slopes of this region are clothed with thick forests and show plains and lakes, while the southern slopes are rugged and forest clad. The famous Valley of flowers is also situated in this region of Himalayas. The two distinguishing features of this region from the point of view of physiography are the ‘Shiwalik’ and ‘Dun formations’ such as Chandigarh-Kalka dun, Nalagarh dun. Dehra Duns the largest of all the duns with an approximate length of 35-45 km and a width of 22-25 km. In the Great Himalayan range, the valleys are mostly inhabited by the Bhotias. These are nomadic groups who migrate to ‘Bugyals’ (the summer grasslands in the higher reaches) during summer months and return to the valleys during winters. The places of pilgrimage such as the Gangotri, Yamunotri, Kedarnath, Badrinath and Hemkund Sahib are also situated in this part. The region is also known to have five famous Prayags - Vishnu Prayag, Nand Prayag, Karn prayag, Rudra Prayag and Dev Prayag, in the descending flow sequence of their occurrence. In this section of Lesser Himalayas, the altitude between 1,000-2,000 m especially attracted to the British colonial administration, and subsequently, some of the important hill stations such as Dharamshala, Mussoorie, Shimla, and the cantonment towns and health resorts such as Shimla, Kasauli etc. were developed in this region. DARJILING AND SIKKIM HIMALAYAS The Darjiling and Sikkim Himalayas are flanked by Nepal Himalayas in the west and Bhutan Himalayas in the east. It is relatively small but is a most significant part of the Himalayas. As compared to the other sections of the Himalayas, these along with the Arunachal Himalayas are conspicuous by the absence of the Shiwalik formations. In place of the Shiwaliks here, the ‘duar formations’ are important, which have also been used for the development of tea gardens. Known for its fast-flowing rivers such as Tista, it is a region of high mountain peaks and deep valleys. Kanchenjunga (8598 m), 3rd highest peak of the world, is situated on the border of India and Nepal. This region has very few passes. The passes of Nathu-La and Jelep-La connect Gangtok (Sikkim) with Lhasa, Tibet (China). The higher reaches of this region are inhabited by Lepcha tribes while the southern part, particularly the Darjiling Himalayas, has a mixed population of Nepalis, Bengalis and tribals from Central India. The British, taking advantage of the physical conditions such as moderate slope, thick soil cover with high organic content, well distributed rainfall throughout the year and mild winters, introduced tea plantations in this region. Sikkim and Darjiling Himalayas are also known for their scenic beauty and rich flora and fauna, particularly various types of orchids. ARUNACHAL HIMALAYAS Arunachal Himalayas extend from the east of the Bhutan Himalayas up to the Diphu pass in the east. The general direction of the mountain range is from southwest to northeast. In this part, the Himalayas rise very rapidly from the plains of Assam. Some of the important mountain peaks of the region are Kangtu and Namcha Barwa. These ranges are dissected by fast-flowing rivers from the north to the south, forming deep gorges. Brahmaputra flows through a deep Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

gorge after crossing Namcha Barwa. Some of the important rivers are the Kameng, the Subansiri, the Dihang, the Dibang and the Lohit. These are perennial with the high rate of fall, thus, having the highest hydro-electric power potential in the country. Due to heavy rainfall, fluvial erosion is quite pronounced here. Few important passes of this region are Bomdi La, Diphu , Pangsau La etc. An important aspect of the Arunachal Himalayas is the numerous ethnic tribal communities inhabiting in these areas. Some of the prominent ones from west to east are the Monpa, Daffla, Abor, Mishmi, Nishi and the Nagas. Most of these communities practise Jhumming (shifting cultivation). This region is rich in biodiversity which has been preserved by the indigenous communities. Due to rugged topography, the inter-valley transportation linkages are nominal. Hence, most of the interactions are carried through the duar region along the Arunachal-Assam border. EASTERN HILLS AND MOUNTAINS OR PURVANCHAL Eastern hills or Purvanchal are part of the Himalayan mountain system. On the southern border of Arunachal Pradesh, the Himalayas take a southerly turn and the ranges are arranged in a north-south direction. They are known by different local names. In the north, they are known as Patkai Bum (Arunachal Pradesh), Naga hills (Nagaland), the Manipur hills (Manipur) and in the south as Mizo or Lushai hills (Mizoram). Most of these ranges are separated from each other by numerous small rivers. The Barak is an important river in Manipur and Mizoram. The physiography of Manipur is unique by the presence of a large lake known as ‘Loktak’ lake at the centre, surrounded by mountains from all sides. Mizoram which is also known as the ‘Molassis basin’ is made up of soft unconsolidated deposits. Most of the rivers in Nagaland form the tributary of the Brahmaputra. These are low hills, inhabited by numerous tribal groups practicing Jhum cultivation.

THE NORTHERN PLAINS The northern plains of India are remarkably homogeneous surface with an imperceptible slope. In fact, they are a featureless alluvial fertile plains formed by the alluvial deposits brought by the rivers – the Indus, the Ganga and the Brahmaputra along with their tributaries and Vindhyan rivers flowing towards north. The plain extends from the arid and semi-arid areas of Rajasthan in the west to Brahmaputra valley in the east. The average width of these plains varies between 150-300 km. The maximum depth of alluvium deposits varies between 1,0002,000 m. Its average height is 200 metres above the mean se level. Due to a very gentle slope towards the sea, the rivers in this plain flow very leisurely and at times even sluggishly. The slope from Varanasi upto the mouth of Ganga is only 10 cm. per km. The land around Ambala is a bit more elevated. Due to almost flat land, changing river courses in the areas of frequent floods is a unique geomorphic process in the plains. The Kosi (The Sorrow of Bihar) is one of two major tributaries of Ganga, the other river being Gandak, draining the plains of north Bihar, the most floodprone area of India. Over the last 250 years, the Kosi River has shifted its course over 120 kilometres and the unstable nature of the river is attributed to the heavy silt which it carries

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

during the monsoon season (figure 12).From north to south, northern plains can be divided into three major zones: the Bhabar, the Tarai and the alluvial plains. The alluvial plains can be further divided into the khaddar and the Bhangar.

Figure 12 – Shifting course of river Kosi in last 250 years THE BHABAR PLAIN Bhabar is a narrow belt ranging between 8-10 km parallel to the Shiwalik foothills at the breakup of the slope. Its width is, however, more in the western plains than in the eastern plains of Assam. The streams and rivers coming from the mountains deposit heavy materials of rocks and boulders, and at times, disappear in this zone due to high porosity. These rivers carry very coarse load with them. This load becomes too heavy for the streams to be carried over gentler gradients and gets dumped and spread as a broad low to high cone shaped deposit called alluvial fan ath the foothills of Shiwalik. Usually, the streams which flow over fans are not confined to their original channels for long and shift their position across the fan forming many channels called distributaries. The Bhabar tract is not suitable for cultivation of crops. Only big trees with large roots thrive in this region. The inhabitants are largely the cattle keeping Gujjars. THE TARAI TRACT South of the Bhabar is the Tarai belt, with an approximate width of 10-20 km where most of the streams and rivers re-emerge without having any properly demarcated channel, thereby, creating marshy and swampy conditions known as the Tarai. Unlike Bhabar tracts, Tarai is wider in the eastern parts of the Great plains, especially in Brahmaputra valley due to heavy rainfall. This has a luxurious growth of natural vegetation and houses a varied wild life. Many parts of the Tarai, especially in Uttarakhand, Uttar Pradesh, Haryana, Punjab and Jammu, have been reclaimed, for agricultural crops such as sugarcane, rice, wheat, maize etc. This marshy tract is infested with mosquitoes and infamous for Japanese Encephalitis (JE) disease. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

BHANGAR PLAINS The south of Tarai is a belt consisting of old and new alluvial deposits known as the Bhangar and Khadar respectively. The Bhangar represents the upland alluvial tracts formed by the older alluviums. The largest part of the northern plains is formed of this older alluvium. The Bhangar formations were deposited during the middle Pleistocene period. The Bhangar land lies above the flood limits of the rivers. The soil is dark in colour, rich in humus content and productive. It contains concentration and nodules of impure calcium carbonate or kankar. KHADAR PLAINS New alluvial deposits along the courses of the rivers are known as the khadar lands. Himalayan rivers have more flood area in the eastern India and thus, Khadar plains are wider here as compared to western area. The khadar tracts are enriched by fresh deposits of silt every year during the rainy season. The khadar land consists of sand silt, clay and mud. Most of the Khadar land has been brough under the cultivation and devoted to sugarcane, rice, wheat, maize, oilseeds. Together alluvial plains (Khadar and Bhangar) are stretched over 100kms from north to south direction. These plains have characteristic features of mature stage of fluvial erosional and depositional landforms such as sand bars, meanders, oxbow lakes and braided channels. The Brahmaputra plains are known for their riverine islands and sand bars. It is also home to first green revolution that took place in 1960s-70s in India. THE DELTA PLAINS The mouths of these mighty rivers also form some of the largest deltas of the world, for example, the famous Sunderbans delta. Otherwise, this is a featureless plain with a general elevation of 50-150 m above the mean sea level. The deltaic plains are extension of the Khadar land. It covers 1.9 lakh sqkm of area in lower reaches of the Ganga River. In fact, it is an area of deposition as the river flows in this tract sluggishly. The deltaic plain consists of old mud, new mud and marsh.

Figure 13 – Different section of northern plains of India

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

On the basis of geo-climatic and topographical characteristics, the northern plains of India may be divided into the following four meso-regions, namely (i) the plains of Rajasthan; (ii) the Punjab-Haryana plains; (iii) the Ganga plains; and (iv) the Brahmaputra Plains (figure 13). THE PLAINS OF RAJASTHAN They lie to the west of Aravallis. These plains cover a total area of about 175,000 sqkm. A substantial part of this plain has been formed by the recession of the sea as is evidenced by the presence of salt water lakes such as Sambhar lake near Jaipur city. During the Permocarboniferous period, the greater part of the Rajasthan plain was under the sea. It has several dry beds of rivers like Saraswati which indicate that the area earlier was fertile. At present, the greater part of these plains is a desert covered with sand dunes and barchans. The Indira Gandhi canal has led to intensive agriculture in north-western Rajasthan. THE PUNJAB HARYANA PLAINS Stretching over an area of about 650km from northeast to southwest and 300km from west to east, the Punjab-Haryana plain is an aggradational plain, deposited by Satluj, Ravi and Beas rivers. Delhi ridge divides plains from the Gangetic plain. The height of the plains varies from 300 m in the north to 200 m in south east. The general direction of slope is from northeast to southwest and south. A plain between two rivers is called doab such as Bist doab between the Beas and Satluj. THE GANGA PLAINS The Ganga plains lie between the Yamuna catchment in the west to the Bangladesh border in the east. It is about 1400km in length and has an average width of 300km. the general gradient of the plain is about 15cm per km. The ganga plains can be subdivided into the following subregions The upper Ganga plain – includes the Ganga-Yamuna Doab, Rohilakhand division and parts of the Agra division. The catchment area of the Yamuna river makes its western boundary, Shiwalik in the north. Its height varies from 100m to 300m. Kali, Sharda are other rivers feeding these plains. It is one of the most productive plains of India in which the Green revolution is a big success. Main crops grown here are sugarcane, wheat, rice, maize, mustard, vegetables etc. The middle Ganga plain – sprawling over an area of 150, 000 sqkm, it includes central and eastern Uttar Pradesh, Bihar up to Muzaffarpur and patna. It has thick alluvial deposits with less kankar. Being a low gradient plain, the rivers often change their courses in this region as described above about Kosi river. Son, Gandak are major tributaries of Ganga. The lower ganga plain – extends from Patna to the Bay of Bengal. It is bordered by Assam, Bangladesh in the east and Chotanagpur plateau in the west and Sundarban delta in the south. It is drained also by Tista, Sankosh, Mahananda, Damodar, Subarnarekha rivers. These plains have filled faults with sediment created during movement of Indian plate. Ganga is divided into several distributaries in the delta region. Hooghly is the best example of a distributary of Ganga.







Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

THE BRAHMAPUTRA PLAIN Stretching over an area of around 56,000sqkm, it is the eastern most part of plains. It is about 720 km long, 80 km wide and altitude varies from 30 m to 130 m. The region is surrounded by high mountains except in western side. Assam valley is characterized by a steep slope along northern margin. Majuli with area of around 930sqkm is the largest river island of India and the second largest of world. But this island is undergoing severe erosion and needs special protection. The tributaries descending from Himalayas form a series of alluvial fans. The fertile valley is conducive to grow rice and jute. It is also famous for its tea and two national parks – Kaziranga and Manas.

THE PENINSULAR PLATEAU The Great Peninsular plateau is a tableland composed of the old crystalline, igneous and metamorphic rocks. It lies to the South of the Great Northern Plains. It covers an area of about 16 lakh square km, i.e., about half of the total area of the country. It is an irregular triangle rising from the height of 150 m above the river plains up to an elevation of 600-900 m. Delhi ridge in the northwest, (extension of Aravalis), the Rajmahal hills in the east, Gir range in the west and the Cardamom hills in the south constitute the outer extent of the peninsular plateau. However, an extension of this is also seen in the northeast, in the form of Shillong and KarbiAnglong plateau separated from Peninsular by Malda fault. One of the distinct features of the peninsular plateau is the black soil area known as Decean Trap. This is of volcanic origin hence the rocks are igneous. When Indian plate was moving over Reunion hotspot, basalt lava spread to form these igneous rocks. Actually these rocks have denuded over time and are responsible for the formation of black soil. The Peninsular India is made up of a series of patland plateaus such as the Hazaribagh plateau, the Palamu plateau, the Ranchi plateau, the Malwa plateau, the Coimbatore plateau and the Karnataka plateau, etc. This is one of the oldest and the most stable landmass of India. The general elevation of the plateau is from the west to the east, which is also proved by the pattern of the flow of rivers. Rivers such as Krishna, Kaveri, Godavari, all rise from Western Ghats, makes delta in the Bay of Bengal side. Plateau has been subjected to large scale denudation. Its mountains are generally of relic type. Because of their old age, all the rivers have almost attained their base level and have built up broad and shallow valleys. Some of the important physiographic features of this region are tors, block mountains, rift valleys, spurs, bare rocky structures, series of hummocky hills and wall-like quartzite dykes offering natural sites for water storage. This Peninsular plateau has undergone recurrent phases of upliftment and submergence accompanied by crustal faulting and fractures. These spatial variations have brought in elements of diversity in the relief of the peninsular plateau. The northwestern part of the plateau has a complex relief of ravines and gorges. The ravines of Chambal, Bhind and Morena are some of the well-known examples. On the basis of the prominent relief features, the peninsular plateau can be divided into three broad groups: (i) The Deccan Plateau; (ii) The Central Highlands; and (iii) The Northeastern Plateau.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 14 – Peninsular India: Relief THE DECCAN PLATEAU This physiographic division is the largest region (about 7 lakh square km) of the Great Indian Plateau. The shape of this plateau is triangular and lies to the south of the river Narmada. This is bordered by the Western Ghats in the west, Eastern Ghats in the east and the Satpura, Maikal range and Mahadeo hills in the north.The Satpura range is formed by a series of scarped plateaus on the south, generally at an elevation varying between 600-900 m. It is a classic example of the relict mountains which are highly denuded and form discontinuous ranges. The Deccan Plateau is higher in the west and slopes gently eastwards. Western Ghats are locally known by different names such as Sahyadri in Maharashtra, Nilgiri hills in Karnataka and Tamil Nadu and Anaimalai hills and Cardamom hills in Kerala. These are block mountains formed due to the downwarping of a part into the Arabian Sea. Western ghats lie parallel to the western coast from mouth of Tapi rover to Kanyakumari. The western slope is steeper as compared to gentle eastern slope. Thal, Bhor and pal Ghats are major passes of Western Ghats. The Eastern Ghats stretch from the Mahanadi Valley to the Nigiris in the south. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The Eastern Ghats are discontinuous and irregular and dissected by rivers such as Mahanadi, the Godavari, the Krishna, the Kaveri draining into the Bay of Bengal. Shevroy Hills and the Javadi Hills are located to the southeast of the Eastern Ghats. Western Ghats are comparatively higher (900-1600m) in elevation and more continuous than the Eastern Ghats (600m). Their average elevation is about 1,500 m with the height increasing from north to south. ‘Anaimudi’ (2,695 m), the highest peak of Peninsular plateau is located on the Anaimalai hills of the Western Ghats followed by Dodabetta (2,637 m) on the Nilgiri hills. Mahendragiri (1,501 metres) is the highest peak in the Eastern Ghats. The Eastern and the Western Ghats meet each other at the Nilgiri hills. THE CENTRAL HIGHLANDS It extends between Vindhayalchal range in South and Great Northern Plains in nroth. The Aravallis form the west-northwestern edge of the Central Highlands. An eastern extension of the Central Highland is formed by the Rajmahal hills. Malwa plateau forms the dominant part of the Central Highlands. The part of the Central Highlands which extends to the east of Malwa Plateau is known as Bundelkhand and is further followed by Baghelkhand and the well known Chhotanagpur Plateau with large mineral reserves. Chhotanagpur is drained by Damodar river. The Mahadeo Hills, Kaimur Hills and Maikal Range lie towards further east. The valley of Narmada has been formed due to the subsidence of the land mass between the Vindhyas and the Satpuras. The general elevation of the Central Highlands ranges between 700-1,000 m and it slopes towards the north and northeastern directions. Most of the tributaries (Chambal, Sind, Betwa, Ken) of the river Yamuna have their origin in the Vindhyan and Kaimur ranges. Banas, tributary of the river Chambal, originates from the Aravalli in the west. The extension of the Peninsular plateau can be seen as far as Jaisalmer in the West, where it has been covered by the longitudinal sand ridges and crescent-shaped sand dunes called barchans. Aravallis hills extend from Gujarat, through Rajasthan to Delhi in the northeasterly direction for a distance of about 700 km till Delhi. The highest peak of the Aravalli hills is Gurushikhar (1722 m) near Mt. Abu, hill station. THE NORTH-EASTERN PLATEAU It is an extension of the main Peninsular plateau in the northeast– locally known as the Meghalaya and Karbi-Anglong Plateau. It is separated by Malda fault from the Chotanagpur Plateau. Later, this depression got filled up by the deposition activity of the numerous rivers. The Meghalaya plateau is further sub-divided into three: (i) The Garo Hills; (ii) The Khasi Hills; (iii) The Jaintia Hills, named after the tribal groups inhabiting this region. An extension of this is also seen in the Karbi Anglong hills of Assam. Shillong is the highest peak in this plateau. Similar to the Chotanagpur plateau, the Meghalaya plateau is also rich in mineral resources like coal, iron ore, sillimanite, limestone and uranium. This area receives maximum rainfall from the south west monsoon. As a result, the Meghalaya plateau has a highly eroded surface

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

THE INDIAN DESERT The Indian desert lies towards the western margins of the Aravali Hills. It is a land of undulating topography dotted with longitudinal dunes and barchans. This region receives low rainfall below 150 mm per year; hence, it has arid climate with low vegetation cover. Low precipitation and high evaporation makes it a water deficit region. Streams appear during the rainy season. Luni is the only large river in this region. It is believed that during the Mesozoic era, this region was under the sea. This can be corroborated by the evidence available at wood fossils park at Aakal and marine deposits around Brahmsar, near Jaisalmer. Land features present here are mushroom rocks, shifting dunes and oasis. the desert can be divided into two parts: the northern part is sloping towards Sindh and the southern towards the Rann of Kachchh.

THE COASTAL PLAINS The Peninsular plateau is flanked by stretch of narrow coastal strips, running along the Arabian Season the west and the Bay of Bengal on the east. WESTERN COASTAL PLAINS West Coastal Plain extends along the Arabian Sea from the Rann of Kutchch in the north to Kanyakumari in the south. These plains are an example of submerged coastal plain. Because of this submergence it is a narrow belt and provides natural conditions for the development of ports and harbours. Kandla, Mazagaon, JLN port Navha Sheva, Marmagao, Mangalore, Cochin, etc. are important natural ports. Extending from the Gujarat coast in the north to the Kerala coast in the south, the western coast may be divided into following divisions – the Kutch and Kathiawar coast in Gujarat, Konkan coast in Maharashtra, Goan coast and Malabar coast in Karnataka and Kerala respectively. The plains of Gujarat are made up of black soil. There are a number of long and narrow lagoons on Malabar Coast. Kochi port is situated on one of the lagoons. These plains are narrow in the middle and get broader towards north and south. The rivers flowing through this coastal plain do not form any delta. The Malabar coast has got certain distinguishing features in the form of ‘Kayals’(backwaters), used for fishing, inland navigation, tourism. EASTERN COASTAL PLAINS The eastern coastal plain is broader, leveled and is an example of an emergent coast. These plains are formed by the alluvial fillings. The monotony of plains is broken by the numerous hills. In the northern part, it is referred to as the Northern Circar, while the southern part is known as the Coromandal Coast. There are well developed deltas here, formed by rivers Mahanadi, Krishna, Godavari, Kaveri etc.Lakes such as Chilika, Pulicat, and Kolluru are the famous lagoons of this plain. Because of its emergent nature, it has less number of ports and harbours. The continental shelf extends up to 500 km into the sea, which makes it difficult for the development of good ports and harbours. Paradip, Visakhapatnam, Ennor, Chennai, Tuticorin are important ports along eastern coast. Rice is the intensively grown here.

THE ISLANDS There are two major island groups in India – one in the Bay of Bengal and the other in the Arabian Sea. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

ANDAMAN AND NICOBAR ISLANDS The Bay of Bengal island groups consist of about 572 islands/islets. These are situated roughly between 6°N-14°N and 92°E -94°E (Figure 15a). The entire group of island is divided into two broad categories – the Andaman in the north and the Nicobar in the south. They are separated by a water body which is called the Ten degree channel. It is believed that island group is an extension of submarine mountains. However, some smaller islands are volcanic in origin. Barren island, the only active volcano in India is also situated here. The coastal line has some coral deposits, and beautiful beaches. These islands lie close to equator and thus, experience equatorial climate. The islands have thick forest cover due to heavy convectional rainfall.

(a) – Andaman and Nicobar Islands

(b) Lakshadweep Islands

Figure 15 – Island groups of India LAKSHADWEEP ISLANDS Lakshadweep Islands are situated in the Arabian Sea, at a distance of 280-480km off the coast of Kerala. These are scattered between 8°N-12°N and 71°E -74°E (Figure 15b). All these islands are of coral origin. They have been built up by corals. Only 11 out of 36 islands are inhabited. The largest island among these, the Minicoy, has an area of 4.5 square km only. The entire group of islands is broadly divided by the Eleventh degree channel, north of which is the Amini Island and to the south of the Canannore Island. Landform features are storm beaches consisting of unconsolidated pebbles, shingles, cobbles and boulders. In overall, it would be clear that each region complements the other and makes the country richer in its natural resources. The northern mountains are the major sources of water and forest wealth. The northern plains are the granaries of the country. They provide the base for early civilisations. The plateau is a storehouse of minerals, which has played a crucial role in the industrialisation of the country. The coastal region and island groups provide sites for fishing and port activities.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

DRAINAGE Rivers have always been of supreme importance to man, providing focal points for habitation, water for cultivation and avenues to travel, water power and recreation. A river or stream is a body of water flowing in a channel. The term ‘drainage’ describes the river system of an area. It is an integrated system of a river and its tributaries which collect and funnel surface water to the sea. The area drained by a single river system is called a drainage basin. The boundary line separating one drainage basin from the other is known as the watershed. A river drains the water collected from a specific area, which is called its ‘catchment area’. The catchments of large rivers are called river basins while those of small rivulets and rills are often referred to as watersheds. Watersheds are small in area while the basins cover larger areas.

DRAINAGE PATTERN A geometric arrangement of streams in a region; determined by slope, differing rock resistance to weathering and erosion, climate, hydrologic variability, and structural controls of the landscape is known as drainage pattern. The rivers that existed before the upheaval of the Himalayas and cut their courses by making gorges in the mountains are knows as the antecedent rivers. Indus, Satluj, Ganga are some important antecedent rivers. The rivers which follow general direction of slope are known as the consequent rivers. Godavari and Krishna etc. rivers descending from the Western Ghats are some consequent rivers. The drainage pattern resembling the branches of a tree is known as “dendritic” the examples of which are the rivers of northern plain. It develops where the river channel follows the slope of the terrain. When the rivers originate from a hill and flow in all directions, the drainage pattern is known as ‘radial’. The rivers originating from the Amarkantak range present a good example of it. When the primary tributaries of rivers flow parallel to each other and secondary tributaries join them at right angles, the pattern is known as ‘trellis’. It develops where hard and soft rocks exist parallel to each other. Right bank tributaries of Brahmaputra rivers make trellis pattern while the left bank tributaries exhibit the

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 22

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Figure 16–Drainage patterns

Student Notes: dendritic pattern. When the rivers discharge their waters from all directions in a lake or depression, the pattern is known as ‘centripetal’. It is reverse of radial and occurs in the areas of karst topography. A combination of several patterns may be found in the same drainage basin.

DRAINAGE SYSTEM OF INDIA The drainage systems of India are mainly controlled by the broad relief features of the subcontinent. Indian drainage system may be divided on various bases. On the basis of discharge of water (orientations to the sea), it may be grouped into: (i) the Arabian Sea drainage; and (ii) the Bay of Bengal drainage. They are separated from each other through the Delhi ridge, the Aravalis and the Sahyadris (water divide is shown by a line in Figure 17).Many rivers have their sources in the Himalayas and discharge their waters in the Bay of Bengal except Indus river system which discharge into Arabian Sea. Ganga, Yamuna, Gandak, Tista and Brahmaputra rivers are major example of it.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 23

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 17 – Water divide between east flowing and west flowing rivers Large rivers flowing on the Peninsular plateau have their origin in the Western Ghats and discharge their waters in the Bay of Bengal. Krishna, Godavari, Kaveri, Tungabhadra are some example of it. The Narmada and Tapi are two large rivers which are exceptions. They along with many small rivers discharge their waters in the Arabian Sea. These small rivers have origin in Western Ghats such as Mandavi, Netravati, Sharavati, and Periyar rivers. Nearly 77 per cent of the drainage area consisting of the Ganga, the Brahmaputra, the Mahanadi, the Krishna, etc. is oriented towards the Bay of Bengal while 23 per cent comprising the Indus, the Narmada, the Tapi, the Mahi and the Periyar systems discharge their waters in the Arabian Sea.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 24

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 18 – Major river Basins of India On the basis of mode of origin, the drainage of India may be divided into (i) Himalayan Drainage; and (ii) Peninsular drainage. However, many of the Peninsular rivers like the Chambal, Betwa, Ken, Son are tributaries of Ganga river system which originate in Himalayas (figure 17). On the basis of the size of the watershed, the drainage basins of India are grouped into three categories: (i) Major river basins with more than 20,000 sq. km of catchment area (figure 18). It includes 14 drainage basins such as the Ganga, the Indus, the Godavari, the Krishna, the Brahmaputra, the Mahanadi, the Narmada, the kaveri, the Tapi, the Pennar, the Brahmani, the Mahi, the Sabarmati, the Barak, the Suvarnarekha; (ii) Medium river basins with catchment area between 2,000-20,000 sq. km incorporating 44 river basins such as the Kalindi, the Periyar,

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 25

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

the Meghna, etc.; and (iii) Minor river basins with catchment area of less than 2,000 sq. km include fairly good number of rivers flowing in the area of low rainfall.

THE HIMALAYAN DRAINAGE SYSTEM The Himalayan drainage system has evolved through a long geological history. There is no unanimity among geologists about the origin of the Himalayan rivers. However, it is believed that a mighty river, namely Shiwalik or Indo-Brahma was flowing west from Assam to Sind and finally discharged into Gulf of Sind during Miocene period. The remarkable continuity of the Shiwalik and its lacustrine origin and alluvial deposits consisting of sands, silt, clay, boulders and conglomerates support this viewpoint. This mighty Shiwalik river was dismembered into three main systems which are now called as Indus, Ganga and Brahmaputra systems (figure 19).The dismemberment is attributed to upheaval in the Western Himalayas including uplift of the Potwar Plateau (or Delhi Ridge). This ridge act as a water divide between Indus and Ganga river systems. Similarly, the down thrusting of the Malda fault (area between Rajmahal Hills and the Meghalaya Plateau) caused the Ganga and the Brahamputra systems to flow towards Bay of Bengal. The giant gorges, sudden bends towards South and other such features are evidence in support that these rivers are older than the Himalayas.

Figure 19 – evolution of Himalayan Drainage Currently, Indus, Ganga and Brahamputra with their respective tributaries make major drainage systems of Himalayas. Since these are fed both by melting of snow and precipitation, rivers of this system are perennial. LANDFORMS OF HIMALAYAN RIVERS The Himalayan rivers are in their youthful stage carving out a number of erosional landforms. These rivers pass through the giant gorges carved out by the erosional activity carried on simultaneously with the uplift of the Himalayas. Satluj, Indus forms great gorges near Gilgit and Sukkur respectively. Besides deep gorges, these rivers also form V-shaped valleys, rapids and waterfalls in their mountainous course. While entering the plains, they form depositional Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 26

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

features like flat valleys, ox-bow lakes, flood plains, braided channels, and deltas near the river mouth. In the Himalayan reaches, the course of these rivers is highly tortuous, but over the plains they display a strong meandering tendency and shift their courses frequently. THE INDUS SYSTEM The Indus (Sindhu) is one of the most important drainage systems of the Indian subcontinent and one of the largest in the world. It covers an area of 11, 65,000 sq. km and length of 2,880 km, out of which 321, 289 sqkm area and 1,114 km length is in India. The Indus is the westernmost of the Himalayan rivers in India. Indus has origin from a glacier near Bokar Chu in the Kailash Mountain range in the Tibet province of China. In Tibet, it is known as ‘Singi Khamban; or Lion’s mouth. After flowing in a constricted valley in Tibet, it follows a long, nearly straight course between the Ladakh and Zaskar ranges in the northwest direction where it receives Zaskar below Leh town. It cuts across the Ladakh range, forming a spectacular gorge near Gilgit which is 5200m in height. In this region, transverse glaciers and landslides periodically dam the river. River passes Nanga Parbat and turns south-west to enter Pakistan near Chillar in the Dardistan region. In the Jammu and Kashmir, Indus receives a number of Himalayan tributaries such as the Shyok, the Gilgit, the Hunza, the Nubra, the Shigar, the Gasting and the Dras. Right bank tributaries such as the Khurram, the Tochi, etc. originate in Sulaiman ranges. Down in the Punjab province of Pakistan, Indus receives ‘Panjnad’, five rivers of Punjab, namely the Satluj, the Beas, the Ravi, the Chenab and the Jhelum. River finally drains into the Arabian Sea, east of Karachi city. These rivers do not meet Indus separately but as a single river. The Jhelum (Vitasta) rises from a spring at Verinag Spring situated at the foot of the Pir Panjal. It flows through Srinagar and the Wular lake before entering Pakistan through a deep narrow gorge. It joins the Chenab in Pakistan. It is the most important river of Kashmir. The Chenab (Asikni) flows in India for about 1180km draining around 26,755 sqkm area. It is the largest tributary of the Indus. It is formed by two streams, the Chandra and the Bhaga, which join at Tandi near Keylong in Himachal Pradesh. Hence, it is also known as Chandrabhaga. Major hydro power plants installed in Chenab are Salal, Baghliar, and Dulhasti. The Ravi (Parushni) river flows for about 725 km and drains 6000 sqkm area in India. It rises near the Rohtang Pass in Kullu hills in Himachal Pradesh, very close to the source of the Beas river. It flows through the famous Chamba valley. It drains an area lying between Pir Panjal and Dhauladhar ranges. It also cuts a gorge in Dhaula Dhar range. In plains of Punjab, it runs along the Indo-Pak border and joins Chenab near Sarai Sidhu in Pakistan. The Beas (Vipasa) river originates from the Beas Kund near the Rohtang Pass at an elevation of 4,000 m. The river flows through the Kullu valley and forms gorges at Kati and Largi in the Dhaula Dhar range. Further down, it flows through the Kangra valley. It enters the Punjab plains where it meets the Satluj near Harike in India’s Punjab. Indira Gandhi Canal that feeds western Rajasthan has origin at Harike, confluence of Beas and Satluj. The Satluj (Satadru) river rises from the Rakas Lake near Mansarovar (4,555m) in Tibet. This is an antecedent river. It flows almost parallel to the Indus for about 400 km before entering Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 27

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

India, and comes out of a gorge across the Great Himalayas. It passes through the Shipki La (4300 m) on the Himalayan ranges at India-China border. It cuts the Zaskar ranges, Dhaula Dhar range, Shiwalik and finally enters the Punjab plains. It feeds the canal system of the Bhakra Nangal project. The Ghaggar (Saraswati) is an inland drainage which rises in the talus fan of the Shiwalik near Ambala, Haryana. After entering the plains, it disappears but reappears at Karnal. Further on, the stream disappears near Hanumargarh in Bikaner. It is believed that it is an old tributary of the Indus. THE GANGA SYSTEM The Ganga is the most important river of India both from the point of view of its basin and cultural significance. The river has a length of 2,525 km. It is the largest river basin in India with about one-fourth area of the country under it. It rises in the Gangotri glacier near Gaumukh (3,900 m) in the Uttarakhand where it is known as the Bhagirathi. At Devprayag, the Bhagirathi meets the Alaknanda and both makes Ganga. The Alaknanda consists of the Dhauli and the Vishnu Ganga which meet at Vishnuprayag. Pindar joins Alaknanda at Karnaprayag while Mandakini meets it at Rudraprayag. At Haridwar, Ganga enters into plains. Further on, it moves in west-east direction and split into two distributaries, namely the Bhagirathi and the Hugli in Bengal. Along with Brahmaputra, it makes largest delta of the world. The Ganga river is having a number of perennial and non-perennial rivers originating in the Himalayas in the north and the Peninsula in the south, respectively. It flows through major cities of India – Kanpur, Allahabad, Patna, and Kolkata. The Yamuna river, the western most and the longest tributary of the Ganga, has its source in the Yamunotri glacier on the western slopes of Banderpunch range (6,316 km). It flows parallel to Ganga and finally meets the same at Allahabad (Prayag). The right bank tributaries involves the Chambal, the Sind, the Betwa and the Ken which originates in the Peninsular plateau while the Hindan, the Rind, the Sengar, the Varuna, etc. join it on its left bank. It is a major source to feed the canals of Haryana and Uttar Pradesh. It flows through cities such as Karnal, Delhi, and Agra. The Gandak river comprises two streams, namely Kaligandak and Trishulganga. It rises in the Nepal Himalayas between Dhaluagiri and Mt. Everest. It enters the Ganga Plains of India in Champaran, Bihar and joins Ganga at Sonpur near Patna. This river changes its course frequently. The Ghaghara originates in the glaciers of Mapchachungo. It comes out of the mountain, cutting a deep gorge at Shishapani. The river Sarda joins it in the plain before it finally meets the Ganga at Chhapra. It flows through famous Ayodhya town. The Ramganga is the first major tributary to join the Ganga from its left near Kannauj. It rises in the Garhwal hills near Gairsain. A large dam has been built on this river near Kalagarh. The Damodar drains the eastern parts of the Chotanagpur Plateau where it flows through a rift valley and finally joins the Hugli at Falta. The Barakar is its main tributary. Once known as the Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 28

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

‘sorrow of Bengal’, the Damodar has been now tamed by the Damodar Valley Corporation, a multipurpose project. The Chambal rises near Mhow in the Malwa plateau from Vindhyan range and flows northwards through a gorge up wards of Kota in Rajasthan. From Kota, it traverses down to Bundi, Sawai Madhopur and Dholpur, and finally joins the Yamuna at Etawah. The Chambal is famous for its badland topography called the Chambal ravines. Ravines are being reclaimed for agricultural and pastoral activities. Banas river is its main tributary. The main dams across the river are Gandhi Sagar (Kota), Rana Pratap Sagar and Jawahar Sagar. The Son originates from the Amarkantak plateau. It has length of 780km and drains areas of around 54,000 sqkm. After forming a series of waterfall at the edge of plateau, it reaches Arrah, west of Patna to join the Ganga. The Sarda or Saryu river rises in the Milan glacier in the Nepal Himalayas where it is known as the Goriganga. Along the Indo-Nepal border, it is called Kali or Chauk, where it joins the Ghaghara. The Mahananda is another important tributary of the Ganga rising in the Darjiling hills. It joins the Ganga as its last left bank tributary in West Bengal. THE BRAHMAPUTRA SYSTEM The Brahmaputra is one of the largest river of not only India but the world. Its total length is 2900km and basin area is 5,80,000 sqkm (916 km and 1,87,00 sqkm in India). Its origin is in the Chemayungdung glacier of the Kailash range near the Mansarovar lake. From here, it flows parallel to the Greater Himalayas in the dry and flat Tibetan region where it is known as Tsangpo. It emerges as a turbulent and dynamic river after carving out a deep gorge in the Central Himalayas near Namcha Barwa (7,755 m). The river emerges from the foothills under the name of Siang or Dihang. It enters India west of Sadiya town in Arunachal Pradesh. It receives its main left bank tributaries, viz., Dibang or Sikang and Lohit; thereafter, it is known as the Brahmaputra. In the Assam valley, its major left bank tributaries are the Burhi Dihing, Dhansari (South) and Kalang whereas the important right bank tributaries are the Subansiri, Kameng, Manas and Sankosh. The Brahmaputra enters into Bangladesh near Dhubri and flows southward. In Bangladesh, the Tista joins it on its right bank from where the river is known as the Yamuna. The Brahmaputra is well-known for floods, channel shifting and bank erosion. This is due to the fact that most of its tributaries are large, and bring large quantity of sediments owing to heavy rainfall in the region

THE PENINSULAR DRAINAGE SYSTEM The Peninsular drainage system is older than the Himalayan one. This is evident from the broad, largely-graded shallow valleys, and the maturity of the rivers. Rivers follow the relief pattern of the plateau. Except for the rivers flowing through fault valleys, the slope of all rivers is very gentle.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 29

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

EVOLUTION OF PENINSULAR DRAINAGE SYSTEM Three major geological events in the distant past have shaped the present drainage systems of Peninsular India: (i) Subsidence of the western flank of the Peninsula leading to its submergence below the sea during the early tertiary period. Generally, it has disturbed the symmetrical plan of the river on either side of the original watershed. Earlier the area to the west of the Western ghats was also a landmass in ancient times. At that time, rivers flowed in both directions from the water divide formed by the Ghats and there was a symmetrical distribution of rivers. (ii) Upheaval of the Himalayas when the northern flank of the Peninsular block was subjected to subsidence and the consequent trough faulting. The Narmada and The Tapi flow in trough faults and fill the original cracks with their detritus materials. Hence, there is a lack of alluvial and deltaic deposits in these rivers. (iii) Slight tilting of the Peninsular block from northwest to the southeastern direction gave orientation to the entire drainage system towards the Bay of Bengal during the same period. RIVER SYSTEMS The Western Ghats situated near the western coast form the major water divide between the major Peninsular rivers, discharging their water in the Bay of Bengal and as small rivulets joining the Arabian Sea. Except Narmada and Tapi, all major rivers flow in east direction. The other major river systems of the Peninsular drainage are – the Mahanadi the Godavari, the Krishna and the Kaveri. Peninsular rivers are characterised by fixed course, absence of meanders and ephemeral flow of water. The Narmada and the Tapi which flow through the rift valley are, however, exceptions. Peninsular rivers receive water from Southwest monsoon and Tamil Nadu rivers gets water from retreating or northeast monsoon also. EAST FLOWING RIVERS The Mahanadi rises near Sihawa, Amarkantak hills in the highlands of Chhattisgarh and runs through Orissa to discharge its water into the Bay of Bengal. It is 851 km long and its catchment area spreads over 1.42 lakh sq. km. Some navigation is carried on in the lower course of this river. Deltaic stretch of this river is part of National Waterways 5(NW5). The Godavari is the largest Peninsular river. It rises from the slopes of the Western Ghats in the Nasik district of Maharashtra. It is also called Dakshinganga. It is 1,465 km long with a catchment area spreading over 3.13 lakh sq. km 49 per cent of this, lies in Maharashtra. The Penganga, the Indravati, the Pranhita, and the Manjra are its principal tributaries. It forms a picturesque gorge in Eastern Ghats. The Godavari is subjected to heavy floods in its lower reaches. It is navigable only in the deltaic stretch. The river after Rajamundri splits into several branches forming a large delta. The Krishna is the second largest east-flowing Peninsular river which rises from a spring near Mahabaleshwar. Its total length is 1,401 km. The Koyna, the Tungbhadra and the Bhima are its major tributaries. Its drainage basin is shared by Maharashtra, Karnataka and Andhra Pradesh. The Kaveri rises in Brahmagiri hills (1,341m) of Kogadu district in Karnataka. Its length is 800 km and it drains an area of 81,155 sq. km. Since the upper catchment area receives rainfall during the southwest monsoon season (summer) and the lower part during the northeast monsoon season (winter), the river carries water throughout the year. It flows into the Bay of Bengal at Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 30

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Kaveripatnam. It drains parts of Tamil Nadu, Karnataka and Kerala. Its important tributaries are the Kabini, the Bhavani and the Amravati. The Brahmani and the Subernarekha rivers drain a part of area between the Ganga and the Mahanadi into the Bay of Bengal. Their drainage area extends over parts of Bihar, Odisha, West Bengal and Madhya Pradesh. It supplies water to the Tata steel plant at Jamshedpur. WEST FLOWING RIVERS The Narmada originates on the western flank of the Amarkantak plateau at a height of about 1,057 m. Flowing in a rift valley between the Satpura in the south and the Vindhyan range in the north, it forms a picturesque gorge in marble rocks and Dhuandhar waterfall near Jabalpur. It meets the Arabian Sea south of Bharuch, forming a broad 27 km long estuary. Its length is 1312 km and catchment area of 98,796 sqkm. All the tributaries are very short and make trellis pattern. The Sardar Sarovar Project has been constructed on this river. Narmada has been joined with other Gujarat rivers to shift its water. The Tapi is the other important westward flowing river. It originates from Multai in the Betul district of Madhya Pradesh and discharge in Surat district, Gujarat. It is 724 km long and drains an area of 65,145 sq. km. The Purna, Girna and Panjhra are its important tributaries. Luni is the largest river system of Rajasthan, west of Aravali. It originates near Pushkar in two branches, i.e. the Saraswati and the Sabarmati, which join with each other at Govindgarh. It flows towards the west till Telwara and then takes a southwest direction to join the Rann of Kutch. The Mahi river rises in the Satmala hills of the Vindhyan mountains. After flowing for 533km, it drains into the Gulf of Khambhat. The Sabarmati riverrises in the Aravalli hills and flows into Arabian Sea after flowing over a distance of 300km. Small west flowing rivers are numerous which rises in the Western Ghats and have short runoff. The Shetruniji is one such river which rises near Dalkahwa in Amreli district. The Bhadra originates near Aniali village in Rajkot district. The Dhadhar rises near Ghantar village in Panchmahal district. The Vaitarna rises from the Trimbak hills in Nasik district at an elevation of 670 m. The Kalinadi rises from Belgaum district and falls in the Karwar Bay. The Sharavati is another important river in Karnataka flowing towards the west. The Sharavati originates in Shimoga district of Karnataka. Goa has two important rivers which can be mentioned here. One is Mandovi and the other is Juari. The longest river of Kerala, Bharathapuzha rises near Annamalai hills. It is also known as Ponnani. It drains an area of 5,397 sq. km. The Periyar is the second largest river of Kerala. Its catchment area is 5,243 sq. km.

COMPARISON BETWEEN HIMALAYAN AND PENINSULAR RIVERS Difference between the rivers rising in the Himalayas and those rising in the Peninsular plateau are primarily a result of the differences between the two areas in terms of relief and climate. Following table shows major differences between these two groups.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 31

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF S. No. Aspects 1 Place of Origin 2 Nature of flow 3 Type of drainage

www.UPSCPDF.com

https://t.me/UPSC_PDF

Himalayan River Peninsular River Himalayan mountain covered with Peninsular plateau and central glaciers highland Perennial Ephemeral

Antecedent and Consequent Super imposed, rejuvenated leading to dendritic pattern resulting in trellis, radial and rectangular Patterns Nature of Long course, flowing through the Smaller, fixed course with wellriver rugged mountains experiencing adjusted valleys; headward erosion and river capturing; In plains meandering and shifting of Course; Catchment Very large basins Relatively smaller basin area Age of the Young, active and deepening of Old rivers with graded profile and river valley lateral erosion Irrigation Flows through plains and canal Flows over uneven plateau; canals system only in deltaic region HydroEastern region has very high Natural waterfalls for generating electricity potential and large dams are electricity building up

4

5 6 7 8

NATIONAL RIVER LINKING PROJECT The idea of linking water surplus Himalayan rivers with water scarce parts of western and peninsular India has been doing the rounds for the past 150 years. The rivers of India carry huge volumes of water per year but it is unevenly distributed both in time and space. There are perennial rivers carrying water throughout the year while the non-perennial rivers have very little water during the dry season. During the rainy season, much of the water is wasted in floods and flows down to the sea. Similarly, when there is a flood in one part of the country, the other area suffers from drought. Such linkage is said to provide major benefits such as irrigation, assured drinking water, flood and draught prevention, generation of electricity, and inland navigation. Nevertheless, project is facing several challenges in its implementation. Project involves hundreds of billions of dollars that India could not afford. Water shortage Peninsular plateau has higher altitude compare to water surplus Ganges plains. Carrying water to higher level required either electricity to pump water or create chain of deep channels which seems very difficult in rocky Peninsular. Project will have to acquire lakhs of hectares of land. It will affect the ecosystem(submergence of forest land, deforestation, flora and fauna) and rehabilitation issue of lakhs of displaced persons.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 32

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 20 – Inter-linking of rivers Ironically, rivers of northern plains have water surplus during or just after monsoon. This time Peninsular rivers also have sufficient water. While the water availability in the southern rivers may be increased, the main reason why such project is not being put to implementation is the apprehension of future water shortage in the Northern plains as a result of Climate change, whose effects are now not known. Shifting huge quantity of water would have affect on heat balance of Indian subcontinent which may affect monsoon pattern and intensity also. It will also affect the temperature and salinity of Bay of Bengal water near Bengal region. NDA government's proposal of river interlinking met with stiff opposition from several quarters. The Supreme Court cleared the river-linking project. A group of citizens has filed review petition in the Supreme Court. Recent report of planning commission also does not support the project due to environmental and monsoon issues. Rivers linkage crosses political boundaries of states. Consensus among states is another challenge. Linkage at small scale is feasible and few links of this river projects are under analysis or under construction. For instance, many links in Gujarat are connected. Five Peninsular links namely (i) Ken – Betwa, (ii) Parbati – Kalisindh – Chambal, (iii) Damanganga – Pinjal, (iv) Par – Tapi – Narmada & (v) Godavari (Polavaram) - Krishna (Vijayawada) have been identified as priority links for taking up their Detailed Project Reports (DPRs) by ministry of water resources in 2012. DPR of one priority link namely Ken-Betwa has been completed and was communicated to the party states. Solution envisaged in the 12thfive year plan is the water management. Locally available water needs to be managed with proper conservation techniques and by use of best Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 33

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

available technologies in agriculture, industry with full incentive to be given for recycling of water.

NATIONAL WATERWAYS An efficient transport sector is vital for development of the economy of any country. Compare to European countries, China etc., India has poor performance in using Inland river navigation for goods

Figure 21 – NATIONAL WATERWAYS (NWS) OF INDIA transportation. Inland Water Transport (IWT) is a fuel efficient, environment friendly and cost effective mode of transport. Currently, there are five national waterways(NW) and sixth is being under consideration(figure 21). Following is the details of NWs: NW1 is from Allahabad to Haldia with total length of 1620 kms. It is being used by tourism vessels, ODC carriers, IWAI vessels. Many coal based plants are located along Ganga and thus, are potential revenue source for inland navigation sector. NW2 waterways is from Sadiya town

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 34

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

in Assam to Dhubri at Bangladesh border with total length of 891 km. it is used by tourism vessels, Border security forces, Assam government, and private vessels. NW3 waterway involves multiple canals on the western coast. It involves West coast canal(168km), Udyogmandal canal(23km), and Champakara canal (14km). It is one of the most navigable and tourism potential area in India. Raw material for fertilizer plants is major part of movement. Similarly, NW4 waterway involves Kakinada-Puducherry canala (767km), Godavari river (171 km), and Krishna river (157 km). Coal on Godavari river, Cement on Krishna river and rice on both rivers, and other such food commodities are major transport on this waterway. NW5 waterway consists of stretches such as Mahanadi Delta(101km), Brahmani and others (265km), Matai river(40km) and Geonkhali-Charbatia(217km). Coal is the major commodity on transportation here. Declaration of Barak river from Bhanga to Lakhipur (121 km) in the State of Assam as National Waterway is under consideration of Govt. Budget 2013 stressed on waterways connectivity for northeast India. Poor maintenance of NW is a major challenge for the government. Inland water navigation is cheaper as compared to other transport modes but does not get same level of subsidy by the government for transporting various commodities such as PDS food etc.

SOIL Soil constitutes a major element in the natural environment, linking climate and vegetation, and they have a profound effect on man’s activities through their relative fertility. It is a valuable resource and the most important layer of the earth’s crust. Soils are very much dynamic entities in which physical, chemical and biological activities are continually taking place.

SOIL PROPERTIES Soil is the mixture of rock debris and organic materials which develop on the earth’s surface. It contains matter in all three states: solid, liquid and gaseous. The solid portion is partly organic and partly inorganic. The inorganic part is made up of particles derived from the parent material, the rocks which weather to form the soil. The organic portion consists of living and decayed plant and animal materials such as roots and worms. Soil water is a dilute but complex chemical solution derived from direct precipitation and from run-off, and groundwater. The soil atmosphere fills the pore spaces of the soil when these are not occupied by water. Soil atmosphere and water are present in inverse proportion to each other. The actual amounts of each of these components depend upon the type of soil. The Texture of a soil refers to the sizes of the solid particles composing the soil. The sizes range from clay (less than 0.002mm) to gravel (more than 2mm). The proportions of the different sizes present vary from soil to soil and from layer to layer. Texture largely determines the water-retention properties of soil. Loam texture is best for plant growth (figure 22(i)).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 35

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

(i)

Soil textural classes structures

(ii) Four basic soil

Figure 22 – soil texture and structure The soil structure is the way the soil particles are arranged. Because of cementing action of ions in the soil, individual particles in a soil tend to aggregate together in lumps. According to the shape of the lumps, soils can be described as having a platy, prismatic, crumby and Granular structure (figure 22(ii)). The presence of humus helps the formation of a crump structure. The soil structure has an important bearing on its east of cultivation. Soils with a crumb structure are best for seed germination. Forking, raking, ploughing and harrowing are few techniques to improve the soil structure. Soil colloids - tiny particles with unusual chemical properties – may be organic (very finely divided humus) or mineral (minute thin flakes called clay mineral). Together, the two types Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 36

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

make up a clay-humus complex. Clay minerals have a vast surface area in relation to their weight and are net negatively charged. This is invariably neturalised by the attraction to their surface of positively charged ions (cations) of calcium, magnesium, potassium and sodium (bases). They are only held loosely in an exchangeable position by the clay minerals and may be given up in the process of exchange to plants in forms of nutrients which require them for growth. These cations are generally replaced by hydrogen ions. Over a period of time, this process makes soil more acid, unless the bases are replenished in some way. It is possible naturally with decomposition of animals and plants or artificially in form of fertilizer. Soil acidity is a property related to the proportion of exchangeable hydrogen in the soil in relation to other elements. A pH value of about 6.5 is normally regarded as the most favourable for the growth of cereal crops. Colour varies considerably in soil and can tell us much about how a soil is formed and what it is made of. In recently formed soils, the colour will largely reflect that of the parent material, but in many other cases, the colour is different from the underlying rocks. Soils can range from white to black, usually depending on the amount of humus. In cool humid areas, most soils contain relatively high humus content and are generally black or dark brown, wheras in desert or semi-desert areas, little humus is present and soils are light brown or grey. Reddish colours in soills are associated with the presence of ferric compounds and usually soil is well drained. In humid climates, grayish colours relect poor drainage conditions.

SOIL HORIZONS A vertical section of soil from the surface down to the bedrock consisting of many layers is collectively known as soil profile. These different sections are called soil horizons. We can easily observe different horizons in a mine or roads dug under the ground. The recognition of different soil horizons is based on the physical and chemical characteristics of soils. Scientists have divided the soil into three main horizons (figure 23). ‘Horizon A’ is the topmost zone, where organic materials have got incorporated with the mineral matter, nutrients and water, which are necessary for the growth of plants. ‘Horizon B’ is a transition zone between the ‘Horizon A’ and ‘Horizon C’, and contains matter derived from below as well as from above. It has some organic matter in it, although the mineral matter is noticeably weathered. ‘Horizon C’ is composed of the loose parent material. This layer is the first stage in the soil formation process and eventually forms the above two layers. Underneath these three horizons is the rock which is also known as the parent rock or the bedrock.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 37

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 23 – cross section of Soil profile along a tree

SOIL FORMING FACTORS There are five main factors which controls the operation of soil processes, namely (i) parent material; (ii) topography; (iii) climate; (iv)biological activity; and (v) time. Climate and biological activity active control factors while Time, Topography and Parent Material are passive control factors. Active factors are those which supply energy that acts on the mass for the purpose of soil formation.

Parent Material Parent material can be any in-situ or on-site weathered rock debris or transported deposits. Soil formation depends upon the texture, structure as well as the mineral and chemical composition of the rock debris. Nature, rate and depth of weathering are important considerations under parent materials. There may be differences in soil over similar bedrock and dissimilar soils above them. Generally young soils or the lowermost horizon shows similarity with the parent material. Ultimately, parent material’s effect is seen through the texture and fertility. For instance, soils of limestone area show clear relation with the parent rock. Topography The influence of topography is felt through the amount of exposure of a surface to sunlight, drainage condition, and slope angle etc. In middle latitudes pole-facing slopes may have slightly Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 38

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

different soil conditions from equator-facing slopes due to poor exposure to sunlight. Soils on hillsides tend to be much better drained than those in valleys, where gleying may take place. The susceptibility of soil to erosion increases with gradient, and soils on steep slopes are normally thinner than those on flat sites. Climate This factor has a major influence in governing the rate and type of soil formation, particularly through precipitation in terms of its intensity, frequency, duration; and temperature in terms of seasonal and diurnal variations. The effect of temperature is to influence the rate of chemical and biological reactions. In cool climates, bacterial action is relatively slow while in tropics, bacteria thrive. Soil of hot tropical region show deeper profiles as compared to soils of cold tundra region. Although the leaf fall in tropical forest is great, much of this is consumed and translocated down the soil profile. This is the reason why soil in tropical forests is poor in nutrients. It is the net precipitation (after subtracting evapo transpiration) that works on the soil. Biological Activity The vegetative cover and organism that occupy the parent materials from the start to later stages help in adding organic matter, moisture retention, nitrogen (nitrogen fixation by bacterias such as Rhizobium) etc. Dead plants provide humus. Some organic acids which form during humification aid in decomposing the minerals of the soil parent materials. Humus accumulates in cold climate as bacterial growth is low and thus layers of peat develop in subarctic and tundra climates. The organisms affecting soil development range from microscopic bacteria to large mammals, including man. Besides providing much of the humus, vegetation influences the soil in several other ways. By intercepting direct rainfall and binding the soil with roots, plants check soil erosion. They counteract percolation by transpiration, reducing the effectiveness of the rainfall. They also help in maintaining the fertility of soil by brining bases (calcium, Magnesium) from the lower parts of the soil into stems and leaves, and then releasing them into the upper soil horizons. A change in vegetation may cause a change in soil. The influence of animals on soils is both mechanical and chemical. For example, earthworms rework the soil by burrowing and also change its texture and chemical composition by passing it through their digestive systems. Equally, soil characteristics closely determine the type of animal present in the soil. Time Generally, the length of time the soil forming processes operate, determines maturation of soils and profile development. However, it is difficult to be precise about the role of time in soil formation, since soils vary greatly in their rates of development. On porous materials such as sandstones, soil formation is much more rapid than on impermeable materials, at least initially. On glacial hills, a few hundred years may be enough to form a soil; on dense basalt very much longer is likely to be required. Renewed evolution takes place in soils when climate or other Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 39

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

factors change, causing the soil to adjust. In practice, many soils in mid-latitude regions are polycyclic.

SOIL CLASSIFICATION Soil is not found same everywhere. A soil of one place is different from that of the other. Early classifications followed biological principles to group soils. One of the most important classifications of soils has been the zonal system. This was proposed by Russian pedologists who recognized the strong relationship between climate, vegetation and soil zones throughout the world. Three main classes of soil are recognized. Zonal soils are those that are well developed and reflect the influence of climate as the major soil-forming factor. They can be subdivided into podzol soils, Tundra soils, brown earth, Ferralsol, Chernozem, Chestnut and Prairie soils. Sierozem of desertic and semi-desertic areas is extreme form of chestnut. Intrazonal types are well-developed soils formed where some local factor such as parent material, terrain or age is dominant. They can be subdivided into Calcimorphic soil(on calcareous parent material), Halomorphic soils(saline), and Hydromorphic soil (marshes, swamps or poorly drained upland). Azonal soils are those that are immature or poorly developed. It lacks a B-horizon. Thus, Ahorizon likes immediately above the C-horizon of weathered parent material. This may happened because of characteristics of parent material or nature of terrain or simply the lack of time for development. It is commonplace on active flood plains, volcanic soils, newly deposited glacial drift, windblown sand, marine mud-flats. Azonal soils are subdivided into Lithosol (erosion removes soil almost as fast as it is formed on steep slopes), Regosol (dry and loose dune sands) and alluvial soils(regular supply of sediments). SOIL CLASSIFICATION IN INDIA In ancient times, soils used to be classified into two main groups – Urvara and Usara, which were fertile and sterile, respectively. The National Bureau of Soil Survey and the Land Use Planning an Institute under the control of the Indian Council of Agricultural Research (ICAR) did a lot of studies on Indian soils. ICAR has classified Indian soils into eight types on the basis of their formation, colour, composition and location. These are described shortly below. Alluvial Soil – it is formed by rivers by depositing sediments brought from the mountains. The new alluvium is called Khadar while older deposited one is called Bangar. Khadar is renewed annually with fresh floods. Alluvial soils are most widespread in the northern plains and the covers about 40 per cent of the total area of the country. Through a narrow corridor in Rajasthan, they extend into the plains of Gujarat. In the Peninsular region, they are found in deltas of the east coast and in the river valleys. These soils are more loamy and clayey in the lower and middle Ganga plain and the Brahamaputra valley. The sand content decreases from the west to east. They are generally rich in potash but poor in phosphorous. Alluvial soils are intensively cultivated.



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 40

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Black Soil – it is formed from the volcanic lava. On account of high iron content and humus it is of black colour. It is also known as the Regur soil or black cotton soil. It covers most of the Deccan Plateau. In the upper reaches of the Godavari and the Krishna, and the north western part of the Deccan Plateau, the black soil is very deep. Black soil is spread over 5.18 lakh sqkm area of the country. These soils are known for their ‘self ploughing’ nature. The black soils are generally clayey, deep and impermeable. They swell and become sticky when wet and shrink when dried. So, during the dry season, these soils develop wide cracks. the black soil retains the moisture for a very long time, which helps the crops, especially, the rain fed ones, to sustain even during the dry season. Red and Yellow Soil – it is formed from weathering of crystalline granite (igneous rocks) and gneiss (metamorphic rocks) in areas of low rainfall in the eastern and southern part of the Deccan plateau. Along the piedmont zone of the Western Ghat, long stretch of area is occupied by red loamy soil. The soil develops a reddish colour due to a wide diffusion of iron in crystalline and metamorphic rocks. It looks yellow when it occurs in a hydrated form. They are generally rich in minerals like Iron, lime and potash but poor in nitrogen, phosphorous and humus. Laterite Soil – it is formed under specific monsoon conditions of climate. The dry season after rainfall is one of the speciality of monsoon climate. Under such conditions, leaching of soils is accelerated. This process reduces the silica content of rocks in soils leaving the soil rich in iron and aluminum content. Humus content of the soil is removed fast by bacteria that thrive well in high temperature. These soils are poor in organic matter, nitrogen, phosphate and calcium, while iron oxide and potash are in excess. Hence, laterites are not suitable for cultivation; however, application of manures and fertilizers are required for making the soils fertile for cultivation. Red laterite soils in Tamil Nadu, Andhra Pradesh and Kerala are more suitable for tree crops like cashewnut. Laterite soils are widely cut as bricks for use in house construction. Arid Soil – in the deserts, accelerated weathering of rocks take place on account of heating during day and cooling during night. In this type of soil mainly sand grains are found with little or no humus. In some areas, the salt content is so high that common salt is obtained by evaporating the saline water. It has also less capacity to hold moisture. Its colour varies from red to brown. Nitrogen is insufficient and the phosphate content is normal. Arid soils are characteristically developed in western Rajasthan and semi-arid type in southern Punjab and Haryana.









Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 41

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 24 – Major Soil types of India Forest Soil – it is formed in the mountain ranges of Himalayas, Purvanchal, Sahaydri etc. where sufficient rainfall is available. Soil is loamy and silty on valley sides and coarse-grained in the upper slopes. The lower valleys soil is fertile. On steep slopes, soil is very thin and less productive. This soil is spread over approximately 3 lakh sqkm area of the country. Saline Soil or Usara Soil – it contain a larger proportion of sodium, potassium and magnesium, and thus, they are infertile, and do not support any vegetative growth. They have more salts, largely because of dry climate and poor drainage. Their structure ranges from sandy to loamy. They lack in nitrogen and calcium. They are found in arid and semi-arid regions, western Gujarat, deltas of the eastern coast and in Sunderban areas of West Bengal. Seawater intrusions in the deltas promote the occurrence of saline soils. In the areas of intensive cultivation with excessive use of irrigation, especially in areas of green revolution, the fertile alluvial soils are becoming saline. In such areas, especially in Punjab and Haryana, farmers are advised to add gypsum to solve the problem of salinity in the soil. Peaty and Marshy Soil – it is found in areas of heavy rainfall and high humidity such as Kerala, Odisha, Bengal, Coastal areas of Tamil Nadu. Large quantity of dead organic matter accumulates in these areas, and this gives a rich humus and organic content to







Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 42

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

the soil. Organic matter in these soils may go even up to 40-50 per cent. The vegetation grows very dense in these areas. At many places, they are alkaline also due to presence of salt.

SOIL DEGRADATION In simple terms, soil degradation is defined as the decline in the soil quality or the soil fertility. It can happen either by declining share of nutrients or low population of micro-organism in the soil such as earthworms or change in soil structure or change in pH (alkinity) or addition of toxic elements and pollutants etc. For instance, animals walking on the land or human removing upper layers of soil may results into soil degradation. Soil degradation is the main factor leading to the depleting soil resource base in India. The degree of soil degradation varies from region to region according to the topography, wind, precipitation and anthropogenic factors. Soil degradation includes soil erosion, physical deterioration, chemical deterioration and biological deterioration.

SOIL EROSION It is the removal of soil at a greater rate than its replacement by natural agencies. Soil forming and erosional processes go on simultaneously. When the balance between these two different processes is disturbed by natural or human factors, result into net removal of soil. Some soil erosion occurs without the intervention of human activities but the latter often accelerates the natural processes, e.g. vegetation clearance, over-grazing, some land-drainage schemes. Problem of soil erosion increases with pressure of increasing population on the land. Natural vegetation is cleared for agricultural, pastoral and construction activities. Topography, rainfall, wind, lack of vegetation cover, land use practices etc. are the causes of soil erosion. The rugged topography and steep slopes affect soil erosion rate through its morphological characteristics. Two of these, namely gradient and slope length, are essential components in quantitative relationships for estimating soil loss. Erosion increases dramatically because the increased angle facilitates water flow and soil movement. Two main elements of climate – wind and rainfall – are powerful agents of soil erosion. Erosive processes are set in motion by the energy transmitted from either rainfall or wind or a combination of these forces. Wind erosion is significant in arid and semi-arid regions. Regions with heavy rainfall have dominance of water in erosional processes. Removal may be in the form of splash erosion, Sheet wash, Rill erosion, gullying erosion (figure 25). Splash erosion is the first stage in soil erosion and it occurs when raindrop hit bare soil. Sheet erosion, takes place on level of lands after a heavy shower, removes finer and fertile top soil. Gullies cut the agricultural lands into small fragments and make them unfit for cultivation. Chambal region of central India is infamous for its ravines (large number of deep gullies).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 43

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 25 – Gully erosion The lowest soil erosion rate is found in undisturbed forests. However, once forest land is converted to agriculture, erosion rates increase because of vegetation removal, over-grazing, and tilling. Vegetation cover reduces erosion. Living and dead plant biomass reduces soil erosion by intercepting and dissipating raindrops and wind energy. Plant roots physically bind particles, thus stabilising the soil and increasing its resistance to erosion. The uptake of water by plant roots also depletes the soil water content and thereby further increases infiltration rates. Land use practices such as agricultural and pastoral activities are causes of soil erosion. Croplands are vulnerable because the soil is repeatedly tilled and left without a protective cover of vegetation. Excessive grazing by animals lead to poor vegetation cover and thus, enhances wind and water-led soil erosion processes. Over-irrigation results into removal of top nutrient soil with excess water. It also brings salts to the surface and destroys fertility. Without proper humus, addition of chemical fertilizer hardens the soil.

SOIL MANAGEMENT Soil management is not a single and straight process. It concerns all operations, practices that are used to maintain the quality of soil. If soil erosion and exhaustion are caused by humans; by corollary, they can also be prevented by humans. Soil erosion is essentially aggravated by faulty practices. For instance, recommended ratio of nitrogen, phosphorus and potassium (NPK) fertilizer in India is 4:2:1 but actual usage is in the ration of 10:4:1. Lands with a slope gradient of 15 - 25 per cent should not be used for cultivation. If at all the land is to be used for agriculture, terraces should carefully be made. Over-grazing and shifting cultivation are other major faulty practices. It should be regulated and controlled by villagers collectively. Contour bunding, Contour terracing, check dams, regulated forestry, cover cropping, mixed farming and crop rotation are some other sustainable methods to manage soil quality. In arid and semi-arid areas, shelter belts or green belts should be constructed around the cultivable land to protect them from progressive sand dunes.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 44

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 26 – soil management techniques The Central Soil Conservation Board, set up by the Government of India, has prepared a number of plans for soil conservation in different parts of the country. These plans are based on the climatic conditions, configuration of land and the social behaviour of people. Centrally sponsored scheme entitled “National project on management of soil health and fertility (NPMSF)” has been formulated by the centre in 2008-09. It aims to facilitate and promote Integrated Nutrient Management (INM) through judicious use of chemical fertilizers in conjunction with organic fertilizers. It also aims to strengthen soil testing facilities by installing more soil testing laboratories. One of the components is to build up capacity through training of farmers and field demonstration etc. Project also envisages preparing database for balanced use of fertilizer, which is site specific. Other project/missions such as National Mission on Sustainable Agriculture (NMSA), National project on promotion of organic farming, Mahatma Gandhi national rural employment guarantee act (MGNREGA), soil and land use survey projects of centre etc. have bearing on managing the quality of soil.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 45

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 9

COMPOSITION AND STRUCTURE OF THE ATMOSPHERE

Contents: 1. Composition of the Atmosphere 1.1 Gases 1.2 Water Vapour 1.3 Dust Particles 1.4 Changes in the Atmosphere 1.4.1 Air Pollution 1.4.2 Global Warming 1.4.3 Ozone Depletion 1.4.4 Ozone Pollution 2. Structure of the Atmosphere 2.1 2.2 2.3 2.4 2.5

Troposphere Stratosphere Mesosphere Thermosphere Exosphere

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Composition of the Atmosphere In general, atmosphere is a layer of gases and dust surrounding a planet that is held in place by the gravity of the planet body. An atmosphere is more likely to be retained if the gravity is high and the atmosphere's temperature is low. In fact, earth’s atmosphere makes earth unique in the solar system. Planet Earth’s atmosphere is best suitable for life and thus, it is important to understand the composition as well as structure of it. In this context, man has started studying the atmosphere thousands of years before. The Rig Vedic verses have mention of Monsoon, seasons etc. Earth’s atmosphere is composed of gases, water vapours and dust particles. Although other important properties of the atmosphere such as temperature and pressure, can vary considerably in both time and space, its composition in terms of the relative proportions of the gases present in any unit volume, tends to remain remarkably constant. Thus, the atmosphere generally tends to act very much as a single gas, which we commonly known as ‘air’. The horizontal variation in the per cent share of these components of atmosphere has less variation as compare to vertical variation.

Gases The main component gases of dry air are listed in Table 1. It should be noticed that nitrogen and oxygen together make up about 99 per cent of the volume, and that the other one per cent is chiefly Argon. Other gases such as Methane, Ozone are found in traces. Constituent gas Percentage volume Nitrogen 78.08 Oxygen 20.95 Argon 0.93 Carbon dioxide 0.036 Neon 0.002 Helium 0.0005 Krypton 0.001 Xenon 0.00009 Hydrogen 0.00005 Table 1 – Average composition of dry air Nitrogen does not easily enter into chemical union with other substances, but it is an important constituent of many organic compounds. Atmospheric nitrogen acts as a reservoir pool for nitrogen cycle. Nitrogen fixing organisms such as Rhizobium use free nitrogen of the atmosphere to convert it to usable form such as nitrates. Oxygen is an important part of the atmosphere and is necessary to sustain terrestrial life as it is used in respiration. It is also used in combustion. It is believed that first oceans got saturated with oxygen and after that it started flowing into the atmosphere. Source of oxygen is plants with photosynthesis. Mountain climbers sometime require oxygen cylinders due to low concentration of oxygen at greater heights. Argon is an inert gas. Argon extracted from the atmosphere is used for industrial purposes such as bulb manufacturing, welding equipments etc. Carbon dioxide is released from the earth’s interior, respiration, soil processes, deforestation, and combustion. Carbon dioxide is meteorologically a very important gas as it is transparent to the incoming solar radiation but opaque to outgoing terrestrial radiations. It absorbs a part of

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

terrestrial radiation and reflects back some part of it towards the earth’s surface. It is largely responsible for the greenhouse effect. Ozone is another important constituent of atmosphere. Ozone is made up of three atoms of oxygen when three molecules of oxygen gas convert into two molecules of Ozone using sun’s high energy radiations. It is found in very small quantity (0.00005 per cent by volume) in the upper atmosphere, 15-50km above the earth’s surface. Maximum concentration is found at the height of 15-35km. It protects the life on earth by absorbing ultra-violet rays radiating from the sun and prevents them from reaching the surface of the earth. In the absence of the ozone layer, high energy ultra-violet rays would have made earth unfit for habitation.

Water Vapour Table 1 refers to the average constituents of dry air. The lower parts of the atmosphere, up to 10-15 km, contain in addition water vapour, which is largely derived by evaporation from water bodies on the earth and by transpiration from plants. It is one of the ‘most variable’ components of the atmosphere. It decreases with altitude and not found at great heights because mixing and turbulence is not sufficiently strong to carry it up very far. In the warm and wet tropics, it may account for 4% of the air by volume, while in the dry and cold areas of desert and polar regions, it may be less than 1% of the air. Water vapour also decreases from the equator towards the poles. Water vapour, too, is capable of absorbing heat and acts like a blanket allowing the earth neither to become too cold nor too hot. Water vapour is fundamental to many essential meteorological processes, such as rain-making. It is source of all clouds and precipitation. In the condensation process, vast amount of energy is released in form latent heat of condensation, ultimate driving force for most of the storms. The actual amount of the water vapour present in the atmosphere is known as the absolute humidity. It is the weight of water vapour per unit volume of air. The absolute humidity differs from place to place on the surface of the earth. The percentage of moisture present in the atmosphere as compared to its full capacity at a given temperature is known as the relative humidity. It is greater over the oceans and least over the continents. The air containing moisture to its full capacity at a given temperature is said to be saturated. Moisture holding capacity of the air is directly proportional to its temperature.

Dust Particles The atmosphere also carries in suspension variable amounts of solid material in the lower layers of atmosphere. Convectional air currents may transport them to great heights. The higher concentration of dust particles is found in subtropical and temperate regions due to dry winds in comparison to equatorial and polar regions. The term ‘dust particles’ includes all the solid particles present in the air except the gases and water vapour. It includes sea salts, fine soil, smoke-soot, ash, pollen, dust and disintegrated particles of meteors and originates from different sources. Dust particles provide the necessary nuclei on which water vapour can condense to form clouds and eventually precipitation. Condensation on these fine particles near the surface causes formation of fog. Large amount of dust tend to make the atmosphere hazy, and in extreme cases, where pollution is involved, dust particles can be positively harmful to health. By the process of scattering, dust particles contribute to the varied colours of red and orange at sunrise and sunset. The blue colour of the sky is also due to selective scattering by dust particles. The duration of twilight is also affected by the presence of these dust particles in the air. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Changes in the Atmosphere Since industrial revolution, human activities have caused various changes into earth’s atmosphere. We look at four very different atmospheric changes here. Air Pollution Air pollution is the introduction of chemicals, particulates, biological materials or other harmful materials into the earth’s atmosphere. These pollutants can be solid particles, liquid, and gases. Major pollutants are carbon oxides (COx), Nitrous Oxides (NOx), Volatile organic compounds, particulates, sulphur dioxide, Toxic metals such as lead and mercury etc. Many of these are new compounds in the atmosphere which have changed the composition to negligible level but their presence throws challenges for humans. It causes damage, disease and death of humans and other living organisms or infrastructure. Air pollution causes respiratory infections, heart disease, and lung cancer etc. Major sources of these pollutants involves vehicular emission, power plants, industries, waste incinerators, agricultural practices, fumes, waste deposition etc. Acid rain is the result of increased pollutants in the atmosphere. Rain water is naturally acidic due to atmospheric carbon dioxide which makes weak acid with rain water. Acid rain is caused by other gases released when fossil fuels are burnt. Two gases are the main culprits: Sulphur dioxide (forms sulphuric acid) and Nitrogen oxides (forms nitric acid). These increase the acidity of rainwater. The dilute acid falls to ground as acid rain which causes the following problems: Lakes become acidic and plants and fishes die as a result Tree growth is damaged, whole forests can die as a result Acid rain attacks metal structures and also buildings made of limestone

  

Global Warming In very cold regions, glass houses are constructed for growing vegetables. These are known as Greenhouses. In these houses, glass covering allows short wavelength sunrays to enter but does not allow it to be radiated back to atmosphere. At atmospheric level, the greenhouse gases do not allow thermal radiation from a planetary surface (long waves) to pass and reradiate them in all directions. Since part of this re-radiation is back towards the surface and the lower atmosphere, it results in an elevation of the average surface temperature above what it would be in the absence of the gases. Major greenhouse gases are: carbon dioxide, methane, nitrous oxide, water vapour and Ozone. With increase in the percentage of greenhouse gases, it is believed that temperature of earth is increasing dramatically. This is termed as global warming. Main contributor for this rise in temperature is carbon dioxide (CO2). The scientists have observed that CO2 is largely contributed from burning of fossil fuels. The burning of fossil fuels and extensive clearing of native forests has contributed to a 40% increase in the atmospheric concentration of carbon dioxide, from 280 to 392 parts per million (ppm) in 2012. Other gases such as Methane, water vapour, Nitrous oxide, Hydroflurocarbons (HFCs), Perflurocarbons (PFCs), Sulphur hexafluoride (SF6) are playing considerable role in global warming. SF6, PFCs etc. are present only in traces but their life span and greenhouse potency is very high. For instance, SF6 is the most potent greenhouse gas in existence. With a global warming potential 23,900 times greater than carbon dioxide, one pound of SF6 has the same global warming impact of 11 tons of carbon dioxide. It is also very persistent in the atmosphere with a lifetime of 3,200 years. SF6 is widely used in circuit breakers, gas-insulated substations, and other switchgear to manage the high voltages. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Global warming would adversely affect the ecosystem on the Earth and the weather patterns around the world in the following ways:  Melting of ice at polar regions and glaciers on high mountains. It would increase the sea level.  Many climatic and weather events are expected to change drastically. Recent examples of extreme temperature, precipitation are associated with the global warming.  Global warming would change the habitats of organism. Those unable to adjust to these rapid changes may not be able to survive. Ozone Depletion The release of chemical compounds such as Chlorofluorocarbons (CFCs) from earth into the atmosphere poses a serious threat to ozone layer. CFCs are synthetic industrial chemical compounds containing chlorine, fluorine, and carbon atoms. CFCs are widely used as cooling fluids in the refrigerating systems. CFCs when released in air are transported by the vertical atmospheric circulation and reach the ozone layer in the stratosphere. The CFCs absorb the ultra-violet radiation and decompose to chlorine oxide molecules and can convert the ozone into ordinary oxygen molecules. A study of the ozone layer based on data provided by the satellites, showed a substantial decline in the total ozone gas. The scientists have discovered a hole in the ozone layer over the continent of Antarctica. CFCs are transported to Antarctica region by atmospheric wind systems. Here, CFCs get trapped in the Antarctica cold air by polar vortex1 and deplete ozone layer. Ozone Pollution Ozone occurs at ground-level naturally in low concentrations. The two major sources of natural ground-level ozone are hydrocarbons, which are released by plants and soil, and small amounts of stratospheric ozone, which occasionally migrate down to the earth's surface. Neither of these sources contributes enough ozone to be considered a threat to the health of humans or the environment. But the ozone that is a byproduct of certain human activities does become a problem at ground level. With more automobiles, and more industry, there's more ozone in the lower atmosphere. Tropospheric ozone is formed by the interaction of sunlight, particularly ultraviolet light, with hydrocarbons and nitrogen oxides, which are emitted by automobiles, gasoline vapors, fossil fuel power plants, refineries, and certain other industries. High ozone levels usually occur during the warm, sunny summer months (from May through September). Typically, ozone levels reach their peak in mid to late afternoon. A hot, sunny, still day is the perfect environment for ozone pollution production. Near the earth’s surface, ozone molecules damages forests and crops; destroys nylon, rubber, and other materials; and injures or destroys living tissue. It is a particular threat to people who already have respiratory problems.

Structure of the Atmosphere It is the lower part of the atmosphere which has interested man from times immemorial. But from the beginning of the 20th century, when aeroplanes and radio waves were invented, the knowledge of the upper part of the atmosphere became rather essential. The earth’s atmosphere consists of zones or layers arranged like spherical shells according to altitude above earth’s surface. Each zone has a unique set of characteristics. For the most part the layers are not at all sharply defined, and their boundaries are arbitrarily established. The 1

The stratospheric polar vortex is a large-scale region of air that is contained by a strong west-to-east jet stream that circles the polar region.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

density, temperature and composition of the atmosphere varies with altitude. Density is highest near the surface of the earth and decreases with increasing altitude. The temperature changes differently in different layers. Heavy gases such as Oxygen exist near the surface. At greater heights, the lightest gases do in fact separate out, forming several concentric gas envelopes around the Earth. The atmosphere is divided into the five different layers depending upon the temperature condition. They are: troposphere, stratosphere, mesosphere, thermosphere and exosphere.

Troposphere Troposphere is the lowermost layer of the atmosphere. Its average height is 13 km and extends roughly to a height of 8 km near the poles and about 18 km at the equator. It is thickest at the equator because strong convection currents transport heat to such great heights. It contains 75 per cent of the total gaseous mass of the atmosphere. This layer contains dust particles and water vapour also. The temperature in this layer decreases at the rate of 1°C for every 165m of height (or at a mean rate of 6.5 degree C /km).The decrease occurs because air is compressible and its density decreases with height allowing rising air to expand and thereby cool. It is interesting to note that the lowest temperature in the entire troposphere is found over the equator and not at the poles. The air temperature at the top of troposphere is about minus 800C over the equator and about minus 450C over the poles. Word ‘troposphere’ is derived from the Greek word ‘tropos’ meaning ‘mixing’. Troposphere is marked by turbulence and eddies. It is also called the convective region, for all the convective cease at the upper limit of the troposphere. All changes in climate and weather take place in this layer. Clouds formation, thunderstorms etc. occur in this layer. Wind velocity increase with height and attain the maximum at the top. At the top of the troposphere there is a shallow layer separating it from the next thermal layer of the atmosphere. This shallow layer is known as the tropopause. Tropopause has its greatest height near the equator. In the middle and high latitudes, the height of the tropopause varies according to seasons. For example, at latitudes 45N&S the average height of the tropopause in January is about 12.5 km while in July it becomes 15 km.

Figure 1 – Structure of atmosphere on the basis of temperature Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Stratosphere The stratosphere is found above the tropopause and extends up to a height of 50 km. The lower stratosphere is isothermal in character. This temperature region is found to be present up to about 20 km and after this temperature rises. In summers, the increase in the stratospheric temperature with latitudes continues upto the poles. But during the winter season the stratosphere is warmest between latitudes 500 – 600. Onwards, temperature decreases again. The thickness of the stratosphere is highest at the poles. This layer is free of any clouds of weather changes. It is an ideal place for flying of big planes. At about 50 km, temperature begins to fall. This is end of stratosphere, and is called the stratopause. The portion of the stratosphere having maximum concentration of ozone is called ozonosphere. The rise in temperature with height in stratosphere is because of the absorption of ultra-violet by the ozone gas. Details of ozone gas are already discussed above.

Mesosphere The mesosphere lies above the stratopause, and extends up to a height of 80 km from 50km. In this layer, once again, temperature starts decreasing with the increase in altitude and reaches up to minus 100° C at the height of 80 km. It is the coldest layer in the atmosphere. The exact upper and lower boundaries of the mesosphere vary with latitude and with season, but the lower boundary of the mesosphere is usually located at heights of about 50 km above the Earth's surface and the mesopause is usually at heights near 100 km. In summers, the height of mesosphere descends down to 85km at middle and high latitudes. The upper limit of mesosphere is known as the mesopause.

Thermosphere The thermosphere is located between 80 and 400 km above the mesopause. In this layer the temperature increases rapidly with increase in height. It is estimated that the temperature reaches 1500 degree C. The air is so thin that a small increase in energy can cause a large increase in temperature. Because of the thin air in the thermosphere, scientists can't measure the temperature directly. They measure the density of the air by how much drag it puts on satellites and then use the density to find the temperature. The Earth's thermosphere also includes the region called the ionosphere. It contains electrically charged particles known as ions, and hence, it is known as ionosphere. Ionization of molecules and atoms occurs mainly as a result of ultra-violet, x-rays and gamma radiations. The high temperatures in the thermosphere also cause molecules to ionize. This is why an ionosphere and thermosphere can overlap. Radio waves transmitted from the earth are reflected back to the earth by this layer. This layer also protects the earth from meteorites and remains of abandoned satellites. They are burned and reduced to ashes due to high temperature as they enter this layer. Ionosphere also includes some parts of mesosphere and exosphere. Ionosphere is further divided into different layers, namely D-layer (upto 99km), E-layer (90-130km), Sporadic E-Layer, F1 & F2 layer (150-380km) and G-layer (>400km). Layers such as D-layer, E-layer, exist only during day time and vanishes as soon as sun sets.

Exosphere The uppermost layer of the atmosphere above the thermosphere is known as the exosphere. This is the highest layer but very little is known about it. It lies beyond 400km to 1000s of kms Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

where it merges with outer space. At such great height the density of atoms is extremely low. It is largely home to Helium and Hydrogen. Temperature increases with height and may cross 50000C. Stratification of atmosphere can also be done on the basis of chemical composition. According to International Space Symposium 1962, atmosphere can be divided into two broad layers, namely Homosphere and Heterosphere. Former is the lower layer and extends up to 88km from the earth’s surface. The proportions of the component gases are uniform at different levels. The three main-sub divisions of Homosphere are troposphere, stratosphere and mesosphere. Heterosphere extends beyond 88 km to more than 3500 km. Here, atmosphere is not uniform in its composition. It is also referred to as thermosphere as temperature rises with height. In this sphere, gases are arranged in roughly spherical shells. The innermost of these is a Nitrogen layer, found at heights between 100 and 200km; this is succeeded in turn by layers of Oxygen (200-1100km) and Helium (1100-3500km); and finally beyond 3500km only Hydrogen exists.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 10

INSOLATION, EARTH’S HEAT BALANCE, DIFFERENT ATMOSPHERIC CIRCULATIONS – GLOBAL WINDS, CYCLONES

Contents: 1.

Insolation 1.1 1.2

2.

Heat Budget 2.1

3.

Latitudinal Heat Balance

Temperature 3.1 3.2 3.3 3.4

4.

Factors influencing Insolation Heating and Colling of the Atmosphere

Distribution of Temperature Temperature Anomaly Temperature Inversion Temperature Ranges

Atmospheric Circulation 4.1 Atmospheric Pressure 4.2 Pressure Variations 4.3 Forces Governing Air Movement 4.3.1 Pressure Gradient 4.3.2 Coriolis Force 4.3.3 Centripetal Force 4.3.4 Frictional Force 4.4 Geostrophic Wind 4.5 Distribution of Pressure Belts 4.6 Shifting of Belts 4.7 General Circulation of the Atmosphere 4.7.1 Planetary Winds 4.8 Local Winds 4.8.1 The Land and sea Breeze 4.8.2 The Mountain and Valley Breezes 4.8.3 Hot Local Winds 4.8.4 Cold Local Winds 4.9 Upper Air Circulation 4.9.1 Jet Streams

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 4.9.2 4.9.3 Air Mass

6.

Fronts

7.

https://t.me/UPSC_PDF

Index Cycle of the Jet Streams Jet Streams and Surface Weather

5.

6.1 6.2 6.3 6.4

www.UPSCPDF.com

Warm Front Cold Front Stationary Front Occluded Front

Cyclones 7.1 7.2 7.3

Extra-Tropical Cyclones Tropical Cyclones Thunderstorms and Tornadoes

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Insolation The earth’s atmosphere is very much a dynamic entity. Large volumes of air are continually being moved both up and down and across the face of the Earth. As a proof, we feel air when it is in motion. There must be some energy involved here. It needs to be understood that the atmosphere is not a closed system. It is in contact with both the earth and with space, and receives energy from both directions. However, Earth itself directly contributes only a negligible amount of energy to the atmosphere, and its main role is to reflect energy from elsewhere. The ultimate sole source of atmospheric energy is in fact heat and light received through space from the Sun. This energy is known as solar insolation. The Earth receives only a tiny fraction of the total amount of Sun’s radiations. Only two billionths or two units of energy out of 1,00,00,00,000 units of energy radiated by the sun reaches the earth’s surface due to its small size and great distance from the Sun. The unit of measurements of this energy is Langley (Ly). On an average the earth receives 1.94 calories per sq. cm per minute (2 Langley) at the top of its atmosphere.

Factors Influencing Insolation The insolation received on earth is not same everywhere. The amount and the intensity of insolation vary from place to place, during a day, in a season and in a year. The factors that cause these variations in insolation are: 1. Revolution of earth around sun – earth revolves in an elliptical orbit around the sun. Thus, distance between the Sun and the earth vary. The earth is farthest from the sun on 4th July. This position of the earth is called aphelion. On 3rd January, the earth is the nearest to the sun. This position is called perihelion. Therefore, the annual insolation received by the earth at perihelion is slightly more than the amount received at aphelion. However, the effect of this variation in the solar output is masked by other factors like the distribution of land and sea and the atmospheric circulation. Hence, this variation in the insolation does not have great effect on daily weather changes on the surface of the earth. 2. The rotation of earth on its axis – earth rotates around its axis and makes an angle of 66½ with the plane of its orbit round the sun. This particular characteristic of earth has great amount of influence on the amount of insolation received at different latitudes. The seasons in each hemisphere are dictated not by the closeness to the sun but by the axial tilt of the earth. 3. The angle of inclination of the sun’s rays – Since the earth is round, the sun’s rays strike the surface at different angles at different places. The angle formed by the sun’s ray with the tangent of the earth’s circle at a point is called angle of incidence. It influences the insolation in two ways as follows: 

When the sun is almost overhead, the rays of the sun are vertical. The angle of incidence is large. Hence, they are concentrated in a smaller area, giving more amount of insolation at that place. If the sun’s rays are oblique, angle of incidence is small and sun’s rays have to heat up a greater area, resulting in less amount of insolation received there.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 1 – effect of angle of inclination on Insolation 

The sun’s rays with small angle traverse more of the atmosphere than rays striking at a large angle. Longer the path of sun’s rays, greater is the amount of reflection and absorption of heat by atmosphere. As a result the intensity of insolation at a place is less (figure 1). Angle of inclination of solar radiation depends on latitude of a place. The higher the latitude the less is the angle they make with the surface of the earth resulting in slant sun rays. Figure 1 show the winter Solstices in the Northern Hemisphere where angle of inclination is zero at 66 ½ N latitude. Latitude

0°

20°

40°

60°

90°

December 22 (winter solstice)

12h 00m

10h 48m

9h 8m

5h 33m

0m

June 21(summer Solstice)

12h

13h 12m

14h 52m

18h 27m

6 months

Table 1 – Length of Day on winter and summer Solstices in the Northern Hemisphere 4. The length of the day – the duration of day is controlled partly by latitude and partly by the season of the year. The amount of insolation has close relationship with the length of the day. It is because insolation is received only during the day. Other conditions remaining the same, the longer the days the greater is the amount of insolation. In summers, the days being longer the amount of insolation received is also more. As against this in winter the days are shorter the insolation received is also less. On account of the inclination of the earth on its axis at an angle of 23 ½ 0, rotation and revolution, the duration of the day is not same everywhere on the earth. At the equator there is 12 hours day and night each throughout the year. As one moves towards poles duration of the days keeps on increasing or decreasing. It is why the maximum insolation is received in equatorial areas. Table 1 show the duration of day (in hours & minutes) on winter and summer solstices in the Northern hemisphere. 5. The transparency of the atmosphere – The earth’s atmosphere is more or less transparent to short wave solar radiation which has to pass through the atmosphere before striking the earth’s surface. The transparency depends upon cloud cover, its thickness, water vapour and solid particles, as they reflect, absorb or transmit insolation. High energy ultra-violet rays are absorbed by the Ozone layer. Thick clouds hinder the insolation to reach the earth while clear sky helps it to reach the surface. Water vapour absorbs insolation, resulting in less amount of insolation reaching the surface. Very small-suspended particles in the troposphere scatter visible spectrum both to the space and towards the earth surface. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

6. Solar variation – It is the change in the amount of radiation emitted by the Sun. These variations have periodic components, the main one being the approximately 11year sunspot cycle. Sunspots are temporary phenomena on the photosphere of the Sun that appear visibly as dark spots compared to surrounding regions. When there is an increase in sun spots it leads to increase1 in the amount of solar radiation. But this change is almost negligible.

Figure 2 – average annual insolation on the surface of the earth 7. Topographical variations – Earth does not have a featureless surface. The topographical variations are the major factors modifying the distribution of insolation. Variability in elevation, surface orientation (slope and aspect), and obstruction by surrounding topographic features creates strong local gradients of insolation. Similarly, in the northern hemisphere a south-facing slope (more open to sunlight and warm winds) will therefore generally be warmer and dryer due to higher levels of evapotranspiration than a north-facing slope.[1] This can be seen in the Swiss Alps, where farming is much more extensive on south-facing than on north-facing slopes. In the Himalayas, this effect can be seen to an extreme degree, with south-facing slopes being warm, wet and forested, and north-facing slopes cold, dry but much more heavily glaciated. Vegetation, human activities are more visible on the slopes where insolation is more relatively. Under combined effect of the above discussed factors, the amount of total annual insolation received by different regions is different. The insolation received at the surface varies from about 320 Watt/m2 in the tropics to about 70 Watt/m2 in the poles. Maximum insolation is received over the subtropical deserts. Equator receives comparatively less insolation than the tropics due to presence of clouds. Generally, at the same latitude the insolation is more over the continent than over the oceans because more clouds over the oceans reflect sun rays back into space. Isohels are lines connecting points on the earth surface that receive equal amounts of sunshine. Isohels are more or less parallel to latitudes, especially in southern hemisphere (figure 2).

Heating and Cooling of the Atmosphere Sun is the ultimate source of the atmospheric heat and energy, but its effect is not direct. For example, as we climb a mountain or ascend in the atmosphere, temperature become Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

steadily lower, rather than higher, as we might expect. This is because the mechanism of heating the atmosphere in not simple. Four common types of energy transport are involved in heating of the atmosphere (figure 3). They are: i.

Radiation – it is the process where transference of heat is directly from space to atmosphere through electromagnetic radiations2. Photon3 particles in the radiations collide with the air molecules in the atmosphere and transfer energy in this process. All objects whether hot or cold emit radiation continuously. The wavelength at which a body radiates depends on its surface temperature. The shorter the wavelength, higher the energy carried by the radiations The sun, having an extremely hot surface temperature, radiates fairly short wavelengths, part of which is felt as warmth, part of which are visible as light. The Earth, on the other hand, having a cool surface, reradiates heat at much longer wavelengths. The re-radiate heat from the earth is called Terrestrial radiation. Atmosphere is transparent to short waves and opaque to long waves. The long wave radiation is absorbed by the atmospheric gases particularly by carbon dioxide and the other green house gases. Hence energy leaving the earth’s surface heats up the atmosphere more than the incoming solar radiation.

ii.

Conduction - When two objects of unequal temperature come in contact with each other, heat energy flow from the warmer object to the cooler object and this process of heat transfer is known as conduction. The flow continues till temperature of both the objects becomes equal or the contact is broken. The conduction in the atmosphere occurs at zone of contact between the atmosphere and the earth’s surface by terrestrial radiations. However, this is a minor method of heat transfer in terms of warming the atmosphere since it only affects the air close to the earth’s surface. This is because of the fact that the air is poor conductor of heat4.

iii.

Convection – In this process, energy is transferred through motion of molecules itself. The air in contact with the earth rises vertically on heating in the form of currents and further transmits the heat of the atmosphere. The heating of the air leads to its expansion. Its density decreases and it moves upwards. Continuous ascent of heated air creates vacuum in the lower layers of the atmosphere. As a consequence, cooler air comes down to fill the vacuum. This process of vertical heating of the atmosphere is known as convection. The convective transfer of energy is confined only to the troposphere.

Figure 3 – (a) processes of heating and cooling of atmosphere and (b) per cent share of processes in heating up of atmosphere Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF iv.

www.UPSCPDF.com

https://t.me/UPSC_PDF

Advection - The transfer of heat through horizontal movement of air is called advection. These winds take the characteristics of their source of origin with them. The temperature of a place will rise if it lies on the path of winds coming from warmer regions. The temperature will fall if the place lies on the path of the winds blowing from cold regions. Horizontal movement of the air is relatively more important than the vertical movement. In summer seasons, ‘Loo’ of north India is a hot wind and ‘Sirocco’ is also a hot wind carries heat of Sahara desert to Mediterranean regions. In middle latitudes, most of diurnal (day and night) variation in daily weather is caused by advection alone.

Heat Budget The average temperature of the earth overall does not change in spite of continuous supply of sun rays. This is possible only when an equal amount of energy is sent back to space by the earth’s system. In the way there is balance between incoming solar radiation and outgoing terrestrial radiations. This balance is known as the heat budget of the earth. Figure 4 depicts the heat budget of the planet earth. Consider that the insolation received at the top of the atmosphere is 100 per cent. While passing through the atmosphere some amount of energy is reflected, scattered and absorbed. Only the remaining part reaches the earth surface. Roughly 35 units are reflected back to space even before reaching the earth’s surface. The details of this reflected radiation are as under:   

Reflected from the top of clouds Reflected by ice-fields on earth Reflected by the atmosphere Total

-

27 units 02 units 06 units 35 units

The reflected amount of radiation is called the albedo of the earth. The above given radiation does neither heat the atmosphere nor the earth’s surface. The remaining 65 units are absorbed as:  

Absorbed by the atmosphere Absorbed by the earth Total

-

14 units 51 units (Scattered + direct radiation) 65 units

Figure 4 – Heat Budget of the Earth

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Scattering takes place by gas molecules and dust particles. This takes place in all directions, some of it earthwards and some towards space. In overall, earth receives 51 units of radiation which in turn radiates back in the form of terrestrial radiation. The details of this reflected radiation are as under:  

Radiated to space directly Radiated to atmosphere

-

17 units 34 units

The details of 34 units radiation absorbed by atmosphere from terrestrial radiations are as under   

Absorbed directly Absorbed through convection and turbulence Absorbed through Latent heat of condensation5 Total

-

06 units 09 units 19 units 34 units

Total units absorbed by the atmosphere are 48 (14 units insolation + 34 units Terrestrial radiation). These are radiated back into space. Thus, the total radiation returning from the earth and the atmosphere respectively is:  

Radiated back by earth Radiated back by atmosphere Total

-

17 units 48 units 65 units

These returning 65 units balance the total of 65 units received from the sun. This account of incoming and outgoing radiation always maintains the balance of heat on the surface of the earth. This is termed the heat budget or heat balance of the earth.

Figure 5 – heat energy budget by latitudes

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Latitudinal Heat Balance Although the earth as a whole maintains balance between incoming solar radiation and outgoing terrestrial radiation. But this is not true when we observe at different latitudes. Heat budget at latitudinal level is non-zero. As previously discussed, the amount of insolation received is directly related to latitudes. Some part of the earth has surplus radiation balance while the other part has deficit. Figure 5 depicts the latitudinal variation in the net radiation balance of the earth — the atmosphere system. The figure shows that there is a surplus of net radiation balance between 400 N & S degrees and the regions near the poles have a deficit. This in theory should mean that tropical areas should get steadily warmers, and the Arctic and Antarctic even colder. But such is not the case. The surplus heat energy from the tropics is redistributed pole wards and as a result the tropics do not get progressively heated up due to the accumulation of excess heat or the high latitudes get permanently frozen due to excess deficit. This transfer of surplus heat from tropics to polar region is being performed by atmospheric and oceanic circulations such as winds and ocean currents. According to one estimate, about 75 per cent of heat transfer is carried out by atmospheric circulation and the remaining 25 per cent by the ocean currents. In fact, winds and ocean currents are produced due to imbalance of heat.

Temperature The temperature is the measurement in degrees of how hot (or cold) a thing (or a place) is. The temperature of the atmosphere is not same across the Earth. It varies in spatial and temporal dimensions. The temperature of a place depends largely on the insolation received by that place. The interaction of insolation with the atmosphere and the earth’s surface creates heat which is measured in terms of temperature. It is important to know about the temperature distribution over the surface of the earth to understand the weather, climate, vegetation zones, animal and human life etc. following factors determine the temperature of air at any place. 1. The latitude of the place – Intensity of insolation depends on the latitude. The amount of insolation depends on the inclination of sun rays, which is further depends upon the latitude of the place. At the equator sun’s rays fall directly overhead throughout the year. Away from the equator towards poles, the inclination of the Sun’s rays increases. In conclusion, if other things remain the same, the temperature of air goes on decreasing from the equator towards poles. 2. The altitude of the place – the atmosphere is largely heated indirectly by re-radiated terrestrial radiation from the earth’s surface. Therefore, the lower layers of the atmosphere are comparatively warmer than the upper layers, even in the same latitudes. For example, Ambala (30 21’ N) and Shimla (31 6’) are almost at the same latitude. But the average temperature of shimla is much lower than the Ambala. It is because Ambala is located in plain at an altitude of 272 m above sea level whereas Shimla is located at an altitude of 2202 m above sea level. In other words, the temperature generally decreases with increasing height (figure 6(a)). The rate of decrease of temperature with height is termed as the normal lapse rate. It is 6.5°C per 1,000 m. That’s why, the mountains, even in the equatorial region, have snow covered peaks, like Mt. Kilimanjaro, Africa.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3. Distance from the Sea – the land surface is heated at a faster rate than the water surface. Thus the temperature of the air over land and water surfaces is not the same at a given time. In summers, the sea water is cooler than the land and in winters, land is much colder than the sea water. The coastal areas experience the sea breezes during the daytime and the land breezes during the night time. This has a moderating influence on the temperature of the coastal areas. Against this the places in the interior, far away from the sea, have extreme climate. The daily range of temperature is less near the coastal area and it increases with increase in distance from the sea coast (figure 6(b)). The low daily range of temperature is the characteristic of marine climate. That’s why, the people of Mumbai have hardly any idea of extremes of temperature.

(a) – effect of altitude (b) – maritime influence Figure 6 – effect of altitude & distance from sea on temperature

Figure 7 – (a) effect of ocean currents & (b) effect of slope on temperature 4. Ocean Currents – the effect of warm ocean currents and the cold ocean currents is limited to the adjoining coastal areas. The warm ocean currents flow along the eastern coast of tropical and sub-tropical regions and western coast of higher latitudes. On the other hand, cold ocean currents flow along the eastern coast of higher latitude and along the western coast of tropical and sub-tropical areas. The North Atlantic drift, an extension of Gulf Stream, warm the coastal districts of Western Europe (such as Norway) and British Isles keeping their ports ice-free (figure 7(a)).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

5. Air-mass circulation – air masses in form of winds helps in the redistribution of temperature. The places, which come under the influence of warm air-masses experience higher temperature and the places that come under the influence of cold air masses experience low temperature. The effect of these winds is, however, limited to the period during which they blow. Local winds like cold Mistral of France considerably lower the temperature and Sirocco, a hot wind that blows from Sahara desert raises the temperature of Italy, Malta etc. The temperature rises at the time of arrival of temperate cyclones, while it falls sharply after their passage. Sometimes, local winds can cause sudden change in temperature. In northern India, ‘Loo’, a local hot wind, raise the temperature to such an extent that heat waves prolong for several days in continuation and many people die of sunstroke. 6. Slope, Shelter and aspect – slopes of a mountain facing the Sun experiences high temperature than the slopes on the leeward side due to more insolation (figure 7(b)). A steep slope experiences a more rapid change in temperature than a gentle one. Mountain ranges that have an east-west alignment like the Alps show a higher temperature on the south-facing ‘sunny slope’ than the north facing ‘sheltered slope’. Consequently, there are more settlements in southern side and it is better utilized for agricultural and other purposes. The mountain ranges at certain places stop the cold winds and prevent the temperature from going down. This is found in areas where mountains lie in the direction facing the winds as in the case of Himalayas. In the absence of Himalayas, winters of India would have been very different. 7. Nature of ground surface – the nature of surface in terms of colour, vegetation, soil, land use, snow cover etc. affects the temperature of a place. In the tropical and subtropical deserts, the sandy surface record high temperature because they absorb most of the solar radiations. Snow has very high albedo6 and thus, reflects much of the insolation without absorption. Thick vegetation (such as Amazon forest) cuts off much of the in-coming insolation and in many places sunlight never reaches the ground. It is cool in the jungle and its shade temperature is a few degrees lower than that of open spaces in corresponding latitudes. Light soils reflect more heat than darker soils. Dry soils like sands are very sensitive to temperature changes, whereas wet soils, like clay retain much moisture and warm up more slowly. Urban areas have relatively higher temperature than the surrounding.

Distribution of Temperature The global distribution of temperature can well be understood by studying the isotherms. The Isotherms are lines joining places having equal temperature. As already discussed, latitudes have pronounced effect on the temperature, the isotherms are generally parallel to the latitude. The deviation from this general trend is more pronounced in January than in July, especially in the northern hemisphere. Figure 8 and 9 show the distribution of surface air temperature in the month of January and July. In the northern hemisphere the land surface area is much larger than in the southern hemisphere. Hence, the effects of land mass and the ocean currents are well pronounced. Following are the chief features of isotherms:

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 8 – isotherms in the month of January The isotherms are generally parallel to equator. They show successive temperature decrease towards the poles. The rate of change of temperature is indicated by the spacing between isotherms. Closely drawn isotherms indicate rapid change in temperature and vice-versa. The isotherms deviate to the north over the ocean and to the south over the continent in January. It is for two reasons – warm and cold ocean currents and difference between the temperature of land and water. For example, the presence of warm ocean currents, Gulf Stream and North Atlantic drift, make the Northern Atlantic Ocean warmer and the isotherms bend towards the north. Over the land the temperature decreases sharply and the isotherms bend towards south in Europe. The mean January temperature along 60° E longitude is minus 20° C both at 80° N and 50° N latitudes. In the southern hemisphere, the isotherms are more or less parallel to the latitudes due to less landmass and the variation in temperature is more gradual than in the northern hemisphere. The isotherm of 20° C, 10° C, and 0° C runs parallel to 35° S, 45° S and 60° S latitudes respectively. In July the isotherms generally run parallel to the latitude.

  





Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 9 – isotherms in the month of July

Temperature Anomaly The difference between the mean temperature of any place and the mean temperature of its parallels is known as temperature anomaly. On the map the lines joining the places of equal temperature anomaly are known as Isothermal anomaly lines. Temperature anomaly could be positive or negative. Due to uneven distribution of land and water the maximum temperature anomalies are found in the Northern Hemisphere and minimum in the Southern Hemisphere.

Temperature Inversion As already discussed, temperature decreases with increase in altitude. In normal conditions, as we go up, temperature decreases with normal lapse rate. It is 6.5°C per 1,000 m. Against this normal rule sometimes, instead of decreasing, temperature may rise with the height gained. The cooler air is nearer the earth and the warmer air is aloft. This rise of temperature with height is known as Temperature inversion. Temperature inversion takes place under certain specific conditions. These are discussed below: Long winter nights – if in winters the sky is clear during long nights, the terrestrial radiation is accelerated. The reason is that the land surface gets cooled fairly quickly. The bottom layer of atmosphere in contact with the ground is also cooled and the upper layer remains relatively warm. Cloudless clear sky – The clouds obstruct the terrestrial radiation. But this radiation does not face any obstacles for being reflected into space when the sky is clear. Therefore the ground is cooled quickly and so is the air in contact with it cooled.





Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 10 – temperature inversion Dry air – humid air absorbs the terrestrial radiation but dry air is no obstruction to terrestrial radiation and allows the radiation to escape into space. Calm atmosphere – the blowing of winds bring warm and cold air into contact. Under conditions of calm atmosphere the cold air stays put near the ground. Ice covered surface – in ice covered areas due to high albedo less insolation is received. During night due to terrestrial radiation most of the heat is lost to atmosphere and the surface is cooled. The air in contact with it is also cooled but the upper layer remains warm.

  

The stability of the night time temperature inversion is usually destroyed soon after sunrise as the sun's energy warms the ground, which warms the air in the inversion layer. The warmer, less dense air then rises, destroying the stability that characterizes the nightly inversion. The phenomenon of inversion of temperature is especially observed in valleys. During winters the mountain slopes cool very rapidly due to the quick radiation of heat. The air resting above them also becomes cold and its density increases. Hence, it moves down the slopes and settles down in the valleys. This air pushes the comparatively warmer air of valleys upwards and leads to the phenomenon of inversion of temperature. That is why, apple orchids in Himalayan region, tea garden of Darjeeling are found in upper slopes of the valleys. Effect on Humans: In cities, impurities present in the atmosphere such as smoke, dust particles and other pollutants do not go up in the air due to temperature inversion. They form dense fog near the earth’s surface, especially in winters. It causes problems in breathing. Frost formed may be harmful for crops in fields. At some places, people lit fire or use big blowers to mix hot and cold air in order to drain off the area of the adverse conditions created by temperature inversion. In valleys people make terraced fields in the upper slopes and also settle down there.



 

Temperature Ranges Temperature of a place varies within a day and also differs in different seasons. Range of temperature is the difference between maximum and minimum temperatures. There are two terms which are used to consider temperature ranges.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

1. Diurnal range of temperature – the daily pattern of temperature change that we normally experience illustrates energy changes on a small time scale. On a calm day with little cloud, air temperatures usually reach their minimum just before sunrise, because the ground has been giving off long-wave radiation all through the night, gradually becoming colder and cooling the air above by conduction. With sunrise, temperature of the ground begins to rise. Maximum insolation receives at midday. But the peak of air temperature is usually about 2:00 PM. After sun-set, the air initially remains fairly warm as it is still being heated by long-wave radiation from the ground, but this gradually expires. Desert areas typically have the greatest diurnal temperature variations while Low lying, humid areas typically have the least range. 2. Annual average range of temperature – it is the monthly range of temperature or the difference between the average temperature of hottest month and average temperature of the coldest month of the year. The annual range is lower in low latitudes and higher in high latitudes. In the same latitudes, it is higher over the continents and lower over the oceans and coastal regions. The highest annual range of temperature is more than 60° C over the north-eastern part of Eurasian continent. This is due to continentality. The least range of temperature, 3°C, is found between 20° S and 15° N.

Atmospheric Circulation Varying amount of insolation received by the earth causes differential heating of the earth and its atmosphere. Temperature difference thus produced account for the density differences in the air. Air expands when heated and gets compressed when cooled. This results in variations in the atmospheric pressure. The result is that it causes the movement of air from high pressure to low pressure, setting the air in three-dimensional motion on global scale. Air in horizontal motion is wind. Atmospheric pressure also determines when the air will rise or sink. The wind redistributes the heat and moisture across the planet, thereby, maintaining a constant temperature for the planet as a whole. The vertical rising of moist air cools it down to form the clouds and bring precipitation. There is, in fact, an intimate relationship between winds and pressure, and knowledge of pressure variations is a prerequisite to understanding air motion.

Atmospheric Pressure The atmosphere is held on the earth by the gravitational pull of the earth. A column of air exerts weight in terms of pressure on the surface of the earth. The weight of a column of air contained in a unit area from the mean sea level to the top of the atmosphere is called the atmospheric pressure. Pressure is normally measured in millibars or pascals and spatial variations of pressure are depicted on maps by means of isobars, which are lines connecting places having the same barometric pressure. The actual pressure at a given place and at a given time fluctuates and it generally ranges between 950 and 1050 millibars. Air pressure is measured with the help of a mercury barometer or the aneroid barometer. The gradual change of pressure between different areas is known as the barometric slope or pressure gradient. The closer the isobars are together, the greater the pressure gradient; for example, widely spaced isobars indicate a weak pressure gradient.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Pressure Variations In the lower atmosphere the pressure decreases rapidly with height with decrease in density of air. It does not always decrease at the same rate. But to make calculations simple, a decrease of about 1 mb for each 10 m increase in elevation is taken into consideration (figure 11). In spite of high vertical pressure gradient, we do not experience strong vertical air currents. This is possible because of equal and opposite gravitation force acting upon air.

Figure 11 - vertical pressure variation

Figure 12 - Isobars, High pressure and Low pressure system

The effects of low pressure are more clearly experienced by the people living in the hilly areas as compared to those who live in plains. In high mountainous areas rice takes more time to cook because low pressure reduces the boiling point of water. Breathing problem such as faintness and nose bleedings are also faced by many trekkers from outside in such areas because of low pressure conditions in which the air is thin and it has low amount of oxygen content. Unlike vertical high pressure gradient, small horizontal pressure gradients are highly significant in terms of the wind direction and velocity. In order to eliminate the effect of altitude on pressure, it is measured at any station after being reduced to sea level for purposes of comparison. Figure 12 shows the patterns of isobars corresponding to pressure systems. Low pressure system is enclosed by one or more isobars with the lowest pressure in the centre. High-pressure system is also enclosed by one or more isobars with the highest pressure in the centre. The terms ‘high pressure’ and ‘low pressure’ do not usually signify any particular absolute values, but are used relatively. Sea-level pressure conditions over the globe for both January (figure 13) and July (figure 14) show some marked differences between the two hemispheres. The northern hemisphere tends to have the greater seasonal contrasts in its pressure distributions and the southern hemisphere exhibits much simpler average pressure patterns overall. These differences are largely related to the unequal distribution of land and sea between the two hemispheres. Ocean areas, which dominate the southern hemisphere, tend to be much more equable than continents in both temperature and pressure variations.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 13 – Distribution of pressure (in mb) for January month

Figure 14 – Distribution of pressure (in mb) for July month

Forces Governing Air Movement We know that the air pressure is unevenly distributed in the atmosphere and air attempts to balance this unevenness. Hence, it moves from high pressure areas to low pressure areas. Horizontal movement of air in response to difference in pressure is termed as wind while vertical or nearly vertical moving air is called air current. Both winds and air currents form the system of circulation in the atmosphere. Pressure Gradient The existence of pressure differentials in the atmosphere is the immediate primary force causing air movement. The rate of change of pressure with respect to distance is the pressure gradient. The pressure gradient force always acts down the pressure gradient, attempting to cause the general movement of air away from high-pressure towards low pressure areas. The

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

force exerted is proportional to the steepness of the gradient (figure 15(a)). The gentler the pressure gradient slower is the speed of the wind and vice-versa. If alone this force is exerted to the air, wind would have direction perpendicular to the isobars. However, there are other forces also which, in fact, make wind to flow more nearly parallel to the isobars. Coriolis Force Winds do not cross the isobars at right angles as the pressure gradient directs them. They get deflected from their original paths. One of the most potent influences on wind direction is the deflection caused by the earth’s rotation on its axis. This deflection is always to the right of the direction of motion in the northern hemisphere and to the left in the southern hemisphere (figure 15(b)). This influence is known as Coriolis force.

(a) Relationship between pressure action gradient and speed of winds

(b) Coriolis force under

Figure 15 – forces governing air movement Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

The degree of the deflecting force varies with the speed of the moving air and with latitude. The faster the wind, the greater the effect of rotation can be. Similarly, the rate of deflection increases with the increasing distance from the Equator because the Coriolis force is zero at the Equator and maximum at Poles. It must be noted that it is an apparent or relative deflection. If viewed from outer space, objects moving across the face of the earth would not in fact appear to be deflected. In relation to star positions, they would travel in a straight line, while the earth rotates beneath them. The phenomenon affects all freely moving objects – air, ocean currents, rockets and projectiles etc. Thus, it is not actually any force. But it is simplest to accept that deflection is caused by a force. Centripetal Force This force applies when the isobars are curved, as within cyclones. The fact that air is following a curved path means that in addition to the pressure gradient and the Coriolis force, a third force is acting centripetally, pulling air inwards. Wind which is in balance with these three forces is known as the gradient wind. Frictional Force It lessens the speed of the wind. It is greatest at the surface and its influence generally extends upto an elevation of 1 - 3 km. Over the sea surface the friction is minimal. By reducing speed of wind, it weakens the Coriolis force. This allows the pressure gradient to assert its greater strength by causing the air to flow more towards low pressure. Thus, the usual situation is that surface winds flow at a slight angle to the isobars (figure 16(b)).

Geostrophic Wind The velocity and direction of the wind are the net result of the wind generating forces. The winds in the upper atmosphere, 2 - 3 km above the surface, are free from frictional effect of the surface and are controlled by the pressure gradient and the Coriolis force. At such height in the free atmosphere, winds generally blow at right angles to the pressure gradient: this indicate that the pressure gradient force is exactly balanced by the Coriolis force acting in a diametrically opposite direction. This sort of air motion is known as the geostrophic wind (figure 16(a)).

Figure 16 – forces governing air movement: (a) geostrophic balance between pressure gradient and Coriolis force; (b) the additional effect of frictional force on surface wind Not all winds are exactly geostrophic. As pressure pattern change, the balance is upset, but the wind always strives to readjust itself until it obtains the new geostrophic speed.

Distribution of Pressure Belts The horizontal distribution of air pressure across the latitudes is characterized by high or low pressure belts (figure 17(a)). These pressure belts are: Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Equatorial low pressure belt –This belt extends from equator to 100N and 100S latitudes. This belt is thermally produced due to heating by Sun.. Due to excessive heating horizontal movement of air is absent here and only vertical currents are experienced in this belt. Therefore, this belt is called doldrums (the zone of calm). . This belt is also known as-Inter Tropical Convergence Zone (ITCZ) because the trade winds flowing from sub tropical high pressure belts converge here. Sub-tropical high pressure belt – these extend roughly between 250 and 350 latitudes in both the Hemispheres. The existence of these pressure belts is due to the fact that the up rising air of the equatorial region is deflected towards poles due to the earth’s rotation. After becoming cold and heavy, it descends in these regions and get piled up. This results in high pressure. Calm conditions with feeble and variable winds are found here.. In southern hemisphere, this belt is broken by small low-pressure areas in summer over Australia and South Africa. In northern hemisphere, the belt is more discontinuous by the presence of land masses, and high pressure occurs only over the ocean areas as discrete cells; these are termed the Azores and Hawaiian cells in the Atlantic and Pacific areas respectively.





These belts are also called Horse latitudes. In older days, vessels with cargo of horses passing through these belts found difficult in sailing under these calm conditions. They used to throw the horses in the sea in order to make the vessels lighter. In the upper atmosphere over this belt the upper level westerlies and anti-trade winds converge and set up descending currents in the atmosphere. Sub-polar low pressure belt – it extends along 600 latitudes (550-650) in both the hemisphere. These belts are not thermally induced instead the winds coming from the sub-tropics and the polar regions converge in this belt and rise upward. The great temperature contrast between the subtropical and the polar regions, gives rise to cyclonic storms in this belt. In Southern hemisphere, this low pressure belt is more pronounced due to vast presence of ocean and also referred as the sub-antarctic low. But in the northern hemisphere, there are large land masses along 600 latitudes which are very cold. Therefore, the pressures over these landmasses are increased. Thus, the continuity of the belt is broken. Polar high pressure belt - Because of low temperature, air compresses and its density increases. Hence, high pressure is found here throughout the year. This is more marked over the land area of the Antarctic continent than over the ocean of the North Pole. In northern hemisphere, high pressure is not centered at the pole, but it extends from Greenland to Islands situated in the northern part of Canada.





Figure 17 – (a) global pressure belts and (b) shifting of pressure belts Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Shifting of Belts Pressure belts are not fixed. The main cause of their formation is the uneven distribution of temperature on the surface of earth. Consequently, the pressure belts swing either to the north (in July) or the south (in December) of the equator by following the apparent annual migration of the sun (figure 17(b)). Sun’s movement is recorded between tropic of Cancer and tropic of Capricorn. During the month of July, low pressure equatorial belt extends upto the tropic of Cancer in Asian region. While in January, it extends to latitudes 100-150 S. Most profound effect of shifting of belts is seen in the temperate region. Winds blowing from the Horse latitudes in the form of westerlies create unique climatic conditions in the temperate parts of the world, especially in the Mediterranean region.

General Circulation of the Atmosphere As discussed earlier that wind is the result of pressure gradient which is largely caused by differential heating of the earth. Winds in the atmosphere are neither unidirectional nor have a same pattern as we go up in the atmosphere. In fact, winds may change their direction and intensity multiple times within same day. Largely, wind movement in the atmosphere may be classified into three broad categories: Primary circulation – it includes planetary wind systems which are related to the general arrangement of pressure belts on the earth’s surface. The pattern of the movement of the planetary winds is called the general circulation of the atmosphere. In fact, it is the primary circulation patterns which prepare the broad framework for the other circulation patterns. Secondary circulation – it consists of cyclones and anti-cyclones, monsoon Tertiary circulation – it includes all the local winds which are produced by local causes such as topographical features, sea influences etc. Their impact is visible only in a particular area.



 

Planetary Winds Primary or planetary winds blow from high pressure belts to low pressure belts in the same direction throughout the year. They blow over vast area of continents and oceans. Trade winds, Westerlies and polar easterlies together form the planetary wind circulation (figure 18). These are described below: The air at the Inter Tropical Convergence Zone (ITCZ) rises because of convection caused by high insolation and a low pressure is created. The winds from the tropics converge at this low pressure zone. The converged air rises along up. It reaches the top of the troposphere up to an altitude of 14 km. and moves towards the poles. This causes accumulation of air at about 300 N and S. Part of the accumulated air sinks to the ground and forms a subtropical high. Another reason for sinking is the cooling of air when it reaches 300 N and S latitudes. Down below near the land surface the air flows towards the equator as the easterlies1 or tropical easterlies or trade winds. Because of Coriolis force, their direction becomes north-east and south-east in northern and southern hemisphere respectively. The easterlies from either side of the equator converge in the Inter Tropical Convergence Zone (ITCZ). Thus, winds originated at ITCZ come back in a circular fashion. Such a cell in the tropics is called Hadley Cell.



1

Wind direction is reported by the direction from which it originates. For example, a easterly wind blows from the east to the west.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

In the middle latitudes (300-600) the circulation is that of sinking cold air that comes from the poles and the rising warm air that blows from the subtropical high pressure belt. These winds are deflected due to coriolis force and become westerly in both the hemisphere. Deflected wind is called westerlies. These winds meet along the sub-polar low pressure belt to raise high in the troposphere. From here, air moves away in both directions – towards pole and equator. These winds start descending down above the sup-tropical high pressure belt and polar high pressure belt to form cells. These cells are called Ferrel cell and Polar cell respectively.



Figure 18 – Planetary winds The prevailing westerlies are relatively more variable than the trade winds both in direction and intensity. There are more frequent invasions of polar air masses along with the travelling cyclones and anti-cyclones. These moving cells of low and high pressures largely affect the movement of westerlies. The westerlies are stronger in the cold. In the southern hemisphere, westerlies are so powerful and persistent due to absence of land between 400-600 S that these are called ‘roaring forties’, ‘furious fifties’ and ‘screaming sixties’ along 400 S, 500 S and 600 S latitudes. Winds move away from polar high pressure to sub-polar low pressure along the surface of the earth in Polar cell. Their direction becomes easterlies due to coriolis force. These are called polar easterlies. Winds coming from the sub-tropical and the polar high belts converge to produce cyclonic storms or low pressure conditions. This zone of convergence is also known as polar front (see fronts and cyclones).







Local Winds Besides major wind systems of the earth’s surface, there are certain types of winds which are produced by purely local factors and therefore, are called local winds. These local winds play a significant role in the weather and climate of a particular locality. Following is a brief account of some of the well-known local winds which are found in different parts of the world.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

The Land and sea Breezes These winds are defined as the complete cycle of diurnal local winds occurring on sea coasts due to differences in the surface temperature of sea and adjacent land (figure 19). There is complete reversal of wind direction of these coastal winds. The land and sea breeze system is very shallow with average depth of 1-2km. Over lakes, the height of circulation is much less. Warm tropical areas, where intense solar heating persists throughout the year, experience stronger and regular breezes compare to higher latitudes. Details of land and sea breezes are given in table 2.

Figure 19 – Sea and Land Breezes Sea Breeze

Land Breeze

During the day the land heats up faster and In the night, the land cools up faster than the becomes warmer than the sea. The heated air surrounding sea. This creates relatively high rises giving rise to a low pressure area, pressure on land. whereas the sea is relatively cool and the pressure over sea is relatively high. Pressure gradient is created from sea to land.

Pressure gradient is created from land to sea.

the wind blows from the sea to the land as the wind blows from the land to the sea as the the sea breeze land breeze Reaches at maximum intensity in mid- Reaches at peak shortly before the sunrise afternoon Helpful for fishermen in returning from sea In morning, fishermen enter into sea with the after a good catch. help of land breeze and stays there till midafternoon. Table 2 – land and sea breezes The Mountain and Valley Breezes Another combination of local winds that undergoes a daily reversal consists of the mountain and valley breezes (figure 20). During the day the slopes get heated up more than the valleys. Hence, the pressure is low over the slopes while it is comparatively high in the valleys below. Air moves up from slope and to fill the resulting gap the air from the valley blows up the valley. This wind is known as the valley breeze or anabatic wind. The valley breeze is sometimes accompanied by the formation of cumulus cloud near mountain peaks to cause orographic rainfall.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

During the night the slopes get cooled and the dense air descends into the valley as the mountain wind. The cool air, of the high plateaus and ice fields draining into the valley is called mountain breeze or katabatic wind.

Figure 20 – mountain and valley breezes Hot Local Winds Local winds that are hot are caused by the advection of hot air from a warm source region. They may also be produced by dynamic heating of air as it descends from an elevated area to lowland. Few famous hot winds are: ‘Loo’ is a hot and dry wind, which blows very strongly over the northern plains of India and Pakistan in the months of May and June. Their direction is from west to east and they are usually experienced in the afternoons. Their temperature varies between 45°C to 50°C. ‘Foehn’ is strong, dusty, dry and warm local wind which develops on the leeward side of the Alps mountain ranges. Regional pressure gradient forces the air to ascend and cross the barrier. Ascending air sometimes causes precipitation on the windward side of the mountains. After crossing the mountain crest, the Foehn winds starts descending on the leeward side or northern slopes of the mountain as warm and dry wind. The temperature of the winds varies from 15°C to 20°C which help in melting snow. Thus making pasture land ready for animal grazing and help the grapes to ripe early. ‘Chinook’ is the name of hot and dry local wind, which moves down the eastern slopes of the Rockies in U.S.A. and Canada. The literal meaning of chinook is ‘snow eater’ as they help in melting the snow earlier. They keep the grasslands clear of snow. Hence, they are very helpful to ranchers. ‘Sirocco’ is a hot, dry dusty wind, which originates in the Sahara desert. It is most frequent in spring and normally lasts for only a few days. After crossing the Mediterranean sea, the Sirocco is slightly cooled by the moisture from the sea. Still it is harmful for vegetation, crops in that region. Its other local names are Leveche in Spain, Khamsin in Egypt, Gharbi in Aegean Sea area.









Harmattan is a strong dry wind that blows over northwest Africa from the northeast. Blowing directly from the Sahara desert, it is a hot, dry and dusty wind. It provides a welcome relief from the moist heat and is beneficial to health of people hence also known as ‘the doctor’. It is full of fine desert dust which makes the atmosphere hazy and causes problems to the caravan traders. It may cause severe damage to the crops.



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 22

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Cold Local Winds There are certain local winds which originate in the snow-capped mountains during winter and move down the slopes towards the valleys. Few of important these are: ‘Mistral’ originates on the Alps and move over France towards the Mediterranean Sea through the Rhone valley. They are very cold, dry and high velocity winds. They bring down temperature below freezing point in areas of their influence. As a protective measure, many of the houses and orchards of the Rhone valley have thick rows of trees and hedges planted to shield them from the Minstral. ‘Bora’ is a cold, dry north-easterly wind blowing down from the mountains in the Adriatic Sea region. It is also caused by pressure difference between continental Europe and the Mediterranean Sea. This is usually occurs in winter. It sometimes attain speeds of over 150 kmph. ‘Blizzard’ is a violent and extremely cold wind laden with dry snow. Such blizzards are of common occurrence in the Antarctic. Wind velocity sometimes reaches 160 kmph and temperature is as low as -70C.







Upper Air Circulation It is now realized that the causes of weather on the ground are intricately bound up with what happens at higher levels in the atmosphere. This applies especially to the development of anticyclones and depressions and to the general circulation of winds around the globe. Such phenomena can only be appreciated by understanding air circulation in the upper layers. Broadly speaking, wind speed tend to increase with altitude because of lower air density, lower frictional force etc. Direction of wind also is not same. For instance, during the month of July, surface wind(monsoonal) blow from south-west direction in India while at the height of 10km there are swift winds blowing from east to west. On a global scale, pressure patterns higher up tend to be much simpler than those at the surface level, largely because of the diminished thermal and mechanical effects of land masses. There is a falling pressure gradient from the sub-tropical areas towards the poles. The gradient is strongest in winter, when the temperature contrasts between the respective polar areas and the equator are most marked. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 23

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 21 – different vertical temperature gradients in the two columns create an increasing pressure gradient. Jet Streams Changes in pressure distribution with height are largely related to changes of temperatures. We can see how this can be so with references to two adjacent columns of air in the troposphere depicted in figure 21. At ground level the pressure exerted by the two is the same, but important changes ensue if we assume that column A is warmer, and therefore less dense throughout than column B. This means that for any level higher up in the two columns, for instance at 2km, there is a greater pressure of air still above this level of column A than in column B. Therefore, a pressure gradient from A to B gradually develops and intensifies with height, where none existed at the surface. Now, it can be visualized that a gradual change of velocity of the wind with height, the wind at the top of the air layers being very much stronger than that lower down.

Figure 22 – jet streams: (a) maximum speed at centre; (b) Polar and subtropical jetstreams in both hemispheres; (c) cross-sectional view of jet streams

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 24

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Applying this on a global scale by associating poles with cold air column and equator with warm air column, the gradual poleward decrease of temperature in the atmosphere from the equator should result in a large westerly component in the upper winds. It was found in 1940s during Second World War that high-flying aircraft encountered upper winds of very great velocity. These are known to be concentrated bands of rapid air movement, which are termed jet streams. Few of the features of jet streams are: These are narrow belts at the high altitude near the top of the troposphere. Their speed varies from about 110 km per hour (kmph) in the summer season to more than 180 kmph in the winter season. Their shape is circular. Speed in the jet streams decreases radially outwards (figure 22(a)). One way of visualizing this is to consider a river. The river's current is generally the strongest in the center with decreasing strength as one approaches the river's bank. It can be said that jet streams are "rivers of air". They are several hundred kilometers wide and about 2 km to 5km deep. The flow of jet streams is not in form of straight line. Their circulation path is wavy and meandering. These meandering winds are called Rossby waves They dip and rise in altitude/latitude, splitting at times and forming eddies, and even disappearing altogether to appear somewhere else. Jet streams also "follow the sun" in that as the sun's elevation increases each day in the spring, the average latitude of the jet stream shifts poleward. (By Summer in the Northern Hemisphere, it is typically found near the U.S. Canadian border.) As autumn approaches and the sun's elevation decreases, the jet stream's average latitude moves toward the equator. On occasions the jet stream breaks through the tropopause and enters into the lower stratosphere. Certain amount of water vapour manages to reach in lower stratosphere with jet streams and this layer exhibits occasional cirus clouds. At times, the jet stream effect extends down to an altitude of about 3 km from the earth’s surface. There is a well marked longitudinal variation in the strength of the jet stream. In winter, the highest wind velocities of the jet stream are found near the east coast of Asia and weakest over the eastern Atlantic and Pacific Oceans. In summer, strongest jet is positioned along the Canadian border and Mediterranean region.

  

   





Two permanent jet stream zones occur in each hemisphere. One is sub-tropical jet stream and another is polar front jet stream. There is another jet stream which moves seasonally near equator. Description of these three streams is give below: The polar front jet stream It is originated because of temperature difference. It is associated with the polar front zone7 in each hemisphere (figure 23). It runs at a more meandering path than the Sub Tropical Jet Stream It extends between 40 and 60 latitudes in both Hemispheres. It is found at a height between 6km and 9km in the atmosphere. It swings towards poles in summers and towards equator in winter. When swinging to south it takes very cold air with it to subtropical region.

     

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 25

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 23 – origin of the Polar front Jet stream at polar front zone Sub-tropical jet stream It runs between 250 and 300 latitudes in both the hemispheres. It blows constantly Its speed is comparatively lower than polar jet streams The air currents arising near about the equator descend at 300 N and S latitudes. A part of these air currents takes the form of Sub Tropical Jet streams. It swings to the north of Himalayas in summer in North India.

    

Eastern Tropical Jet Stream It is a seasonal Jet Stream. It blows between equator and 200N latitude at the time of South-West Monsoon in summer over south-east Asia, India and Africa. Its direction is opposite to that of other two jet streams. It runs in eastern direction. It is located comparatively at higher height between 14km and 16km Its speed is around 180 km per hour.

    

Consequence of Jet Stream They affect weather conditions They substantially contribute to originating cyclones, anticyclones, storms and depressions and influence their behaviour. The bursting of monsoon in India is said to be closely related to Eastern Tropical Jet streams. If the weather is not disturbed the aeroplanes running in their parallel directions gain great speed and considerably save fuel. Sometimes aeroplanes cannot be flown in opposite direction. These jet streams are still being investigated with respect to their effect on weather conditions.

     

Air Mass When the air remains over a homogenous area for a sufficiently longer time, it acquires the characteristics of the area. Such homogenous areas have uniform characteristics in terms of temperature, pressure and moisture. The air with distinctive characteristics in terms of temperature and humidity is called an air mass. It is defined as a large body of air having little horizontal variation in temperature and moisture. The homogenous surfaces, over which air masses form, are called the source regions. There are five major source regions. These are: Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 26

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF i. ii. iii. iv. v.

https://t.me/UPSC_PDF

N

Warm tropical and subtropical oceans The subtropical hot deserts The relatively cold high latitude oceans The very cold snow covered continents in high latitudes Permanently ice covered continents in the Arctic and Antarctica

Student Notes:

The air masses are classified according to the source regions. Air masses originated from tropical region are warm while those originated from polar region are cold. Air masses originated from these regions are called primary air masses. Accordingly, following types of airmasses are recognised:

Figure 25 – Airmasses i. ii. iii. iv. v.

Maritime tropical (mT) Continental tropical (cT) Maritime polar (mP) Continental polar (cP) Continental arctic (cA).

Where ‘m’ stands for Maritime; ‘c’ stands for continental; ‘T’ stands for tropical; ‘P’ stands for polar and ‘A’ stands for arctic region. As these air masses move around the earth they can begin to acquire additional attributes. For example, in winter an arctic air mass (very cold and dry air) can move over the ocean, picking up some warmth and moisture from the warmer ocean and becoming a maritime polar air mass (mP) - one that is still fairly cold but contains moisture. If that same polar air mass moves south from Canada into the southern U.S. it will pick up some of the warmth of the ground, but due to lack of moisture it remains very dry. Another way of changes is internal modification in the airmasses. The resultant air mass by these processes is termed as secondary air mass. Air masses can control the weather for a relatively long time period: from a period of days, to months. Most weather occurs along the periphery of these air masses at boundaries called fronts.

Fronts When two different air masses with distinct properties (temperature, moisture, density, pressure etc.) meet, the boundary zone between them is called a front. These air masses are brought together by converging movements in the general atmospheric circulation. The process of formation of the fronts is known as frontogenesis while Frontolysis is the end stage of a front (table 3). The fronts do not mix readily. In fact, they come in contact with one Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 27

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

another along sloping boundaries. These sloping boundaries are actually a transition zone across which a sharp contrast in weather condition occurs. The air masses are of vast size covering tens of thousands of square kilometers. Therefore, frontal zones of discontinuity about 15 to 200 kms wide are relatively narrow. So on the weather map they are represented by only a thick line. A front can be recognized with following observations: Sharp temperature changes over a relatively short distance. Sometimes change of 100 to 200 C may be observed. Change in moisture content Rapid shifts in wind direction Pressure changes Clouds and precipitation patterns

    

Frontogenesis

Frontolysis

creation of altogether new fronts

destruction or dying of a front

Only after the process of frontogenesis have Process of frontolysis must continue for some been in operation for quite some time, front time in order to destroy an existing front. do come into existence is likely to occur when the wind blow in such a likely to occur when fronts move into regions way that the isotherms become packed along of divergent air flow on crossing the subthe leading edge of the intruding air mass tropical high pressure regions, the fronts generally disappear Convergence of the wind toward a point or divergence of the wind from a point is helpful contraction towards a line augments the to the process of frontolysis process of Frontogenesis. Cyclonic wind shear witnesses the creation of fronts. Contrarily, the areas of anti-cyclonic wind shear do not allow the formation of fronts. Even the pre-existing fronts degenerate in such areas. Table 3 – difference between frontogenesis and frontolysis As a result of the observations of atmospheric conditions at the surface and aloft, the following types of fronts are identified:

Warm Front When a warmer and lighter air mass moves against an existing cold and dense airmass, it rises over the coldet and denser air mass. This type of front is known as warm front. (figure 26a). As the warm air gradually ascends the gently sloping surface of the wedge of cold air lying ahead, it cools. This cooling leads to the cloudy condensation and precipitation. Unlike the cold front, the changes in temperature and wind direction are gradual.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 28

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 26 – Fronts: (a) Warm front; (b) Cold front

Cold Front When a cold and dense airmass forces its way under warm and lighter airmass it makes the warm and lighter airmass to ride over it. This type of front is called cold front. The effect of friction retards the air motion near the ground, while the free air aloft has a higher velocity. This causes the cold front to become much steeper than the warm front. STATIONARY FRONT A stationary front forms when a cold front or warm front stops moving. This happens when two masses of air are pushing against each other but neither is powerful enough to move the other. Winds blowing parallel to the front instead of perpendicular can help it stay in place. OCCLUDED FRONT Sometimes a cold front follows right behind a warm front. A warm air mass pushes into a colder air mass (the warm front) and then another cold air mass pushes into the warm air mass (the cold front). Because cold fronts move faster, the cold front is likely to overtake the warm front. This is known as an occluded front. At an occluded front, the cold air mass from the cold front meets the cool air that was ahead of the warm front. The warm air rises as these air masses come together. Occluded fronts usually form around areas of low atmospheric pressure. The fronts occur in middle latitudes and are characterised by steep gradient in temperature and pressure. They bring abrupt changes in temperature and cause the air to rise to form clouds and cause precipitation There are two types of occlusion namely, cold front occlusion and war front occlusion (figure 27). The differences are given below in table 6.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 29

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 27- cold front occlusion and warm front occlusion Figure 28 – symbols used for Fronts Cold front occlusion

Warm front occlusion

Occurs when the cold air which overtakes the Occurs when the retreating cold air mass is warm air is colder than the retreating cold air colder than the advancing cold air mass In the initial stage, weather system of the warm front persists. At the later stages the weather conditions resemble those of the cold front. Overtaking cold airmass plows under both air Advancing cold air being relatively less dense masses overrides the retreating cold air mass Table 6 – Occluded fronts – difference between cold front occlusion and warm front occlusion

Cyclones The atmospheric disturbances which involve a closed circulation about a low pressure centre, anticlockwise in the northern atmosphere and clockwise in the southern hemisphere are called cyclones. They fall into the following two broad categories: (a) Extra-tropical and (b) tropical cyclones.

Extra-Tropical Cyclones Extra-tropical cyclones are the weather disturbances in the mid and high latitude, beyond the tropics. These latitudes are an area of convergence where contrasting air masses generally meet to form polar fronts.. . The stages of development of extra-tropical cyclone are described below with diagram.  

Initially, the front is stationary (figure 29-1). In the northern hemisphere, warm air blows from the south and cold air from the north of the front. When the pressure drops along the front, the warm air moves northwards and the cold air move towards, south setting in motion an anticlockwise cyclonic circulation(figure 29-2).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 30

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF    

www.UPSCPDF.com

https://t.me/UPSC_PDF

The cyclonic circulation leads to a well developed extra tropical cyclone, with a warm front and a cold front (figure 29-3). The warm air glides over the cold air and a sequence of clouds appear over the sky ahead of the warm front and cause precipitation (figure 29-4). The cold front approaches the warm air from behind and pushes the warm air up (figure 29-5). As a result, cumulus clouds develop along the cold front. The cold front moves faster than the warm front ultimately overtaking the warm front. The warm air is completely lifted up and the front is occluded and the cyclone dissipates (figure 29-6).

Figure 29 – life cycle of a extra-tropical cyclone

There is great degree of variation in shape and size of extra-tropical cyclones. Generally, the isobars are almost circular or elliptical. However, in certain depressions, the isobars take the shape of the letter ‘V’. Such storms are called V-shaped depression. At times, the cyclones become so broad and shallow that they are referred to as troughs of low pressure.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 31

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 30 – world: pathways of cyclones (Numbers indicate average frequency of cyclones) Paths and movement of extra-tropical cyclone – the general direction of movement of temperate cyclones is from west to east with frequent trends towards the southeast to northeast (figure 30). They are subject to the general westerly flow of atmosphere in temperate zone. The heavy concentration of storms tracks in the vicinity of the Aleutian(Islands west to the Alaska Peninsula) and Icelandic lows is the most important feature of the distribution of extra-tropical cyclones. During winter months, the opposing air masses have greater contrasts in their properties. So the winter cyclones are greater in number and are more intense. On an average cyclone may cover a distance of about 1000 km per day. Cyclones invariably move towards higher latitudes. Secondary cyclones – under the normal conditions, in the later stages of occlusion the cyclone weakens and ultimately dissipates. But sometimes, during the late maturing stage of a cyclone, a new low develops on the equatorward margin of the original cyclone. Thus, a secondary cyclone is formed which passes through different stages of its life cycle and matures very rapidly. It may follow the tract of primary cyclone or may move along new path. Cyclone families – It is found that an extra-tropical cyclone never appears alone. It is usually followed by three or four cyclones forming a series. The primary or the leading cyclone gets occluded, while the new ones originate on the trailing front and are in an incipient stage. In the rear of the last member of the cyclone family there is an outbreak of polar air which builds up an anti-cyclone. Original cyclone would be in high latitudes and each secondary cyclone would follow progressively a more southerly path. Cyclone families frequent the oceans in a larger number. Extra-tropical cyclone and Jet stream – there is a close relationship between the flow aloft and the cyclonic storm at the surface. Rossby waves produced at the top of troposphere helps in transporting large bodies of polar air to the lower latitudes and tropical air masses are carried to the higher latitudes. This results in the intensity of surface cyclonic activity. There are instances when extra-tropical cyclones form without the prior existence of a polar front. These depressions are actually initiated by a trough in the upper-air westerlies. Once such storms originate in the lower atmosphere they attract different air masses together which leads to the generation of fronts.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 32

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Tropical Cyclones The tropical cyclone develops from the ‘warm core’ of extremely low pressure area in the tropical oceanic areas. They are energized from the condensation process in the towering cumulonimbus clouds, surrounding the centre of the storm. The arrangement of isobars is almost circular. With continuous supply of moisture from the sea, the storm is further strengthened. On reaching the land the moisture supply is cut off and the storm dissipates. The place where a tropical cyclone crosses the coast is called the landfall of the cyclone. The conditions favourable for the formation and intensification of tropical storms are: Large sea surface with temperature higher than 27° C Presence of the Coriolis force Small variations in the vertical wind speed A pre-existing weak low-pressure area or low-level-cyclonic circulation Upper divergence above the sea level system.

    

Large and continuous supply of warm and moist air from the ocean provides necessary energy in the form of latent heat of condensation. Coriolis force causes cyclonic circulation. At the equator, the Coriolis force is zero and the wind blows perpendicular to the isobars. The low pressure gets filled instead of getting intensified. That is the reason why tropical cyclones are not formed near the equator. Because of small variations in the vertical wind speed or wind shear, cyclone formation processes are limited to latitudes equatorword of the sub-tropical jet stream. It is the preexisting low pressure area which intensifies and develops as cyclone. It must be pointed out that only a few of these disturbances develop into true tropical cyclones. Upper divergence helps in ascending air currents to be pumped out to maintain the low pressure at the centre of the cyclone. Tropical cyclone shown in figure 31 has following features: Eye – it is the centre of cyclone around which strong spirally winds circulate in a mature tropical cyclone. It is a region of calm with subsiding air. Eye Wall – there is a strong spiraling ascent of air to greater height reaching the tropopause. The wind reaches maximum velocity in this region, reaching as high as 250 km per hour. Torrential rain occurs here. From the eye wall rain bands may radiate and trains of cumulus and cumulonimbus clouds may drift into the outer region. The diameter of the circulating system can vary between 150 and 250 km. The diameter of the storm over the Bay of Bengal, Arabian Sea and Indian Ocean is between 600 - 1200 km. The system moves slowly about 300 - 500 km per day.

 

 

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 33

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 31 – tropical cyclone

Figure 32 – different names of tropical cyclone

Impact on humans This is one of the most devastating natural calamities. They move over to the coastal areas bringing about large scale destruction caused by violent winds, very heavy rainfall and storm surges. The cyclones, which cross 20oN latitude generally, re-curve and they are more destructive. Trees are uprooted and broken and the loose objects swept away. A particular location on the land surface encounters opposite winds twice from the circular fashion of the cyclone. These winds create more damage to objects. Torrential rains that occur in the towering cumulonimbus clouds inundate the low-lying areas, cause floods and landslides resulting in great loss of life and property damage. Strom waves of great heights are great hazard to shipping. These are called storm surge whose height may go up to 20 meters. If cyclone wave combines with the spring tide, the result is disastrous.



    

Naming of tropical cyclones - In the beginning, storms(tropical cyclone) were named arbitrarily. Then the mid -1900's saw the start of the practice of using feminine names for storms. In the pursuit of a more organized and efficient naming system, meteorologists later decided to identify storms using names from a list arranged alphabetically. There is a strict procedure to determine a list of tropical cyclone names in an ocean basin(s) by the Tropical Cyclone Regional Body responsible for that basin(s) at its annual/biennial meeting. There are five tropical cyclones regional bodies. The Regional Specialized Meteorological Centre (RSMC) – Tropical cyclones is responsible for monitoring and prediction of tropical cyclones over their respective regions. They are also responsible to name the cyclones.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 34

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

In general, tropical cyclones are named according to the rules at a regional level. The WMO/ESCAP Panel on Tropical Cyclones at its twenty-seventh Session held in 2000 in Muscat, Sultanate of Oman agreed in principal to assign names to the tropical cyclones in the Bay of Bengal and Arabian Sea. After long deliberations among the member countries, the naming of the tropical cyclones over north Indian Ocean commenced from September 2004. The list of names India has added to the database includes Agni, Akash, Bijli, Jal (cyclones which have all occurred since 2004). The Indian names in the queue are Leher, Megh, Sagar and Vayu, while those suggested by Pakistan include Nilofar, Titli and Bulbul. If public wants to suggest the name of a cyclone to be included in the list , the proposed name must meet some fundamental criteria. The name should be short and readily understood when broadcast. Further the names must not be culturally sensitive and not convey some unintended and potentially inflammatory meaning. A storm causes so much death and destruction that its name is considered for retirement and hence is not used repeatedly. Names are usually assigned to tropical cyclones with one-, three-, or ten-minute sustained wind speeds of more than 65 km/h depending on which area it originates. Importance for naming tropical cyclones: It would help identify each individual tropical cyclone. It helps the public to become fully aware of its development. Local and international media become focused to the tropical cyclone. It does not confuse the public when there is more than one tropical cyclone in the same area. The name of the tropical cyclone is well remembered by million of people as it is unforgettable event whose name will long be remembered. Warnings reach a much wider audience very rapidly. It heightens interest in warnings and increases community preparedness.

      

Difference between extra-tropical cyclone and tropical cyclone is given in table 7 below: Extra-tropical cyclone

Tropical cyclone

have a clear frontal system and get energy from the horizontal temperature contrasts that exist in the atmosphere

Fronts are not present and get energy from warm and moist air of ocean

Large size (1500-3000km)

Relatively small in size

can originate over the land and sea

originate only over the seas

Travel both on oceans and land

on reaching the land they dissipate.

Affects a much larger area as compared to the tropical cyclone. Wind velocity in a tropical cyclone is much higher and it is more destructive. move from west to east

move from east to west

Table 7 – comparison between tropical and extra-tropical cyclone

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 35

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Thunderstorms and Tornadoes Unlike Tropical Cyclones, thunderstorms and tornadoes are highly localized weather phenomenon. They are of short duration, occurring over a small area but are violent. They are so small and short lived as to make their prediction very difficult. A storm accompanied by thunder and lightning is called thunderstorm. It is associated with the cumulonimbus clouds.. Thunderstorms are caused by intense convection on moist hot days. When the clouds extend to heights where sub-zero temperature prevails, hails are formed and they come down as hailstorm. If there is insufficient moisture, a thunderstorm can generate dust storms. Stages in the development of thunderstorm are described below and shown in figure 33. 1. Cumulus stage – Warm, moist air rises in a buoyant plume or in a series of convective updrafts. As this occurs the air begins to condense into a cumulus cloud. As the warm air within the cloud continues to rise, it eventually cools and condenses. The condensation releases heat into the cloud, warming the air. This, in turn, causes it to rise adiabatically. The convective cloud continues to grow upward, eventually growing above the freezing level where super-cooled water droplets and ice crystals coexist Precipitation begins once the air rises above the freezing level. 2. Mature stage – it is characterized by the presence of both updrafts and downdrafts within the cloud. The downdrafts are initiated by the downward drag of falling precipitation. Cold descending air in the downdraft will often reach the ground before the precipitation. As the mature-stage thunderstorm develops, the cumulus cloud continues to increase in size, height and width. Cloud to ground lightning usually begins when the precipitation first falls from the cloud base. During this phase of the life cycle, the top of the resulting cumulonimbus cloud will start to flatten out, forming an anvil shape often at the top of the troposphere.

Figure 33 – three stages in the development of a thunderstorm: (a) cumulus stage; (b) Mature stage; (c) Dissipating stage

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 36

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

3. Dissipating stage – It is characterized by downdrafts throughout the entire cloud. Decay often begins when the super-cooled cloud droplets freeze and the cloud becomes glaciated, which means that it contains ice crystals. The cloud begins to collapse because no additional latent heat is released after the cloud droplets freeze, and because the shadow of the cloud and rain cooled downdrafts reduce the temperature below the cloud. What Causes Lightning and Thunder The rising air in a thunderstorm cloud causes various types of frozen precipitation to form within the cloud. Included in these precipitation types are very small ice crystals and much larger pellets of snow and ice. The smaller ice crystals are carried upward toward the top of the clouds by the rising air while the heavier and denser pellets are either suspended by the rising air or start falling toward the ground. Collisions occur between the ice crystals and the pellets, and these collisions serve as the charging mechanism of the thunderstorm. The small ice crystals become positively charged while the pellets become negatively charged. As a result, the top of the cloud becomes positively charged and the middle to lower part of the storm becomes negatively charged. When the strength of the charge overpowers the insulating properties of the atmosphere, lightning happens. At the same time, the ground underneath the cloud becomes charged oppositely of the charges directly overhead. When the charge difference between the ground and the cloud becomes too large, a conductive channel of air develops between the cloud and the ground, and a small amount of charge (step leader) starts moving toward the ground. When it nears the ground, an upward leader of opposite charge connects with the step leader. At the instant this connection is made, a powerful discharge occurs between the cloud. The channel of air through which lightning passes can be heated to 50,000°F—hotter than the surface of the sun! The rapid heating and cooling of the air near the lightning channel causes a shock wave that results in the sound we know as “thunder.”

Why thunders are cause of concern Each year, many people are killed or seriously injured by severe thunderstorms despite the advance warning. While severe thunderstorms are most common in the spring and summer, they can occur at just about any time of the year. Cloud-to-ground lightning, Hail, Tornadoes and waterspouts, Flash flood and Downburst are some of the hazards associated with thunderstorm. There is no safe place outside during a thunderstorm but building constructed according to current guidance could provide safe seltor and avoid injury or death. Tornado – From severe thunderstorms sometimes spiraling wind descends like a trunk of an elephant with great force, with very low pressure at the centre causing massive destruction on its way. Such a phenomenon is called a tornado. Excessive instability and steep lapse rate in the Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 37

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

atmosphere are necessary pre-requisite for the development of a tornado. Tornadoes generally occur in middle latitudes. The tornado over the sea is called water sprouts. Chief features of tornadoes are: Tornado’s funnel can have size of 90-460m in diameter. Tornadoes generally occur in middle latitudes. Tornadoes are the most violent of all the storms. They are very small in size and of short duration which makes weather prediction difficult. The velocity of winds revolving tightly around the core reaches more than 300 km per hour. It causes massive destruction on its way. When looked at from the ground, the funnel appears dark because of the presence of condensed moisture and the dust and debris picked up from the ground by the whirling tornado. Tornadoes may be found to be moving singly or in families of several individual tornadoes. These generally move in straight paths.

      

 

These violent storms are the manifestation of the atmosphere’s adjustments to varying energy distribution. The potential and heat energies are converted into kinetic energy in these storms and the restless atmosphere again returns to its stable state.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 38

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

References: 1. Since sunspots are darker than the surrounding photosphere it might be expected that more sunspots would lead to less solar radiation and a decreased solar constant. However, the surrounding margins of sunspots are brighter than the average, and so are hotter; overall, more sunspots increase the Sun's solar constant or brightness. 2. Electromagnetic radiation is a term used to describe all the different kinds of energies released into space by stars such as the Sun. 3. A photon is an elementary particle, the quantum of light and all other forms of electromagnetic radiation 4. Conductor of heat - Ability to transfer heat to adjacent molecules. 5. The latent heat of condensation for water is defined as the heat released when one mole of the substance condenses to form liquid droplets from water vapour. The temperature does not change during this process, so heat released goes directly into changing the state of the substance. The heat of condensation of water is equal to 40.8 kJ/mol. The heat of condensation is numerically exactly equal to the heat vaporization, but has the opposite sign. 6. Albedo – it is reflectivity or reflecting power of a surface. It is defined as the ratio of reflected radiation from the surface to incident radiation upon it. Albedos of typical materials in visible light range from up to 0.9 for fresh snow to about 0.04 for charcoal, one of the darkest substances. 7. The polar front is the boundary between the polar cell and the Ferrel cell in each hemisphere. At this boundary a sharp gradient in temperature occurs between these two air masses, each at very different temperatures. 8. An adiabatic process is a process that occurs without the transfer of heat or matter between a system and its surroundings.

UPSC Previous Years’ mains questions 1. The recent cyclone on east coast of India was called 'Phailin'. How are the tropical cyclones named across the world? Elaborate. (100 words)(UPSC 2013/5 marks) 2. What do you understand by the phenomenon of 'temperature inversion' in meteorology? How does it affect weather and the habitants of the place? (100 words) (UPSC 2013/5 marks) 3. List the significant local storms of the hot-weather season in the country and bring out their socio-economic impact. (UPSC 2010/12 Marks) 4. Write about Nor’westers in 20 words. (UPSC 2008/15 Marks)

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 39

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 11

PRECIPITATION AND RELATED PHENOMENA

Contents: 1. Introduction 2. Water vapour Importance of Water vapour 3. The Water Cycle 4. Humidity Absolute Humidity Specific Humidity Relative Humidity Significance of relative humidity The horizontal distribution of relative humidity 5. Evaporation 6. Condensation Latent heat Saturated Air Hygroscopic Nuclei Dew point 7. Dew 8. Frost 9. Fog Impact of Fog 10. Mist 11. Smog 12. Haze 13. Atmospheric Brown Cloud (ABC)/ Asian brown cloud 14. Clouds

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

15. Types of Clouds (1) Cirrus(curl of hair) Clouds (2) Cumulus(heap) Clouds (3) Stratus(layer) Clouds 16. International Classification of Clouds 17. Precipitation 18. Necessary conditions for RAINFALL 19. Types of Rainfall Convectional Rainfall Orographic Rain Cyclonic or Frontal Rainfall 20. Distribution of Precipitation Season Distribution of Rainfall Prelims Questions

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Introduction Precipitation is vital for life on Earth, but it can also be an inconvenience. Precipitation is any product of the condensation of atmospheric water vapour that falls under gravity. The main forms of precipitation include drizzle, rain, sleet, snow, graupel and hail. Let us first discuss some basic concepts

Water vapour Water is present in the atmosphere in three forms namely – gaseous, liquid and solid.. The water vapour constitute about 2 per cent of the total composition of the atmosphere. This percentage varies from zero per cent in cold dry air of the Arctic regions during the winter season to as much as 5 per cent of the volume in warm humid equatorial regions. The temperature of the atmosphere is the most important factor, as the capacity of the warm air to hold water vapour is more than that of the cold air. About half of the total moisture present in the atmosphere is concentrated in the lower layer of the atmosphere up to a height of about 2 kilometres.

Importance of Water vapour The water vapour present in the atmosphere is an important factor for the weather conditions in a particular region. The amount of water vapour present in the atmosphere influences the nature and amount of precipitation, the amount of loss of heat through radiation from the earth’s surface, the surface temperature, the latent heat of the atmosphere, the stability and instability of the air masses. Necessary energy for the development of storms (cyclones, hurricanes etc.) is provided by the water vapour in the form of latent heat energy.

The Water Cycle There is a constant and continuous circulation of water from the Earth’s surface to the atmosphere and back to the Earth’s surface. This circulation of water is called the water cycle or the hydrological cycle. The water cycle has no beginning or end, rather it is an intricate combination of evaporation, transpiration, air mass movement, condensation, precipitation, run-off and groundwater movement. The Sun's heat provides energy to evaporate water from the Earth's surface (oceans, lakes, etc.). Plants also lose water to the air (this is called transpiration). The water vapor eventually condenses, forming tiny droplets in clouds. When the clouds meet cool air over land, precipitation (rain, sleet, or snow) is triggered, and water returns to the land (or sea). Some of the precipitation soaks into the ground. Some of the underground water is trapped between rock or clay layers; this is called groundwater. But most of the water flows downhill as runoff (above ground or underground), eventually returning to the seas as slightly salty water.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Humidity Humidity refers to the amount of water vapour present in the atmosphere at a particular time and place. Humidity in the air is due to the various processes of evaporation from the land and water surfaces of the Earth. It can be expressed as an absolute, specific or a relative value.

Absolute Humidity The Absolute Humidity is the weight of actual amount of water vapour present in a unit volume of air. Generally it is expressed as grams per cubic meter of air. The absolute humidity varies from place-to-place and from time-to-time. It decreases from the equator towards the poles. . Generally, the absolute humidity changes as air temperature or pressure changes. However, if temperature increases but there is no excess water for evaporation then absolute humidity will not change.

Specific Humidity The Absolute Humidity is the weight of actual amount of water vapour present in a unit weight of air. Generally it is expressed as grams per kilogram of air.

Relative Humidity Relative humidity is a better way of expressing the level of humidity in the air. It is the ratio of actual amount of water vapour present in air at a given temperature to the amount of water vapour air can hold at the same temperature. The Relative Humidity is expressed in percentages. (

= (













ℎ



ℎ

ℎ ℎ

ℎ

)



)



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Generally capacity to hold water vapour increases with increase in temperature and decreases with decrease in temperature. Thus, the relative humidity of the air decreases with increase in temperature and vice versa Changes in the Relative Humidity of Air1 Changes in Relative Humidity can occur in the following three ways: I.

The temperature remaining the same and amount of water vapour in air increases. Its relative humidity will also increase. When the temperature of air rises its humidity retentive capacity also rises correspondingly and the Relative Humidity decreases. If the temperature of air decreases its humidity retentive capacity also decreases and Relative Humidity increases.

II. III.

Significance of relative humidity The absolute humidity determines the amount of precipitation while the relative humidity tells us about the possibility of precipitation. The high and low relative humidity indicates the possibility of wet and dry conditions respectively. Evaporation decreases when there is high relative humidity and vice versa. Relative humidity is directly related to human health. That is why, the equatorial region with high temperature and high relative humidity, and the tropical hot deserts with very low relative humidity are unfavourable for human health.

Absolute Humidity

Relative Humidity

It helps us to know the actual amount of It shows the ratio of water vapour actually water vapour present in air. present in the air at a given temperature to the retentive capacity of humidity of the same parcel of air at the same temperature. It does not take temperature into account.

It takes temperature into account.

It is expressed in grams per cubic metre.

It is expressed in percentages.

It Is not a useful measure of humidity It is a useful measure of humidity because it can because it does not tell us the amount of show how far the air is humid. water vapour required for the air to become saturated.

The horizontal distribution of relative humidity The equatorial region is characterized by the highest relative humidity. Relative humidity gradually decreases towards the Tropical high pressure belts (between 25°—35° latitudes) . After this, the relative humidity again increases polewards. The zones of high and low relative humidity shift northward and southward with the apparent migration of the Sun, during the summer and winter solstices respectively. Relative humidity is maximum in the mornings and minimum in the evenings.

Evaporation The process of transformation of liquid (water) into gaseous form (water vapour) is called evaporation. The amount and rate of evaporation at a particular place depend upon the aridity 1

If any question based on change of a property(say temperature) is asked consider other factors (say moisture) as constant unless otherwise specified.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

(vapour pressure), temperature and the movement of air. Evaporation is faster in dry air than in the wet air. There is more evaporation from the ocean than from the land. A special case of evaporation is transpiration which entails loss of water from the leaves and stems of the plants.

Condensation The process of transforming of water vapour into water (liquid) and ice (solid) is called condensation. Condensation takes place due to the loss of heat and can occur in one of the following ways: a. When the warm moist air rises upwards and expands. b. When the warm moist air comes in contact with the cold surface. c. When the warm moist air mixes with the air coming from the colder regions.

Latent heat: At the time of evaporation, heat is absorbed and conserved in water vapour (This is why Evaporation leads to cooling). It is known as latent heat. It is this same heat which is released when water vapour again changes into water through the process of condensation. Latent heat is essential for development of typhoons (storms, cyclones).

Saturated Air: If at any given temperature the humidity retentive capacity of air equals its absolute humidity the air is said to be saturated. In other words the same parcel of air can no longer absorb or accept any further amount of water vapour at the same temperature. 100 per cent humid air is called saturated air.

Hygroscopic Nuclei: Condensation always takes place around some particles present in air. These may be dust particles, smoke, oceanic salts or carbon dioxide which act as nuclei to hold water. They are thus called condensation nuclei or hygroscopic nuclei.

Dew point Condensation of water vapour in the atmosphere begins when the saturated air mass reaches the dew point. This is level at which the air is not in a position to take up any more moisture. Any further fall in temperature, beyond the dew point, would cause the condensation of the moisture present in the air. In the atmosphere, the nuclei for the condensation of the moisture is provided by the smoke and the dust particles. Once the condensation of water vapour in the atmosphere has taken place, the moisture present in the atmosphere may take one of the following forms— dew, frost, fog, mist, clouds, etc. This will be according to the conditions prevalent in the atmosphere.

Dew When the relative humidity of the air is low, even a drop in temperature during the winter nights fails to saturate the air. Hence condensation does not take place in free air but on some solid objects like leaves, flowers, grass blades, pieces of rocks, etc., which become comparatively cool due to the quick radiation at night. When the cool air comes in contact with these objects, the dew point is reached and condensation takes place. The deposition of water droplets on these objects is called dew. Some favourable conditions for the formation of dew are the following: 1) Long Nights: During long nights earth’s surface is cooled. With the coming into contact of humid air with this surface, condensation occurs. 2) Cloudless Clear Sky: On account of cloudless and clear sky there is more heating during the day. Hence evaporation will also be more and also rapid cooling of surface at night due to terrestrial radiation. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

3) Calm Air: Calm air remains in contact with the surface for longer duration. It is a favourable condition for condensation. 4) Relative Humidity: High relative humidity promotes more condensation. That is why condensation can be more in the months of August -September in India.

Frost Frost is actually frozen dew. It is formed when temperature of dew point fall below freezing point. Under such conditions droplets of condensation near or on the ground are frozen. Generally for formation of dew and frost the conditions are similar. Only temperature should fall below freezing point for the formation of frost Dew

Frost

It can be seen as droplets of water on leaves of It can be found on solid surfaces of earth’s small plants or blades of grass. crust as ice or snow crystal. It Is formed when temperature of dew point is It is formed when temperature is below above freezing point. freezing point. It is useful for plants.

It is harmful for plant growth.

Fog Fog is a special type of thin cloud consisting of very small water droplets which remain suspended in air close to the surface of the Earth. Fog is formed due to condensation of water droplets suspended in the atmosphere in the vicinity of the earth’s surface under certain conditions, such as low temperature and high relative humidity.. During the winter season, excessive radiation at night results in the fall of air temperature. The condensation of water vapour takes place around the dust and smoke particles that remain suspended in the air. It is called fog. The formation of fog near the surface of the Earth does not involve ascent and consequent expansion of air. The visibility is greatly reduced (less than one km). Fog is of three types: 1) Radiation Fog: The surface is cooled at night due to terrestrialradiation and the air which come into contact with it also gets cooled. Consequently tiny droplets forming the clouds are called radiation fog. It is not very thick and this thickness varies from 10 to 30 metres. 2) Advection Fog: It is formed when there is fall in temperature of warm moist air moving horizontally over a cold surface. It is cooled by contact and sometimes by mixing with cold air prevailing over cold surfaces. 3) Frontal or Precipitation Fog: The dividing line separating cold and warm air masses are known as fronts. At these fronts convergence of warm and cold air takes place and fog is formed. The warm air in the frontal area is light and rises above the cold air mass. It then begins to cool and when the temperature reaches dew point, frontal fog is formed.

Impact of Fog Fog hinders travel by land, air and sea. When the fog is polluted it becomes poisonous and causes serious health hazards. Agriculture sector is also affected since fog adversely hits lateRajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

N

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

sowing crops. Fog is beneficial to the tea and coffee plants as it protects them from the scorching sunlight on the hill slopes.

Mist It is also a type of fog but is relatively less dense. The only difference between mist and fog is density and its effect on visibility. A cloud that reduces visibility to less than 1 km is called fog, whereas it's called mist if visibility range is between 1 and 2 km. Mists are frequent over mountains as the rising warm air up the slopes meets a cold surface. Fogs are drier than mist and they are prevalent where warm currents of air come in contact with cold currents. Mist can occur as part of natural weather or volcanic activity or could be created artificially.

Smog It refers to a mixture of smoke and fog. It also results from sun’s effect on certain pollutants in the air, notably those from automobile exhaust. There are two main types of smog— photochemical and industrial.

The photochemical smog is a mixture of primary and secondary pollutants. The primary pollutants are hydrocarbons and nitrogen oxides and their main source is the motor vehicles. The secondary pollutants are formed when sunlight acts upon motor vehicle exhaust gases to form harmful substances such as ozone (O3), aldehydes and peroxyacetylnitrate (PAN). Photochemical smog formation requires (1)a still, sunny day and (2)temperature inversion (pollutants accumulate in the lower inversion layer). The photochemical smog directly affect lungs and eyes, causing irritation in these organs.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

The industrial smog is a mixture of sulphur dioxide and a variety of solid and liquid particles suspended in air.It comes from the stationary sources, such as furnaces, power plants, etc., than from motor vehicles. Sulphur dioxide in combination with water and oxygen can turn into sulphuric acid in the atmosphere and falls on the earth as acid rain. It can dissolve marble and eat away iron and steel. In human it can affect the respiratory system. Name:

Industrial smog (New York smog, gray smog)

Photochemical smog (Los Angeles smog, Denver smog, brown smog)

Weather:

cool, damp

sunny

Content:

particulates, sulfur oxides

NOx, ozone, hydrocarbons, PAN

Sources:

coal, etc.

gasoline(Petrol), combustion.

Haze is traditionally an atmospheric phenomenon where dust, smoke and other dry particles obscure the clarity of the sky. The World Meteorological Organization manual of codes includes a classification of horizontal obscuration into categories of fog, ice fog, steam fog, mist, haze, smoke, volcanic ash, dust, sand and snow. Sources for haze particles include farming (ploughing in dry weather), traffic, industry, and wildfires. One way to distinguish between smog and naturally-occurring haze is by color. Natural haze is typically white, gray or even blue. Smog is almost always yellowish or brown in color. The international definition of fog is a visibility of less than 1 kilometre; mist is a visibility of between 1 kilometre and 2 kilometres and haze from 2 kilometres to 5 kilometres . Fog and mist are generally assumed to be composed principally of water droplets, haze and smoke can be of smaller particle size.

Atmospheric Brown Cloud (ABC)/ Asian brown cloud The ABC originally referred to the enormous blanket of pollution spreading across Asia, distorting normal weather patterns in the region and threatening to devastate many countries’ economies. It was called the ‘Asian Brown Cloud’ in 2002, when a UN report first warned of this layer of pollution comprising ash, acids and aerosols. At that time, the two-mile thick haze extended ominously across the most densely populated areas of the world: southern, southeastern, and eastern Asia. Subsequently, however, similar patterns were detected elsewhere in the world and it was renamed ‘Atmospheric Brown Cloud’. Asia is particularly vulnerable as the ABC causes changes in the winter monsoon season, sharply reducing rain over northwestern parts of the continent and increasing rain along the eastern coast. However, India's scientific community have said the atmospheric brown clouds over Asia are a seasonal, temporary phenomena which may look bad, but have none of the catastrophic implications mentioned in the UN report.

Clouds When the moist air ascends, it expands, loses temperature, becomes cool, and gets saturated. With further decrease in temperature beyond the dew point, condensation of the moisture takes place high up in the air and it results in the formation of clouds. Clouds are droplets of water or tiny ice crystals which collect around the dust particles present in the atmosphere. The water droplets and tiny ice crystals that remain suspended in the air can be disturbed by Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

the slightest movement of the air. All forms of precipitation occur from the clouds. It should be noted that not all clouds yield precipitation but no precipitation is possible without the clouds. The clouds play a major role in the heat budget of the Earth and the atmosphere, as they reflect, absorb and diffuse some part of the incoming solar radiation. They also absorb a part of the outgoing terrestrial radiation and then re-radiate it back to the Earth’s surface. Whenever there are clouds in the sky, some sort of precipitation always occurs, although we do not feel it on the Earth. Much of it is re-evaporated during its descent through the warm and dry air. Clouds are more common on the windward slopes of the mountains than on the leeward slopes. Clouds are more frequent during the cyclones than during the anticyclones.

Types of Clouds Luke Howard, an English biologist, was the first to classify clouds in 1803. He used Latin names which are still in vogue. Clouds are usually classified on the basis of altitude, shape, expanse, density, colour, transparency, opaqueness, moisture content, etc. They exist at various elevations from the sea level to about 20 km above the sea level. There are three basic groups depending upon the height and shape of clouds. These are the cirrus clouds, the cumulus clouds and the stratus clouds.

(1) Cirrus (curl of hair) Clouds: Cirrus clouds are formed at high altitudes (8,000 - 12,000m). Being at considerable height these clouds are formed of ice crystals and therefore are white and thin. They are detached, fibrous, feathery, often with silky sheen in direct sunlight.

(2) Cumulus (heap) Clouds: Cumulus clouds look like cotton wool. They are generally formed at a height of 4,000 -7,000 m. They exist in patches and can be seen scattered here and there. With a flat base on rising they appear like domes at the top. Their appearance and structure is like that of a Cauliflower.

(3) Stratus (layer) Clouds: As their name implies, these are layered clouds covering large portions of the sky. These clouds are generally formed either due to loss of heat or the mixing of air masses with different temperatures. The rain bearing clouds are generally the low level clouds and are given the prefix or suffix‘nimbus’, a Latin word meaning a rainy cloud. Note: Whichever clouds you see in the sky these might be one or more of their types or their combinations or even in changed appearances.

International Classification of Clouds The World Meteorological Organisation presented a detailed International Atlas of Clouds mentioning three main groups and ten main types of clouds.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF Cloud Group

Height in meters

https://t.me/UPSC_PDF

N

Cloud Types

Student Notes:

High Clouds = Cirrus

6000-12000

1. Cirrus 2. Cirrostratus2 3. Cirrocumulus

High-level clouds form above 6,000 meters and since the temperatures are so cold at such high elevations, these clouds are primarily composed of ice crystals. High-level clouds are typically thin and white in appearance, but can appear in a magnificent array of colors when the sun is low on the horizon.

Middle Clouds = Alto

2000-6000

4. Altostratus 5. Altocumulus

The bases of mid-level clouds typically appear between 2,000 to 6,000 meters. Because of their lower altitudes, they are composed primarily of water droplets, however, they can also be composed of ice crystals when temperatures are cold enough.

Low Clouds = Stratus

below 2000

6. Stratus 7. Stratocumulus 8. Nimbostratus

Low clouds are of mostly composed of water droplets since their bases generally lie below 2,000 meters. However, when temperatures are cold enough, these clouds may also contain ice particles and snow.

Clouds with Vertical Growth

Special Clouds

9. Cumulus 10. Cumulonimbus

Probably the most familiar of the classified clouds is the cumulus cloud. Generated most commonly through either thermal convection or frontal lifting, these clouds can grow to heights in excess of 12,000 meters, releasing incredible amounts of energy through the condensation of water vapor within the cloud itself.

Mammatus Lenticular Fog Contrails

2

Sun’s Halo is produced by the ice crystals in cirrostratus clouds high (5–10 km) in the upper troposphere.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Precipitation The process of continuous condensation in free air helps the condensed particles to grow in size. When the resistance of the air fails to hold them against the force of gravity, they fall on to the earth’s surface. So after the condensation of water vapour, the release of moisture is known as precipitation. This may take place in liquid or solid form. The precipitation in the form of water is called rainfall, when the temperature is lower than the 00C, precipitation takes place in the form of fine flakes of snow and is called snowfall. Moisture is released in the form of hexagonal crystals. These crystals form flakes of snow. Usually the amount of snowfall is included in the rainfall figures. Besides rain and snow, other forms of precipitation are sleet and hail, though the latter are limited in occurrence and are sporadic in both time and space.

Sleet: Snow is not frozen rain. The term sleet is used for the frozen raindrops and the refrozen melted snow water in the cold layer of the air near the Earth’s surface. Sleet also refers to a mixture of snow and rain. Hailstones: Sometimes, drops of rain after being released by the clouds become solidified into small rounded solid pieces of ice and which reach the surface of the earth are called hailstones.

Hailstone mostly in the cumulo-nimbus clouds. Small droplets of water are formed in the lower part of the clouds due to condensation. Many of these small droplets join together to form large ones. The strong rising convection current carries these raindrops to the higher levels, which causes freezing and gives rise to small ice pellets. The strength of the vertical current is highly variable. Thus the ice pellets are not taken up continuously. They fall for some distance, slightly melt at the lower levels and are carried up again. This happens several times until the weight of the ice pellets becomes so heavy that they cannot be carried up by the current. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Ultimately these ice pellets fall as hailstones on the Earth. Hailstones have several concentric layers of ice one over the other. The size of the halistones depends upon the amount of ice it collects during its ascent and descent in the atmosphere by the convection current. Hailstones occur widely in the world, except in the polar regions, the hot deserts and the equatorial region. The occurrence of hailstones is common during the spring and the early summer in the sub tropical and the temperate regions.

Necessary conditions for RAINFALL (a) there should be sufficient amount of evaporation from the water bodies( airmass must be saturated with water vapour) (b) there should be wind to carry the water vapour from one place to another, and (c) there should be some way of decreasing the temperature of the moist air. The rainfall does not occur unless these cloud droplets become so large that the air is not able to hold them in suspension. Rainfall occurs only when the cloud droplets change to raindrops. The diameter of a raindrop is about 5 mm and one raindrop contains about 8 million cloud droplets.

Types of Rainfall According to the way, the cooling of the warm moist airmass takes place, the rainfall can be of the following three types: -

Convectional Rainfall As it rises, it expands and loses heat and consequently, condensation takes place and cumulous clouds are formed. With thunder and lightening, heavy rainfall takes place but this does not last long. Such rain is common in the summer or in the hotter part of the day. It is very common in the equatorial regions and interior parts of the continents, particularly in the northern hemisphere. In the equatorial regions convectional rainfall is received almost daily in the afternoons. In these regions ground starts heating up early morning and by afternoon convectional currents start rising. The whole sky soon is overcast with clouds. Late in the afternoon thunderstorms and lightning occur. It generally happens regularly at 4 P.M. throughout the year. For this reason it is also called 4’O clock rainfall.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

N

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Orographic Rain It is also known as the relief rain. When the saturated air mass comes across a mountain, it is forced to ascend and as it rises, it expands; the temperature falls, and the moisture is condensed. The chief characteristic of this sort of rain is that the windward slopes receive greater rainfall. After giving rain on the windward side, when these winds reach the other slope, they descend, and their temperature rises. Then their capacity to take in moisture increases and hence, these leeward slopes remain rainless and dry. The area situated on the leeward side, which gets less rainfall is known as the rain-shadow area. For example, Mahabaleshwar lying on the windwardside of Western Ghats receives annual rainfall of about 622 cm as against Pune on the leeward side only 70 km away from Mahabaleshwar receives only 66 cm annual rainfall. The windward slope of a mountain, at the time of rainfall, has cumulus clouds while the leeward slope has stratus clouds. The orographic rainfall may occur in any season. It is longer duration. The orographic rainfall is supported by convectional and cyclonic processes of condensation. Most of the precipitation in the world is orographic in nature. In India, Cherrapunji in Meghalaya plateau, the Western Ghats and the entire Himalayan region receive Orographic Rainfall.

Cyclonic or Frontal Rainfall Cyclones have low pressure at the centre, surrounded by high pressure. When wind from all directions blow towards centre, air masses of different characteristics meet creating fronts. The warm air being the lighter, rises above the cold air. The rising warm air cools and condensation takes place, causing rainfall. This type of rainfall is associated with temperate and tropical cyclones. Since the lifting of warm air along the warm front of the temperate cyclone is slow and gradual, the condensation is also slow and gradual. Thus the precipitation occurs in the form of drizzle3, It is widespread and continues for a longer duration. Most of the rainfall in the temperate region is received through frontal or cyclonic rains. The tropical cyclone, regionally known as typhoons, hurricanes, tornadoes, etc., yield heavy downpour in China, Japan, Southeast Asia, India, USA, etc.

3

When the drops of rain are very small, it is called drizzle.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Distribution of Precipitation The mean annual rainfall on Earth is about 100 cm but different places on the earth’s surface receive different amounts of rainfall in a year and that too in different seasons. Factors controlling the distribution of rainfall over the earth's surface are the belts of convergingascending air flow (doldrums; polar front etc.), air temperature, moisture-bearing winds, ocean currents, distance inland from the coast, and mountain ranges. In general, as we proceed from the equator towards the poles, rainfall goes on decreasing steadily. The coastal areas of the world receive greater amounts of rainfall than the interior of the continents. The rainfall is more over the oceans than on the landmasses of the world because of being great sources of water. Between the latitudes 350 and 400 N and S of the equator, the rain is heavier on the eastern coasts and goes on decreasing towards the west. But, between 450 and 650 N and S of equator, due to the westerlies, the rainfall is first received on the western margins of the continents and it goes on decreasing towards the east. Wherever mountains run parallel to the coast, the rain is greater on the coastal plain, on the windward side and it decreases towards the leeward side. On the basis of the total amount of annual precipitation, major precipitation regimes of the world are identified as follows. Areas of Heavy Rainfall: The regions receiving more than 200 cm of annual precipitation are included in this belt. The main areas are the equatorial belt, the mountain slopes along the western coasts in the cool temperate zone and the coastal areas of the monsoon lands. Areas of Moderate Rainfall: The regions receiving 100 cm to 200 cm of annual precipitation are included in this belt. The main areas lie adjacent to the regions of heavy rainfall. The coastal areas in the warm temperate zone also receive moderate precipitation. Areas of Low Rainfall: The regions receiving 50 cm to 100 cm of annual precipitation are included in this belt. The main areas lie in the central part of the tropical lands and in the eastern and the interior parts of the temperate lands. Areas of Scanty Rainfall: The regions receiving less than 50 cm of annual precipitation are included in this belt. The main areas are the rain shadow areas on the leeward slopes of the mountain ranges, the interior of the continents, the lands in the high latitudes, western margins of the continents in the tropical areas and the arid deserts.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Seasonal Distribution of Rainfall The conditions, which can cause precipitation, do not exist in the same combination throughout the year. This leads to the variations in the seasonal distribution of rainfall. However, most of the areas in the world receive a major part of the precipitation during the summer season. The main characteristics of the seasonal distribution of rainfall      

Heavy rainfall occurs throughout the year in the equatorial region. A few degrees north or south of the equator have wet summers and dry winters. The monsoon circulation brings more seasonal contrasts resulting in wet summers, as the wind blows onshore, and dry winters as the wind blows offshore. Seasonal variation, due to the monsoons, is well-developed in the Indian Subcontinent and in Southeast Asia. Most of the western coastal areas in the mid- latitudes have dry summers and wet winters due to the presence of the sub-tropical high pressure belts. In the temperate region the precipitation is cyclonic in nature and the cyclones are more common in the winter season. Thus heavy rainfall occurs in winters and not in summers.

The monthly distribution of precipitation throughout the year is often more significant than the average annual precipitation because rainfall is important for the various human activities, especially agriculture. The dependence on rainfall is a matter of great concern to farmers in the sub-humid and semi-arid lands where any departure from the normal regime may result in crop failure.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Prelims Questions

Student Notes:

Clouds 1.

Which one of the following statements is correct? (a) Circus clouds are composed office crystals (b) Cirrus clouds exhibit a flat base and have the appearance of rising domes (c) Cumulus clouds are white and thin and form delicate patches and give a fibrous and feathery appearance (d) Cumulus clouds are classified as high clouds. (2004)

2.

Sun’s halo is produced by the refraction of light in (a) Water vapour in Stratus clouds (b) Ice crystals in Cirro-Cumulus clouds (c) Ice crystals in Cirrus clouds (d) Dust particles in Stratus clouds (2004)

Precipitation: Distribution 3.

"Assertion (A): Bangalore received much higher average rainfall than that of Mangalore. Reason (R): Bangalore has the benefit of receiving rainfall both from south – west and north – east monsoons." (2004)

4.

"Assertion (A): The eastern coast of India produces more rice than the western coast. Reason (R): The eastern coast receives more rainfall than the western coast." (2003)

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 12

OCEAN BASICS AND OCEAN RESOURCES

Contents: 1. Ocean Basics 1.1. Relief of the Ocean Floor 1.1.1.Continental Shelf 1.1.2.Continental Slope 1.1.3.Continental Rise 1.1.4.Deep Sea Plain 1.1.5.Oceanic deeps or Trenches 1.2. Minor relief features of the Ocean Floor 1.3. The Oceanic Deposits of the Ocean Floor 1.4. Temperature 1.4.1.Factors affecting Temperature Distribution 1.4.2.Vertical Distribution of Temperature 1.4.3.Horizontal Distribution of temperature 1.5. Salinity 1.5.1.Factors affecting ocean salinity 1.5.2.Vertical Distribution of Salinity 1.5.3.Horizontal Distribution of Salinity 2. Movements of Ocean Water 2.1. Waves 2.1.1.Characteristics of waves 2.1.2.Wave Motion 2.2. Tides 2.2.1.Causes of Tides 2.2.2.Types of Tides 2.2.3.Tides based on frequency 2.2.4.Tides based on height 2.2.5.Characteristics of Tides

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

2.2.6.Importance of Tides 2.3. Ocean Currents 2.3.1.Causes of Ocean Currents 2.3.2.Types of Ocean Currents 2.3.3.Currents based on depth 2.3.4.Currents based on temperature 2.3.5.Characteristics of Ocean Currents 2.3.6.Currents of the Atlantic Ocean 2.3.7.Currents of the Pacific Ocean 2.3.8.Currents of the Indian Ocean 2.3.9.Effects of Ocean Currents 3. Ocean Resources 3.1. Fishing 3.1.1.Major Fishing grounds 3.2. Climate Buffer 3.3. Phytoplankton 3.4. Mining 3.4.1.Deep Sea Mining 3.4.2.Major Deep Sea Minerals 3.4.3.Constraints in Deep Sea mining 4. UPSC questions related to above topics

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

1] Ocean Basics Water is an essential component of all life forms. The earth fortunately has an abundant supply of water on its surface. Hence, our planet is called the Blue Planet. About 97 per cent of the planetary water is found in the oceans. Oceans account for more than 70 per cent or 140 million square miles of the earth's surface. Oceanography, the science of the oceans, has become such an important subject in recent years and many researches into the deep seas have been conducted. The oceans, unlike the continents, merge so naturally into one another that it is hard to demarcate them. The geographers have divided the oceanic part of the earth into four oceans, namely the Pacific, the Atlantic, the Indian and the Arctic.

1.1 Relief of the Ocean Floor Ocean Floor refers to the land under the waters of the oceans. The ocean floor exhibits complex and varied features similar to those observed over the land. The floors of the oceans are rugged with the world’s largest mountain ranges, deepest trenches and the largest plains. These features are formed, like those of the continents, by the factors of tectonic, volcanic and depositional processes. The ocean floors can be divided into following four major divisions: 1.1.1 Continental Shelf The continental shelf is the extended margin of each continent occupied by relatively shallow seas. It is the shallowest part of the ocean showing an average gradient of1° or even less. The shelf typically ends at a very steep slope, called the shelf break. The widths of the continental shelves vary from one ocean to another. The average width of continental shelves is about 80 km. The shelves are almost absent or very narrow along some of the margins like the coasts of Chile, the west coast of Sumatra, etc. On the contrary, the Siberian shelf in the Arctic Ocean, the largest in the world, stretches to 1,500 km in width. The depth of the shelves also varies. It may be as shallow as 30 m in some areas while in some areas it is as deep as 600 m. The continental shelves are covered with variable thicknesses of sediments brought down by rivers, glaciers, wind, from the land and distributed by waves and currents. Massive sedimentary deposits received over a long time by the continental shelves, become the source of fossil fuels. 1.1.2 Continental Slope The continental slope connects the continental shelf and the ocean basins (bottom of the ocean). It begins where the bottom of the continental shelf sharply drops off into a steep slope. The gradient of the slope region varies between 2-5°. The depth of the slope region varies between 200 and 3,000m. The slope boundary indicates the end of the continents. Canyons and trenches (discussed later in minor relief features of ocean floor) are observed in this region.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

1.1.3 Continental Rise Where the continental slope ends, the gently sloping continental rise begins. Its general relief is low and with increasing depth, the continental rise becomes virtually flat to merge with the deep sea plains. 1.1.4 Deep Sea Plain Deep sea plains are gently sloping areas of the ocean basins. These are the flattest and smoothest regions of the world. The depths vary between 3,000 and 6,000m. These plains are covered with fine-grained sediments like clay and silt. Deep sea plains cover two-thirds of the ocean floor and are also known as abyssal plains. They also contain features like ridges, guyots and oceanic islands that sometimes rise above the sea level in the midst of oceans. 1.1.5 Oceanic deeps or Trenches These areas are the deepest parts of the oceans. The trenches are relatively steep sided, narrow basins. They are some 3-5 km deeper than the surrounding ocean floor. They occur at the bases of continental slopes and along island arcs and are associated with active volcanoes and strong earthquakes. That is why they are very significant in the study of plate movements. As many as 57 deeps have been explored so far; of which 32 are in the Pacific Ocean; 19 in the Atlantic Ocean and 6 in the Indian Ocean. The greatest known ocean deep is the Mariana Trench near Guam Island, which is more than 36,000 feet deep. Figure 1. Major relief features of the ocean floor.

1.2 Minor relief features of the Ocean Floor Apart from the above mentioned major relief features of the ocean floor, following minor but significant features predominate in different parts of the oceans: 1. Mid-oceanic ridges: A mid-oceanic ridge is composed of chains of mountains separated by a large depression. Oceanic ridge is also known as an oceanic spreading center, which is responsible for seafloor spreading. The uplifted sea floor results from Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

convection currents which rise in the mantle as magma at a linear weakness in the oceanic crust, and emerge as lava, creating new crust upon cooling. A mid-ocean ridge demarcates the boundary between two tectonic plates, and consequently is termed a divergent plate boundary. The mountain ranges can have peaks as high as 2,500 m and some even reach above the ocean’s surface. Iceland, a part of the mid-Atlantic Ridge, is an example. 2. Seamount: It is a mountain with pointed summits, rising from the seafloor that does not reach the surface of the ocean. Seamounts are volcanic in origin. These can be 3,000-4,500 m tall. The Emperor seamount, an extension of the Hawaiian Islands in the Pacific Ocean, is a good example. 3. Submarine canyons: These are deep valleys, found cutting across the continental shelves and slopes, extending from the mouths of large rivers. The Hudson Canyon is the best known submarine canyon in the world. Figure 2. Minor Relief features of the ocean floor.

4. Guyots: It is a flat topped seamount. They show evidences of gradual subsidence through stages to become flat topped submerged mountains. It is estimated that more than 10,000 seamounts and guyots exist in the Pacific Ocean alone. 5. Atoll: These are low islands found in the tropical oceans consisting of coral reefs surrounding a central depression. It may be a part of the sea (lagoon), or sometimes form enclosing a body of fresh, brackish or highly saline water.

1.3 The Oceanic Deposits of the Ocean Floor Materials eroded from the earth which are not deposited by rivers or at the coast are eventually dropped on the ocean floor. The dominant process is slow sedimentation where the eroded particles very slowly filter through the ocean water and settle upon one another in layers. All oceanic deposits can be classified as follows: 1. Muds: These are terrigenous deposits because they are derived from land and are mainly deposited on the continental shelves. The muds are referred to as blue, green or red muds; their colouring depends upon their chemical content. 2. Oozes: These are pelagic deposits because they are derived from the oceans. They are made of the shelly and skeletal remains of marine microorganisms with calcareous or

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

siliceous parts. Oozes have a very fine, flour-like texture and either occur as accumulated deposits or float about in suspension. 3. Clays: These occur mainly as red clays in the deeper parts of the ocean basins, and are particularly abundant in the Pacific Ocean. Red clay is believed to be an accumulation of volcanic dust blown out from volcanoes during volcanic eruptions.

1.4 Temperature Like land masses, ocean water varies in temperature from place to place both at the surface and at great depths. Ocean water gets heated by solar energy just as land. The process of heating and cooling of the oceanic water is slower than land. This is due to higher specific heat of water as compared to land as a result of which greater amount of energy is required to raise the temperature of water as compared to land. 1.4.1 Factors affecting Temperature Distribution The factors which affect the distribution of temperature of ocean water are: 1. Latitude: The temperature of surface water decreases from the equator towards the poles because the amount of insolation decreases poleward. 2. Unequal distribution of land and water: The oceans in the northern hemisphere receive more heat due to their contact with larger extent of land than the oceans in the southern hemisphere. 3. Prevailing winds: The winds blowing from the land towards the oceans drive warm surface water away from the coast resulting in the upwelling of cold water from below. It results into the longitudinal variation in the temperature. Contrary to this, the onshore winds pile up warm water near the coast and this raises the temperature. 4. Ocean currents: Warm ocean currents raise the temperature in cold areas while the cold currents decrease the temperature in warm ocean areas. All these factors influence the temperature of the ocean currents locally. The enclosed seas in the low latitudes record relatively higher temperature than the open seas; whereas the enclosed seas in the high latitudes have lower temperature than the open seas. 1.4.2 Vertical Distribution of Temperature It is a well-known fact that the maximum temperature of the oceans is always at their surfaces because they directly receive the heat from the sun and the heat is transmitted to the lower sections of the oceans through the process of convection. It results into decrease of temperature with the increasing depth, but the rate of decrease is not uniform throughout. The temperature falls very rapidly up to the depth of 200 m and thereafter, the rate of decrease of temperature is slowed down. The temperature profile of oceans shows a boundary region between the surface waters of the ocean and the deeper layers. The boundary usually begins around 100-400m below the sea surface and extends several hundred of metres downward. This boundary region, from where there is a rapid decrease of temperature, is called the thermocline. About 90 per cent of the total volume of water is found below the thermoclinein the deep ocean. In this zone, temperatures approach 0°C.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 3. Variation of temperature with depth in oceans

The temperature structure of oceans over middle and low latitudes can be described asa three-layer system from surface to the bottom: The first layer represents the top layer of warm oceanic water and it is about 500m thick with temperatures ranging between 20° and25° C. This layer, within the tropical region, is present throughout the year but in mid-latitudes it develops only during summer. The second layer called the thermocline layer lies below the first layer and is characterized by rapid decrease in temperature with increasing depth. The thermocline is 500 -1,000 m thick. The third layer is very cold and extends up to the deep ocean floor. Here the temperatures are close to 0° C.







In the Arctic and Antarctic circles, surface water temperatures are close to 0° C and so the temperature change with the depth is very slight. Here, only one layer of cold water exists, which extends from surface to deep ocean floor. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

1.4.3 Horizontal Distribution of temperature The average temperature of surface water of the oceans is about 27°C and it gradually decreases from the equator towards the poles. The rate of decrease of temperature with increasing latitude is generally 0.5°C per latitude. The average temperature is around22°C at 20° latitudes, 14° C at 40° latitudes and 0° C near poles. The oceans in the northern hemisphere record relatively higher temperature than in the southern hemisphere. The highest temperature is not recorded at the equator but slightly towards north of it. The average annual temperatures for the northern and southern hemisphere are around 19° C and 16°C respectively. This variation is due to the unequal distribution of land and water in the northern and southern hemispheres.

Figure 4. Horizontal Distribution of temperature of oceans around the world

1.5 Salinity Salinity is used to define the total content of dissolved salts in sea water. It is calculated as the amount of salt (in gm) dissolved in 1,000 gm (1 kg) of seawater. It is usually expressed as parts per thousand or ppt. Salinity is an important property of sea water. Salinity of 24.7 ppt has been considered as the upper limit to demarcate brackish water(saltier than fresh water, but not as salty as seawater). 1.5.1 Factors affecting ocean salinity Major factors are as mentioned below: The salinity of water in the surface layer of oceans depends mainly on evaporation and precipitation.



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Surface salinity is greatly influenced in coastal regions by the fresh water flow from rivers, and in polar-regions by the processes of freezing and thawing of ice. Wind also influences salinity of an area by transferring water to other areas. The ocean currents contribute to the salinity variations.

  

Salinity, temperature and density of water are interrelated. Hence, any change in the temperature or density influences the salinity of water in an area. 1.5.2 Vertical Distribution of Salinity Salinity changes with depth but the way it changes depends upon the location of the sea. Salinity at the surface increases by loss of water to ice or evaporation, or decreases by the input of fresh water, such as from the rivers. Salinity at depth is very much fixed, because there is no way that water is lost, or the salt is added. There is a marked difference in the salinity between the surface zones and the deep zones of the oceans. The lower salinity water rests above the higher salinity dense water. Salinity, generally, increases with depth and there is a distinct zone called the halocline, where salinity increases sharply. Other factors being constant, increasing salinity of seawater causes its density to increase. High salinity seawater, generally, sinks below the lower salinity water. This leads to stratification by salinity. 1.5.3 Horizontal Distribution of Salinity The salinity for normal open ocean ranges between 33 ppt and 37 ppt. In the land locked Red sea, it is as high as 41 ppt, while in the estuaries and the Arctic, the salinity fluctuates from 0 – 35 ppt, seasonally. In hot and dry regions, where evaporation is high, the salinity sometimes reaches to 70 ppt. The salinity variation in the Pacific Ocean is mainly due to its shape and larger areal extent. Salinity decreases from 35 ppt - 31 ppt on the western parts of the northern hemisphere because of the influx of melted water from the Arctic region. In the same way, after 15° - 20° south, it decreases to 33 ppt The average salinity of the Atlantic Ocean is around 36 ppt. The highest salinity is recorded between 15° and 20° latitudes. Maximum salinity (37 ppt) is observed between20° N and 30° N and 20° W - 60° W. It gradually decreases towards the north. The North Sea, in spite of its location in higher latitudes, records higher salinity due to more saline water brought by the North Atlantic Drift. Baltic Sea records low salinity due to influx of river waters in large quantity. The Mediterranean Sea records higher salinity due to high evaporation. Salinity is, however, very low in Black Sea due to enormous fresh water influx by rivers. The average salinity of the Indian Ocean is 35 ppt. The low salinity trend is observed in the Bay of Bengal due to large influx of river water. On the contrary, the Arabian Sea shows higher salinity due to high evaporation and low influx of fresh water.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 5. Surface salinity of World Oceans.

2] Movements of Ocean Water Ocean water is dynamic. The horizontal motion refers to the ocean currents and waves. The vertical motion refers to tides. The upwelling of cold water from subsurface and the sinking of surface water are also forms of vertical motion of ocean water.

2.1 Waves Waves are actually the energy, not the water as such, which moves across the ocean surface. Water particles only travel in a small circle as a wave passes. Wind provides energy to the waves. Wind causes waves to travel in the ocean and the energy is released on shorelines. The motion of the surface water seldom affects the stagnant deep bottom water of the oceans. As a wave approaches the beach, it slows down. This is due to the friction occurring between the dynamic water and the sea floor and when the depth of water is less than half the wavelength of the wave, the wave breaks. The largest waves are found in the open oceans. Waves continue to grow larger as they move and absorb energy from the wind. A wave’s size and shape reveal its origin. Steep waves are fairly young ones and are probably formed by local wind. Slow and steady waves originate from faraway places, possibly from another hemisphere. The maximum wave height is determined by the strength of the wind, i.e. how long it blows and the area over which it blows in a single direction. 2.1.1 Characteristics of waves Important terms associated with waves are: 

Wave crest and trough: The highest and lowest points of a wave are called the crest and trough respectively.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

     

Wave height: It is the vertical distance from the bottom of a trough to the top of a crest of a wave. Wave amplitude: It is one-half of the wave height. Wave period: It is the time interval between two successive wave crests or troughs as they pass a fixed point. Wavelength: It is the horizontal distance between two successive crests. Wave speed: It is the rate at which the wave moves through the water, and is measured in knots. Wave frequency: It is the number of waves passing a given point during a one second time interval.

2.1.2 Wave Motion Waves travel because wind pushes the water body in its course while gravity pulls the crests of the waves downward. The falling water pushes the former troughs upward, and the wave moves to a new position. The actual motion of the water beneath the waves is circular. It indicates that things are carried up and forward as the wave approaches, and down and back as it passes.

Figure 6. Motion of waves and water molecules

2.2 Tides The periodical rise and fall of the sea level, once or twice a day, mainly due to the attraction of sun and the moon, is called a tide. Movement of water caused by meteorological effects (winds and atmospheric pressure changes) are called surges. Surges are not regular like tides. The study of tides is very complex, spatially and temporally, as it has great variations in frequency, magnitude and height. Causes of Tides 2.2.1 The moon’s gravitational pull to a great extent and to a lesser extent the sun’s gravitational pull, are the major causes for the occurrence of tides. Another factor is centrifugal force, which is the force that acts to counterbalance the gravity. Together, the gravitational pull and the centrifugal force are responsible for creating the two major tidal bulges on the earth.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

Figure 7. Relation between gravitational forces and centrifugal forces The ‘tide-generating’ force is the difference between the gravitational attraction of the moon and the centrifugal force. On the surface of the earth, nearest the moon, pull or the attractive force of the moon is greater than the centrifugal force, and so there is a net force causing a bulge towards the moon. On the opposite side of the earth, the attractive force is less, as it is farther away from the moon, the centrifugal force is dominant. Hence, there is a net force away from the moon. It creates the second bulge away from the moon. 2.2.2 Types of Tides Tides vary in their frequency, direction and movement from place to place and also from time to time. Tides may be grouped into various types based on their frequency of occurrence in one day or based on their height. 2.2.3 Tides based on frequency 1. Semi-diurnal tide: The most common tidal pattern, featuring two high tides and two low tides each day. The successive high or low tides are approximately of the same height. 2. Diurnal tide: There is only one high tide and one low tide during each day. The successive high or low tides are approximately of the same height. 3. Mixed tide: Tides having variations in height are known as mixed tides. These tides generally occur along the west coast of North America and on many islands of the Pacific Ocean.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

2.2.4 Tides based on height The height of rising water (high tide) varies appreciably depending upon the position of sun and moon with respect to the earth: 1. Spring tides: On full moon and new moon days, the Sun, the Moon and the Earth are almost in the same line. On these days, the Sun and the Moon exert their combined gravitational force on the Earth. Thus on these two days the high tides are the highest and are known as spring tides. The height of a spring tide is about 20 per cent more than the normal high tide. They occur twice every month. 2. Neap tides: On half Moon days (i.e. first and last quarter phases of the Moon), the Sun and the Moon are at right angles to the centre of the Earth. The tide producing forces of the Moon and the Sun, work in opposite directions and they partly cancel each other's force. In such cases, the high tide is lower than the normal and low tide is higher than the normal. The difference is about 20 per cent. This is known as the neap tide. 2.2.5 Characteristics of Tides 

Tidal range: The difference between the high tide water and the low tide water is called the tidal range. The time between the high tide and low tide, when the water level is falling, is called the ebb. The time between the low tide and high tide, when the tide is rising, is called the flow or flood. Once in a month, when the moon’s orbit is closest to the earth (perigee), unusually high and low tides occur. During this time the tidal range is greater than normal. Two weeks later, when the moon is farthest from earth (apogee),the moon’s gravitation force is limited and the tidal ranges are less than their average heights. When the earth is closest to the sun (perihelion), around 3rd January each year, tidal ranges are also much greater, with unusually high and unusually low tides. When the earth is farthest from the sun (aphelion), around 4th July each year, tidal ranges are much less than average.



Tidal current: Tidal currents (a horizontal motion) are a result of the rise and fall of the water level due to tides (a vertical motion). The effects of tidal currents on the movement of water in and out of bays and harbours can be substantial. The tidal bulges on wide continental shelves, have greater height. When tidal bulge shit the mid-oceanic islands they become low. The shape of bays and estuaries along a coastline can also magnify the intensity of tides. Funnel-shaped bays greatly change tidal magnitudes. The highest tides in the world occur in the Bay of Fundy in Nova Scotia, Canada. The tidal bulge is 15 - 16 m.



Tidal bore: When the tide enters the narrow and shallow estuary of a river, the front of the tidal wave appears to be vertical due to the piling up of the river water against the tidal wave and the friction of the river bed. It looks as if a vertical wall of water is moving upstream. This is called a tidal bore. In India tidal bores are common in the Hugli River.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

2.2.6 Importance of Tides Since tides are caused by the earth-moon-sun positions which are known accurately, the tides can be predicted well in advance. This helps the navigators and fishermen plan their activities. Some of the important activities associated with tides are: 1. Tidal flows are of great importance in navigation. Tidal heights are very important, especially harbours near rivers and within estuaries having shallow ‘bars’ at the entrance, which prevent ships and boats from entering into the harbour. Large ships enter the harbour of a shallow sea during high tide and they go back also at the time of high tide. London and I have become important ports due to the tidal nature of the mouths of the Thames and Hugli rivers respectively. 2. The river mouths and estuaries are kept clean of sedimentation due to the action of tidal currents. The force of the outgoing tide and the river current carries the silt away to the open sea. This helps in navigation. 3. The tidal force can also be used as a source for generating electricity. A 3 MW tidal power project at Durgaduani in Sunderbans of West Bengal is under way. 4. The inflow of the salty tidal water, especially along the coast of cold countries, retards the process of freezing and prevents the harbours from becoming ice-bound. 5. The fishing industry is helped by the rhythm of high and low tides. The fishermen mostly sail out to the open sea during low tides and return to the coast at high tides.

2.3 Ocean Currents Ocean currents are like river flow in oceans. They represent a regular volume of water in a definite path and direction. 2.3.1 Causes of Ocean Currents Ocean currents are influenced by two types of forces namely:  

Primary forces that initiate the movement of water. Secondary forces that influence the currents to flow.

The forces that influence the currents are: 1. Heating by solar energy causes water to expand. That is why, near the equator the ocean water is about 8 cm higher in level than in the middle latitudes. This causes a very slight gradient and water tends to flow down the slope. There is much difference in the temperature of ocean waters at the equator and at the poles. As warm water is lighter and rises, and cold water is denser and sinks, warm equatorial waters move slowly along the surface polewards, while the heavier cold waters of the polar regions creep slowly along the bottom of the sea equatorwards. 2. Wind blowing on the surface of the ocean pushes the water to move. Friction between the wind and the water surface affects the movement of the water body in its course. Most of the ocean currents of the world follow the direction of the prevailing winds. 3. Coriolis force causes the water to move to the right in the northern hemisphere and to the left in the southern hemisphere. These large accumulations of water and the flow around them are called Gyres. These produce large circular currents in all the ocean basins.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

4. Salinity of ocean water varies from place to place. Waters of high salinity are denser than waters of low salinity. Hence on the surface, waters of low salinity flow towards waters of high salinity while at the bottom, waters of high salinity flow towards waters of low salinity. 5. The configuration of the coastline serves as an obstruction for the natural flow of ocean currents and succeeds in changing its direction. This is quite conspicuous in the equatorial region where the landmasses deflect the current towards the north and the south. 2.3.2 Types of Ocean Currents The ocean currents may be classified based on their depth or temperature. 2.3.3 Currents based on depth 1. Surface currents constitute about10 per cent of all the water in the ocean, these waters are the upper 400 m of the ocean. 2. Deep water currents make up the other 90 per cent of the ocean water. Deep waters sink into the deep ocean basins at high latitudes, where the temperatures are cold enough to cause the density to increase. 2.3.4 Currents based on temperature 1. Cold currents bring coldwater into warm water areas. These currents are usually found on the west coast of the continents in the low and middle latitudes (true in both hemispheres) and on the east coast in the higher latitudes in the Northern Hemisphere. 2. Warm currents bring warm water into cold water areas and are usually observed on the east coast of continents in the low and middle latitudes (true in both hemispheres). In the northern hemisphere they are found on the west coasts of continents in high latitudes. 2.3.5 Characteristics of Ocean Currents The currents are strongest near the surface and may attain speeds over five knots. At depths, currents are generally slow with speeds less than 0.5knots. The speed of a current is known as its drift. Drift is measured in terms of knots. The strength of a current refers to the speed of the current. A fast current is considered strong. A current is usually strongest at the surface and decreases in strength (speed) with depth. Most currents have speeds less than or equal to 5 knots. 2.3.6 Currents of the Atlantic Ocean Major currents of the Atlantic Ocean are: North and South Equatorial Current  

To the north and south of the equator, there are two westward moving currents-the North Equatorial Current and the South Equatorial Current. Due to the rotation of the Earth (Coriolis Effect), these currents move almost due west along the equator.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N



    

The North Equatorial Current moves northwards due to the presence of the South American continent and the Coriolis force, and takes the north-west direction. It enters the Gulf of Mexico to form the Gulf Stream. The South Equatorial Current originates from the western coast of Africa, from where it moves towards South America. The east coast of Brazil obstructs the South Equatorial Current which then bifurcates into two branches. The northward branch merges with the North Equatorial Current, while the second branch flows along the east coast of Brazil and is known as the Brazilian Current. The North Equatorial Current and the South Equatorial Current are warm currents.

Gulf Stream 

   

    

The Gulf Stream is one of the largest warm currents. It originates from the Gulf of Mexico (about 20° N) and moves in a north-easterly direction along the eastern coast of North America. The average speed is about 33 km per day and its average width is about 70 km. Under the impact of the Westerlies, this warm current reaches the western coast of Europe (about 70° N latitude). The general direction of flow of the Gulf Stream, north of 30° N latitude, is northward. Near Newfoundland, its water mixes with the cold water of the Labrador Current, which forms very dense fog. The foggy conditions around Newfoundland hamper the navigation of ships. From here, the Gulf Stream moves northeastwards. This current gradually widens and its speed decreases. It becomes a prominent, slowmoving current known as the North Atlantic Drift. Near Western Europe, it splits into two parts. One part moves northwards, past UK and Norway, while the other part is deflected southwards as the cold Canary Current. The warm water of the Gulf Stream modifies the weather conditions off the eastern coast of North America and the western coast of Europe. On the western coast of Europe, the seaports remain open even in the severe winter season due to the warm water of the Gulf Stream.

Labrador Current      

The cold Labrador Current of the North Atlantic Ocean, has its origin in the Arctic Ocean. This current flows from north to south between Greenland and the Baffin islands. The Labrador Current merges with the Gulf Stream near Newfoundland. This helps in the growth of plankton- a feed for fish. Thus the Grand Banks near Newfoundland have become the ideal fishing ground in the world. The average speed of the Labrador Current is about 25 km per day. This current brings huge icebergs with it from the Arctic Ocean.

Canary Current 

The Canary Current is a cold current and flows along the western coast of Spain and Portugal and the north-west coast of North Africa. .

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

 

The average speed of this current is about 45 km per day. The relative coolness of the Canary Current reduces the relative humidity and thus causes scanty rainfall in the greater parts of the Sahara Desert.

Brazil Current    

The Brazil Current is a warm current and flows southward along the east coast of South America (about 40° S latitude). The average speed of the Brazil Current is about 30 km per day. From 40° S, it is deflected eastwards due to the Earth's rotation and flows in easterly direction. It modifies the weather conditions along the eastern coasts of Brazil and Argentina.

Falkland Current  

The cold waters of the Antarctic Sea flow as Falkland Current from south to north along the eastern coast of South America up to Argentina. The Falkland Current brings huge icebergs from the Antarctic region to the South American coast.

Benguela Current    

The Benguela Current is a cold current which originates in the Antarctic region and flows along the coast of south-west Africa. The Benguela Current helps in reducing the relative humidity of the eastward moving warm and moist air masses. The Kalahari Desert is largely formed under the influence of this current. Further northwards, the Benguela Current merges with the South Equatorial Current.

South Atlantic Drift   

The eastward continuation of the Brazil Current is called the South Atlantic Drift or the West Wind Drift. It develops at about 40° S latitude due to the impact of the Westerlies. The eastward movement is due to the Earth's rotation.

2.3.7 Currents of the Pacific Ocean Major currents of the Pacific Ocean are: North Equatorial Current    

The North Equatorial Current is a warm current which originates off the western coast of Mexico and flows in the westerly direction. It runs parallel to the equator and reaches the islands of Philippines after covering a distance of about 12,000 km. Near Philippines, under the impact of Coriolis force, it turns northwards. One branch of the North Equatorial Current flows northward to join the Kuroshio Current, while the southern branch turns eastwards to form the Counter Equatorial Current.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

South Equatorial Current   

The South Equatorial Current is a warm current which originates due to the influence of South-east Trade winds and flows from east to west. It bifurcates into northern and southern branches near New Guinea. The northern branch turns eastward and joins the Counter Equatorial Current, while the southern branch flows along the north-eastern coast of Australia.

Kuroshio Current 

    

Kuroshio Current is an important warm current, which develops partly due to the Coriolis force and partly due to the obstruction by the Philippines in the flow of the North Equatorial Current. The average velocity is about 30 km per day and the average surface temperature is about 20°C. This current keeps the eastern coast of Japan warm even in the coldest month (January), when it is snowing heavily in Honshu and Hokkaido. A branch of Kuroshio Current enters the Sea of Japan as Tsushima Current and keeps the western coast of Japan comparatively warm. Around 35° N, the Kuroshio current comes under the impact of the Westerlies and flows in the north-east direction to reach the western coast of North America. Further northwards, it is known as the Aleutian Current.

Kurile or Oyashio Current 

 

  

The Kurile or Oyashio Current is a cold current which originates from the Bering Strait and moves southwards along the coast of the Kamchatka peninsula to touch the island of Kurile. It carries with it the cold water and icebergs from the Arctic Ocean to the coast of eastern Russia and Japan. Near 50° N latitude, it is bifurcated into two branches. One of them merges with Kuroshio Current and creates dense fog which is hazardous to navigation, but ideal for abundant growth of plankton. Thus the north-eastern coast of the Japanese islands is an important fishing ground in the world. The second branch moves up to the Japanese coast. The Oyashio Current is comparable to the Labrador Current of the North Atlantic Ocean.

California Current 

 

The California Currents is a cold current which flows southwards along the Pacific coastline of USA, and is comparable to the Canary Current of the Atlantic Ocean in most of its characteristics. After reaching the Mexican coast, it turns westward and merges with the North Equatorial Current. Dense sea fogs are experienced off the coast of San Francisco.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Peru Current   

The Peru Current is a cold current, also known as the Humboldt Current, which flows along the western coast of South America. It flows from south to north along the coast of Peru and is caused by the northward deflection of the West Wind Drift. It affects the coastal climate of Chile and Peru.

East Australian Current 

 

The East Australian Current is a warm current which is the southern branch of the South Equatorial Current, which flows from north to south along the eastern coast of Australia. New Zealand is surrounded by this current. It raises the temperature along the east Australian and the New Zealand coasts for considerable distance southwards.

West Wind Drift    

It is a strong, cold current, flowing from between Tasmania and South American coast. It flows under the influence of the Westerlies and is largely confined between 40° Sand 50° S latitudes. This current becomes very strong due to large volume of water and high velocity winds (Roaring Forties). One of its branch enters the Atlantic Ocean through Cape Hom, and the other branch turns northwards and joins the Peru Current.

Figure 8. Major Ocean currents Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

2.3.8 Currents of the Indian Ocean The ocean currents of the Indian Ocean are largely controlled and modified by the landmasses and the Monsoon winds. The ocean currents of the North Indian Ocean flow under the influence of the north-east and the south-west Monsoon winds. Thus the ocean currents change the direction of flow twice a year. The currents in the southern Indian Ocean follow the general pattern of other oceans and are not affected by the seasonal changes in the direction of Monsoon winds. Major currents of the Indian Ocean are: North-east Monsoon Current  

In the winter season, the north-east Monsoon winds blow from land to ocean and from the northeast to the south-west in the Northern Hemisphere. Under the influence of these winds, the ocean current also flows from the north-east to the southwest.

South-west Monsoon Current 

 

There is a complete reversat in the direction of Monsoon winds during the summer season and they blow from the south-west to the north-east in the Northern Hemisphere. This also reverses the direction of the ocean current. Now the direction of the ocean current also changes from the south-west to the northeast. Two branches of the main current move in the Arabian Sea and the Bay of Bengal.

South Equatorial Current   

The warm South Equatorial Current flows from east to west between 10° Sand 15° S latitudes from the western coast of Australia to the coast of Africa. After being obstructed by the Madagascar Island, this current is divided into many branches. One major branch flows towards the south as the Agulhas Current.

Agulhas Current   

The Agulhas Current is a warm current which is a branch of the South Equatorial Current which flows along the eastern coast of Madagascar. It continues southwards up to about 30° S, where it merges with the Mozambique Current. Around 35° S latitude, it comes under the influence of the Westerlies and flows towards the east.

Mozambique Current  

The Mozambique Current is a warm current which is the northern branch of the South Equatorial Current which enters the Mozambique Channel around 10° S latitude. Moving southwards between Mozambique and Madagascar, it joins the Agulhas Current around 30°S latitude.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

West Wind Drift  

The West Australian Current is a cold current is in the southern part of the Indian Ocean and moves from west to east around 40° S latitude. The West Wind Drift develops under the influence of the Westerlies (Roaring Forties).

West Australian Current   

The West Australian Current is a cold current which flows along the western coast of Australia. This current turns towards west and north-west near the Tropic of Capricorn and finally merges with the South Equatorial Current. The second branch flows to the south of Australia and finally merges with the West Wind Drift in the Pacific Ocean.

2.3.9 Effects of Ocean Currents 









The oceanic circulation transports heat from one latitude belt to another in a manner similar to the heat transported by the general circulation of the atmosphere. The cold waters of the Arctic and Antarctic circles move towards warmer water in tropical and equatorial regions, while the warm waters of the lower latitudes move polewards. West coasts of the continents in tropical and subtropical latitudes (except close to the equator) are bordered by cool waters. Their average temperatures are relatively low with narrow diurnal and annual ranges. There is fog, but generally the areas are arid. West coasts of the continents in the middle and higher latitudes are bordered by warm waters which cause a distinct marine climate. They are characterised by cool summers and relatively mild winters with a narrow annual range of temperatures. Warm currents flow parallel to the east coasts of the continents in tropical and subtropical latitudes. This results in warm and rainy climates. These areas lie in the western margins of the subtropical anti-cyclones. The mixing of warm and cold currents help to replenish the oxygen and favour the growth of planktons, the primary food for fish population. The best fishing grounds of the world exist mainly in these mixing zones.

3] Ocean Resources The ocean is one of Earth's most valuable natural resources. It provides food in the form of fish and shellfish. It's used for transportation—both travel and shipping. It provides a treasured source of recreation for humans. It is mined for minerals and drilled for crude oil. We discuss all these in greater detail below:

3.1 Fishing The oceans have been fished for thousands of years and are an integral part of human society. Fish have been important to the world economy for all of these years. Fisheries of today provide about 16% of the total world's protein with higher percentages occurring in developing nations. Marine fisheries are very important to the economy and well-being of coastal communities, providing food security, job opportunities, income and livelihoods as well as traditional cultural identity. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

The word fisheries refers to all of the fishing activities in the ocean, whether they are to obtain fish for the commercial fishing industry, for recreation or to obtain ornamental fish or fish oil. Fishing activities resulting in fish not used for consumption are called industrial fisheries. Due to the relative abundance of fish on the continental shelf, fisheries are usually marine and not freshwater. 3.1.1 Major Fishing grounds The major commercial fishing grounds are located in the cool waters of the northern hemisphere in comparatively high latitudes. Commercial fishing is little developed in the tropics or in the southern hemisphere. The best fishing grounds are found above continental shelves which are not more than 200 metres below the water surface, where plankton of all kinds are most abundant. The world's most extensive continental shelves are located in high or mid-latitudes in the northern hemisphere, e.g., the banks of Newfoundland, the North Sea and the continental shelf off north-western Europe, and the Sea of Japan. Plankton are in plentiful supply in polar waters, at the meeting of cold and warm ocean currents as on the Newfoundland 'banks' and the Sea of Japan, or where cold water from the ocean floor wells up to the surface as it does off the west coast of South America. The continental shelves of the tropics are relatively less rich in plankton because the water is warm. The amount of fish available in the oceans is an ever-changing number due to the effects of both natural causes and human developments. It will be necessary to manage ocean fisheries in the coming years to make sure the number of fish caught never makes it to zero.

3.2 Climate Buffer Water has a very high specific heat capacity. This means that a lot of energy is needed to increase its temperature (energy is needed to overcome the hydrogen bonds). As the Earth is 71% water, energy from the sun causes only small changes in the planet's temperature. This stops the Earth getting too hot or too cold and makes conditions possible for life. Heat is stored by the ocean in summer and released back to the atmosphere in winter. Oceans, therefore, moderate climate by reducing the temperature differences between seasons. By far the largest carbon store on Earth is in sediments, both on land and in the oceans, and it is held mainly as calcium carbonate. The second biggest store is the deep ocean where carbon occurs mostly as dissolved carbonate and hydrogen carbonate ions. About a third of the carbon dioxide from fossil fuel burning is stored in the oceans and it enters by both physical and biological processes.

3.3 Phytoplankton Phytoplankton accounts for around 90% of the world's oxygen production because water covers about 70% of the Earth and phytoplankton are abundant in the photic zone of the surface layers. Some of the oxygen produced by phytoplankton is absorbed by the ocean, but most flows into the atmosphere where it becomes available for oxygen dependent life forms.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

Student Notes:

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

3.4 Mining The oceans hold a veritable treasure trove of valuable resources. Sand and gravel, oil and gas have been extracted from the sea for many years. In addition, minerals transported by erosion from the continents to the coastal areas are mined from the shallow shelf and beach areas. These include diamonds off the coasts of South Africa and Namibia as well as deposits of tin, titanium and gold along the shores of Africa, Asia and South America. Natural gas and oil have been extracted from the seas for decades, but the ores and mineral deposits on the sea floor have attracted little interest. Yet as resource prices rise, so too does the appeal of ocean mining. 3.4.1 Deep Sea Mining Back in the early 1980s there was great commercial interest in marine mining. This initial euphoria over marine mining led to the International Seabed Authority (ISA) being established in Jamaica, and the United Nations Convention on the Law of the Sea (UNCLOS) being signed in 1982 – the “constitution for the seas”. Since entering into force in 1994, this major convention has formed the basis for signatories’ legal rights to use the marine resources on the sea floor outside national territorial waters. After that, however, the industrial countries lost interest in resources. For one thing, prices dropped making it no longer profitable to retrieve the accretions from the deep sea and utilize the metals they contained. Also, new onshore deposits were discovered, which were cheaper to exploit. The present resurgence of interest is due to:  



The sharp increase in resource prices and attendant rise in profitability of the exploration business. Strong economic growth in countries like China and India which purchase large quantities of metal on world markets. Even the latest economic crisis is not expected to slow this trend for long. The industrial and emerging countries’ geopolitical interests in safeguarding their supplies of resources also play a role. In light of the increasing demand for resources, those countries which have no reserves of their own are seeking to assert extraterritorial claims in the oceans.

3.4.2 Major Deep Sea Minerals The major focus is on manganese nodules, which are usually located at depths below 4000 metres, gas hydrates (located between 350 and 5000 metres), and cobalt crusts along the flanks of undersea mountain ranges (between 1000 and 3000 metres), as well as massive sulphides and the sulphide muds that form in areas of volcanic activity near the plate boundaries, at depths of 500 to 4000 metres. Manganese Nodules Manganese nodules are lumps of minerals covering huge areas of the deep sea with masses of up to 75 kilograms per square metre. Manganese nodules are composed primarily of manganese and iron. The elements of economic interest, including cobalt, copper and nickel, are Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

present in lower concentrations and make up a total of around 3.0 per cent by weight. In addition there are traces of other significant elements such as platinum or tellurium that are important in industry for various high-tech products. These chemical elements are precipitated from seawater or originate in the pore waters of the underlying sediments. The greatest densities of nodules occur off the west coast of Mexico, in the Peru Basin, and the Indian Ocean. Cobalt crusts These crusts accumulate when manganese, iron and a wide array of trace metals dissolved in the water (cobalt, copper, nickel, and platinum) are deposited on the volcanic substrates. The cobalt crusts also contain relatively small amounts of the economically important resources. Extracting cobalt from the ocean is of particular interest because it is found on land in only a few countries (Congo, Zaire, Russia, Australia and China), some of which are politically unstable. Cobalt crusts form at depths of 1000 to 3000 metres on the flanks of submarine volcanoes, and therefore usually occur in regions with high volcanic activity such as the territorial waters around the island states of the South Pacific. Massive Sulphides Sulphur deposits produced from underwater volcanic areas are known as black smokers. These occurrences of massive sulphides form at submarine plate boundaries, where an exchange of heat and elements occurs between rocks in the Earth’s crust and the ocean due to the interaction of volcanic activity with seawater. Cold seawater penetrates through cracks in the sea floor down to depths of several kilometres. Near heat sources such as magma chambers, the seawater is heated to temperatures exceeding 400 degrees Celsius. Upon warming, the water rises rapidly again and is extruded back into the sea. These hydrothermal solutions transport metals dissolved from the rocks and magma, which are then deposited on the sea floor and accumulate in layers. This is how the massive sulphides and the characteristic chimneys (black smokers) are produced. So far only a few massive sulphide occurrences which are of economic interest due to their size and composition are known. While the black smokers along the East Pacific Rise and in the central Atlantic produce sulphides comprising predominantly ironrich sulphur compounds – which are not worth considering for deep-sea mining – the occurrences in the southwest Pacific contain greater amounts of copper, zinc and gold. The largest known sulphide occurrence is located in the Red Sea Here, the sulphides are not associated with black smokers, but appear in the form of iron rich ore muds.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 22

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 9. Distribution of Deep Sea Minerals

3.4.3 Constraints in Deep Sea mining Major problems associated with deep sea mining are: 







The most limiting factors associated with deep-sea marine mining are the political and legal aspects. Legal and political issues surrounding exploration, exploitation, and marketing of sea floor minerals must be resolved. The excavation of marine minerals would considerably disturb parts of the seabed. Huge amounts of sediment, water, and countless organisms would be dug up with the nodules, and the destruction of the deep-sea habitat would be substantial. It is not yet known how, or even whether, repopulation of the excavated areas would occur. Sea floor mining will only be able to compete with the substantial deposits presently available on land if there is sufficient demand and metal prices are correspondingly high. The excavation technology has yet to be developed. There are serious technological difficulties in separating the crusts from the substrate which combined with the problems presented by the uneven sea floor surface further reduce the economic potential of the marine mining.

Despite the challenges, deep sea mining has some potential benefits over terrestrial mining:   

The minerals are often much closer to the surface, so operations have to dig and displace less rock, meaning a smaller footprint and fewer carbon emissions. Seabed mining infrastructure is both moveable and reusable, unlike roads and buildings often left behind at abandoned mines on land. And no residents will be directly displaced by mining.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 23

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

4] UPSC questions related to above topics 1. ‘Temperature, salinity and density differences in ocean water are the prime causes of ocean water circulation.’ Elaborate. (Geography Mains – 2011, 30 marks) 2. Write short notes on ocean deposits. (Geography Mains – 2010, 15 marks) 3. Write short notes on Ocean Currents of the North Atlantic Ocean.(Geography Mains2007, 200 words) 4. Present a concise account of bottom relief of the Indian Ocean. (Geography Mains 2003) 5. Give a reasoned account of the distribution of salinity in the oceans and partially enclosed seas. (Geography Mains 1994) 6. Discuss the features of Gulf Stream. (IFoS-2011) 7. The major fishing grounds of the world are located in areas where cool and warm currents converge. Discuss. (IFoS-2011) 8. Give an account of oceanic mineral resources. (IFoS-2010) 9. List the processes that initiate ocean currents and influence their speed and direction. (IFoS-2009) 10. Distinguish between continental crust and continental rise. (IFoS – 2009) 11. What are ocean currents? State the uses of ocean currents. (IFoS – 2005)

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 24

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 13

CORAL REEFS AND INDIAN OCEAN

Contents: 1. Coral Reefs 1.1 Corals 1.1.1 Types of Corals 1.2 Zooxanthellae 1.3 Coral Formation and Types 2. Conditions needed for growth of Coral Reefs 2.1 Location of Coral Reefs 2.2 Importance of Coral Ecosystems 2.3 Threats to Coral Reefs 2.3.1 Climate Change 2.3.2 Unsustainable Fishing 2.3.3 Pollution 2.4 Coral Reefs in India 3. Indian Ocean 3.1 Significance of Indian Ocean for India 4. UPSC questions related to above topics

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

1] Coral Reefs Coral reefs are some of the most diverse ecosystems in the world. Thousands of species rely on reefs for survival. Thousands of communities all over the world also depend on coral reefs for food, protection and jobs. A reef is a strip or ridge of rocks, sand, or coral that rises to or near the surface of a body of water. The best-known reefs are the coral reefs developed through biotic processes dominated by corals and calcareous algae.

1.1 Corals Corals are animals, even though they may exhibit some of the characteristics of plants and are often mistaken for rocks. Corals can exist as individual polyps (a small sea animal that has a body shaped like a tube), or in colonies and communities that contain hundreds to hundreds of thousands of polyps. Corals are found throughout the oceans, from deep, cold waters to shallow, tropical waters. 1.1.1 Types of Corals Corals are classified as under: 1. Hard Corals: Hard corals, also known as stony corals, produce a rigid skeleton made of calcium carbonate in crystal form called aragonite. Hard corals are the primary reefbuilding corals. Hard corals consisting of hundreds to hundreds of thousands of individual polyps are cemented together by the calcium carbonate 'skeletons' they secrete. Living coral grow on top of the skeletons of their dead predecessors. Hard corals that form reefs are called hermatypiccoral. 2. Soft Corals: Soft coral, also known ahermatypic coral, do not produce a rigid calcium carbonate skeleton and do not form reefs, though they may be present in a reef ecosystem. Soft corals are also mostly colonial i.e. what appears to be a single large organism is actually a colony of individual polyps combined to form a larger structure. Soft coral colonies tend to resemble trees, bushes, fans, whips, and grasses.

1.2 Zooxanthellae Most reef-building corals contain photosynthetic algae, called zooxanthellae, that live in their tissues. The corals and algae have a mutualistic relationship. The coral provides the algae with a protected environment and compounds they need for photosynthesis. In return, the algae produce oxygen and help the coral to remove wastes. Zooxanthellae supply the coral with glucose, glycerol, and amino acids, which are the products of photosynthesis. The coral uses these products to make proteins, fats, and carbohydrates, and produce calcium carbonate. This is the driving force behind the growth and productivity of coral reefs. In addition to providing corals with essential nutrients, zooxanthellae are responsible for the unique and beautiful colors of many stony corals. Sometimes when corals become physically stressed, the polyps expel their algal cells and the colony takes on a stark white appearance. This is commonly described as coral bleaching. If the polyps go for too long without zooxanthellae, coral bleaching can result in the coral's death. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

1.3 Coral Formation and Types Coral reefs begin to form when free-swimming coral larvae attach to submerged rocks or other hard surfaces along the edges of islands or continents. As the corals grow and expand, reefs take on one of three major characteristic structures: Fringing reefs, which are the most common, project seaward directly from the shore, forming borders along the shoreline and surrounding islands. Barrier reefs also border shorelines, but at a greater distance. They are separated from their adjacent land mass by a lagoon of open, often deep water. An atoll forms if a fringing reef forms around a volcanic island that subsides completely below sea level while the coral continues to grow upward. Atolls are usually circular or oval, with a central lagoon.

  

Figure 1. Types of Coral Reefs

2] Conditions needed for growth of Coral Reefs Corals are found throughout the oceans, from deep, cold waters to shallow, tropical waters. Conditions favourable to growth of corals reefs can be discussed as under: 1. Shallow coral reefs grow best in warm water (70–85° F or 21–29° C). It is possible for soft corals to grow in places with warmer or colder water, but growth rates in these types of conditions are very slow. 2. Reef-building corals prefer clear and shallow water, where lots of sunlight filters through to their symbiotic algae. The most prolific reefs occupy depths of 18–27 m. 3. Corals also need salt water to survive, so they also grow poorly near river openings with fresh water runoff. 4. Other factors influencing coral distribution are availability of hard-bottom substrate and the availability of food such as plankton. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

2.1 Location of Coral Reefs Coral reefs develop in shallow, warm water, usually near land, and mostly in the tropics. There are coral reefs off the eastern coast of Africa, off the southern coast of India, in the Red Sea, and off the coasts of northeast and northwest Australia and on to Polynesia. There are also coral reefs off the coast of Florida, USA, to the Caribbean, and down to Brazil. The Great Barrier Reef (off the coast of NE Australia) is the largest coral reef in the world. It is over 2000 km long.

Figure 2. Global distribution of Coral Reefs

2.2 Importance of Coral Ecosystems Coral reefs are some of the most diverse and valuable ecosystems on Earth. Coral reefs support more species per unit area than any other marine environment, including about 4,000 species of fish, 800 species of hard corals and hundreds of other species. They are often referred to as the Rainforests of the Sea. Healthy coral reefs have rough surfaces and complex structures that dissipate much of the force of incoming waves. This buffers shorelines from currents, waves, and storms, helping to prevent loss of life, property damage, and erosion. Reefs are also a source of sand in natural beach replenishment. Being storehouses of immense biological wealth, reefs also provide economic and environmental services to millions of people. Healthy reefs contribute to local economies through tourism. Diving tours, fishing trips, hotels, restaurants, and other businesses based near reef systems provide millions of jobs and contribute billions of dollars all over the world. Coral reefs serve as habitat for many commercially important species targeted for fishing. Coral ecosystems have proven to be beneficial for humans through the identification of potentially beneficial chemical compounds and through the development of medicines, both derived from organisms found in coral ecosystems. Many drugs are now being developed from coral reef animals and plants as possible cures for cancer, arthritis, human bacterial infections, viruses, and other diseases.









Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

N

Student Notes:

2.3 Threats to Coral Reefs An estimated 20 per cent of the world’s reefs are damaged beyond recovery and about half of the remaining coral reefs are under risk of collapse. The top threats to coral reefs are: 2.3.1 Climate Change Climate change impacts have been identified as one of the greatest global threats to coral reef ecosystems. As temperature rise, mass bleaching, and infectious disease outbreaks are likely to become more frequent. Additionally, carbon dioxide absorbed into the ocean from the atmosphere has already begun to reduce calcification rates in reef-building and reef-associated organisms by altering sea water chemistry through decreases in pH (ocean acidification). In the long term, failure to address carbon emissions and the resultant impacts of rising temperatures and ocean acidification could make many other coral ecosystem management efforts futile. 2.3.2 Unsustainable Fishing Coral reefs and associated habitats provide important commercial, recreational and subsistence fishery resources. But coral reef fisheries, though often relatively small in scale, may have disproportionately large impacts on the ecosystem if conducted unsustainably. Rapid human population growth, demand for fishery resources, use of more efficient fishery technologies, and inadequate management and enforcement have led to the depletion of key reef species and habitat damage in many locations. 2.3.3 Pollution Impacts from land-based sources of pollution (e.g. agriculture, deforestation, storm water, coastal development, road construction, and oil and chemical spills) on coral reef ecosystems include increased sedimentation, nutrients, toxins, and pathogen introduction. These pollutants and related synergistic effects can cause disease and mortality in sensitive species, disrupt critical ecological functions, cause trophic structure and dynamics changes (i.e. eutrophic conditions), and impede growth, reproduction, and larval settlement. These threats—combined with other threats like coral disease; tropical storms; tourism and recreation; vessel damage; marine debris, and aquatic invasive species—compound upon each other, making conservation efforts more difficult.

2.3 Coral Reefs in India The coral reef ecosystems are found in four regions of India which are: Region

Type of Reef

Andaman & Nicobar Islands Gulf of Mannar (Tamil Nadu) Gulf of Kutchh (Gujarat) Lakshadweep Islands

Fringing Reefs Fringing Reefs Fringing Reefs Atolls

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

Figure 3. Coral Reefs of India There are no coral reefs on the central east and west coasts of India. The conditions here, especially salinity and high sediment load, are not ideal for coral growth. Most major rivers of India, like the Ganges, flow into the sea on the east coast, bringing in lots of sediments that would not allow the corals to grow. On the west coast, the monsoon is intense from June to August. The fresh water flow into the sea at this time reduces salinity to less than half of the normal and the sea water becomes murky brownish with the sediments. The Indian coral reefs are world famous but least explored, studied and utilised. On the other hand, they are indiscriminately damaged by human exploitation mainly for the cement industry (calcium carbide), road and building material in certain areas like the Gulf of Mannar and the Gulf of Kutch. The other two regions, the Andaman and Nicobar Islands and the Lakshadweep, because of their far-flung location from the mainland, are comparatively less affected by human depredations.

3] Indian Ocean The Indian Ocean is the third largest of the world's oceanic divisions, covering approximately 20% of the water on the Earth's surface. It is bounded by Asia—including India, after which the ocean is named on the north, on the west by Africa, on the east by Australia, and on the south by the Southern Ocean. As one component of the World Ocean, the Indian Ocean is delineated from the Atlantic Ocean by the 20° east meridian running south from Cape Agulhas (South Africa), and from the Pacific Ocean by the meridian of 146°55' east. The northernmost extent of the Indian Ocean is approximately 30° north in the Persian Gulf. The ocean is nearly 10000 km wide at the southern tips of Africa and Australia, and its area is 73556000 km² including the Red Sea and the Persian Gulf. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Island nations within the ocean are Madagascar, Comoros, Seychelles, Maldives, Mauritius, and Sri Lanka. The archipelago of Indonesia borders the ocean on the east.

Figure 4. Geography of Indian Ocean

3.1 Significance of Indian Ocean for India Significance of Indian Ocean for India can be discussed under following heads: 1. Geopolitical Significance: The Indian Ocean Region (IOR), comprising the ocean and its littorals, is India’s regional or immediate geo-strategic environment. It exists on the fringes of our boundaries and has a significant impact on the internal state of affairs.Indian Ocean defines the Indian Navy’s primary Area of Maritime Interest, where it seek to address the challenges having a bearing on national security and the nation’s overall socio-economic development. With substantial economic activity, including 90% trade by volume and bulk of our energy imports, happening over the sea, maritime security is central to overall development of our nation. Concurrently, India cannot hope to develop and grow peacefully with an unstable and turbulent neighbourhood. Prevalence of peace in the Indian Ocean Region is therefore a key national security imperative. Riding on the benefits of globalisation, littorals of the IOR are now re-emerging to achieve their original potential. The emergence of many regional countries, as economic powerhouses, reflects this reality. Consequently, several regional economic groupings such as ASEAN, BIMSTEC, SAARC, IOR-ARC, GCC and few others have evolved over time in the IOR to harness the advantages of economic integration. India’s geo-strategic location positions us right at the confluence of major arteries of world trade. The Indian Navy is therefore viewed by some of the littorals as a suitable agency to facilitate regional maritime security in the IOR as a net security provider. India’s standing as a benign power provides credence to this perception, making us a preferred partner for regional security. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Economic security is central to the comprehensive approach to security. In this globalised world, the Indian economy is integrated with, and consequently interdependent on other world economies. The prospect of disruption of trade at critical chokepoints, such as the Strait of Hormuz or Malacca, can be catastrophic for the global economy. The downstream effects of such economic upheaval are certainly disastrous for regional peace. Maintaining unimpeded flow of energy and other commodities over the sea is therefore a prime concern for all nations, including ours. Maritime terrorism is another grave challenge. The events of 26/11 brought to fore the porosity of our long coastline and its resultant vulnerability to terror attacks perpetrated from the sea. Moreover, the prospect of terror attacks on off-shore infrastructure and sea-borne traffic, close to the coast, puts a premium on ensuring coastal security. Consequent to government directives, the Navy is now responsible for overall maritime security of the country, including the coast. The region’s natural bounties and maritime trade carried over its sea lanes drive the global economy. The fact that two-thirds of the world’s oil shipments, one-third of its bulk cargo and half of the container traffic transit over its sea lanes, and through its choke points, a large part of which is meant for countries outside the region, underscores the Indian Ocean’s importance for the world at large. In conclusion, maintenance of a peaceful maritime environment is an imperative, for our nation and the region, to sustain our growth trajectories and to achieve our national aspirations. The oceans are vast, challenges too many, and resources limited, for any individual state to assure security of the global commons. This, therefore, calls for a cooperative approach. By virtue of India’s geo-strategic location in the Indian Ocean and her maritime capabilities, the Indian Navy is deemed by many to be the net security provider in the IOR. 2. Economic Significance: Economic importance of the Indian Ocean is immense. It can be discussed on the following points: a. About 30% of world trade is handled in the ports of the Indian Ocean. b. Half of the world’s container traffic passes through Indian Ocean. c. Continental shelves cover about 4.2% of the total area of the Indian Ocean and are reported to be very Rich in minerals including Tin, Gold, Uranium, Cobalt, Nickel, Aluminium and Cadmium although these resources have been largely not exploited, so far. d. 40 out of 54 types of raw materials used by U.S. industry are supplied by the Indian Ocean. e. Several of the world’s top container ports, including Port Kelang and Singapore, are located in Indian Ocean as well as some of the world’s fastest growing and busiest ports. f. Indian Ocean possesses some of the world’s largest fishing grounds, providing approximately 15%of the total world’s fish catch (approximately 9 million tons per annum). g. 55% of known world oil reserves are present in Indian Ocean. h. 40% of the world’s natural gas reserves are in Indian Ocean littoral states.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

Student Notes:

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

N

Student Notes:

4] UPSC questions related to above topics 1. What is the importance of Indian Ocean for India?(UPSC 1999/15 Marks) 2. Mention the advantages which India enjoys being at the end of the Indian Ocean. (UPSC 1996/15 Marks) 3. Describe the ideal conditions for coral reef formation. (Geography Mains 2008) 4. Write short note on formation of coral reefs. (Geography Mains 2001/200 words) 5. Write short note on coral reefs. (Geography Mains 1988/200 words) 6. Examine economic significance of the resources of the Continental Shelf of the Indian Ocean. (Geography Mains 2009/30 marks) 7. Assess the geographical significance of Indian Ocean. (Geography Mains 2008/200 words) 8. Analyse the role of India in the geo-politics of the Indian Ocean Region. (Geography Mains 2003,2000/200 words) 9. Discuss the geopolitical importance of Indian Ocean area. (Geography Mains 1999/200 words)

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 14

GEOGRAPHY (10)

Contents: 1

Introduction 1.1

2

Factors Determining the Climate of India 2.1 2.2 2.3 2.4

3

Salient Features of Indian Climate

Factors Related to Location and Relief Factors Related to Air Pressure and Wind Weather Conditions in Winter Weather Conditions in the Summer Season

Indian Monsoon 3.1 Thermal Concept 3.2 Recent Concept about the Origin of Indian Monsoon 3.2.1 Role of Himalayas and Tibetan Plateau 3.2.2 Role of Jet Stream 3.2.3 Role of ENSO 3.2.4 Walker Cell 3.2.5 Indian Ocean Dipole 3.3 Nature of Indian Monsoon 3.4 Onset and Advance of Monsoon 3.5 Rain Bearing Systems and Distribution of Rainfall 3.6 Break in the Monsoon 3.7 Retreat of Monsoon 3.8 Features of Monsoon Rainfall 3.9 Monsoons and the Economic Life in India

4

Seasons 4.1

Traditional Indian Seasons

5

Distribution of Annual Rainfall

6

Variability of Annual Rainfall

7

Climatic Regions of India

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

1] Introduction Climate is an important element of the physical environment of mankind. It is the aggregate of atmospheric conditions involving heat, moisture and air movement. In a developing country like India climatic characteristics have a dominant role in affecting the economic pattern, way of life, mode of living, food preferences, costumes and even the behavioural responses of the people. In India despite a lot of scientific and technological developments our dependence on monsoon rainfall for carrying out successful agricultural activities, has not been minimized. The climate of India belongs to the ‘tropical monsoon type’ indicating the impact of its location in tropical belt and the monsoon winds. Although a sizeable part of the country lying north of the Tropic of Cancer falls in the northern temperate zone but the shutting effects of the Himalayas and the existence of the Indian Ocean in the south have played significant role in giving India a distinctive climatic characteristics. 1.1 Salient Features of Indian Climate Following are the salient features of the Indian climate: Reversal of winds – the Indian climate is characterized by the complete reversal of wind system with the change of season in a year. During the winter season winds generally blow from north-east to south-west in the direction of trade winds. These winds are dry, devoid of moisture and are characterized by low temperature and high pressure conditions over the country. During summer season complete reversal in the direction of the winds is observed and these blow primarily from south-west to north-east. Formation of Alternatively High and Low pressure areas over the land – there is a change in the atmosphere pressure conditions with the change of season. During winter season due to low temperature conditions high pressure areas is formed over the northern part of the country. On the other hand the intense heating of the land during summer season leads to the formation of a thermally induced low pressure cell over the north-western part of the country. These pressure areas control the direction and intensity of wind. Seasonal and variable rainfall – In India over 80 per cent of annual rainfall is obtained in the latter part of the summer whose duration ranges from 1-5 months in different parts of the country. Since the rainfall is in the form of heavy downpour, it creates problems of floods and soil erosion. Sometimes there is continuous rain for many days and sometimes there is a long spell of dry period. Similarly, there is a spatial variation in the general distribution of rainfall. Cherrapunji has received in a single day an amount equal to 10 years of rainfall at Jaisalmer, Rajasthan.







In fact Indian climate is so varied and complex that it denotes climatic extremes and climatic varieties. While it provides enough heat to grow crops and carry on agricultural activities all over the country it also helps in the cultivation of a number of crops belonging to tropical, temperate as well as frigid1 areas.

1

The Polar Regions have a very cold climate. These places are sometimes called the Frigid Zones.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Plurality of seasons – the Indian climate is characterized by constantly changing weather conditions. There are three main seasons but on broader consideration their number goes to six a year (winter, fall of winter, spring, summer, rainy and autumn). Unity of Indian Climate – the Himalayas and the associated mountain ranges extend to the north of India from east to west. These tall mountain ranges prevent the cold northerly winds of Central Asia from entering into India. Therefore, even the parts of India extending north of the Tropic of Cancer experience a tropical climate. These ranges force the monsoon winds to cause rainfall over India and the entire country comes under the influence of the monsoon winds. In this manner the climate in the entire country becomes monsoon type. Diversity of Indian Climate – In spite of the unity of Indian climate, it is characterized by regional differences and variations. For example, while in the summer the mercury occasionally touches 55°C in the western Rajasthan, it drops down to as low as minus 45°C in winter around Leh. These differences are visible in terms of winds, temperature, rainfall, humidity and aridity etc. These are caused by differences in the location, altitude, distance from the sea, distance from mountains and general relief conditions at difference places. Characterized by natural calamities – Due to its peculiar weather conditions especially rainfall the Indian climate is characterized by natural calamities like floods, droughts, famines and even epidemics.









2] Factors Determining the Climate of India India’s climate is controlled by a number of factors which can be broadly divided into two groups – Factors related to Location and Relief Factors related to air pressure and winds

 

2.1 Factors Related to Location and Relief Latitude - the Tropic of Cancer passes through the central part of India in east-west direction. Thus, northern part of the India lies in sub-tropical and temperate zone and the part lying south of the Tropic of Cancer falls in the tropical zone. The tropical zone being nearer to the equator, experiences high temperatures throughout the year with small daily and annual range. Area north of the Tropic of Cancer being away from the equator, experiences extreme climate with high daily and annual range of temperature. The Himalayan Mountains – as already discussed, the lofty Himalayas in the north along with its extensions act as an effective climatic divide between central Asia and Indian subcontinent. The cold and chilly winds that originate near the Arctic Circle are obstructed by the Himalayas and give a distinctive taste to climate of India. Distribution of Land and Water – India is flanked by the Indian Ocean on three sides in the south and girdled by a high and continuous mountain-wall in the north. As







Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

compared to the landmass, water heats up or cools down slowly. This differential heating of land and sea creates different air pressure zones in different seasons in and around the Indian subcontinent. Distances from the Sea – With a long coastline, large coastal areas have an equable climate. Areas in the interior of India are far away from the moderating influence of the sea. Such areas have extremes of climate. That is why, the people of the Konkan coast have hardly any idea of extremes of temperature and the seasonal rhythm of weather. On the other hand, the seasonal contrasts in weather at places in the interior of the country such as Kanpur and Amritsar affect the entire sphere of life. Altitude – Temperature decreases with height. Due to thin air, places in the mountains are cooler than places on the plains2. For example, Agra and Darjiling are located on the same latitude, but temperature of January in Agra is 16°C whereas it is only 4°C in Darjiling. Relief – The physiography or relief of India also affects the temperature, air pressure, direction and speed of wind and the amount and distribution of rainfall. The windward sides of Western Ghats and Assam receive high rainfall during June-September whereas the southern plateau remains dry due to its leeward situation along the Western Ghats.







2.2 Factors Related to Air Pressure and Wind Air pressure and wind system is different at different altitude which affects the local climates of India. Consider the following factors: Distribution of pressure and surface winds. Upper air circulation and the movement of different air masses and the jet stream. Rainfall caused by the westerly disturbances in winter and the tropical depressions in south-west monsoon season.

  

The mechanism of these three factors can be understood with reference to winter and summer seasons of the year separately.

2.3 Weather Conditions in Water Surface Pressure and Winds – During northern hemisphere’s winter, high pressure is built up in the Central and West Asia. This centre of high pressure gives rise to the flow of air at the low level from the north towards the Indian subcontinent, south of the Himalayan mountain range, in the form of a dry continental air mass. These continental winds come in contact with trade winds over northwestern India. The contact zone is not stable and sometimes it shifts up to the middle Ganga valley thus bringing the entire north-western India under the influence of the north-westerly winds.



2

Thin air=> low pressure=> low temperature

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Figure 1 – Winter Monsoon: Surface Winds Jet stream and Upper Air Circulation – a different pattern of air circulation is observed at a height of about 3 km above the surface. Direction and velocity of winds at this height are different from those of the surface winds. All of Western and Central Asia remains under the influence of westerly winds along the altitude of 9-13 km from west to east (Figure 2). These winds blow across the Asian continent at latitudes north of the Himalayas roughly parallel to the Tibetan highlands. These are known as Jet Streams3. Tibetan highlands act as a barrier in the path of these jet streams. As a result, jet streams gets bifurcate – one to the south and other to the north of this mountain chain along 25° N latitude. This jet stream is responsible for bringing western disturbances4 from the Mediterranean region into Indian sub-continent. Winter rain and hail storms in northwestern plains and occasional heavy snowfall in hilly regions are caused by these disturbances.



Figure 2 - Direction of Winds in India in winter at the Height of 9-13 km

3

For more details about jet stream, See document “INSOLATION, EARTH’S HEAT BALANCE, DIFFERENT ATMOSPHERIC…” 4 For more details about extra-tropical cyclones (known as western disturbances in Indian subcontinent), See document “INSOLATION, EARTH’S HEAT BALANCE, DIFFERENT ATMOSPHERIC…”

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Western Cyclonic Disturbance and Tropical Cyclones – The western cyclonic disturbances which enter the Indian subcontinent from the west and the northwest during the winter months originate over the Mediterranean Sea and are brought into India by the westerly jet stream. An increase in the prevailing night temperature generally indicates an advance in the arrival of these cyclones disturbances. It brings little rain in winter months. This rain is considered to be very good for wheat crops in northern plains.



Tropical cyclones originate over the Bay of Bengal and the Indian Ocean. These tropical cyclones have very high wind velocity and heavy rainfall and hit the Tamil Nadu, Andhra Pradesh and Orissa coast. Most of these cyclones are very destructive due to high wind velocity and torrential rain that accompanies it.

2.4 Weather Conditions in the Summer Reason Surface Pressure and Winds - As the summer sets in and the sun shifts northwards, the wind circulation over the subcontinent undergoes a complete reversal at both, the lower as well as the upper levels. By the middle of July, the low pressure belt nearer the surface, termed as Inter Tropical Convergence Zone (ITCZ), shifts northwards, roughly parallel to the Himalayas between 20° N and 25° N (Figure 3). It extends from Punjab to the Chota Nagpur plateau. By this time, the westerly jet stream withdraws from the Indian region. There is a cause and effect relationship between the northward shift of the ITCZ and the withdrawal of the westerly jet stream from over the North Indian Plain.



Being an area of low pressure, the ITCZ attracts winds from all around. The maritime tropical airmass (mT) from the southern hemisphere, after crossing the equator, rushes to the low pressure area in the general southwesterly direction (Figure 4). These winds cross the Equator between 40°E and 60°E longitudes. Blowing over the ocean for a long distance, they pick up a large amount of moisture. It is this moist air current which is popularly known as the southwest monsoon.

Figure 3 – position of Inter-tropical Convergence Zone (ITCZ) in the month of January and July

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Figure 4 – summer monsoon winds: Surface circulation Jet Streams and Upper Air Circulation – at the upper layers of the troposphere, the winds blow in a direction reverse to that of the surface winds. An easterly jet stream flows over the southern part of the Peninsula in June, and has a maximum speed of 90 km per hour (Figure 5). In August, it is confined to 15o N latitude, and in September up to 22o N latitudes.



Figure 5 – The direction of winds at upper atmosphere in summer season Tropical cyclones – The easterly jet stream steers the tropical depressions into India. These depressions play a significant role in the distribution of monsoon rainfall over the Indian subcontinent. The tracks of these depressions are the areas of highest rainfall in



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

India. Their frequency, direction and intensity determine the rainfall pattern during the southwest monsoon period.

3] Indian Monsoon We already know that India’s climate is ‘tropical monsoon’ type. The word ‘monsoon’ has been derived from the Arabic word ‘Mausim’ which means ‘season’. Originally, this word was used by Arab traders to describe a system of seasonal reversal of winds along the shores of the Indian Ocean. Monsoons are especially prominent within the tropics on the eastern sides of the great landmass, but in Asia, it occurs outside the tropics in China, Korea and Japan. Monsoon is a complex meteorological phenomenon. Experts of meteorology have developed a number of concepts about the origin of the monsoon. Some of the important concepts about the origin of monsoon have been given as under.

3.1 Thermal Concept Halley, a noted astronomer, hypothesized that the primary cause of the annual cycle of the Indian monsoon circulation was the differential heating effects of the land and the sea. According to this concept monsoon are the extended land breeze and sea breeze on a large scale. During winter the huge landmass of Asia cools more rapidly than the surrounding oceans with the result that a strong high pressure centre develops over the continent. On the other hand, the pressure over adjacent oceans is relatively lower. As a consequence the pressuregradient directed from land to sea. Therefore there is an outflow of air from the continental landmass towards the adjacent oceans so that it brings cold, dry air towards the low latitudes. In summer the temperature and pressure conditions are reversed. Now, the huge landmass of Asia heats quickly and develops a strong low pressure centre. Moreover, the pole-ward shift of the Inter-tropical Convergence Zone (ITCZ) to a position over Southern Asia reinforces the thermally induced low pressure centre. The pressure over the adjacent oceans being high, a sea-to-land pressure gradient is established. The surface air flow is, therefore, from the highs over the oceans towards the lows over the heated land. The air that is attracted into the centers of low pressure from over the oceans is warm and moist. Halley’s concept is criticized on following lines: 

It fails to explain the intricacies of monsoon such as sudden burst of monsoon, breaks in monsoon, spatial and temporal distribution of monsoon.



The low pressure areas are not stationary. The rainfall is not only convectional but a mix of orographic, cyclonic and convectional rainfall.

3.2 Recent Concept about the Origin of Indian Monsoon After world war second, the upper atmospheric circulation has been studied significantly. It is now believed that the differential heating of sea and land alone can’t produce the monsoon circulation. Apart from it, recent concept of monsoon rely heavily on the role of Himalayas and Tibetan plateau as a physical barrier and a source of high-level heat. Circulation of upper air jet streams in the troposphere.

 

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Existence of upper air circum-polar whirl over north and south poles in the troposphere. The occurrence of ENSO (El-Nino and Southern Oscillation) in the South Pacific ocean Walker cell in Indian Ocean. Indian Ocean Dipole

   

3.2.1 Role of Himalayas and Tibetan Plateau In 1970s, it was found that Tibet plateau plays a crucial role in initiating the monsoon circulation. The plateau of Tibet extends over an area of about 4.5 million sq. km. The average height of these highlands is 4000 m. Due to its enormous height it receives 2-3oC more insolation than the neighbouring areas. Heating of these areas leads to a clockwise air circulation in the middle troposphere and two-wind streams originate from this area. One of these wind streams blow southward and develops into the tropical easterly jet stream (TEJ). The other stream blows in an opposite direction towards the North Pole and becomes the westerly jet stream over Central Asia.

Figure 6 – Tibet anti-cyclone and Easterly Jet stream 3.2.2 Role of Jet Stream As already discussed, sub-tropical westerly jet stream is bifurcated by the high-land Tibet in winters. Northward branch extends up to 20oN-35oN (Figure 6). Tropical easterly jet stream (TEJ), that branch off from anticyclone developed over Tibet, sometimes reaches to the tip of Peninsular India. Apart from this, Jet speed winds are also reported over other parts of Peninsular. This jet descends over the Indian Ocean and intensifies its high pressure cell known as Mascarene High. It is from this high pressure cell that the onshore winds start blowing towards the thermally induced low pressure area, developed in the northern part of the Indian Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

subcontinent. After crossing the equator such winds become south-westerly and are known as the south-westerly summer monsoon. 3.2.3 Role of ENSO The Indian monsoon is also influenced by EL-Nino, southern oscillation and Somalian current. We know that El Nino is the reversal of normal condition in the Pacific Ocean’s sea surface temperature. Though there is no direct correlation between bad monsoon and El Nino, but both are generally associated. There are years when India faced severe drought and those are not El Nino years and vice-versa. Southern Oscillation is the see-saw pattern of atmospheric pressure between the eastern and western Pacific Ocean. The oscillation has a period varying from 2-7 years. It is measured with Southern Oscillation Index (SOI) by measuring pressure difference between two points in Pacific Ocean (Tahiti and Darwin). A negative value of SOI implies high pressure over north Indian Ocean during the winter season and a poor monsoon. The Somalian current changes its direction of flow after every six months. During the NorthEast Monsoon the Somali Current flows to the south-west, while during the South-West Monsoon it is a major western boundary current, comparable with the Gulf Stream (Figure 7). Normally, there remains a low pressure area along the eastern coast of Somalia. In exceptional years, after every six or seven years, the low pressure area in western Arabian Sea becomes a high pressure area. Such a pressure reversal results into a weaker monsoon in India.

Figure 7 – Somali current 3.2.4 Walker Cell It is observed that there is an east-west atmospheric circulation over the tropical oceanic regions. Such circulation in Pacific Ocean is generally called walker cell. However, many scientists use the term ‘walker cell’ for all east-west circulations in different oceans. Walker cell is associated with southern oscillation and its strength fluctuates with that of Southern Oscillation Index (SOI). With a high positive SOI, there would be a zone of low atmospheric pressure over Australia and Indonesian archipelago. The rising air from this region deflects in upper atmosphere in both directions towards Africa and South America. In Indian Ocean, the air descends down at high pressure zone from where surface winds blow as Southwest monsoon towards Indian sub-continent in summers. During La-Nina Indian ocean branch of walker cell get strengthen and surface winds are more intense. La-Nina condition is generally associated with good monsoon. During appearance of El-Nino or negative SOI, the ascending branch of the walker cell shifts to the central regions of the Pacific Ocean from west pacific region (Figure 8). In result, the Indian Ocean cell shifts towards east. The surface winds or Southwest monsoon winds are weaker than normal conditions.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Figure 8 – walker cell and Indian Monsoon 3.2.5 Indian Ocean Dipole The Indian Ocean Dipole (IOD) also known as the Indian Nino is a coupled Ocean-atmosphere phenomenon in the Indian Ocean. It is defined by the difference in sea surface temperature between two areas (or poles, hence a dipole) – a western pole in the Arabian Sea (western Indian Ocean) and an eastern pole in the eastern Indian Ocean south of Indonesia. The IOD involves a periodic oscillation of sea-surface temperatures (SST), between "positive", "neutral" and "negative" phases. A positive phase sees greater-than-average sea-surface temperatures and greater precipitation in the western Indian Ocean region, with a corresponding cooling of waters in the eastern Indian Ocean—which tends to cause droughts in adjacent land areas of Indonesia and Australia (Figure 9). The negative phase of the IOD brings about the opposite conditions, with warmer water and greater precipitation in the eastern Indian Ocean, and cooler and drier conditions in the west.

Figure 9 – Indian Ocean Dipole Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

The IOD is one aspect of the general cycle of global climate, interacting with similar phenomena like the El Niño-Southern Oscillation (ENSO) in the Pacific Ocean. Positive and negative IOD both has been seen coupled with La Nina. Thus, there is no direct correlation between IOD and ENSO. The IOD also affects the strength of monsoons over the Indian subcontinent. Positive IOD which is associated with warm sea-surface temperatures of western Indian Ocean is favourable for monsoon in Indian subcontinent.

3.3 Nature of Indian Monsoon Systematic studies of the causes of rainfall in the South Asian region help to understand the salient features of the monsoon, particularly some of its important aspects, such as:    

Onset and advance of monsoon Rain-bearing systems and the relationship between their frequency and distribution of monsoon rainfall. Break in the monsoon retreat of the monsoon

3.4 Onset and Advance of Monsoon The differential heating of land and sea is still believed to be the primary cause of the monsoon by many meteorologists. Low pressure at ITCZ which is located over north India in month of May becomes so intense that it pulls the trade winds of the southern hemisphere northwards (Figure – summer monsoon winds). These southeast trade winds cross the equator and enter the Bay of Bengal and the Arabian Sea, only to be caught up in the air circulation over India. Passing over the equatorial warm currents, they bring with them moisture in abundance. With the northwards shift of ITCZ, an easterly jet stream develops over 15oN. The rain in the south-west monsoon season begins rather abruptly. One result of the first rain is that it brings down the temperature substantially. This sudden onset of the moisture-laden winds associated with violent thunder and lightning, is often termed as the “break” or “burst” of the monsoons. Southwest monsoon first of all reaches in Andaman-Nicobar Islands on 15th May. Kerala coast receives it on 1st June. It reaches Mumbai and Kolkata between 10th and 13th June. By 15th of July, Southwest monsoon covers whole of India (Figure 10).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Figure 10 – India: Normal dates of Onset of the Southwest Monsoon

3.5 Rain Bearing Systems and Distribution of Rainfall The southwest monsoon splits into two branches, the Arabian Sea Branch and the Bay of Bengal Branch near the southernmost end of the Indian Peninsula. Hence, it arrives in India in two branches: the Bay of Bengal branch and the Arabian Sea Branch (Figure 11). First originate in the Bay of Bengal causing rainfall over the plains of north India. Second is the Arabian Sea current of the southwest monsoon which brings rain to the west coast of India. The latter extends toward a low-pressure area over the Thar Desert and is roughly three times stronger than the Bay of Bengal branch. The monsoon winds originating over the Arabian Sea further split into three branches: 



One branch is obstructed by the Western Ghats. These winds climb the slopes of the Western Ghats and as a result of orographic rainfall phenomenon, the windward side of Ghats receives very heavy rainfall ranging between 250 cm and 400 cm. After crossing the Western Ghats, these winds descend and get heated up. This reduces humidity in the winds. As a result, these winds cause little rainfall east of the Western Ghats. This region of low rainfall is known as the rain-shadow area. Another branch of the Arabian Sea monsoon strikes the coast north of Mumbai. Moving along the Narmada and Tapi river valleys, these winds cause rainfall in

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

extensive areas of central India. The Chotanagpur plateau gets 15 cm rainfall from this part of the branch. Thereafter, they enter the Ganga plains and mingle with the Bay of Bengal branch.

Figure 11 – Arabian Sea and Bay of Bengal branches of Southwest Monsoon 



A third branch of this monsoon wind strikes the Saurashtra Peninsula and the Kutch. It then passes over west Rajasthan and along the Aravallis, causing only a scanty rainfall. In Punjab and Haryana, it too joins the Bay of Bengal branch. These two branches, reinforced by each other, cause rains in the western Himalayas. The intensity of rainfall over the west coast of India is, however, related to two factors: o The offshore meteorological conditions. o The position of the equatorial jet stream along the eastern coast of Africa.

The Bay of Bengal branch strikes the coast of Myanmar and part of southeast Bangladesh. But the Arakan Hills along the coast of Myanmar deflect a big portion of this branch towards the Indian subcontinent. The monsoon, therefore, enters West Bengal and Bangladesh from south and southeast instead of from the south-westerly direction. From here, this branch splits into two under the influence of the Himalayas and the thermal low is northwest India.  



One branch moves westward along the Ganga plains reaching as far as the Punjab plains. The other branch moves up the Brahmaputra valley in the north and the northeast, causing widespread rains. Its sub-branch strikes the Garo and Khasi hills of Meghalaya. Mawsynram, located on the crest of Khasi hills, receives the highest average annual rainfall in the world. The Tamil Nadu coast remains dry during this season because it is situated in rainshadow area of Arabian Sea branch of the south-west monsoon and lies parallel to the Bay of Bengal branch of south-west monsoon.

Frequency of tropical depressions originating over the Bay of Bengal varies from year to year. The path of these depressions also keeps changing with the position of the ITCZ, also known as monsoon trough (Figure – position of Inter-tropical Convergence Zone (ITCZ) in the month of January and July). As the axis of the monsoon trough oscillates with the apparent movement of sun between Tropic of Cancer and Tropic of Capricorn, there are fluctuations in the track and Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

direction of these depressions, and the intensity and the amount of rainfall vary from year to year. The amount of rainfall in north India varies with the frequency of the tropical depressions. On an average, one to three depressions are observed every month and the life span of one depression is about one week [4]. The rain which comes in spells, displays a declining trend from west to east over the west coast, and from the southeast towards the northwest over the North Indian Plain and the northern part of the Peninsula. Rajasthan desert receives low rainfall in spite of being in the path of Arabian Sea branch of monsoon. This branch blows parallel to Aravalis mountain chain without obstruction and thus, does not release moisture here.

3.6 Break in the Monsoon During the south-west monsoon period after having rains for a few days, if rain fails to occur for one or more weeks, it is known as break in the monsoon. These dry spells are quite common during the rainy season. These breaks in the different regions are due to different reasons: i. ii.

In northern India rains are likely to fail if the rain-bearing storms are not very frequent along the monsoon trough or the ITCZ over this region. Over the west coast the dry spells are associated with days when winds blow parallel to the coast.

3.7 Retreat of Monsoon Monsoon starts retreating in September (Figure 12). On the first of September it starts retreating from north-western part of India. This day is the last day of rainy season in Jaisalmer and Barmer in Rajasthan. By 15th September, monsoon leaves Punjab, Haryana, Rajasthan and Gujarat. The area under the monsoon influence shrinks slowly and the monsoon retreats from all parts of India except the southern peninsular region. Monsoon winds in most parts of the country are replaced by the north-easterly trade winds. These winds blowing over the Bay of Bengal pick up moisture from there and cause rainfall in Tamil Nadu.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Figure 12 – India: Normal dates of withdrawal of the Southwest Monsoon

3.8 Features of Monsoon Rainfall  







Monsoon rain is seasonal in character which occurs between June and September. Spatial distribution of rainfall is largely governed by relief or topography. For instance the windward side of the Western Ghats registers a rainfall of over 250 cm. Again, the heavy rainfall in the northeastern states can be attributed to their hill ranges and the Eastern Himalayas. Rainfall ranges from 20 cm in western Rajasthan to more than 400 cm in certain parts of Western Ghats and North-East India. The monsoon rainfall has a declining trend with increasing distance from the sea. Rainfall decreases from east to west in plains as one branch of monsoon enters from eastern side. Kolkata receives 119 cm, Allahabad 76 cm and Delhi 56 cm only. Breaks (discussed above) in rainfall are related to the cyclonic depressions mainly formed at the head of the Bay of Bengal, and their crossing into the mainland. Besides the frequency and intensity of these depressions, the passage followed by them determines the spatial distribution of rainfall. The rains sometimes end considerably earlier than usual, causing great damage to standing crops and making the sowing of winter crops difficult.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

3.9 Monsoons and the Economic Life in India Monsoon is that axis around which revolves the entire agricultural cycle of India. It is because about 64 per cent people of India depend on agriculture for their livelihood and agriculture itself is based on southwest monsoon. Except Himalayas all the parts of the country have temperature above the threshold level to grow the crops or plants throughout the year. Regional variations in monsoon climate help in growing various types of crops. Agricultural prosperity of India depends very much on timely and adequately distributed rainfall. If it fails, agriculture is adversely affected mainly in areas where irrigation is not developed. Sudden monsoon burst creates problem of soil erosion over large areas in India.



  



4] Seasons Seasons are a special feature of Indian climate. Temperature, pressure, wind direction and the amount and duration of rain varies from one season to the other. Meteorologists identify four seasons in India. They are described briefly in table 1 below Season

Duration

Winter season

MidNovember to February

General Temperature characteristics Clear skies, Mean daily fine weather, temperature low humidity below 21oC in North India. Some part experience temperature below freezing point. Temperature increases from north to south.

Wind, disturbances High pressure over northwestern India. Winds blow from northwest to southeast. Around four or five westerly disturbances are carried by westerly jet stream.

Summer season

April, May, Excessive heat, Temperature June hot loo, dust rises up to storms and 45oC in north dryness India.

Low pressure over northwestern part of India and

rainfall Westerly disturbances cause rainfall in northern plains. Rainfall decreases from west to east in plains but increases in north-east again as it catch water from Bay of Bengal. Northeast monsoon causes winter rainfall in southern Andhra Pradesh, Tamil Nadu etc. Completely dry season. Dust storms and thunder storms

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Temperature has increased to 50oC in Ganganagar earlier. Summer in south India is not so extreme.

Southwest monsoon

June – Whole of India September under southwest monsoon. India faces severe cyclones, thunderstorms etc.

Retreating monsoon

OctoberNovember

Monsoon winds are retreating gradually and sudden rise of temperature with October heat.

high pressure over southern parts of Bay of Bengal. ITCZ shifts to Ganges plain. Wind direction varies from one part of India to the other. Dust storms are frequency experienced in the afternoon in northern plains. June is the Winds are hottest southmonth. westerly over Temperature mainland remains low India. during July and August which rises high in September with decreasing amount of precipitation. Day Winds are temperature is northhigh and easterly. Clear nights are cool skies and and pleasant. gentle breeze The average are minimum characteristics temperature of this season. fall below 20oC.

provide some rainfall. Eastern regions receives more rainfall comparatively.

India receives its 80% precipitation in this season. There is decline of rainfall from east to west in plains. Details are discussed under ‘monsoon’ above.

Southern Peninsular region (Tamil Nadu, Kerala, and Southern Andhra Pradesh) receives rain. Cyclonic activities are more frequent in Peninsular region.

Table 1 – Different seasons of India with their characteristics

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

4.1 Traditional Indian Seasons In the Indian tradition, a year is divided into six two-monthly seasons. This cycle of seasons, which the common people in north and central India follow is based on their practical experience and age-old perception of weather phenomena. However, this system does not match with the seasons of south India where there is little variation in the seasons. Season Vasanta Grishma Varsha Sharada Hemanta Shishira

Months according to Indian Calendar Chaitra-Vaisakha Jyaistha-Asadha Sravana-Bhadra Asvina-Kartika Margashirsa-Pausa Magha-Phalguna Table 2 – Indian seasons

Months according to English Calendar March-April May-June July-August September-October November-December January-February

5] Distribution of Annual Rainfall The distribution of average annual rainfall in India is shown in figure 13. A glance on this map indicates that the distribution of rainfall in India is uneven. On the basis of the distribution of rainfall, India can be divided into the following four regions as shown below in table 3. Category Heavy Rainfall

Moderate rainfall

Low rainfall

Inadequate rainfall

Rainfall in cms More than 200

regions Western coast, western ghats, sub-Himalayan region of north-east, Garo, Khasi and Jaintia hills of Meghalaya. In some parts, rain exceeds 1000 cm. Between 100 to 200 100 cm isohyet extends from Gujarat to south up to Kanyakumari parallel to western ghats. Northern Andhra Pradesh, eastern part of Maharashtra, Madhya Pradesh, Odisha, some parts of Jammu and Kashmir Between 60 to 100 Most parts of Tamil Nadu, Karnataka, Andhra Pradesh, eastern Rajasthan, southwestern Uttar Pradesh Less than 60 Punjab, Haryana, northwestern Rajasthan, Kachchh, Kathiawar Table 3 – Different rainfall regions of India

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Figure 13 – India: Annual rainfall

6] Variability of Annual Rainfall Variability of rainfall refers to variations in rainfall from the average amount. The variability of rainfall is computed with the help of the following formula: C.V. = (Standard Deviation / Mean) x 100; where C.V. is the coefficient of variation. Study of variability of rainfall in an agricultural country such as India is very important. The rainfall in India is highly variable. The actual rainfall of a place in a year deviates from its average rainfall by 10 to over 60 per cent. The mean annual rainfall variability of rainfall in India has been plotted in figure 14. Description of annual rainfall’s variability is details as: 



It may be noted from figure 13 and figure 14 that the highest variability is found in the areas where the average annual rainfall is the lowest such as desert areas of Rajasthan. Here, variability of rainfall is around 60 per cent. Contrary to this, in the areas where the average annual rainfall is over 200 cm (Meghalaya plateau, Western Ghats), the annual variability of rainfall is less than 10 per cent.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

 

A very large part of India falls in the category of 15 to 30 per cent annual variability of rainfall. Tamil Nadu, Karnataka, Andhra Pradesh, Maharashtra etc. fall in this category Variability of annual rainfall increases from the western coast to the interior of the Peninsular region and from West Bengal and Odisha towards north and north-west.

Figure 14 – India: variability of annual rainfall

7] Climatic Regions of India India is often referred to as a country with tropical monsoon type of climate. However, the large latitudinal extent, the presence of Himalayas in the north, the India Ocean in the south have resulted in great variations in the distribution of temperature and precipitation in the India. The climate of north is different from that of south and so is the climate of east from that of the west. To study the variations of climate in various parts, India is divided into a large number of climatic regions of small size. A climatic region is that area which possesses a broad uniformity of climatic conditions caused by the combined effects of climatic elements – temperature, pressure, winds, humidity and precipitation. Temperature and rainfall are two important Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

elements which are considered to be decisive in all the schemes of climatic classification. There are different schemes of classification of climate. Major climatic types of India based on Koeppen’s scheme have been show in figure 15.

Figure 15 – India: Climatic regions according to Koeppen scheme

Koeppen based his scheme of Climatic classification on monthly values of temperature and precipitation. India’s climate is divided into the following climatic regions:   

Monsoon type with short dry season (Amw) – the western coastal region south of Goa experiences this type of climate. Monsoon type with dry season in summers (AS) – the region of this type of climate extends along the coromandel coast. Tropical Savannah type (Aw) – almost the entire peninsular region except for some coastal parts experiences this type of climate.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:



   

Semi-arid steppe climate (BShw) – this climatic region includes the interior parts of the peninsular plateau and some parts of Gujarat, Rajasthan, Haryana, Punjab and Jammu & Kashmir. Hot desert type (BWhw) – this type of climate is found only in the western part of Rajasthan. Monsoon type with dry winters (Cwg) – Largely Northern plains of India experiences this type of climate. Cold-humid winter type with short summer (Dfc) – this climate of characterized by a short summer season. This region covers the north-eastern parts of India. Polar type (E) – this type of climate is experienced in Jammu & Kashmir and the neighbouring mountain ranges.

Agro Climatic Zones Of India The agro-climatic classification is nothing but an extension of the climate classification keeping in view the suitability to agriculture. Generally, the climate types may be distinguished on the rainfall, temperature and as these two characteristics are influenced by altitude, the climate can also be classified on the basis of above three parameters. National commission on agriculture (1971) classified the country into 127 agro-climatic zones. The planning commission, as a result of mid. term appairasal of planning targets of VII plan (1985 - 90) divided the country into 15 broad agro - climatic zones based on physiographic and climate. The emphasis was given on the development of resources and their optimum utilization in a suitable manner with in the frame work of resource constraints and potentials of each region.

Agro climatic zones of India :- (Planning commission 1989) 1

Western Himalayan Region

2 3

Eastern Himalayan Region Lower Gangatic plants Regions

4

Middle Gangatic plans Region

Ladakh, Kashmir, Punjab, Jammu etc.brown soils & silty loam, steep slopes. Arunachal Pradesh, Sikkim and Darjeeling. Manipur etc. High rainfall and high forest covers heavy soil erosion, Floods. West Bengal Soils mostly alluvial & are prone to floods. Bihar, Uttar Pradesh, High rainfall 39% irrigation, cropping intensity 142%

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 22

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

5

Upper Gangatic Plains Region

6

Trans Gangatic plains Region

7 8

Eastern Plateaus & Hills Region Central Plateau & hills Region

9

Western Plateau & hills Region

10

Southern Plateau & Hills Region

11

East coast plains & hills Region

12

West coast plains & Hills Region

13

Gujarat plains & Hills Region

14

Western Dry Region

15

The Island Region

North region of U.P. (32 dists) irrigated by canal & tube wells good ground water Punjab Haryana Union territory of Delhi, Highest sown area irrigated high Chota Nagpur, Garhjat hills, M.P, W. Banghelkhand plateau, Orissa, soils Shallow to medium sloppy, undulating Irrigation tank & tube wells. M. Pradesh Sahyadry, M.S. M.P. Rainfall 904 mm Sown area 65% forest 11% irrigation 12.4% T. Nadu, Andhra Pradesh, Karnataka, Typically semi and zone, Dry land Farming 81% Cropping Intensity 11% Tamil Nadu, Andhra Pradesh Orissa, Soils, alluvial, coastal sand, Irrigation Sourashtra, Maharashtra, Goa, Karnataka, T. Nadu, Variety of cropping Pattern, rainfall & soil types. Gujarat (19 dists) Low rainfall arid zone. Irrigation 32% well and tube wells. Rajasthan (9 dists) Hot. Sandy desert rainfall erratic, high evaporation. Scanty vegetation, femine draughts. Eastern Andaman, Nikobar, Western Laksh dweep. Typical equatorial, rainfall 3000 mm (9 months) forest zone undulating.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 23

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

UPSC Previous Years’ Mains Questions on Climate: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13.

14.

15.

16.

17.

List the significant local storms of the hot-weather season in the country and bring out their socio-economic impact. (UPSC 2010/12 Marks) Bring out the significance of the various activities of the Indian Meteorological Department. (UPSC 2009/15 Marks) Write about Nor’westers in 20 words. (UPSC 2008/15 Marks) The winter rains in North India are largely related to Jet Streams and Western Disturbances. Bring out the relationship. (UPSC 2008/15 Marks) Write note on winter rains in India. (UPSC 2006/2 Marks) Discuss the distribution of winds and rainfall over India in the summer monsoon season. (UPSC 2002/10 Marks) Explain the causes of the Indian Monsoon. (UPSC 2001/10 Marks) Write short note on Mango Showers. (UPSC 2000/2 Marks) Mention the agro-climatic regions of India starting the basis of classification. (UPSC 2000/10 Marks) Discuss the origin of Monsoon in India. (UPSC 1997/15 Marks) What is ‘intensity of rainfall’? Discuss its importance to Indian farmers. (UPSC 1995/15 Marks) Which part of India receives more rainfall from the north-east monsoon than from the south-west monsoon? Explain why it is so? (UPSC 1994/15 Marks) What is the basis of Monsoon forecasts now prepared by the Indian Meteorological Department, which have been reasonably correct for the last three successive years? (UPSC 1991/20 Marks) How far is it justifiable to state that the financial budget of this country is a gamble, against the Indian monsoon? To what extent have developmental measures solved the problem? (UPSC 1986/20 Marks) Why is India undertaking expeditions to Antarctica? Describe the influence of Antarctica and Antarctic Ocean on the climate of India and on the nutrient and energy supply to Indian Ocean. “Monsoon is known to be an energy released by the sea.” Explain. How does this energy benefit the entire economic system of our country? In what ways could this country prepare itself to fight the vagaries of the monsoons? (UPSC 1982/30 Marks) Unlike most other parts of the country, why is the Tamil Nadu coast wettest in November-December and not in July-August? (UPSC 1980/3 Marks)

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 24

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

UPSC Previous Years’ Prelims Questions on Climate: 1.

La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino? 1. La Nina is characterised by unusually cold ocean temperature in equatorial Indian Ocean whereas El Nino is characterised by unusually warm ocean temperature in the equatorial Pacific Ocean. 2. El Nino has adverse effect on south-west monsoon of India, but La Nina has no effect on monsoon climate. Which of the statements given above is/are correct? (2011) (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

2.

With reference to India, which one of the following statements is not correct? (2002) (a) About one-third of the area of the country records more than 750 millimetres of annual rainfall (b) The dominant source of irrigation in the country is wells (c) Alluvial soil is the predominant type of soil in the northern plains of the country (d) The mountain areas account for about thirty percent of the surface area of the country

3.

The jet aircrafts fly very easily and smoothly in the lower stratosphere. What could be the appropriate explanation? (2011) 1. There are no clouds or water vapour in the lower stratosphere. 2. There are no vertical winds in the lower stratosphere. Which of the statements given above is/are correct in this context? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

4.

The average annual temperature of a meteorological station is 260C, its average annual rainfall is 63 cm and the annual range to temperature is 90C. The station in question is (2002). (a) Allahabad (b) Chennai (c) Cherrapunji (d) Kolkata

5.

If there were no Himalayan ranges, what would have been the most likely geographical impact on India? 1. Much of the country would experience the cold waves from Siberia. 2. Indo-gangetic plain would be devoid of such extensive alluvial soils. 3. The pattern of monsoon would be different from what it is at present. Which of the statements given above is/are correct? (2010) (a) 1 only (b) 1 and 3 only (c) 2 and 3 only (d) 1, 2 and 3

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 25

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 15

CLIMATE AND DIFFERENT WORLD CLIMATES

Contents: 1 Introduction 2 Climate & Weather 2.1 Comparison between Weather and Climate 2.2 Importance of Climate and Weather 2.3 Elements of climate 2.4 Factors affecting climate 2.5 Classification of climate 3 Global Climate Classification 3.1 The Hot, Wet Equatorial Climate 3.2 The Tropical Monsoon and Tropical Marine Climates 3.3 The Savannah or Sudan Climate 3.4 The Hot Desert and Mid-latitude Desert Climates: 3.5 The Warm Temperate Western Margin (Mediterranean) Climate 3.6 The Temperate Continental (Steppe) Climate 3.7 The Warm Temperate Eastern Margin (China Type) Climate 3.8 The Cool Temperate Western Margin (British Type) Climate 3.9 The Cool Temperate Continental (Siberian) Climate 3.10 The Cool Temperate Eastern Margin (Laurentian) Climate 3.11 The Arctic or Polar Climate 4 Mains Questions 5 Prelims Questions

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

1] Introduction Climate holds an important place in our own life. Our life and various economic activities (agriculture, industries, commerce, etc.) are affected by climate. Climate has also an important place in physical geography. Climate is a measure of the average pattern of variation in temperature, humidity, atmospheric pressure, wind, precipitation, atmospheric particle count and other meteorological variables in a given region over long periods of time. Any independent study of each of these elements does not present any comprehensive view of climate. On the basis of these elements, there could be thousands of types of climates in the world.

2] Climate & Weather The difference between weather and climate is that weather consists of the short-term (minutes to months) changes in the atmosphere while climate is the average of weather over time and space. In most places, weather can change from minute-to-minute, hour-to-hour, dayto-day, and season-to-season. Climate, however, is the average of weather over time and space.

2.1 Comparison between Weather and Climate Climate

Weather

Definition

Describes the average conditions expected at a specific place over a long period of time. A region's climate is generated by the climate system, which has five components: atmosphere, hydrosphere, cryosphere, land surface and biosphere.

Describes the atmospheric conditions at a specific place at a specific point in time. Weather generally refers to day-to-day temperature and precipitation activity

Components

Climate may include precipitation, temperature, humidity, sunshine, and wind velocity, phenomena such as fog, frost, and hail storms over a long period of time.

Weather includes sunshine, rain, cloud cover, winds, hail, snow, sleet, freezing rain, flooding, blizzards, ice storms, thunderstorms, steady rains from a cold front or warm front, excessive heat, heat waves and more

Forecast

By aggregates of weather By collecting meteorological data, like air statistics over periods of 30 temperature, pressure, humidity, solar years radiation, wind speeds and direction etc.

Determining factors

Aggregating weather statistics Real-time measurements of atmospheric over periods of 301 years. pressure, temperature, wind speed and direction, humidity, precipitation, cloud cover and other variables.

1

NCERT mentions 50 years but according to WMO it is 30 years.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Time period

Measured over a long period

Measured for short term

Study

Climatology

Meteorology

2.2 Importance of Climate and Weather The influence of climate and weather can be seen in day to day activities of human beings. Forces of nature have regulated to a very great extent the sort of food we eat, what we wear, how we live and work. Conditions of temperature, precipitation and humidity may promote or discourage the growth of fungus and diseases which may be injurious to both men and crops. Today, our activities are becoming more and more dependent upon meteorological services. Meteorological stations are set up all over the globe to provide weather updates and predict future conditions. A fair knowledge of the weather is not only useful but often essential.

2.3 Elements of climate There are various environmental elements which have significant influence on the climate of a region. Among them, temperature, pressure, precipitation and winds are the most important because of their far reaching global influence. These elements are affected in different manner by the following climatic factors: latitude, altitude, continentality, ocean currents, insolation, prevailing winds, slope and aspect, natural vegetation and soil.

2.4 Factors affecting climate Latitude: Due to the earth's inclination, the mid-day sun is almost overhead within the tropics but the sun's rays reach the earth at an angle outside the tropics. Thus, temperature diminishes from equatorial regions to the poles. Altitude: Earth’s atmosphere is mainly heated through conduction from the surface, so places near the surface are warmer than those higher up. Thus temperature decreases with increasing height above sea level. This rate of decrease in temperature with altitude (lapse rate) is never constant, varying from place to place and from season to season. However, for all practical purposes, it may be reckoned that a fall of 6.5°C occurs with an ascent of 1000 meters or 1oC per 165 meters. Continentality (Distance from sea): Land surfaces have higher specific heat capacity of heat as compared to water bodies i.e. it takes less energy to raise the temperature of a given volume of land by 1oC as compared to same volume of water body. This accounts for temperature extremes in the continental interiors as compared to maritime areas. Oceans Currents: Marine areas are influenced by the warm or cold ocean currents. Ocean currents like the Gulf Stream or the North Atlantic Drift warm the coastal districts of Western Europe keeping their ports ice-free. Ports located in the same latitude but washed by cold currents, such as the cold Labrador Current off north-east Canada, are frozen for several months. Cold currents also lower the summer temperature, particularly when they are carried landwards by on-shore winds. Local winds: If winds are warm i.e. they have been blown from a hot area, they will raise temperatures. If winds have been blown from cold areas, they will lower temperatures. Local winds like Fohn, Chinook, Sirocco and Mistral also produce marked changes in temperature. Relief and Topography: Climate can be affected by mountains. Mountains receive more rainfall than low lying areas because as air is forced over the higher ground it cools, causing moist air to Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

condense and fall out as rainfall. The higher the place is above sea level the colder it will be. This happens because as altitude increases, air becomes thinner and is less able to absorb and retain heat.

Latitude Human Influence

ElNino

Slope, Shelter & Aspect

Altitude

Factors Affecting Climate

Natural Vegetation

Relief & Topography

Contineta lity

Ocean Current

Local Winds

Fig 1: Factors Affecting Climate Natural Vegetation and Soil: Natural vegetation affects the temperature of the region significantly. Often areas with dense forest cover like areas in thick foliage of Amazon jungles receive less insolation and are, often, cooler than the areas in open space. Light soils reflect more heat than darker soils which are better absorbers. Such soil differences may give rise to slight variations in the temperature of the region. As a whole, dry soils like sands are very sensitive to temperature changes, whereas wet soils, like clay, retain much moisture and warm up or cool down more slowly. Slope, Shelter and Aspect: A steep slope experiences much rapid change in temperature as compared to a gentle slope. Mountain ranges that have an east-west alignment like the Alps show a higher temperature on the south-facing 'sunny slope' than the north facing 'sheltered slope'. The greater insolation of the southern slope is better suited for vine cultivation and has a more flourishing vegetative cover. Consequently, there are more settlements and it is better utilised than the 'shady slope'. El Niño Effect: El Niño, which affects wind and rainfall patterns, has been blamed for droughts and floods in countries around the Pacific Rim. El Niño refers to the irregular warming of surface water in the Pacific. The warmer water pumps energy and moisture into the atmosphere, altering global wind and rainfall patterns. The phenomenon has caused tornadoes in Florida, smog in Indonesia, and forest fires in Brazil. El Niño is Spanish for 'the Boy Child' because it comes about the time of the celebration of the birth of the Christ Child. The cold counterpart to El Niño is known as La Niña, Spanish for 'the girl child', and it also brings with it weather extremes. Human Influence: The factors above affect the climate naturally. However, we cannot forget the influence of humans on our climate. Early on in human history our effect on the climate would have been quite small. However, as populations increased and trees were cut down in Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

large numbers, so our influence on the climate increased. The number of trees being cut down has also increased, reducing the amount of carbon dioxide that is taken up by forests

2.5 Classification of climate If we were to compare the climates of different places on the basis of climatic elements, we would come across many such places which would have similarity between one and more of these elements. On the basis of these very regional similarities and differences of climatic elements, attempts have been made to classify climate for easy understanding, description and analysis. Three broad approaches have been adopted for classifying climate. They are empirical, genetic and applied. Empirical classification is based on observed data, particularly on temperature and precipitation. Genetic classification attempts to organise climates according to their causes. Applied classification is for specific purpose. Heat Zones Classification: The Greek philosophers were the first to present classification of climates. The temperature of the earth was the main bases of their classifications. They had divided the earth into Torrid, Temperate and Frigid zones. (1) Tropical or Torrid Zone: This zone lies between the Tropic of Cancer and the Tropic of Capricorn. In this zone the sunrays are almost vertical throughout the year. The temperature always remains high. There is no winter season in this zone. (2) Temperate Zone: There are two zones lying between the Tropic of Cancer - the Arctic Circle and the Tropic of Capricorn - the Antarctic Circle.

Fig 2: Heat Zones Classifications (3) Frigid Zone: This zone lies between Arctic Circle and North Pole and the Antarctic Circle and the South Pole. The sunrays in these two zones in the Northern and Southern Hemisphere fall in slanting form throughout the year. Therefore these zones experience very low temperature and high degree of coldness. Therefore, these latitudinal zones are known as Frigid Zone.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Koeppen Classification: The most widely used classification of climate is the climate classification scheme developed by German climatologist and plant geographer V. Koeppen. in 1918. The annual as well as monthly averages of temperature and precipitation formed the basis of Koeppen classification of climate. He also based his classification on the distribution of weather conditions. This classification is both empirical and genetic type. Koeppen in his classification laid great emphasis that all the characteristics of climate can well be expressed through the distribution of natural vegetation that’s why he tried to associate his climate types with vegetation zones of the world. He made use of annual averages of temperature and precipitation in fixing the climate regions of the world. He presented five main climate types. Each of these climate types was represented by capital English alphabets of A, B, C, D and E. He used the letter 'H' for highland type of climates. While keeping temperature and precipitation variations in view these five climate types were further subdivided as shown in the following table: Sr. No.

Chief Climatic Groups

A

Tropical Climate (Average temperature of the coldest month is 18° C or higher)

1. Tropical rain forest type climate 2. Savannah type climate 3. Monsoon type climate

B

Dry Climate precipitation)

exceeds

4. Desert climate 5. Steppe (Semi-desert) climate

C

Temperate Climate (The average temperature of the coldest month is higher than minus 3°C but below 18°C)

6. Mediterranean climate 7. China type climate 8. West European type climate

D

Continental Climate (The average temperature of the coldest month is minus 3° C or below)

9. Taiga climate 10. Eastern coastal climate 11. Continental climate

E

Polar Climate (Average temperature for all months is below 10° C)

12. Tundra climate 13. Snow-capped region type climate

H

Highland Climate (Cold due to elevation)

(Potential

Climatic Types

evaporation

cold

Thornthwaite Classification: Thornthwaite was an American climatologist. He presented his first climate classification in 1931. In 1931, his classification looked similar to Koeppen. Like Koeppen, Thornthwaite also thought that vegetation is the indicator of climate type. Two basic features of this classification are (i) Precipitation Effectiveness, (ii) Temperature Efficiency. On the basis of these two indicators, Thornthwaite divided the world into five humidity regions. Each region had its own special type of vegetation as shown in the table below:

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Sr. No. Humidity Region Special type of Vegetation A

Very Humid

Rain Forest

B

Humid

Forest

C

Semi Humid

Grassland

D

Semi Dry

Steppe

E

Dry

Desert

On the basis of distribution of seasonal rainfall the above types of humidity regions were further divided into following subdivisions: Y = Heavy rainfall in all seasons s = Scarcity of rainfall in summer season w = Scarcity of rainfall in winter season d = Scarcity of rainfall in all seasons After linking precipitation effectiveness and seasonal distribution of rainfall to temperature anomalies, the climates could be of 120 different types.

3] Global Climate Classification The global climatic conditions can be studied under the following twelve classifications. Climatic Zone

Latitude (Approximate)

ClimaticType

Rainfall Regime approx. total)

Equatorial Zone

00-100N and S

1. Hot, wet equatorial

Rainfall all year round : 80 inches

Equatorial rain forests

Hot Zone

100-300N and S

2. a) Tropical Monsoon

Heavy summer rain: 80 inches Much summer rain: 70 inches

Monsoon forests

3. Sudan Type

Rain mainly in summer: 30 inches

Savanna grassland)

4. Desert: a) Saharan type

Little rain: 5 inches

Desert vegetation and scrub

5. Western Margin (Mediterranean type)

Winter rain: 35 inches

Mediterranean forests and shrub

6. Central Continental (Steppe type)

Light summer rain: 20 inches

Steppe or temperate grassland

7. Eastern Margin: a) China type b) Gulf type c) Natal type

Heavier summer rain : 20 inches

Warm, wet and bamboo

b) Tropical Marine

(with

NaturalVegetation

(tropical

b) Mid-latitude type Warm Temperate Zone

30-0400N & S

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

forests

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Cool Temperate Zone

Cold Zone

450-650N & S

650-900 N & S

Alpine Zone

8. Western (British type)

Margin

More rain in autumn & winter: 30 inches

Deciduous forests

9. Central Continental (Siberian type)

Light summer rain: 25 inches

Evergreen forests

10. Eastern Margin (Laurentian type)

Moderate summer rain : 40 inches

Mixed (coniferous deciduous)

11. Arctic or Polar

Very light summer rain : 10 inches

Tundra, lichens

12. Mountain climate

Heavy rainfall (variable)

Alpine pastures, conifers, fern, snow

coniferous forests and mosses,

3.1 The Hot, Wet Equatorial Climate Distribution The equatorial, hot, wet climate is found between 5o and 10 o north and south of the equator. Its greatest extent is found in the lowlands of the Amazon, the Congo, Malaysia and the East Indies. Further away from the equator, the influence of the on-shore Trade Winds, gives rise to a modified type of equatorial climate with monsoonal influences.

Climatic Conditions Temperature: The most outstanding feature of the equatorial climate is its great uniformity of temperature throughout the year. The mean monthly temperatures are always around 27°C with very little variation. There is no winter. Cloudiness and heavy precipitation moderates the daily temperature, so that even at the equator itself, the climate is not unbearable. The diurnal range of temperature is small, and so is the annual range. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Precipitation: Precipitation is heavy, between 60 inches and 100 inches, and well distributed throughout the year. There is no month without rain and a distinct dry season like those of the Savannah or the Tropical Monsoon Climates, is absent. Due to the great heat in the equatorial belt, mornings are bright, and sunny. There is much evaporation and convectional air currents are set up, followed by heavy downpours. Natural Vegetation: It supports a luxuriant type of vegetation – the tropical rain forest. Amazon tropical rain forest is known as Selvas. It comprises a multitude of evergreen trees that yield tropical hardwood, e.g. mahogany, ebony, greenheart, cabinet wood. Lianas, epiphytic and parasitic plants are also found. Trees of single species are very scarce in such vegetation. Life and Development in the Equatorial Regions: The equatorial regions are generally sparsely populated. In the forests most primitive people live as hunters and collectors and the more advanced ones practise shifting cultivation. In the Amazon basin, the Indian tribes collect wild rubber, in the Congo Basin the Pygmies gather nuts and in the jungles of Malaysia the Orang Asli make all sorts of cane products and sell them to people in villages and towns. In the clearings for shifting cultivation, crops like manioc (tapioca), yams, maize, bananas and groundnuts are grown.

3.2 The Tropical Monsoon and Tropical Marine Climates Distribution: It is found in the zones between 5° and 30° latitudes on either side of the equator. These areas are the tropical monsoon lands with on-shore wet monsoons in the summer and off-shore dry monsoons in the winter. They are best developed in the Indian sub-continent, Burma, Thailand, Laos, Cambodia, parts of Vietnam and south China and northern Australia. Outside this zone, the climate is modified by the influence of the on-shore Trade Winds all the year round, and has a more evenly distributed rainfall. Such a climate, better termed the Tropical Marine Climate, is experienced in Central America. West Indies, north-eastern Australia, the Philippines, parts of East Africa, Madagascar, the Guinea Coast and eastern Brazil.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Climatic Conditions: The basic cause of monsoon climates is the difference in the rate of heating and cooling of land and sea. Average temperature of warm dry summer months ranges between 27°C and 32°C. In the summer, when the sun is overhead at the Tropic of Cancer, the great land masses of the northern hemisphere are heated. The seas, which warm up much slower, remain comparatively cool. At the same time, the southern hemisphere experiences winter, and a region of high pressure is set up in the continental interior of Australia. Winds blow outwards as the SouthEast Monsoon, to Java, and after crossing the equator are drawn towards the continental low pressure area reaching the Indian sub-continent as the South-West Monsoon. In the winter, conditions are reversed. The sun is overhead at the Tropic of Capricorn, central Asia is extremely cold, resulting in rapid cooling of the land. A region of high pressure is created with out-blowing winds-the North-East Monsoon. The Seasons of Tropical Monsoon Climate: In regions like the Indian sub-continent which have a true Tropical Monsoon Climate, three distinct seasons are distinguishable - The cool, dry season (October to February), the hot dry season (March to mid-June) and the rainy season (mid-June to September). The Tropical Marine Climate: This type of climate is experienced along the eastern coasts of tropical lands, receiving steady rainfall from the Trade Winds all the time. The rainfall is both orographic, where the moist trades meet upland masses as in eastern Brazil, and convectional due to intense heating during the day and in summer. Its tendency is towards a summer maximum as in monsoon lands, but without any distinct dry period. Natural Vegetation: The natural vegetation of tropical monsoon lands depends on the amount of the summer rainfall. Trees are normally deciduous because of the marked dry period, during which they shed their leaves to withstand the drought. Where the rainfall is heavy, e.g. in Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

southern Burma, peninsular India, northern Australia and coastal regions with a tropical marine climate, the resultant vegetation is forest. The forests are more open and less luxuriant than the equatorial jungle and there are far fewer species. Most of the forests yield valuable timber, and are prized for their durable hardwood. Amongst these teak is the best known. Economy: The main economic activity of the people is agriculture. Major agricrops are rice, cane sugar, jute etc.

3.3 The Savannah or Sudan Climate Distribution: The Savannah or Sudan Climate is a transitional type of climate found between the equatorial forest and the trade wind hot deserts. It is confined within the tropics and is best developed in the Sudan where the dry and wet seasons are most distinct, hence its name the Sudan Climate. The belt includes West African Sudan, and then curves southwards into East Africa and southern Africa north of the Tropic of Capricorn. In South America, there are two distinct regions of savannah north and south of the equator, namely the llanos of the Orinoco basin and the Campos of the Brazilian Highlands.

Climatic Conditions: The Savannah climate is characterized by distinct wet and dry seasons. Mean high temperature throughout the year is between 24°C and 27° C. The annual range of temperature is between 3°C and 8°C, but the range increases as one move further away from the equator. The extreme diurnal range of temperature is a characteristic of Sudan type of climate. The average annual rainfall ranges between 100 cm and 150 cm. The prevailing winds of the region are the Trade Winds which bring rain to the coastal districts. Natural Vegetation: The savannah landscape is typified by tall grass and short trees. The terms 'parkland' or 'bush-veld' perhaps describe the landscape better. Trees grow best towards the equatorial humid latitudes or along river banks but decrease in height and density away from the equator. The trees are deciduous, shedding their leaves in the cool, dry season to prevent Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

excessive loss of water through transpiration, e.g. acacias. Others have broad trunks, with water-storing devices to survive through the prolonged drought such as baobabs and bottle trees. Trees are mostly hard, gnarled and thorny and may exude gum like gum arabic. Animal Life of the Savannah: The savannah, particularly in Africa, is the home of wild animals. It is known as the 'big game country' and thousands of animals are trapped or killed each year by people from all over the world. Some of the animals are tracked down for their skins, horns, tusks, bones or hair, others are captured alive and sent out of Africa as zoo animals, laboratory specimens or pets. Economy: Many tribes live within the Savannah lands. Some tribes live as pastoralists like the Masai and other as settled cultivators like the Hausa of northern Nigeria. However, agriculture is not much developed.

3.4 The Hot Desert and Mid-latitude Desert Climates: Distribution: Deserts are regions of scanty rainfall which may be hot like the hot deserts of the Saharan type or temperate as are the mid- latitude deserts like the Gobi. The major hot deserts of the world are located on the western coasts of continents between latitudes 15º and 30ºN and S. They include the Sahara Desert, the largest single stretch of desert, which is 3,200 miles from east to west and at least 1,000 miles wide. The next biggest desert is the Great Australian Desert which covers almost half of the continent. The other hot deserts are the Arabian Desert, Iranian Desert, Thar Desert, Kalahari and Namib Deserts. In North America, the desert extends from Mexico to USA and is called by different names at different places, e.g. the Mohave Sonoran, Californian and Mexican Deserts. In South America, the Atacama or Peruvian Desert is the driest of all deserts with less than 0.5 inches of rainfall annually. The Patagonian Desert is more due to its rain- shadow position on the leeward side of the lofty Andes than to continentality.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Climatic Conditions: Rainfall: The aridity of deserts is the most outstanding feature of the desert climate. Few deserts whether hot or mid-latitude have an annual precipitation of more than 10 inches while in others less than 0.02 inches. The hot deserts lie astride the Horse Latitudes or the SubTropical High Pressure Belts where the air is descending, a condition least favourable for precipitation of any kind to take place. The rain bearing trade winds blow off shore and the Westerlies, that are on-shore, blow outside the desert limits. Whatever winds reaches the deserts blow from the cooIer to the warmer regions, and their relative humidity is lowered, making condensation almost impossible. Temperature: The deserts are some of the hottest spots on earth and have high temperatures throughout the year. There is no cold season in the hot deserts and the average summer temperature is around 30°C. The highest shade temperature recorded is 58°C at Al Azizia, 25 miles south of Tripoli, Libya, in the Sahara. The diurnal range of temperature in the deserts is very great. Natural Vegetation: All deserts have some form of vegetation such as grass, scrub, herbs, weeds, roots or bulbs. Though they may not appear green and fresh all the time, they lie dormant in the soil awaiting rain which comes at irregular intervals or once in many years. The environment, so lacking in moisture and so excessive in heat, is most unfavourable for plant growth and significant vegetation cannot be expected. The predominant vegetation of both hot and mid-latitude deserts is xerophytes or drought-resistant scrub. This includes the bulbous cacti, thorny bushes, long-rooted wiry grasses and scattered dwarf acacia. Trees are rare except where there is abundant ground water to support clusters of date palms. Life in the Deserts: Despite its inhospitality, the desert has always been peopled by different groups of inhabitants. They struggle against an environment deficient in water, food and other means of livelihood. The desert inhabitants may be grouped under the following categories The primitive hunters and collectors (The Bushmen and The Bindibu), the nomadic herdsmen (The Tuaregs of the Sahara, the Gobi Mongols and The Bedouin of Arabia), the caravan traders, the settled cultivators and the mining settlers.

3.5 The Warm Temperate Western Margin (Mediterranean) Climate Distribution: The Warm Temperate Western Margin Climate is found in relatively, few areas in the world. They are entirely confined to the western portion of continental masses, between 30° and 45° north and south of the equator. The basic cause of this type of climate is the shifting of the wind belts. Though the area around the Mediterranean Sea has the greatest extent of this type of 'winter rain climate', and gives rise to the more popular name Mediterranean Climate. Other Mediterranean regions include California (around San Francisco), the south-western tip of Africa (around Cape Town), southern Australia (in southern Victoria and around Adelaide, bordering the St. Vincent and Spencer Gulfs), and south-west Australia (Swanland).

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Climatic Conditions: The Mediterranean type of climate is characterized by very distinctive climatic features - a warm summer with off-shore trades, a concentration of rainfall in winter with onshore westerlies, bright, sunny weather with hot dry summers and wet, mild winters and the prominence of local winds around the Mediterranean Sea (Sirocco, Mistral). Since all regions with a Mediterranean climate are near large bodies of water, temperatures are generally moderate with a comparatively small range of temperature res between the winter low and summer high. Areas with this climate receive almost all of their yearly rainfall during the winter season, and may go the summer without having any significant precipitation. Natural vegetation: Trees with small broad leaves are widely spaced and never very tall. Though there are many branches they are short and carry few leaves. The absence of shade is a distinct feature of Mediterranean lands. Growth is slow in the cooler and wetter season, even though more rain comes in winter. The warm, bright summers and cool, moist winters enable a wide range of crops to be cultivated. The Mediterranean lands are also known as the world's orchard lands. A wide range of citrus fruits such as oranges, lemons, limes, citrons and grapefruit are grown. Wine production is another speciality of the Mediterranean countries, because the best wine is essentially made from grapes. Some 85 per cent of grapes produced, go into wine. The long, sunny summer allows the grapes to ripen and then they are handpicked. Economy: The area is important for fruit cultivation, cereal growing, wine-making and agricultural industries as well as engineering and mining.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

3.6 The Temperate Continental (Steppe) Climate Distribution Bordering the deserts, away from the Mediterranean regions and in the interiors continents are the temperate grasslands. Though they lie in the Westerly wind belt, they are so remote from maritime influence that the grasslands are practically treeless. These grasslands are so distinctive in their natural vegetation that, although those which occur in the southern hemisphere have a much more moderate climate, they are often dealt with together. In the northern hemisphere, the grasslands are far more extensive and are entirely continental. In Eurasia, they are called the Steppes and stretch eastwards from the shores of the Black Sea across the Great Russian plain to the foothills of the Altai Mountains, a distance of well over 2,000 miles. There are isolated sections in the Pustaz of Hungary and the plains of Manchuria. In North America, the grasslands are also quite extensive and are called Prairies. They lie between the foothills of the Rockies and the Great Lakes astride the American Canadian border. In the case of the Pampas of Argentina and Uruguay, the grasslands extend right to the sea and enjoy much maritime influence. In South Africa, the grasslands are sandwiched between the Drakensberg and the Kalahari Desert; and are further subdivided into the more tropical Bushveld in the north, and the more temperate High Veld in the south.

Climatic Conditions Temperature: Their location in the heart of continents means that they have little maritime influence. Their climate is thus continental with extremes of temperature. Summers are very warm, over 19°C. Winters are very cold in the continental steppes of Eurasia because of the enormous distances from the nearest sea. The winter months are well below freezing. In contrast, the steppe type of climate in the southern hemisphere is never severe. The winters are mild. Temperatures below freezing point even in midwinter (July in the southern hemisphere) are exceptional. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Precipitation: In its continental position, the annual precipitation of the Steppe Climate is light. The average rainfall may be taken as about 20 inches, but this again varies according to location from 10 inches to 30 inches. The maritime influence in the steppe type of climate of the southern hemisphere is even better brought out by the rainfall regime. Its annual precipitation is always more than the average 20 inches because of the warm ocean currents that wash the shores of the steppe-lands. Natural Vegetation: The reference to steppe grassland is taken to mean the temperate grasslands of the mid-latitudes, the Steppes, Prairies, Pampas, Veld and Downs. The steppes are grass covered, differing only in the density and quality of the grass. Their greatest difference from the tropical savannah is that they are practically treeless and the grasses are much shorter. Where the rainfall is moderate, above 20 inches, the grasses are tall, fresh and nutritious and are better described as long prairie grass. The appearance of the temperate grasslands varies with seasons. Trees are very scarce in the steppes, because of the scanty rainfall, long droughts and severe winters. Economy: The grasslands have been ploughed up for extensive, mechanized wheat cultivation and are now the ‘granaries of the world’. Besides wheat, maize is increasingly cultivated in the warmer and wetter areas. The tufted grasses have been replaced by the more nutritious Lucerne or alfalfa grass.

3.7 The Warm Temperate Eastern Margin (China Type) Climate Distribution: This type of climate is found on the eastern margins of continents in warm temperate latitudes, just outside the tropics. It has comparatively more rainfall than the Mediterranean climate in the same latitudes, coming mainly in the summer. It is, in fact, the climate of most parts of China –a modified form of monsoonal climate. It is thus also called the Temperate Monsoon or China Type of climate. In south-eastern U.S.A., bordering the Gulf of Mexico, continental heating in summer induces an inflow of air from the cooler Atlantic Ocean. It is sometimes referred to as the Gulf type of climate. In the southern hemisphere, this kind of climate is experienced along the warm temperate eastern coastlands of all the three continents: in New South Wales with its eucalyptus forests; in Natal where cane sugar thrives; and in the maize belt of the Parana-Paraguay-Uruguay basin.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Climatic Condition: The Warm Temperate Eastern Margin Climate is typified by a warm moist summer and a cool, dry winter. The mean monthly temperature varies between 5°C and 25°C and is strongly modified by maritime influence. The relative humidity is a little high in mid-summer. Rainfall is more than moderate, anything from 25 inches to 60 inches. Another important feature is the fairly uniform distribution of rainfall throughout the year. There is rain every month, except in the interior of central China, where there is a distinct dry season. Rain comes either from convectional sources or as orographic rain in summer, or from depressions in prolonged showers in winter. Local storms, e.g. typhoons, and hurricanes, also occur. It can be sub-divided into three main types – a) The China type: central and north China (including southern Japan (temperate monsoonal). b) The Gulf type: south-eastern United States, (slight-monsoonal). c) The Natal type: the entire warm temperate eastern margin (nonmonsoonal areas) of the southern hemisphere including Natal, eastern Australia and southern Brazil-Paraguay-Uruguay and northern Argentina. Natural Vegetation: The eastern margins of warm temperate latitudes have a much heavier rainfall than either the western margins or the continental interiors and thus have luxuriant vegetation. The lowlands carry both evergreen broad-leaved forests and deciduous trees quite similar to those of the tropical monsoon forests. On the highlands, are various species of conifers such as pines and cypresses that are important softwood. Economy: The warm temperate eastern margins are the most productive parts of the middle latitudes. Besides the widespread cultivation of. Maize and cotton in the Corn and Cotton Belts of U.S.A. fruit and tobacco are also grown. Rice, tea and mulberries are extensively grown in monsoon China. Elsewhere are found other products of economic importance, e.g. cane sugar in Natal, coffee and maize in South America and dairying in New South Wales and Victoria.

3.8 The Cool Temperate Western Margin (British Type) Climate Distribution Climate The cool temperate western margins are under the permanent influence of the Westerlies all round the year. They are also regions of much cyclonic activity, typical of Britain, and are thus said to experience the British type of climate. From Britain, the climatic belt stretches far inland into the lowlands North-West Europe, including such regions as northern and western France, Belgium, the Netherlands, Denmark, western Norway and also north-western Iberia. In the southern hemisphere, the climate is experienced in southern Chile, Tasmania and most parts of New Zealand, particularly in South Island.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Climatic Conditions Temperature: The mean annual temperatures are usually between 5°C and 15°C. The annual range of temperature is small. Summers are, in fact, never very warm. Monthly temperatures of over 18°C even in mid-summer are rare. Precipitation: The British type of climate has adequate rainfall throughout the year with a tendency towards a slight winter or autumn maximum from cyclonic sources. Since the rainbearing winds come from the west, the western margins have the heaviest rainfall. The amount decreases eastwards with increasing distance from the sea. Natural Vegetation: The natural vegetation of this climatic type is deciduous forest. The trees shed their leaves in the cold season. This is an adaptation for protecting themselves against the winter snow and frost. Shedding begins in autumn, the 'fall' season, during which the leaves fall and are scattered by the winds. Some of the more common species include oak, elm, ash, birch, beech, poplar, and hornbeam. Unlike the equatorial forests, the deciduous trees occur in pure stands and have greater lumbering value from the commercial point of view. The deciduous hardwoods are excellent for both fuel and industrial purposes. Economy: The region differs from many others in its unprecedented industrial advancement. The countries are concerned in the production of machinery, chemicals, textiles and other manufactured articles rather than agriculture, fishing or lumbering, though these activities are well represented in some of the countries. Fishing is particularly important in Britain, Norway and British Columbia. A very large part of the deciduous woodlands have been cleared for fuel, timber or agriculture.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

3.9 The Cool Temperate Continental (Siberian) Climate Distribution The Cool Temperate Continental (Siberian) Climate is experienced only in the northern hemisphere where the continents within the high latitudes have a broad east-west spread. On its pole ward side, it merges into the Arctic tundra of Canada and Eurasia at around the Arctic Circle. The Siberian Climate is conspicuously absent in the southern hemisphere because of the narrowness of the southern continents in the high latitudes. The strong oceanic influence reduces the severity of the winter and coniferous forests are found only on the mountainous uplands of southern Chile, New Zealand, Tasmania and south-east Australia.

Climatic Conditions: Temperature: The climate of the Siberian type is characterized by a bitterly cold winter of long duration, and a cool brief summer. Spring and autumn are merely brief transitional periods. The extremes of temperature are so great in Siberia that it is often referred to as the 'cold pole of the earth'. Some of the lowest temperatures in the world are recorded in Verkhoyansk. Precipitation: The interiors of the Eurasian continent are so remote from maritime influence that annual precipitation cannot be high. Generally speaking, a total of 15 to 25 inches is typical of the annual precipitation of this sub-Arctic type of climate. It is quite well distributed throughout the year, with a summer maximum from convectional rain. Natural Vegetation No other trees are as well adapted as the conifers to withstand such an inhospitable environment as the Siberian type of climate. The coniferous forest belts of Eurasia and North America are the richest sources of softwood for use in building construction, furniture, matches, paper and pulp, rayon and other branches of the chemical industry, The world's Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

greatest softwood producers are U.S.S.R, U.S.A., Canada and the Fenoscandian countries (Finland, Norway and Sweden). In the field of newsprint, Canada has outstripped all other producers, accounting for almost half of the world's total annual production. There are four major species in the coniferous forests – a) Pine, e.g. white pine, red pine, Scots pine, Jack pine, b) Fir, e.g., Douglas fir and balsam fir, c) Spruce and d) Larch. Economy: The coniferous forest regions of the northern hemisphere are comparatively little developed. Only in the more accessible areas are the forests cleared for lumbering. There is little agriculture, as few crops can survive in the sub-Arctic climate of these northerly lands. Many of the Samoyeds and Yakuts of Siberia, and some Canadians are engaged in hunting, trapping and fishing.

3.10 The Cool Temperate Eastern Margin (Laurentian) Climate Distribution The Cool Temperate Eastern Margin (Laurentian) Climate is an intermediate type of climate between the British and the Siberian type of climate. It has features of both the maritime and the continental climates. The Laurentian type of climate is found only in two regions. One is north-eastern North America, including eastern Canada, north-east U.S.A., (i.e. Maritime Provinces and the New England states), and Newfoundland. This may be referred to as the North American region. The other region is the eastern coastlands of Asia, including eastern Siberia, North China, Manchuria, Korea and northern Japan. It may be referred to as the Asiatic region. In the southern hemisphere, this climatic type is absent because only a small section of the southern continents extends south of the latitude of 40° S.

Climatic Conditions: The Laurentian type of climate has cold, dry winters and warm, wet summers. Winter temperatures may be well below freezing-point and snow falls to quite a depth. Summers are as Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

warm as the tropics (21° - 27°C) and if it were not for the cooling effects of the off-shore cold currents from the Arctic, the summer might be even hotter. Though rain falls throughout the year, there is a distinct summer maximum from the easterly winds from the oceans. Of the annual precipitation of 30 to 60 inches, two-thirds come in the summer. Winter is dry and cold, because the winds are dry Westerlies that blowout from the continental interiors. Natural Vegetation The predominant vegetation of the Laurentian type of climate is cool temperate forest. The heavy rainfall, the warm summers and the damp air from fogs, all favour the growth of trees. Generally speaking, the forest tends to be coniferous north of the 50° N. parallel of latitude. The increase in the length and severity of the winter excludes forests that are not adaptable to cold conditions. Oak, beech, maple and birch are the principal trees. Economy Lumbering and its associated timber, paper and pulp industries are the most important economic undertaking. Agriculture is less important in view of the severity of the winter and its long duration. Fortunately the maritime influence and the heavy rainfall enable some hardy crops to be raised for local needs. The fertile Annapolis valley in Nova Scotia is the world’s most renowned region for apples. Fishing is, however, the most outstanding economic activity of the Laurentian climatic regions.

3.11 The Arctic or Polar Climate Distribution The polar type of climate and vegetation is found mainly north of the Arctic Circle in the northern hemisphere. The ice-cap is confined to Greenland and to the highlands of these highlatitude regions, where the ground is permanently snow-covered. The lowlands, with a few months ice-free, have tundra vegetation. They include the coastal strip of Greenland, the barren grounds of northern Canada and Alaska and the Arctic seaboard of Eurasia.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Climatic Conditions Temperature: The polar climate is characterized by a very low mean annual temperature and its warmest month in June seldom rises to more than 10°C. In mid-winter (January) temperatures are as low as – 35°C and much colder in the interior. Winters are long and very severe; summers are cool and brief. Precipitation: Precipitation is mainly in the form of snow, falling in winter and being drifted about during blizzards. Snowfall varies with locality; it may fall either as ice crystals or large, amalgamated snowflakes. Convectional rainfall is generally absent because of the low rate of evaporation and the lack of moisture in the cold polar air. There is normally a summer maximum, and the precipitation is then in the form of rain or sleet. Natural vegetation In such an adverse environment as the tundra, few plants survive. The greatest inhibiting factor is the region's deficiency in heat. With a growing season of less than three months and the warmest month not exceeding 10o C (the tree-survival line), there are no trees in the tundra. Such an environment can support only the lowest form of vegetation, mosses, lichens and sedges. Drainage in the tundra is usually poor as the sub-soil is permanently frozen. Ponds and marshes and waterlogged areas are found in hollows. Economy: Human activities of the tundra are largely confined to the coast. Where plateaux and mountains increase the altitude, it is uninhabitable, for these are permanently snow-covered. The few people who live in the tundra live a semi-nomadic life and have to adapt themselves to the harsh environment. The Arctic region, once regarded as completely useless, is now of some economic importance. Apart from the efforts of the various governments in assisting the advancement of the Arctic inhabitants the Eskimos, Lapps, Samoyeds etc., new settlements have sprung up because of the discovery of minerals.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

4] Mains Questions 1. Major hot deserts in northern hemisphere are located between 20-30 degree north and on the western side of the continents. Why? (UPSC 2013/10 Marks) 2. “As regards the increasing rates of melting of Arctic ice, the interests of the Arctic Council nations may not coincide with those of the wider world. “Explain. (UPSC 2011/12 Marks) 3. Why is India undertaking expeditions to Antarctica? Describe the influence of Antarctica and Antarctic ocean on the climate of India and on the nutrient and energy supply to Indian Ocean.

5] Prelims Questions 1.

“Climate is extreme, rainfall is scanty and the people used to be nomadic herders.” The above statement best describes which of the following regions? (2013) (a) African Savannah (b) Central Asian Steppe (c) North American Prairie (d) Siberian Tundra

2.

Which one of the following is the (2012) Characteristic climate of the Tropical Savannah Region? (a) Rainfall throughout the year (b)Rainfall in winter only (c) An extremely short dry season (d) A definite dry and wet season

3.

What could be the main reason/reasons of the formation of African and Eurasian desert belt? (2011) 1. It is located in the sub-tropical high pressure cells. 2. It is under the influence of warm ocean currents. Which of the statements given above is/are correct in this context? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

4.

A geographic region has the following distinct characteristics: 1. Warm and dry climate 2. Mild and wet winter 3. Evergreen oak trees The above features are the distinct characteristics of which one of the following regions? (2010) (a) Mediterranean (b) Eastern China (c) Central Asia (d) Atlantic coast of North America

5.

Consider the following statements: (2002) 1. In equatorial regions, the year is divided into four main seasons. 2. In Mediterranean region, summer receives more rain. 3. In China type climate, rainfall occurs throughout the year. 4. Tropical highlands exhibit vertical zonation of different climates. Which of these statements are correct/ (a) 1, 2, 3 and 4 (b) 1, 2 and 3 (c) 1, 2 and 4 (d) 3 and 4

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 22

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

6.

The temperature and rainfall of a meteorological station are given below: Temperature (0C) Rainfall (cm) (2001)

Average Temperature: 12.80C Average Rainfall: 54.9 cm per annum Identify the region having the above climatic pattern from amongst the following: (a) Mediterranean region (b) Monsoon region (c) Steppe region (d) N.W. European region 7.

Consider the following statements: 1. The annual range of temperature is greater in the Pacific Ocean than that in the Atlantic Ocean. 2. The annual range of temperature is greater in the Northern Hemisphere than that in the Southern Hemisphere. Which of the statements given above is/are correct? (2007) (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 23

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 16

MISCELLANEOUS TOPICS LIKE EL NINO, LA NINA, ENSO, URBAN CLIMATE, APPLIED CLIMATOLOGY, HEAT ISLAND ETC.

Contents: 1

EL NIÑO 1.1 1.2 1.3 1.4

2

EL NIÑO - Southern Oscillation (ENSO) LA NIÑA Walker Circulation EL NIÑO & LA NIÑA Modoki

Urban Climate 2.1 2.2 2.3

Urban Heat Island Atmospheric Pollution Over Cities Urban Climate and Global Climate Change

3

Microclimate

4

Applied Climatology 4.1 4.2 4.3 4.4 4.5 4.6 4.7

Climate and Natural Vegetation Climate and Agriculture Climate and Animal Husbandry Climate and Housing Air Pollution and Health Climate and Economy Climatic Adaptation

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

1] EL NIÑO Near the end of each year as the southern hemispherical summer is about to peak, a weak, warm counter-current1 flows southward along the coasts of Ecuador and Peru in the eastern equatorial Pacific Ocean, replacing the cold Peruvian current (an eastern boundary current along South America). In the past, local residents referred to this annual warming as “El Niño,” (Spanish: meaning “The Boy Child”) due to its appearance around the Christmas season. For Peruvian fishermen, it signifies the end of the fishing season. Normally, these warm countercurrents last for at most a few weeks when they again give way to the cold Peruvian current. However, every three to seven years, this counter-current is unusually warm and strong. It lasts for several months and is often accompanied by heavy rainfall in the arid coastal regions of Ecuador and northern Peru. Over time the term El Niño began to be used in reference to these major warm episodes.

Figure 1 – El Nino conditions: Warm water pool approaches the South American coast. The absence of cold upwelling increases warming. Under normal conditions, the cold Peruvian current flows equatorward along the coast of Ecuador and Peru (figure 2). The Peruvian current is slow and thus not very strong. Near the coast, it is only about 200m deep, while increasing to 700m offshore. In the absence of an El Niño, prevailing surface winds deviates water considerably to the left or away from the coast, with subsequent upwelling of cold water from below. This upwelling of deep, nutrient-filled waters is the primary food source for millions of fish, particularly anchovies along the Pacific Coast of South America.

1

Counter-equatorial current - Between the North and South Equatorial currents, there is a surface current moving down slope west to east, the Equatorial Countercurrent. This current helps to return surface water accumulated against the eastern coast of continents by the Equatorial currents. It is this counter-current in Pacific Ocean that increases in strength and triggers an El-Niño event. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

During El Niño, surface winds are weaker than their average value. Weaker surface winds are beneficial for warm counter-equatorial current that becomes strong and replaces Peruvian current along the coast of South America. This current carries warm water of west Pacific Ocean to central and eastern Pacific Ocean. It increases the Pacific Ocean’s sea surface temperature (SST).

Figure 2 – Normal Pacific pattern: Equatorial winds gather warm water pool toward the west. Cold water upwells along South American coast.

1.1 EL NIÑO – Southern Oscillation (ENSO) ENSO consists of two components. The first, mainly oceanic, is known as El Niño. The second, mainly atmospheric, component of ENSO has been described as the Southern Oscillation. We already know that El Niño is the unusual warm oceanic water at pacific coast of South America. Major El Niño events are intimately related to large-scale atmospheric circulation. Each time an El Niño occurs, the barometric pressure drops over large portions of the south-eastern Pacific, whereas in the western Pacific, near Indonesia and northern Australia, the pressure rises. Then, as a major El Niño event comes to an end, the atmospheric pressure difference between these two regions swings back in the opposite direction. This see-saw pattern of atmospheric pressure between the eastern and western Pacific is known as the "Southern Oscillation". The strength of the Southern Oscillation is measured by the Southern Oscillation Index (SOI). The SOI is computed from fluctuations in the surface air pressure difference between Tahiti, French Polynesia and Darwin, Australia. El Niño episodes are associated with negative values of the SOI, meaning there is below normal pressure over Tahiti and above normal pressure of Darwin. ENSO appears to be a necessary mechanism for maintaining long-term global climate stability by transporting heat from the Tropics to the higher latitudes. Effects of EL NINO/ENSO The abnormally strong winds originating from the west push masses of warm surface water from the equatorial region against the South-American coast, and are ultimately deflected towards Mexico, Peru, and Ecuador, creating an area of warm water



Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

thousands of kilometers in length. The sun warms the surface layer still further, thus enhancing the effect. The thermocline2 falls, and along with it the pool of nutrient rich water. In an immediate effect, this warm blob of water blocks off the upwelling of colder along South American coast, nutrient rich water driving anchovies fish into starvation. These fish do no longer support large population of fish-feeding birds, whose droppings (guano) are mined for fertilizer. With the disappearance of anchovies and other marine organisms, predators like seabirds, further up the food-chain, experience a drastic decline in nutritional resources. In a long-lasting ENSO event, the dissolved seawater oxygen content becomes depleted. This favours production of foul-smelling hydrogen-sulfide and other gases, blackening the "lead paint" on ships and producing other discoloring effects During El Nino, some inland areas of South America that are normally arid receive an uncommon abundance of rain. Here pastures and cotton fields have yields far above the norm. Most important aspect of an ENSO event is the change in the precipitation patterns over the globe (Figure 3).









Figure 3 – global precipitation pattern during El Nino

2

Thermocline – is a thin but distinct layer in a large body of fluid (e.g. water, such as an ocean or lake, or air, such as an atmosphere) in which temperature changes more rapidly with depth than it does in the layers above or below. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

1.2 LA NIÑA La Niña (Spanish: meaning “The Girl Child”) is a counterpart of El Niño. During La Niña, the cold pool in the eastern tropical Pacific intensifies and the trade winds strengthen. During a period of La Niña, the sea surface temperature (SST) across the equatorial Eastern Central Pacific Ocean will be lower than normal by 3–5 °C. Effects of LA NIÑA Africa - La Niña results in wetter-than-normal conditions in Southern Africa from December to February, and drier-than-normal conditions over equatorial East Africa over the same period. Asia - During La Niña years, the formation of tropical cyclones, along with the subtropical ridge position, shifts westward across the western Pacific ocean, which increases the landfall threat to China. Generally, South Asian monsoon is good during La Nina events as it strengthens the Indian Ocean loop of walker cell.





Figure 4 – global precipitation pattern during La Nina South America - During a time of La Niña, drought plagues the coastal regions of Peru and Chile. North America - La Niña causes mostly the opposite effects of El Niño, aboveaverage precipitation across the Northern California, and the northern Rockies etc. There are above average hurricanes in the Atlantic and less in the Pacific.

 

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

1.3 Walker Circulation The Walker Circulation refers to an east-west circulation of the atmosphere above the tropical Pacific, with air rising above warmer ocean regions (normally in the west), and descending over the cooler ocean areas (normally in the east). Its strength fluctuates with that of the Southern Oscillation. The characteristics of the Walker Circulation were largely determined by the coupling between the tropical atmosphere and oceans. Walker Circulation is closely tied to that of the Southern Oscillation and El Niño. The term Walker Circulation was first introduced in 1969 by Jacob Bjerknes. After Bjerknes, there have been reports of similar east–west circulation cells spanning different longitudinal sectors along the Equator. Compared to pacific cell, these cells cover smaller longitude ranges and tend to have weaker vertical motions (figure 5). The Indian Ocean cell is associated with the development of the South Asian monsoon. Generally, walker circulation is associated with only cells of Pacific Ocean.

Figure 5 - east–west atmospheric circulation along the longitude–height plane over the Equator. The cell over the Pacific Ocean is referred to as the Walker Circulation. The easterly trade winds are part of the low-level component of the Walker Circulation. Typically, the trade winds bring warm moist air towards the Indonesian region. Here, moving over normally very warm seas, moist air rises to high levels of the atmosphere. The air then travels eastward before sinking over the eastern Pacific Ocean. The rising air is associated with a region of low air pressure, towering cumulonimbus clouds and rain. High pressure and dry conditions accompany the sinking air. Sinking air completes the loop. During El Niño event, the Walker Circulation and accompanying east–west circulations differ significantly from normal conditions (figure 6a). Rising motions prevailed at almost all longitudes. In particular, strong ascent in the mid-troposphere replaced descending air motion over the central and eastern Pacific, where the water was anomalously warm due to El Niño. The Walker Circulation is weakened and became less organized. Walker Circulation may even reverse in the more intense episodes of El Niño. In this instance westerly winds are observed over parts of the equatorial western and central Pacific where normally easterly (trade) winds would be expected. Oceans around Australia cool, and slackened trade winds feed less moisture into the region.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Figure 6 – Walker circulation during La Niña and El Niño During La Niña, or reverse El Niño, the Walker Circulation is enhanced and became very pronounced, with well-defined rising and sinking branches (figure 6b). While the cells in Pacific and Atlantic Oceans intensify, the Indian Ocean cell weakens. Impacts on world climate The Walker Circulation regulates global exchange of momentum, heat, and water vapor within the tropics via massive overturning motions. In doing so, it plays an important role in the balance of atmospheric energy in the equatorial region and in determining the characteristics of weather and climate in the tropics. The strongest atmospheric impacts associated with the fluctuations of the Walker Circulation are found over tropical and subtropical regions around the Pacific Rim. During an El Niño, the weakening Walker Circulation causes widespread drought in Indonesia/maritime continent, drought in northeastern Brazil, severe floods in Peru and Ecuador, and in south-eastern Brazil and northern Argentina. During a La Niña, the Walker Circulation intensifies and leads to rainfall anomalies with reverse sign compared to El Niño. The Walker Circulation also represents the fundamental link between the changes in sea surface temperature in the eastern Pacific and the variability of the Asian–Australian monsoon. The mechanisms that are responsible for the interactions between the monsoon and El Niño Southern Oscillation have been attributed, in part, to the changes in the Walker Circulation. During El Niño, Walker Circulation is weakened and shifted eastward owing to reduced east– west sea surface temperature gradient across the Pacific Ocean. This suppresses broad-scale convection over the western Pacific and eastern Indian Ocean and leads to weaker South Asian monsoon.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Walker circulation interacts with the Hadley cell3 in the form of an inverse variation between the two circulations. When the cold water belt along the Equator is well developed, the air above it will be too cold and heavy to join the ascending motion in the Hadley circulations. Instead, the equatorial air flows westward between the Hadley circulations of the two hemispheres to the warm west Pacific. These changes are the causes for severe weather and climate anomalies in the Asian–Pacific–American regions.

1.4 EL NIÑO & LA NIÑA Modoki Like El Niño, El Niño Modoki (Japanese: meaning ‘similar, but different’) is a coupled oceanatmosphere phenomenon in the tropical Pacific. El Niño is characterized by strong anomalous warming in the eastern equatorial Pacific. On the other hand, El Niño Modoki is associated with strong anomalous warming in the central tropical Pacific and cooling in the eastern and western tropical Pacific (figure 7b).

Figure 7 – El Nino Modoki and La Nina Modoki La Nina Modoki is associated with low sea surface temperature (SST) in central tropical Pacific Ocean while eastern and western tropical pacific are warm relatively. It produces two walker cells with rising limbs at both ends of tropical pacific and descending limb of both cells fall at central equatorial pacific (figure 7d). Together El Nino Modoki and La Nina Modoki forms ‘ENSO Modoki’. Several studies have shown that the ENSO Modoki has become more prominent in recent times, as compared to ENSO, and thereby changing the teleconnection pattern arising from the tropical Pacific. The ENSO Modoki has distinct teleconnections and affects many parts of the world. For example, the West Coast of United States of America is wet during El Nino but dry during El Nino Modoki. Recent studies show that teleconnections associated with ENSO Modoki influence the rainfall over India and South Africa.

3

Hadley Cells are the low-latitude overturning circulations that have air rising at the equator and air sinking at roughly 30° latitude.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

El Nino results in anomalous two-cell Walker Circulation over the tropical Pacific, with a wet region in the central Pacific. During pre-monsoon and post-monsoon seasons in the North Indian Ocean, more cyclones form in the Bay of Bengal compared with the Arabian Sea. El Nino is found to suppress cyclone formation in the Arabian Sea. While in some years more cyclones form in the Arabian Sea than usual. This is due to El Nino Modoki. During El Nino Modoki, one of the descending limbs of the walker cell is over the Bay of Bengal which causes dry conditions not conducive for cyclone formation. On the other hand, there is large convergence over the Arabian Sea during an El Nino Modoki explaining the large number of cyclones in that region.

2] Urban Climate The urban areas across the world experience a climate distinctive from the regional pattern. The process of urbanization changes the physical surroundings and induces alterations in the energy, moisture, and motion regime near the surface. The agglomeration of buildings interferes with the

wind and atmospheric characteristics to a degree at least equal to that of a large forest. An urban area changes the air’s composition, temperature and precipitation graphs etc. Wind speed is lower in cities than in open areas due to obstructive nature of structure of cities. Actual effect varies with the street design, the season and the time of day. The wind tends to channel down streets parallel to the general direction of flow, especially in a city with canyon like streets (high rise buildings). While if street pattern is at right angle to the wind, strong lee effects may be experienced. During the day, city wind speeds are considerably less than surrounding areas, but at night, turbulence over the city makes contrasts less apparent. Ruralurban contrasts are most marked with strong winds, and the effects are therefore more evident in winter4 than in summers. Cities absorb much less water per area than rural areas, as much of city area is paved or built on. In some areas this creates a need for specific measures to reduce the risk of localised flooding during periods of heavy rainfall. Heavy construction activities in flood plains of rivers flowing through cities increase the period and intensity of flooding. Cities tend to have lower humidity in contrast to rural or forested areas. Due to concrete surface, rapid surface run-off removes water. The lower density of vegetation and general absence of water bodies etc. also contribute for lower humidity and evaporation. On the other hand, it seems likely that under certain conditions, thermal and turbulences over cities may trigger off precipitation or thunderstorms. Many cities encounter more light rain and thunder than surrounding areas, resulting in a slight increase in total precipitation.

2.1 Urban Heat Island The term "heat island" describes built up areas that are hotter than nearby surrounding areas. An urban heat island (UHI) is a metropolitan area that is significantly warmer than its surrounding rural areas due to human activities. The phenomenon was first investigated and

4

There is much greater variation in barometric pressure during the winter than during the summer. On average, high pressure systems are higher pressure and low pressure systems are lower pressure. This leads to a more rapid flow of air between the systems. This fluctuation is caused by much greater variation in temperature during the winter. While most summer days are roughly the same temperature, winter temperatures fluctuate dramatically.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

described by Luke Howard in the 1810s. The temperature difference usually is larger at night than during the day, and is most apparent when winds are weak. The typical temperature difference is several degrees between the center of the city and surrounding fields. It can be as high as 10 °C.

Figure 8 – Urban Heat Island Profile There are three main factors responsible for this: The direct production of heat in city from fires, industry, home Heat conserving properties of the bricks and fabric of the city Blanketing effect by atmospheric pollution on outgoing radiation

  

Heat trapped in concrete buildings, pavements during day time is released very slowly in the form of long wave radiations, making cooling a slow process. With a decreased amount of vegetation, cities also lose the shade and cooling effect of trees, the low albedo of their leaves, and the removal of carbon dioxide. The tall buildings within many urban areas provide multiple surfaces for the reflection and absorption of sunlight, increasing the efficiency with which urban areas are heated. Tall buildings also inhibit cooling by convection and pollution from dissipating. Chemicals emitted by cars, industries affect sunshine in different ways, often trapping it and creating more heat. All these factors cause a change in the energy balance of the urban area. As a population center grows, it tends to expand its area and increase its average temperature. For instance, Los Angeles has been very much affected by its urban heat island. The city has seen its average temperature rise approximately 0.5 °C every decade since the beginning of its super-urban growth since the World War II era. Other cities have seen increases of 0.1°-0.4°C each decade. Each city's urban heat island varies based on the city structure and thus the range of temperatures within the island varies as well (figure 8). Parks and greenbelts reduce temperatures while the Central Business District (CBD), commercial areas, and even suburban housing tracts are areas of warmer temperatures. Every house, building, and road changes the microclimate around it, contributing to the urban heat islands of our cities. Impact on urban dwellers The increased heat of our cities increases discomfort for everyone Homes require an increase in the amount of energy used for cooling purposes.

 

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:





The UHI decreases air quality by increasing the production of pollutants such as ozone, and decreases water quality as warmer waters flow into area streams and put stress on their ecosystems. Increased heat enhances photochemical reactions, which increases the particles in the air and thus contributes to the formation of smog and clouds. For instance, London receives approximately 270 fewer hours of sunlight than the surrounding countryside due to clouds and smog.

The heat island effect can be counteracted in several ways: 



Most prominent is to use light color or white or reflective materials in construction work – roof top, houses, road, and pavements – to increase the albedo. Dark/Black surfaces can be up to 21°C hotter than light surfaces and that excess heat is transferred to the building itself, creating an increased need for cooling. By switching to light colored roofs, buildings can use 40% less energy. Mitigation of the UHI effect can be accomplished through the use of green roofs (figure 9). The roof of a building is partially or completely covered with vegetation and a growing medium, planted over a waterproofing membrane. Rooftop ponds are another form of green roofs which are used to treat grey-water. Apart from mitigating the UHI effect, Green roofs serve several purposes for a building, such as absorbing rainwater, providing insulation, creating a habitat for wildlife, and helping to lower urban air temperatures. Financially, it reduces energy usage, bring tax incentives provided by the government, increases life span of roof etc.

Figure 9 – green roof 



Green Building is constructed in a manner that is resource-efficient, environmentally sustainable. Sun light is used efficiently within the building. It lowers the overall energy usage of the building and thus, helps in reducing the effect of UHI. Another way is to increase the amount of well-watered vegetation. It is empirically tested that the cooling potential per area was highest for street with higher tree density. They increase evapotranspiration, which decreases the air temperature. Trees can reduce energy costs by 10-20%.

Typically heat island mitigation is part of a community's energy, air quality, water, or sustainability effort. Activities to reduce heat islands range from voluntary initiatives, such as cool pavement demonstration projects, to policy actions, such as requiring cool roofs via building codes. Most mitigation activities have multiple benefits, including cleaner air, improved human health and comfort, reduced energy costs, and lower greenhouse gas emissions. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

2.2 Atmospheric Pollution Over Cities Generally any substance that people introduce into the atmosphere that has damaging effects on living things and the environment is considered air pollution. A city atmosphere is affected by soot, ash, gases, fumes, smoke and oxides of sulphur, carbon, nitrogen. Carbon dioxide and other greenhouse gases such as Methane are the main pollutant that is warming Earth. Sulfur dioxide and closely related chemicals are known primarily as a cause of acid rain. These have effect of blanketing the radiation over a city, increasing the city’s albedo. These also act as a condensation nuclei. Under normal conditions, much of this polluted part is diffused upwards by turbulence and removed by stronger winds at height. However, high rise buildings of cities act as obstruction in free movement of these particles. The greatest concentrations of smoke occur with low wind speeds, temperature inversion and high relative humidities. It requires multifold strategies with the active participation of civil society and individual city people. On a larger scale, governments are taking measures to curb the air pollution through legislation, tax benefits and other schemes. Civil society can play its part by spreading environmental awareness among people and helping people in urban forestry etc.

2.3 Urban Climate and Global Climate Change The changes in urban Climate are strongly linked to global climate change. As centres for socioeconomic activities, cities produce large amounts of Green House Gases, most notably CO2 as a consequence of human activities such as transport, development (e.g. concrete production), and waste related to heating and cooling requirements etc. cities are the top consumer of energy produced largely through fossil fuels. Many cities are vulnerable to the projected consequences of climate change (sea level rise, changes in temperature, precipitation, storm frequency) as most develop on or near coast-lines, nearly all produce distinct urban heat islands and atmospheric pollution.

3] Microclimate A microclimate is the distinctive climate of a small-scale area, such as a garden, park, valley or part of a city. The weather variables in a microclimate, such as temperature, rainfall, wind or humidity, may be subtly different to the conditions prevailing over the area as a whole and from those that might be reasonably expected under certain types of pressure or cloud cover. Indeed, it is the mixture of many, slightly different microclimates that actually makes up the climate for a town, city or wood. Microclimate can be caused by several factors such as      

Near water bodies Heat retaining capacity of urban areas Slope of mountains Absence of vegetation such as in central business districts Large presence of vegetation such in protected areas Soil type

There is a distinctive microclimate for every type of environment on the Earth’s surface:

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Upland regions Upland areas have a specific type of climate that is notably different from the surrounding lower levels. Temperature usually falls with height at a rate of between 5 and 10 °C per 1,000 metres, depending on the humidity of the air. This means that even quite modest upland regions can be significantly colder on average. Occasionally, a temperature inversion5 can make air warmer in upland regions, but such conditions rarely last for long. With higher hills and mountains, the average temperatures can be so much lower that winters are longer and summers much shorter. Higher ground also tends to be windier, which makes for harsher winter weather. Katabatic wind6 also creates cold conditions in the valley. The effect of this is that plants and animals are often different from those at low levels. Coastal regions The coastal climate is influenced by both the land and sea between which the coast forms a boundary. The thermal properties of water are such that the sea maintains a relatively constant day to day temperature compared with the land. The sea also takes a long time to heat up during the summer months and, conversely, a long time to cool down during the winter. Coastal microclimates display different characteristics depending on where they occur on the earth’s surface. In the tropics, sea temperatures change little and the coastal climate depends on the effects caused by the daytime heating and night-time cooling of the land. In temperate latitudes, the coastal climate owes more to the influence of the sea than of the land and coasts are usually milder than inland during the winter and cooler in the summer. Around the poles, sea temperatures remain low due to the presence of ice, and the position of the coast itself can change as ice thaws and the sea re-freezes. Forest regions Tropical rainforests cover only about 6% of Earth’s land surface, but it is believed they have a significant effect on the transfer of water vapour to the atmosphere. This is due to a process known as evapotranspiration from the leaves of the forest trees. Woodland areas can be cooler and less windy than surrounding grassland areas, with the trees acting as a windbreak and the incoming solar radiation being ‘filtered’. Urban regions These are perhaps the most complex of all microclimates. Temperature is higher relative to surroundings (see ‘Urban Heat Island’ topic for details). The distribution of rainfall over a town or city is very much influenced by topography with the largest values occurring over the more hilly regions and lowest values in more low—lying areas. The nature of rainfall varies during the year. In summer, rainfall is often of a showery nature, falling over short periods, and is normally more intense than in winter.

5

Temperature inversion – It is a deviation from the normal change of an atmospheric temperature with altitude i.e., an increase in temperature with height, or to the layer ("inversion layer") within which such an increase occurs.

6

Katabatic wind - a wind that carries high density air from a higher elevation down a slope under the force of gravity. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

4] Applied Climatology Weather and climate are important factors in determining our day to day and longer term activities and life styles. The ways in which the climatic elements affect every form of economic and social activity are now receiving increasing attention from climatologists. ‘It is since second world war that new consciousness arose about the potentialities of climatology as an active subject with immense practical utility for planning almost all human requirements ranging from the development of water resources to the eradication of diseases.

4.1 Climate and Natural Vegetation Natural vegetation is an indicator of the climate. But they are interrelated as one influences the other to a great extent. The knowledge of optimum climatic conditions in different stages of the growth of forest trees is essential for those engaged in the task of afforestation for timber, watershed management. In silvicultural7 practices the interrelationship between forests and climate must be taken into account. Microclimate of forest is taken into account for getting higher yields.

4.2 Climate and Agriculture Food is the first and foremost need of humans. As a matter of fact, climate and vegetation are complementary to each other. Weather components – temperature, precipitation, humidity, wind etc. – play the most prominent role in the crop production. For instance, crops like coffee, bananas and sugar cane are very sensitive to frosts. Coconuts and pineapples need temperature above 21 oC for their best growth. In hilly areas, the citrus and other sensitive crops are planted on the slopes exposed to the sun avoiding the valleys which are subject to winter frosts at night.

4.3 Climate and Animal Husbandry Meat and Milk products are obtained by animals which are dependent on pastures and feed crops. Pasture land and crops are highly influenced by climatic factors. Of all the climatic elements affecting the animal husbandry temperature factor is indeed the most important. If the temperature is very high, milk produced from animals is less. It is required to maintain the temperature otherwise continuous high temperature reduces yield of flesh and fat from animals. Precipitation has direct effect on animals. Availability of grass in the pastures is much reduced because of snowfall. Animals feel discomfort in extreme relative humidity conditions. In animal husbandry, natural or artificial shelters are built to keep the animals safe from the negative effect of climate. By heating or air conditioning, temperature is controlled in animal shelters.

4.4 Climate and Housing It is the climate which determines the house types. Igloo in polar region (the house of Eskimos), and open houses in tropical areas are the glaring examples. In terms of building or architectural climatology, the micro-climatic conditions are influenced by a number of factors such as local relief, nearby buildings, landscaping, existing water bodies and industrial wastes. Climate is an important input in green buildings which tries to maximize usage of sunshine, winds etc.

7

Silviculture is the practice of controlling the establishment, growth, composition, health, and quality of forests to meet diverse needs and values.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

In tropical countries, double roofs to ensure free movement of air reduce the flow of absorbed solar heat into a building. The type of roofs designed for houses in different climatic conditions take care of precipitation or snowfall.

4.5 Air Pollution and Health Medical climatology studies the relationship between human health and climate or weather. Some of the local winds like the loo, cold wave etc are said to be the causes of irritability, depression, dizziness and hypertension. High concentration of pollens in air (such as in Bangalore) causes breathing problems to some people. For instance, local Bangalore government put ban on planting flowering saplings in its parks for certain period of the year to reduce the concentration of pollens in air. All the cities are discharging huge quantity of pollutants into the atmosphere. These pollutants convert into acids through chemical reactions and fall as ‘acid rain’ with rainwater. Study of the atmospheric percentage of these chemical helps in regulating the industries. For instance, vehicular traffic and industry is banned in surrounding of Taj Mahal, Agra. Acid rain is also harmful for plant and marine life. Certain diseases are, indeed, associated with certain climates or with a particular season. Cold season controls the insects’ population by forcing hibernation. That’s the reason tropical diseases such as Dengue and Malaria etc. are prevalent in tropical and subtropical regions. There are certain diseases which are closely associated with seasons. Pneumonia, influenza, measles etc can be cited as examples here. Such close association of diseases with season or climate helps in issuing warnings to people or taking other measures by the government to reduce the impact of same. Municipal bodies in cities of South Asia ensure that water is not logged in parts of cities during monsoon seasons to avoid Malaria and other vector born diseases.

4.6 Climate and Economy Climate research benefits the following industries:        

Insurance Tourism Construction Energy Transport Sport Retail Food Retail Clothing

The insurance industry offers financial protection against climate-related damage. This includes direct impacts from damage due to flood, frost, wind etc. Climate research can help reduce the costs to insurers by quantifying the probability of extreme events, providing year-ahead forecasts and identifying vulnerable regions. There is a peak time of tourists to a particular place. This peak time is directly related to the climate of that particular place. For instance, hilly cold areas’ peak time coincide with summer time. Wind is a potential renewable source of energy in every country. Wind atlas of different region and at different altitude is a crucial input to decide the location and height of wind turbines. Similarly, hydro-electricity plants are established in areas which have continuous supply of water either through glacial or rain. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Transport sectors such as air, shipping etc. are directly impacted by the climate or weather. High altitude ports are frozen during winter season which makes them inaccessible for such period. Atmospheric disturbances, extreme weather conditions such as fog, cold waves etc. interrupts the flights’ schedule. Roads are specially designed for areas which faces extreme weather conditions.

4.7 Climatic Adaptation Humans and many other mammals have unusually efficient internal temperature regulating systems that automatically maintain stable core body temperatures in cold winters and warm summers. In addition, people have developed cultural patterns and technologies that help them adjust to extremes of temperature and humidity. Less massive individuals are more often found in warm climates near the equator, while those with greater bulk, or mass, are found further from the equator in colder regions. This is due to the fact that big animals generally have larger body masses which result in more heat being produced. People living in cold climates prefer drinking alcohol as it increases blood flow to the body extremities, thereby providing a feeling of warmth. With the help of technology, researches are able to stay throughout the year in extremely cold Antarctica and Arctic regions. People are able to live in extremely hot climate of tropical region by using air conditioners.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

UPSC Previous Years’ Mains Questions 1. Bring out the causes for the formation of heat islands in the urban habitat of the world. (100 words) (UPSC 2013/5 marks) 2. Bring out the significance of the various activities of the Indian Meteorological Department. (UPSC 2009/15 Marks)

UPSC Previous Years’ Prelim Questions 1.

La Nina is suspected to have caused recent floods in Australia. How is La Nina different from El Nino? (2011) 1. La Nina is characterised by unusually cold ocean temperature in equatorial Indian Ocean whereas El Nino is characterised by unusually warm ocean temperature in the equatorial Pacific Ocean. 2. El Nino has adverse effect on south-west monsoon of India, but La Nina has no effect on monsoon climate. Which of the statements given above is/are correct? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

2.

A new type of El Nino called El Nino Modoki appeared in the news. In this context, consider the following statements: (2010) 1. Normal El Nino forms in the Central Pacific ocean whereas El Nino Modoki forms in Eastern Pacific ocean. Normal El Nino results in diminished hurricanes in the Atlantic ocean but El Nino Modoki results in a greater number of hurricanes with greater frequency. Which of the statements given above is/are correct? (a) 1 only (b) 2 only (c) Both 1 and 2 (d) Neither 1 nor 2

3.

For short-term climatic predictions, which one of the following events, detected in the last decade, is associated with occasional weak monsoon rains in the Indian subcontinent? (2002) (a) La Nina (b) Movement of Jet Streams (c) El Nino and Southern Oscillation (d) Greenhouse effect on global level

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com

GEOGRAPHY: 17

DIFFERENT TYPES OF IRRIGATION AND IRRIGATION SYSTEMS

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS. www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Contents 1 Irrigation and Benefits of Irrigation ........................................................................................... 2 2 Classification of Irrigation Schemes........................................................................................... 3 2.1 Based on Sources ............................................................................................................... 3 2.1.1 Well and Tube-Wells .................................................................................................... 4 2.1.2 Canal ............................................................................................................................ 4 2.1.3 Tank ............................................................................................................................. 4 2.2 Based on Magnitude .......................................................................................................... 6 2.2.1 Major and Medium vis-à-vis Minor Irrigation Projects ............................................... 7 2.3 Based on Technique of Distribution of Water .................................................................... 7 2.4 Based on the way the water is applied .............................................................................. 9 2.5 On the basis of duration of the applied ........................................................................... 10 2.6 Choice of Irrigation Method ............................................................................................. 10 3 Efficiency ................................................................................................................................. 11 4 Irrigation and National Water Policy ....................................................................................... 11 5 Command Area Development and Water Management (CADWM) ....................................... 12 6 Participatory Irrigation Management (PIM) ............................................................................ 13 7 Accelerated Irrigation Benefits Programme (AIBP) ................................................................. 13 8 Repair, Renovation and Restoration of Water Bodies Scheme................................................ 14 9 Virtual Water ........................................................................................................................... 15

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Getting an irrigation system is easy, but getting the most efficient irrigation system for your needs can be quite a bit harder.

1 Irrigation and Benefits of Irrigation The process of supplying water to crops by artificial means such as canals, tube wells, tanks etc. is known as irrigation. It is used to assist in the growing of agricultural crops, maintenance of landscapes, and revegetation of disturbed soils in dry areas and during periods of inadequate rainfall. In contrast, agriculture that relies only on direct rainfall is referred to as rain-fed or dryland farming. Mankind is getting benefits of irrigation system since ancient time. Archaeological investigation has identified evidence of irrigation where the natural rainfall was insufficient to support crops. For example, Perennial irrigation was practiced in Mesopotamian plains, Terrace irrigation in Syria, Basin irrigation in Egypt etc. With the advent of diesel and electric motors in 20th century, humans increased the area under irrigation by pumping more and more ground water and extending the canals etc. In greater part of India, agriculture is rain-fed. In the incidence of failure of monsoon, the crop fails. The behavior of Indian monsoon is highly erratic. Excess rainfall may cause floods, but scanty rainfall may reduce the crop yield substantially, and in acute cases the crop may be a complete failure. India has very large population and it is estimated that India needs more than 450 million tonnes of grain to meet the demand of growing population. Climate change will result into more instances of erratic climatic conditions and thus, crops are more prone to high variability in rain. The present productivity of irrigated land is about 2.5 tonnes/hectare and less than 0.5 tonnes/hectare for rainfed lands. In this context, there is an urgent need to implement and plan irrigation strategies. India possesses 4% of the total average annual run off in the rivers of the world. The per capita water availability of natural run off is at least 1100 cubic meters/yr. The amount of water that can actually be to put to beneficial use is much less due to severe limitations imposed by physiographic, topographic, interstate issues and the present technology to harness water resources economically. Benefits of irrigation 



Increase in crop yield: the production of almost all types of crops can be increased by providing the right amount of later at the right time, depending on its shape of growth. Such a controlled supply of water is possible only through irrigation. Protection from famine: the availability of irrigation facilities in any region ensures protection against failure of crops or famine due to drought. In regions without irrigation, farmers have to depend only on rains for growing crops and since the rains may not provide enough rainfall required for crop growing every year, the farmers are always faced with a risk.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

 









New areas under cultivation: irrigation brings new areas under cultivation and increases the net area under irrigated cultivation. Cultivation of superior crops: with assured supply of water for irrigation, farmers may think of cultivating superior variety of crops or even other crops which yield high return. Production of these crops in rain-fed areas is not possible because even with the slight unavailability of timely water, these crops would die and all the money invested would be wasted. Elimination of mixed cropping: in rain-fed areas, farmers have a tendency to cultivate more than one type of crop in the same field such that even if one dies without the required amount of water, at least he would get the yield of the other. However, this reduces the overall production of the field. With assured water by irrigation, the farmer would go for only a single variety of crop in one field at anytime, which would increase the yield. Economic development: with assured irrigation, the farmers get higher returns by way of crop production throughout the year, the government in turn, benefits from the tax collected from the farmers in base of the irrigation facilities extended. Hydro power generation: usually, in canal system of irrigation, there are drops or differences in elevation of canal bed level at certain places. Although the drop may not be very high, this difference in elevation can be used successfully to generate electricity. Such small hydro electric generation projects, using bulb-turbines have been established in many canals, like Ganga canal, Sarada canal, Yamuna canal etc. Domestic and industrial water supply: some water from the irrigation canals may be utilized for domestic and industrial water supply for nearby areas. Compared to the irrigation water need, the water requirement for domestic and industrial uses is rather small and does not affect the total flow much. For example, the town of Siliguri in the Darjeeling district of West Bengal, supplies its residents with the water from Teesta Mahananda link canal.

2 Classification of Irrigation Schemes Due to difference in topology, water availability, land availability, feasibility of technology etc., different irrigation technologies exist in the world. Irrigation system is classified under various schemes as discussed below:

2.1 Based on Sources Depending on the availability of surface and underground water, slope of land, nature of the soil and the types of crops grown in a region, a number of sources of irrigation are utilized. The main sources of irrigation used in different parts of the country are (figure 1):    

Wells and tube-wells Canals tanks other sources – springs, kuhls, dhenkli, dongs and bokka

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

2.1.1 Well and Tube-Wells This type of irrigation is practiced since ancient time. It accounts for 62 per cent of the total irrigated area of the country. It is the easiest source of irrigation. It can be installed in a short duration of time. It is however expensive and diminishes the underground water-table, if exploited in unsustainable manner. The largest area under tube-well irrigation is in Uttar Pradesh followed by Rajasthan, Punjab, Madhya Pradesh, Gujarat, and Bihar.

Figure 1: Net Area under irrigation by sources (2009-10) 2.1.2 Canal Canal used to be the main source of irrigation in 1950-51, irrigating almost 50 per cent of the total irrigated area of India. In 1960s, there was a tremendous increase in the tube-well irrigated area promoted by the government. Consequently, the percentage of canal irrigated area declined to less than 40 per cent and in 2009-10, it is only 26 per cent. Canals are an effective in low and leveled relief, productive plain areas where perennial source of surface drainage is available. These conditions are ideally found in the Northern plains of India, Kashmir and Manipur valleys and the Eastern Coastal plains (figure 2). High density of canals is found in Uttar Pradesh with Ganga canal system, Punjab, Haryana and Western Rajasthan with Indira Gandhi Canal. In Peninsular region, Damodar, Mahanadi, Godavari, Krishna, Narmada rivers etc. rivers have important canal system. Uttar Pradesh has the first rank in canal irrigation followed by Andhra Pradesh. 2.1.3 Tank An irrigation tank or tank is an artificial reservoir of any size. It can also have a natural or manmade spring included as part of a structure. In some parts of the country, especially in the peninsular India tank is an important source of irrigation. About 3 per cent of the total irrigated area is under tank irrigation. According to the third minor irrigation census carried out in 2000-01, there are about 5.56 lakh tanks in the country, with the most occurring in the following states: Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

      

West Bengal: 21.2 per cent of all the tanks in the country Andhra Pradesh: 13.6 per cent Maharashtra: 12.5 per cent Chhattisgarh: 7.7 per cent Madhya Pradesh: 7.2 per cent Tamil Nadu: 7.0 per cent Karnataka: 5.0 per cent

Figure 2: India – Source of irrigation Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Many of the tanks, however, dry up during the summer season when more irrigation is required. Due to non-use of these 15 percent tanks nearly 1 M-ha of Irrigation potential is lost. Another, around 2 M-ha of potential is lost due to under utilisation of tanks in use. Loss of potential due to non use is more pronounced in Meghalaya, Rajasthan and Arunachal Pradesh (above 30%), whereas loss of potential due to under utilisation is more than 50 percent in case of Gujarat, Nagaland, Rajasthan, A&N Island and Dadar and Nagar Haveli.

2.2 Based on Magnitude Irrigation Projects in India are classified into three categories on the basis of Culturable command area (CCA) [1] as:   

Major - Projects which have a CCA of more than 10,000 hector are termed as Major Projects Medium - Irrigation Projects which have a CCA of less than 10,000 hector but more than 2,000 hector are termed as Medium projects Minor Irrigation - those Irrigation Projects which have a CCA of 2,000 hector or less are known as Minor projects.

The ultimate irrigation potential of the country from major and medium irrigation projects has been assessed as about 64 M-ha. For the country as a whole, 66% of it has been created. The average rate of creation of irrigation potential through Major and Medium projects from 1951 to 1997 has been found to be of the order of 0.51 Million hectare per year. During the year 1997 to 2005, the rate for creation has been found to be 0.92 Million hectare per year. This increase in pace is probably due to fruition of projects started much earlier, which have been expedited due to increased support through AIBP(Accelerated Irrigation Benefit Programme). Minor irrigation projects have both surface and ground water as their source, while Major and Medium projects mostly exploit surface water resources. Ground water minor irrigation is primarily done through individual and cooperative effort of farmers with the help of institutional finance and their own savings. Surface water minor irrigation schemes are generally funded from the public sector only. The ultimate irrigation potential from minor irrigation schemes have been assessed as 75.84 million ha of which partly would be ground water based (58.46 million ha) and covers about two thirds. By the end of the ninth plan, the total potential created by minor irrigation was 60.41 million ha. Minor irrigation schemes contribute a major share in the growing irrigation across the country accounting for about 65% of the total irrigation potential utilized. The Minor irrigation scheme has been categorized broadly into five major types, namely: 1. 2. 3. 4. 5.

Dugwell Shallow tubewell Deep tubewell Surface flow schemes Surface lift schemes

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

2.2.1 Major and Medium vis-à-vis Minor Irrigation Projects While formulating strategies for irrigation development the water resources planner should realize the benefits of each type of project based on the local conditions. For example, it may not always be possible to benefit remote areas using major/medium projects. At these places minor irrigation schemes would be most suitable. Further, land holding may be divided in such a way that minor irrigation becomes inevitable. However, major and medium projects wherever possible is to be constructed to reduce the overall cost of development of irrigation potential.

2.3 Based on Technique of Distribution of Water Various types of irrigation techniques differ in how the water obtained from the source is distributed within the field. In general, the goal is to supply the entire field uniformly with water, so that each plant has the amount of water it needs, neither too much nor too little. The various irrigation techniques are as under: Surface Irrigation: In surface irrigation systems, water moves over and across the land by simple gravity flow in order to wet it and to infiltrate into the soil. It is often called flood irrigation when the irrigation results in flooding or near flooding of the cultivated land. Surface irrigation can be subdivided into: o Basin irrigation has historically been used in small areas having level surfaces that are surrounded by earth banks (figure 3). The water is applied rapidly to the entire basin and is allowed to infiltrate. Basins may be linked sequentially so that drainage from one basin is diverted into the next once the desired soil water deficit is satisfied. o Furrow irrigation is conducted by creating small parallel channels along the field length in the direction of predominant slope (figure 4). Water is applied to the top end of each furrow and flows down the field under the influence of gravity. o Border strip, otherwise known as border check or bay irrigation could be considered as a hybrid of level basin and furrow irrigation. The field is divided into a number of bays or strips; each bay is separated by raised earth check banks (borders). The bays are typically longer and narrower compared to basin irrigation and are orientated to align lengthwise with the slope of the field.



Figure 3: Basin irrigation

Figure 4: Furrow irrigation using siphon tubes

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Localized Irrigation: Localized irrigation is a system where water is distributed under low pressure through a piped network, in a pre- determined pattern, and applied as a small discharge to each plant or adjacent to it. It is also known as low-flow irrigation system/low volume irrigation/micro-irrigation. Drip irrigation, spray or micro-sprinkler irrigation and bubbler irrigation belong to this category of irrigation methods.



o

Drip Irrigation: Drip irrigation, also known as trickle irrigation, functions as its name suggests (figure 5). Water is delivered at or near the root zone of plants, drop by drop. This method can be the most water- efficient method of irrigation, if managed properly, since evaporation and runoff are minimized. The field water efficiency of drip irrigation is 80 to 90 percent. In modern agriculture, drip irrigation is often combined with plastic mulch, further reducing evaporation, and is also the means of delivery of fertilizer. This is known as fertigation.

Figure 5: Drip Irrigation system o

Sprinkler Irrigation: In sprinkler or overhead irrigation, water is piped to one or more central locations within the field and distributed by overhead high-pressure sprinklers or guns (figure 6). A system utilizing sprinklers, sprays, or guns mounted overhead on permanently installed risers is often referred to as a solid-set irrigation system. Higher pressure sprinklers that rotate are called rotors and are driven by a ball drive, gear drive, or impact mechanism. Guns are used not only for irrigation, but also for industrial applications such as dust suppression and logging. Sprinklers can also be mounted on moving platforms connected to the water source by a hose. Automatically moving wheeled systems known as traveling sprinklers (figure 7) may irrigate areas such as small farms, sports fields, parks, pastures, and cemeteries unattended. The field water efficiency of sprinkler irrigation is 60 to 70%.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Figure 6: Sprinkler irrigation 

Figure 7: Travelling Sprinkler irrigation

Sub-irrigation: Sub-irrigation also sometimes called seepage irrigation has been used for many years in field crops in areas with high water tables. It is a method of artificially raising the water table to allow the soil to be moistened from below the plants' root zone. Often those systems are located on permanent grasslands in lowlands or river valleys and combined with drainage infrastructure. A system of pumping stations, canals, weirs and gates allows it to increase or decrease the water level in a network of ditches and thereby control the water table. Sub-irrigation is also used in commercial greenhouse production, usually for potted plants. Water is delivered from below, absorbed upwards, and the excess collected for recycling. Three basic types of subirrigation are: ebb-and-flow, trough, and flooded floor.

There are various challenges to adopt these localized forms of irrigation. Few of them are listed below:    

Expense: initial cost can be more than overhead systems. Waste: the sun can affect the tubes used for drip irrigation, shortening their usable life. Clogging: if the water is not properly filtered and the equipment not properly maintained, it can result in clogging. Waste of water, time and harvest, if not installed properly. These systems require careful study of all the relevant factors like land topography, soil, water, crop and agroclimatic conditions, and suitability of drip irrigation system and its components.

2.4 Based on the way the water is applied The classification of the irrigation systems can also be based on the way the water is applied to the agricultural land as: 

Flow irrigation system: where the irrigation water is conveyed by growing to the irrigated land. This may again be classified into the following. o Direct irrigation: Where the irrigation water is obtained directly from the river, without any intermediate storage. This type of irrigation is possible by constructing a weir or a barrage across a river to raise the level of the river

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:



water and thus divert some portion of the river flow through an adjacent canal, where the flow takes place by gravity. o Reservoir/tank/storage irrigation: The irrigation water is obtained from a river, where storage has been created by construction an obstruction across the river, like a dam. This ensures that even when there is no inflow into the river from the catchment, there is enough stored water which can continue to irrigate fields through a system of canals. Lift irrigation system: Where the irrigation water is available at a level lower than that of the land to be irrigated and hence the water is lifted up by pumps or by other mechanical devices for lifting water and conveyed to the agricultural land through channels flowing under gravity. For instance, a large portion of Indira Gandhi canal in Rajasthan is fed by lift irrigation system.

2.5 On the basis of duration of the applied Classification of irrigation systems may also be made on the basis of duration of the applied water, like: 



Inundation/flooding type irrigation system: In which large quantities of water flowing in a river during floods is allowed to inundate the land to be cultivated, thereby saturating the soil. The excess water is then drained off and the land is used for cultivation. This type of irrigation uses the flood water of rivers and therefore is limited to a certain time of the year. It is also common in the areas near river deltas, where the slope of the river and land is small. Unfortunately, many of the rivers, which were earlier used for flood inundation along their banks, have been embanked in the past century and thus this practice of irrigation has dwindled. Perennial irrigation system: In which irrigation water is supplied according to the crop water requirement at regular intervals, throughout the life cycle of the crop. The water for such irrigation may be obtained from rivers or from walls. Hence, the source may be either surface or ground water and the application of water may be by flow or lift irrigation systems.

2.6 Choice of Irrigation Method As we have discussed above, there are various ways to provide water to crops. However, choosing right kind of method is a challenge. It must suit the particular crop, soil and of course, depends on availability of water. For example, following is a short list of available methods corresponding to the kind of crop. Method Border Strip method Furrow method Basin method

Suitable for crops Wheat, Leafy vegetables, Fodders Cotton, Sugarcane, Potatoes Orchard trees

Table 1: Irrigation method for different crops Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Other methods like sprinkler and drip irrigation systems are adapted where water is scarce and priority for its conservation is more than the consideration for cost. Although most advanced countries are adopting these measures, they have not picked up as much in India mainly due to financial constraints. However, as time passes and land and water resources get scarce, it would be essential to adopt these practices in India, too.

3 Efficiency Irrigation efficiency is defined as the ratio between the water stored in the soil depth inhabited with active plant roots to the water applied by the irrigation system. Thus, water applied by the irrigation system and not being made available to be taken up by plant roots is wasted and reduces irrigation efficiency. The major causes for reduced irrigation efficiency are drainage of excess irrigation water to soil layers deeper than the depth of active roots. Leakage of irrigation water to deep soil layers could result in pollution of the water table. Over-irrigation and under-irrigation, both are injurious to the crop. Thus, the timings of irrigation and the quantity of water supplied are decisive for the satisfactory performance of the crop. In the case of wheat for example, appropriate timing and spacing of irrigation raise the yield as much as 50 per cent with less use of water. The cases of irrigation efficiency of 100 percent are practically none existent even in the most modern irrigation systems. Major difficulties in obtaining high irrigation efficiency stems from the inability to obtain an accurate estimate of the quantity of water needed to recharge the soil root zone depth and the lack of valid, real time information concerning the actual soil depth of active roots. Conservative estimates suggest that even under optimal management practices the average irrigation efficiency is estimated to be 70 percent. Thus, the average water loss under sprinkler and drip irrigation is 30 percent but could drop to values of over 50 percent under furrow and flood irrigation. Efficiency of drip irrigation can reached to 90 per cent with best efforts. Water losses of irrigation water under urban and landscape irrigation could easily reach 50 percent of the applied water. India’s national water mission aims to increase water use efficiency by 20 per cent. Agriculture contributes for more than 80 per cent of water usage in the country. Therefore, a large focus of the mission is on the improving efficiency of various irrigation projects such as Major & minor irrigation schemes, CAP&WM (Command Area programmme & Water Management), and AIBP (Accelerated Irrigation Benefits Programme) etc.

4 Irrigation and National Water Policy India had adapted a national water policy in the year 1987 which was revised in 2002. The policy document lays down the fact that planning and development of water resources should be governed by the national perspective. Certain aspects of policy related to irrigation are quoted below: 

Irrigation planning either in an individual project or in a watershed as a whole should take into account the irrigability of land, cost-effective irrigation options possible from

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

 







all available sources of water and appropriate irrigation techniques for optimizing water use efficiency. Irrigation intensity should be such as to extend the benefits of irrigation to as large a number of farm families as possible, keeping in view the need to maximize production. There should be a close integration of water use and land use policies. Water allocation in an irrigation system should be done with due regard to equity and social justice. Disparities in the availability of water between head-reach and tail end farms and between large and small farms should be obviated by adoption of a rotational water distribution system and supply on a volumetric basis subject to certain ceilings and rational pricing. Concerted efforts should be made to ensure that the irrigation potential created is fully utilised. For this purpose, the command area development approach should be adopted in all irrigation projects. Irrigation being the largest consumer of fresh water, the aim should be to get optimal productivity per unit of water. Scientific management farm practices and sprinkler and drip system of irrigation should be adopted wherever feasible. Reclamation of water-logged/saline affected land by scientific and cost effective methods should form a part of command area development programme.

5 Command Area Development and Water Management (CADWM) The planned development of irrigation sector started in a big way since the First Five Year Plan (1951–56). New projects were taken up in the Second Five Year Plan, the Third Five Year Plan, and the Annual Plans 1966–69. During the Fourth Five Year Plan emphasis was shifted to the completion of ongoing schemes. The widening gap between potential creation and utilization was felt in the Fifth Plan (1974– 78) and accordingly Command Area Development programme (CADP) was launched as a Centrally-sponsored scheme in 1974-75. The CADP is an integrated area development approach towards the command areas of major and medium irrigation projects in the country. The programme is aimed at bridging the gap between created irrigation potential and its utilization in the command area. The CAD programme was initially introduced in the Indira Gandhi Canal Command Area in 1974. Up to March 1998 the total number of projects taken up for command area development increased to 217 with cultivable command area (CCA) of 21.78 million hectares and spreading over 23 states and 2 union territories. This programme was restructured and renamed as Command Area Development and Water Management (CADWM) Programme since April 1, 2004. The scheme is now being implemented as a State sector scheme during the XI Five Year Plan (2008-09 to 2011-12). During the XII Plan, the Scheme is to be implemented pari-passu with Accelerated Irrigation Benefits Programme (AIBP). The total proposed outlay for the XII Plan (Central share) is Rs.15,000 crore to cover about 7.6 Mha.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

The Programme involves execution of on- farm development works like construction of Field channels and Fields drains, land leveling and shaping and conjunctive use of surface and ground-water. Warabandi or the rotational system of water distribution is undertaken with a view to ensuring equitable and timely supply of water to the farmers. Attention is also given to diversification of crore pattern so that water is put to optimum use and productivity of land increased. During such diversion Frication emphasis would be given to the production of oil seeds, pulses etc to eliminate as far as possible their shortage. Under the CAD programme, the Ministry of Water Resources is also introducing and promoting participatory irrigation management (discussed below) in the CAD Projects by creating awareness and providing financial assistance to farmers' associations. Reclamation of waterlogged areas in irrigated commands is also an important component of the Programme. An area of about 20.149 Mha has been covered under the programme since inception up to end of March, 2012.

6 Participatory Irrigation Management (PIM) Any irrigation project cannot be successful unless it is linked to the stakeholders, that is, the farmers themselves. In fact, people’s participation in renovation and maintenance of field channels was the established practice during the pre-independence days. However, the bureaucracy encroached on this function in the post-independence period and a realization has dawned that without the participation of farmers, the full potential of an irrigation scheme may not be realized. The concept of involvement of farmers in management of the irrigation system has been accepted as a policy of the Government of India and has been included in the National Water Policy adopted in 1987. It stated that “Efforts should be made to involve farmers progressively in various aspects of management of irrigation systems, particularly in water distribution and collection of water rates. Assistance of voluntary agencies should be enlisted in educating the farmers in efficient water-use and water management.” Policy guidelines were framed for farmers’ participation in the areas under the Centrally Sponsored Command Area Development Programme. One of the objectives of PIM is to create a sense of ownership of water resources and the irrigation system among the users, so as to promote economy in water use and preservation of the system. At operational level, Water Users’ Association (WUA), Distributary Committee and Project Committees have been formed. With the help of a model act by central government, various states have enacted laws for PIM. Total area covered under various WUA in all states together is approximately 15 million hectare in 2010.

7 Accelerated Irrigation Benefits Programme (AIBP) The government of India launched Accelerated Irrigation Benefits Program (AIBP) in 1996-97. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

This program was launched to give loan assistance to the states to help them a few major irrigation projects which were in advanced stage of completion. The advanced stage of construction would imply that   

At least 50% of latest approved estimated project cost already incurred and At least 50% of physical progress of essential works of the project has taken place; and The proposal of the State for inclusion of project under AIBP must be supported by a credible construction schedule indicating the works already executed and works to be executed along with their costs.

In this program major, medium and Extension, Renovation & Modernization (ERM) irrigation projects which were having investment clearance of Planning Commission and were in advanced stage of construction and can be completed in the next four financial year and also were not receiving any other form of financial assistance were considered for inclusion in the programme. The State Governments have been provided an amount of Rs.43425.6331 crore as CLA/Grant under AIBP since inception of this programme till 1.12.2010 for 283 major/medium irrigation projects and 11655 Surface minor irrigation schemes. After commencement of this Programme 129 major/medium projects and 7969 Surface major/medium irrigation Schemes have so far been reported completed. An additional irrigation potential of 59.39 lakh hectare has been created up to March 2009.

8 Repair, Renovation and Restoration of Water Bodies Scheme In India, tanks/ponds and lakes have traditionally played an important role in conserving water for meeting various needs of the communities. Minor irrigation sources (tanks etc.) have 6.27 million ha. of irrigation potential. Around 15-20 per cent sources are not in use for one reason or the other, as a result of which one million ha of irrigation potential has been lost. Another, around 2 M-ha of potential is lost due to under utilisation of tanks in use. The Government of India sanctioned a Pilot Scheme for “National Project for Repair, Renovation & Restoration (RRR) of Water Bodies directly linked to Agriculture” in January, 2005. Financial share of centre and state is in ration of 3:1. The objectives of the Scheme were to restore and augment storage capacities of water bodies, and also to recover and extend their lost irrigation potential. In its pilot phase, irrigation potential for 1.73 lakh hectare was realized. With the success of pilot scheme, scheme has been extended for twelfth five year plan. It is envisaged to take up RRR works in 10,000 water bodies with a Central Assistance of Rs. 6235 crore. Out of 10000 water bodies, 9000 water bodies are proposed to be in rural areas and balance 1000 water bodies will be in urban areas. The proposal of water bodies where the Integrated Water Management Programme (IWMP) is implemented would be considered to be included under the scheme RRR of water bodies. At gram panchayat level, water users’ associations (WUA) are responsible for detail project report and implementation. There are corresponding bodies at district, state levels and national level also.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Main objectives of the scheme        

Comprehensive improvement and restoration water bodies, thereby increasing tank storage capacity. Ground Water Recharge. Increased availability of drinking water. Improvement in agriculture/horticulture productivity. Improvement of catchment areas of tank commands. Environmental benefits through improved water use efficiency; by promotion of conjunctive use of surface and ground water. Community participation and self-supporting system for sustainable management for each water body. Capacity Building of communities, in better water management.

9 Virtual Water The concept of “virtual water” was introduced by Prof. Allan in the early 1990s and refers to the water that is required for the production of agricultural commodities, or in other words the water “embedded” in agricultural products. For instance, it takes 1,600 cubic meters of water on average to produce one metric tonne of wheat. The water is said to be virtual because once the wheat is grown, the real water used to grow it is no longer actually contained in the wheat. The concept of virtual water helps us realize how much water is needed to produce different goods and services. In semi-arid and arid areas, knowing the virtual water value of a good or service can be useful towards determining how best to use the scarce water available. Virtual water trade refers to the idea that when goods and services are exchanged, so is virtual water. When a country imports one tonne of wheat instead of producing it domestically, it is saving about 1,300 cubic meters of real indigenous water. If this country is water-scarce, the water that is 'saved' can be used towards other ends. If the exporting country is water-scarce, however, it has exported 1,300 cubic meters of virtual water since the real water used to grow the wheat will no longer be available for other purposes. Water-scarce countries like Israel discourage the export of oranges (relatively heavy water guzzlers) precisely to prevent large quantities of water being exported to different parts of the world. Limitation of the Virtual water measures  



Relies on an assumption that all sources of water, whether in the form of rainfall or provided through an irrigation system, are of equal value. Implicitly assumes that water that would be released by reducing a high water use activity would necessarily be available for use in a less water-intensive activity. For example, the implicit assumption is that water used in rangeland beef production would be available to be used to produce an alternative, less water-intensive activity. As a practical matter this may not be the case, nor might the alternatives be economic. Fails as an indicator of environmental harm nor does it provides any indication of whether water resources are being used within sustainable extraction limits. The use of

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:



virtual water estimates therefore offer no guidance for policy makers seeking to ensure that environmental objectives are being met. Importing food could pose the risk of further political dependence. The notion of "Self Sufficiency" is pride among people of many nations.

Figure 8: Virtual water flows by the region In sum, virtual water trade allows a new, amplified perspective on water problems: In the framework of recent developments from a supply-oriented to a demand-oriented management of water resources it opens up new fields of governance and facilitates a differentiation and balancing of different perspectives, basic conditions and interests. Analytically the concept enables one to distinguish between global, regional and local levels and their linkages. This means, that water resource problems have to be solved in problemsheds if they cannot be successfully addressed in the local or regional watershed. Virtual water trade can thus overcome the hydro-centricity of a narrow watershed view. References: [1] Culturable command area (CCA) - The gross command area contains unfertile barren land, alkaline soil, local ponds, villages and other areas as habitation. These areas are called unculturable areas. The remaining area on which crops can be grown satisfactorily is known as cultivable command area (CCA). Culturable command area can further be divided into 2 categories  

Culturable cultivated area: It is the area in which crop is grown at a particular time or crop season. Culturable uncultivated area: It is the area in which crop is not sown in a particular season.

nd Rajinder Nagar: Copyright © by1/8-B, Vision2IASFloor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar:No 103,part 1st Floor, Ansal Building, Behind UCO stored Bank, Delhi-9 All rights are reserved. of thisB/1-2, document may be reproduced, in a retrieval system or transmitted 09650617807, in any form or 09968029039, by any means, 09717162595 electronic, mechanical, photocopying, 16 www.visionias.in ©Vision IAS recording or otherwise, without prior permission of Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS ™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 18

INDIAN AGRICULTURE

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Contents Land Resources and Agriculture..................................................................................................... 3 Land Use Categories ................................................................................................................... 3 Land-use Changes in India.......................................................................................................... 5 Intensity of cropping .............................................................................................................. 6 Common Property Resources ................................................................................................ 6 Agricultural Land Use in India .................................................................................................... 6 Salient Features of Indian Agriculture........................................................................................ 6 Cropping Season in India ............................................................................................................ 7 The Kharif season ................................................................................................................... 7 The Rabi season ..................................................................................................................... 7 The Zaid season ...................................................................................................................... 8 Type of Farming (On Basis of Moisture for crops)...................................................................... 8 Type of Farming (On Basis of Changing Geographical Environment or Historical Background) 9 Shifting Agriculture- ............................................................................................................... 9 Subsistence Agriculture.......................................................................................................... 9 Intensive Agriculture .............................................................................................................. 9 Extensive Agriculture ............................................................................................................. 9 Plantation Agriculture ............................................................................................................ 9 Commercial Agriculture ......................................................................................................... 9 Mixed Farming...................................................................................................................... 10 Cropping Pattern ...................................................................................................................... 10 Food grains ............................................................................................................................... 10 Cereals .................................................................................................................................. 10 Rice.................................................................................................................................................................. 11 Wheat .............................................................................................................................................................12

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Jowar (Sorghum) ............................................................................................................................................. 12 Bajra ................................................................................................................................................................ 12 Maize............................................................................................................................................................... 12 Pulses .............................................................................................................................................................. 12 Gram ............................................................................................................................................................... 12

Oilseeds: ............................................................................................................................... 13 Groundnut ....................................................................................................................................................... 13 Rapeseed and Mustard ................................................................................................................................... 13 Other Oilseeds................................................................................................................................................. 14

Cash Crops ............................................................................................................................ 14 Cotton .............................................................................................................................................................14 Jute .................................................................................................................................................................. 15 Sugarcane........................................................................................................................................................ 15 Tea .................................................................................................................................................................. 15 Coffee .............................................................................................................................................................. 16

Tabular Representation of Various Crop Requirements in India .......................................... 16 Agricultural Development in India ........................................................................................... 17 Indian Council of Agricultural Research (ICAR) .................................................................... 18 Government Steps to Enhance Agricultural Inputs .................................................................. 19 Seeds .................................................................................................................................... 19 Mechanization and Technology ........................................................................................... 20 Integrated Nutrient Management........................................................................................ 20 Irrigation ............................................................................................................................... 20 Major Schemes / Programmes for the Agricultural Sector ...................................................... 20 National Food Security Mission ........................................................................................... 21 Rashtriya Krishi Vikas Yojana ................................................................................................ 21 National Mission for Sustainable Agriculture....................................................................... 22 Bringing Green Revolution to Eastern India(BGREI) ............................................................. 22 Integrated Scheme Of Oilseeds, Pulses, Oilpalm & Maize (ISOPOM) .................................. 23 Problems of Indian Agriculture ................................................................................................ 25 UPSC Questions Covered ......................................................................................................... 26

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 2

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Land Resources and Agriculture Land is an important natural resource, which serves variety of functions. Different types of lands are suited to different uses. Human beings thus, use land as a resource for production as well as residence and recreation. Though, land seems to be in vast amount but its usage pattern and category makes it a limited resource.. There are two main factors determining land-use: I. II.

Physical Factors: These factors are like topography, soils, climate etc. Human Factors: Growth of human population, duration of land control, technology, land rights, social, economic and cultural factors are some of the human factors.

Land Use Categories In India, land-use records are maintained by land revenue department. The land use categories add up to reporting area, which refers to the total area reported by the land revenue department. At a surprising note, it is often different from the geographical area which is the total area as measured by the Survey of India and remains fixed as per the international boundaries. Survey of India Survey of India, The National Survey and Mapping Organization of the country under the Department of Science & Technology, is the OLDEST SCIENTIFIC DEPARTMENT OF THE GOVT. OF INDIA. It was set up in 1767 to help consolidate the territories of the British East India Company. In its assigned role as the National Principal Mapping Agency, Survey of India bears a special responsibility to ensure that the country’s domain is explored and mapped suitably to provide base maps for expeditious and integrated development and ensure that all resources contribute their full measure to the progress, prosperity and security of India. Besides being grouped under ‘‘Scientific Surveys’’ in Government of India Business Rule 1971, it has also been called upon extensively to deploy its expertise in the field of geodetic and geophysical surveys, study of seismicity and seismotectonics, glaciology, participation in Indian Scientific Expedition to Antarctica and projects related to digital cartography and digital photogrammetry, etc., to provide basic data to keep pace with Science and Technology Development. Botanical Survey of India (BSI), Zoological Survey of India (ZSI) and Archaeological Survey of India (ASI) are some other important surveying agencies of government of India. The land-use categories as maintained in the Land Revenue Records1 are as follows: (i) Forests: According to Survey of India report, forest area is one that is notified by the department as land under forests, irrespective of whether it has any tree cover or not. The

1

As per the records of Land Revenue Department

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

land under forest cover is the land exceeding one hectare area having a minimum of 10 per cent tree cover irrespective of any other land-use. Thus, the area under actual forest cover may be different from area classified as forest. Hence, there may be an increase in this category without any increase in the actual forest cover. (ii) Land put to Non-agricultural Uses: This includes the part of the geographic area that is put to non-agricultural uses like settlements, both rural and urban, infrastructure development like roads, railway lines, canals, industries, shops and other similar uses. (iii) Barren and Wastelands: The land classified as a wasteland such as barren hilly terrains, desert lands, ravines, etc. are normally can not be brought under cultivation with the available technology. They remain non suitable for agriculture and generally remain fallow. (iv) Area under Permanent Pastures and Grazing Lands: The above type land is generally owned by the village ‘Panchayat’ or the Government (Forest & Revenue Department). Only a small proportion of this land is privately owned. These lands are not used for cultivation. The land owned by the village panchayat comes under ‘Common Property Resources’. The benefits of this land accrue to the members of the community as a whole. (v) Area under Miscellaneous Tree Crops and Groves: These areas are not included in net sown area. The land under orchards and fruit trees is included in this category. Most of this land is privately owned by the people. (vi) Culturable Waste-Land: Any land which is left fallow (uncultivated) for more than five years is categorised as a culturable wasteland. This land may be marshy, saline land having degraded soil on account of soil erosion or under dense bushes. Such land can be brought under cultivation after improving it through reclamation practices. (vii) Current Fallow: The land which has been left without cultivation for one or less than one agricultural year is known as current fallow. The practise adopted for giving rest to the culturable land is called fallowing. The land recoups the lost fertility through natural processes in the time duration. (viii) Fallow other than Current Fallow: These are also the cultivable land which are left uncultivated for more than a year. The duration for which the land has been left uncultivated should be less than five years. Most of this land is either of poor quality or the cost of cultivation of such land is very high. If the land is left uncultivated for more than five years, it would be categorised as culturable wasteland. (ix) Net Area Sown: Net area sown represents the area sown with crops at least once in any of the crop season of the year counting area sown more than once in the same year, only once2. Net sown area is of

2

Gross Cropped Area: This represents the total area sown once and/or more than once in a particular year, i.e. the area is counted as many times as there are sowings in a year. This total area is also known as total cropped area or total area sown.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 4

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

crucial importance for India because it is the land actually under cultivation of crops and India has the highest percentage of Net Sown Area.

Land-use Changes in India Land-use in a region, to a large extent, is influenced by the nature of economic activities carried out in that region. However, while economic activities change over time, land, like many other natural resources, is fixed in terms of its area. The pattern of land use depends on the economy of the region. With the increase in size of the economy, due to increasing population, change in income level, and updated technology, the pressure on the land increases many folds. Hence, marginal land also comes under usage. Also, with the change in composition of economy, brisk rate of growth of secondary and tertiary sector, there is gradual shift of land from agricultural usage to non-agricultural usage. But, it has been observed that though the share of agricultural land decreases with time, the pressure on land does not decrease. It is so because the number of people that the agricultural sector has to feed is increasing day by day. India has undergone major changes within the economy over the past four or five decades, and this has influenced the land-use changes in the country. It has been observed that share of area under forest, area under non-agricultural uses and current fallow lands have shown an increase. The rate of increase is the highest in case of area under non-agricultural uses. This is due to the changing structure of Indian economy, which is increasingly depending on the contribution from industrial and service sectors. Thus, the area under non-agricultural uses is increasing at the expense of wastelands and agricultural land. Barren and wasteland, culturable wasteland, area under pastures and tree crops and net area sown have shown a decline in the areas. With the pressure on land increasing, wastelands and culturable wastelands have declined. Also, putting more area under the non-agriculture usage has caused a decline in net sown areas.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 5

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Intensity of cropping (To be covered) Common Property Resources Land, according to its ownership can broadly be classified under two broad heads – private land and common property resources (CPRs). While the former is owned by an individual or a group of individuals, the latter is owned by the state meant for the use of the community. CPRs can be defined as community’s natural resource, where every member has the right of access and usage with specified obligations, without anybody having property rights over them. Community forests, pasture lands, village water bodies and other public spaces are examples of the common property resources. CPRs provide fodder for the livestock and fuel for the households along with other minor forest products like fruits, nuts, fibre, medicinal plants, etc. In rural areas, such land is of particular relevance for the livelihood of the landless and marginal farmers, other weaker sections and women.

Agricultural Land Use in India The term 'agriculture' has been derived from two Latin words ager meaning land and culture meaning cultivation. Agriculture thus means cultivation of land. Agriculture also includes horticulture, animal husbandry, forestry, fishing, etc. Agriculture, unlike other secondary and tertiary sectors, depends directly on the on the land use patterns in the country. Quality and fertility of land has a direct bearing on the productivity of agriculture. Besides in rural areas, aside from its value as a productive factor, land ownership has a social value and serves as a security for credit, natural hazards or life contingencies, and also adds to the social status. It has been observed that over the years, there has been a marginal decline in the available total stock of cultivable land as a percentage to total reporting area. The scope for bringing in additional land under net sown area in India is limited. There is, thus, an urgent need to evolve and adopt land-saving technologies. It can be achieved either by increasing the yield of any particular crop per unit area of land or by increasing the total output per unit area of land from all crops grown over one agricultural year by increasing land-use intensity. A high value of cropping intensity3 is desirable for improving the agricultural output in India.

Salient Features of Indian Agriculture Indian agriculture has very wide variations throughout the length and breadth of the country. With growth of technology, more area has been brought under cultivation. Increase in irrigation facilities, coupled with use of fertilizers and pesticides and use of high yield variety of seeds has improved the productivity in the country. Despite the variations, there are some salient features which characterize Indian agriculture. They are:

3

Cropping Intensity is defined as the ratio of Gross Cultivated Area (GCA) to Net Sown Area (NSA). It is generally expressed in percentage.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 6

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

1. Subsistence agriculture4: In general, the Indian agriculture is subsistence in nature. Farmers generally have a small piece of land and crop production is mostly for family use with surplus sold to market. 2. Pressure of population: Agriculture has to provide food for the rapidly increasing population and also employment to a large section of landless labourers. Hence, there is large pressure on agriculture. Besides, the increasing trend of urbanization is diverting the agricultural land to non-agricultural uses. 3. Importance of animals: In India, many of the agricultural operations such as ploughing, irrigation, threshing and transporting of the agricultural products are done by the animals. Animals form a major part of farmer’s life in India. Complete mechanization of the Indian agricultural system is still a distant goal. 4. Dependent upon monsoons: The Indian farmer depends mainly on the monsoons, which are uncertain, unreliable and irregular. Only about 35 per cent of the total cropped area is under perennial irrigation and the rest depends on the monsoons. Thus, the dependency on monsoon makes life of Indian farmers highly vulnerable. 5. Small land holdings: The national average size of the land holdings is only 1.7 hectares. It is uneconomical to cultivate small farms and thus is a great hindrance to the progress of agriculture. Most of the farmers in our country are not owners of the land they cultivate. 6. Variety of crops: Due to highly suitable environmental conditions, the Indian farmers are able to grow a large variety of tropical and temperate crops. It includes food crops and commercial crops. The food crops score over all other crops for land under agriculture. 7. Predominance of food crops: The production of food crops is the first priority of the farmers, as they have to provide enough food for the rapidly increasing population of our country. About two-thirds of the total land under agriculture is devoted to food crops in India. 8. Less importance to fodder crops: India has the largest population of livestock in the world. Still the fodder crops are not given due consideration in the cropping pattern. Thus, we have very poor quality of domestic animals, when compared internationally.

Cropping Season in India There are three distinct cropping seasons in India, namely Kharif, Rabi and Zaid. The Kharif season largely coincides with Southwest Monsoon in the months of June – September. Major crops cultivated in Northern states include Rice, Cotton, Bajra, Maize, Jowar, and Tur. In southern states, major crops are Rice, Maize, Ragi, Jowar, and Groundnut. The Rabi season begins with the onset of winter in October-November and ends in MarchApril. The major crops cultivated in northern states include Wheat, Gram, Rapeseeds and Mustard, Barley. In the southern states, major crops include Rice, Maize, Ragi, Groundnut, and Jowar.

4

Subsistence agriculture is self-sufficiency farming in which the farmers focus on growing enough food to feed themselves and their families.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

The Zaid season is a short duration summer cropping season beginning after harvesting of Rabi crops. The cultivation of watermelons, cucumbers, vegetables and fodder crops during this season is done on irrigated lands. However, this type of distinction in the cropping season does not exist in southern parts of the country. Cropping Season Kharif

Duration Season June-July to Oct.- Rainy season Nov

Rabi

Oct.-Nov. to March- Winter season April

Zaid

March-April to May- Summer season June

Major Crops Rice, maize, jowar, bajra, cotton, sesamum, groundnut and pulses like mung, urad etc. Wheat, barley, gram and oilseeds like linseed, rape and mustard, etc. Vegetables, fruits like watermelon and cucumber and rice, maize etc.

Type of Farming (On Basis of Moisture for crops) On the basis of main source of moisture for crops, the farming can be classified as irrigated farming and rainfed farming (barani). Irrigated farming can be further sub-divided into protective farming or productive farming. Protective irrigation farming is to protect the crops from adverse effects of soil moisture deficiency i.e. irrigation acts as a supplementary source of water over and above the rainfall. Whereas productive irrigation farming is meant to provide sufficient soil moisture in the cropping season to achieve high productivity. In such irrigation the water input per unit area of cultivated land is higher than protective irrigation. Rainfed farming is further classified on the basis of adequacy of soil moisture during cropping season into dryland and wetland farming. . In wetland farming, the rainfall is in excess of soil moisture requirement of plants during rainy season. These areas grow various water intensive crops such as rice, jute and sugarcane. The dryland farming is largely confined to the regions having annual rainfall less than 75 cm. These regions grow hardy and drought resistant crops such as Ragi, Bajra, Moong, Gram and Guar (fodder crops) and practise various measures of soil moisture conservation and rain water harvesting. Chief Features of Dryland Farming are: 1. The techniques of rainwater harvesting are practised.It helps to reduce the gap of dryness between two rainfall periods. 2. Excess rainfall than needed is allowed to seep underground. It helps in water conservation. 3. Soil and water are the two main resources of dryland farming. 4. On account of long periods of aridity soil erosion sets in. 5. On account of destruction of humus in the top layer the soils become unproductive and infertile. 6. Only very poor farmers practice dryland farming. These persons account of lack of funds, are unable to access irrigation and invest in soil fertility. 7. To supplement income animal husbandry is practised. 8. On account of pressure of population grazing lands are is becoming less and less.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Steps taken

Type of Farming (On Basis of Changing Geographical Environment or Historical Background) Various type of farming patterns have developed in India due to highly variable environmental conditions. Based on changing geographical environment and historical background, we can further classify farming into following categories: Shifting Agriculture- Shifting agriculture is also known as slash and burn cultivation. It is mostly practised in backward forest areas with heavy rainfall. Covered patchesof ground are cleared by cutting and burning trees and forests. The cleared land is then cultivated for two or three years in a primitive manner. When soil becomes leached and unproductive, the farmers shift to other part of the forest and follow the same pattern. There are certain disadvantages of shifting agriculture. We find that productivity is high in the first year but slowly the productivity decreases with every passing year. With the cutting of forests, soil gets easily degraded and blown away by wind and rain. The recovery period of the soil is long and it takes time to recover to the original state. Shifting cultivation is practised on a small scale in the forested areas of north eastern states, Orissa, Madhya Pradesh, Andhra Pradesh and parts of Kerala. It is known by different mimes such as Jhum in Assam, Podu in Orissa and Andhra Pradesh, Bewar in Madhya Pradesh and Ponam in Kerala. Subsistence Agriculture – It is practised mainly for consumption purpose and maintenance of one’s family. The farmer produces a variety of crops, and the total production is just enough to meet the requirements of the family. The farms are small and the yield is low. All types of manures, such as household waste, animal droppings, green manures, night soil and a little of chemical fertilizers are used. This type of agriculture is generally practised in the tribal areas of Assam and in the Himalayan region. Intensive Agriculture – It is practised in regions with highly dense populated land with limited cultivable area. The farmer tries to get the maximum possible output from the small piece of land. More than one crop is cultivated in a year. Intensive agriculture is widely practised in the irrigated areas of the northern plains and the coastal plains of India. Extensive Agriculture - This type of agriculture is practised in areas with low population density and the cultivable land is abundant. The farmer specializes in one or two commercial crops. In India, extensive cultivation is widely practised in the Terai region of the Himalayas and the north-western states. Plantation Agriculture - This type of agriculture was introduced by the Europeans in the tropical and the subtropical regions of the country. Large tracts of agricultural land are mostly owned by the companies. In India, the main crops produced on plantations are tea, coffee, spices, coconut and rubber. The success of plantation agriculture depends on accessibility, availability of labour and adequate means of transport. Scientific methods of farming are used with an aim of higher yield and superior product quality. Commercial Agriculture- The main aim of commercial farming is to produce crops as per the market demands. It can be either intensive or extensive. To keep the cost of production low, most modern methods of cultivation are employed. It is generally practised in areas of sparse population. In India, commercial farming is not very common due to heavy pressure of Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

population on land. Commercial agriculture has developed in Punjab, Haryana, Gujarat, Maharashtra, Uttar Pradesh, West Bengal, Assam. Mixed Farming - In this type of farming, livestock is reared along with crop farming. Cattle rearing and rotation of crops are important part of mixed farming. It is practised in thickly populated areas. The yields are generally high. Efficient methods of cultivation, quick means of transport and ready markets are seen as promoters of mixed farming in the country.

Cropping Pattern5 Cropping pattern refers to the yearly sequence and spatial arrangement of crops and fallows on a given area. The farmer’s decision on crops and cropping pattern depends on several factors – soil and climate, household needs, socio-economic issues, market infrastructure, post-harvest storage and processing facilities, labour availability, technological development, government policies etc. By and large, most of the Indian farmers go for cultivation of a number of crops on their farms and rotate a particular crop combination over a period of 3 -4 years. It results in multiplicity of cropping system which remains dynamic in time and space. A large diversity of cropping system exist under rainfed and dryland areas with an over-riding practise of intercropping due to greater risk involved in cultivating large area under a particular crop, while in areas of assured irrigation only a few cropping system are followed, they have a considerable coverage across the region and contribute significantly to food grain production at national level. Three major type of cropping system in India are- (i) Sequential System- In this system, we have sequential multiple cropping using short duration crops and intensive input management. (ii) Intercropping System- Growing of two or more crops simultaneously on the same field; Crop intensification is in both temporal and spatial dimensions. (iii) Alley Cropping System – Growing of annual crops with multipurpose perennial trees or shrubs. It is a way of increasing production potential under fragile environment.

Food grains Food grains are the dominant crop in all parts of the country whether it is subsistence or commercial agricultural economy. On the basis of the structure of grain, the food grains can be classified as cereals and pulses. Cereals: The cereals occupy about 54 per cent of total cropped area in India. The country produces about 11 per cent cereals of the world and ranks third in production after China and U.S.A. India produces a variety of cereals, which are classified as fine grains (rice, wheat) and coarse grains (Jowar, Bajra, maize, Ragi), etc.

5

The crops of India are divided into mainly two types: (a) Food crops (b) Cash crops. A cash crop is an agricultural crop which is grown for sale to return a profit. It is typically purchased by parties separate from a farm. Rice, wheat, maize, millet, barley, mower are the examples of food grains. Jute, cotton, sugarcane, oil seeds and rubber are known as cash crops.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Rice: Rice is the most important cereal crop in India. About 3,000 varieties are grown in different agro-climatic regions of the country. Rice being a tropical and sub-tropical plant requires a fairly high temperature of more than 22°C and amount of rainfall more than 100 cm. Irrigation is necessary in areas of lesser rainfall. Clayey alluvial soil in which water can remain standing is ideal for rice. A good crop of rice can be obtained only if the fields are kept filled with water. Cultivation of rice is labourintensive. India contributes 22 per cent of rice production in the world and ranks second after China. About one-fourth of the total cropped area in the country is under rice cultivation. West Bengal, Punjab, Uttar Pradesh, Andhra Pradesh and Tamil Nadu were five leading rice producing states in the country. Golden Rice Golden Rice is a new type of rice that contains beta carotene, a source of vitamin A. Golden Rice is being developed as a potential new food-based approach to improve vitamin A status. Vitamin A deficiency is a serious public health problem affecting millions of children and pregnant women globally.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Wheat: Wheat is the second most important cereal crop in India after rice. Indian production of wheat is second in the world after China6. It is primarily a crop of temperate zone. Wheat needs about 75 cm of water and winter temperature of 10° to 15° C and summer temperature of 21°C to 26°C during ripening to produce a good crop. It requires a rainfall of 50 to 75 cm. Excessive rainfall is harmful to wheat crop. Roots of the plant are destroyed in standing water. Light loam soil is ideal. Hence, its cultivation in India is done during winter i.e. rabi season. Cultivation of wheat is not labour-intensive. Uttar Pradesh, Punjab, Haryana, Rajasthan and Madhya Pradesh are five leading wheat producing states. Jowar (Sorghum): It is main food crop in semi-arid areas of central and southern India. Jowar is grown both as a Kharif and as a rabi crop. As a Kharif crop, it grows in areas having mean monthly average temperature of 26°C to 33°C. It requires rainfall of about 30cm during the growing season. Jowar can be grown in a variety of soils including loamy and sandy soils. The clayey, regur and alluvium are most suitable for Jowar cultivation. Maharashtra alone produces more than half of the total Jowar production of the country. Other leading producer states of Jowar are Karnataka, Madhya Pradesh and Andhra Pradesh. The grain also makes for an excellent poultry feed. Bajra: Bajra is sown in hot and dry climatic conditions in north-western and western parts of the country. It is grown in areas with rainfall about 40-50 cm and temperature of about 25°C 30°C. It is a hardy crop which resists frequent dry spells and drought in this region. It is cultivated alone as well as part of mixed cropping. Leading producers of Bajra are the states of Maharashtra, Gujarat, Uttar Pradesh, Rajasthan and Haryana. Maize: Maize is a food as well as fodder crop grown under semi-arid climatic conditions and over inferior soils. It requires 50-100cm of rainfall and a temperature ranging from 21°C to 27°C. Maize is sown all over India except eastern and north-eastern regions. The leading producers of maize are the states of Madhya Pradesh, Andhra Pradesh, Karnataka, Rajasthan and Uttar Pradesh. Yield level of maize is higher than other coarse cereals. It is high in southern states and declines towards central parts. Pulses: Pulses are rich source of protein in India. India is a leading producer of pulses and accounts for about one-fifth of the total production of pulses in the world. The cultivation of pulses in the country is largely concentrated in the dryland of Deccan and central plateaus and north-western parts of the country. Gram and tur are the main pulses cultivated in India. Gram is cultivated in subtropical areas. It is mostly a rainfed crop cultivated during Rabi season in central, western and north-western parts of the country. Preferred temperature range is 20°C – 25°C and rainfall in the range of 40-50cm. Madhya Pradesh, Uttar Pradesh, Maharashtra, Andhra Pradesh and Rajasthan are the main producers of this pulse crop. Tur is the second important pulse crop in the country. It is also known as red gram or pigeon pea. It is cultivated over marginal lands and under rainfed conditions in the dry areas of central and southern states of the country. Maharashtra, Uttar Pradesh, Karnataka, Gujarat and Madhya Pradesh are the main producers of Tur.

6

http://faostat.fao.org/site/339/default.aspx

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Oilseeds: The oilseeds are produced for extracting edible oils. Dryland of Malwa plateau, Marathwada, Gujarat, Rajasthan, Telangana and Rayalseema region of Andhra Pradesh and Karnataka plateau are oilseeds growing regions of India. Groundnut, rapeseed and mustard, Soyabean and sunflower are the main oilseed crops grown in India. Groundnut: Groundnut is largely a rainfed Kharif crop of dryland. Gujarat, Tamil Nadu, Andhra Pradesh, Karnataka and Maharashtra are the leading producers. Rapeseed and Mustard: Rapeseed and mustard comprise several oilseeds as rai, sarson, toria and taramira. These are subtropical crops cultivated during rabi season in north-western and central parts of India. Rajasthan contributes about one-third production while other leading producers are Uttar Pradesh, Haryana, West Bengal and Madhya Pradesh. Yields of these crops are comparatively high in Haryana and Rajasthan. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Other Oilseeds: Soyabean and sunflower are other important oilseeds grown in India. Soyabean is mostly grown in Madhya Pradesh and Maharashtra. Sunflower cultivation is concentrated in Karnataka, Andhra Pradesh and adjoining areas of Maharashtra. It is a minor crop in northern parts of the country where its yield is high due to irrigation. Cash Crops Cotton: Cotton is a tropical crop grown in Kharif season in semi-arid areas of the country. India grows both short staple (Indian) cotton as well as long staple (American) cotton called ‘narma’ in north-western parts of the country. Cotton requires clear sky during flowering stage. Ideal temperature range is 21°C – 30°C and rainfall in the range of 50 – 100cm. There are three cotton growing areas, i.e. parts of Punjab, Haryana and northern Rajasthan in north-west, Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 14

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

Gujarat and Maharashtra in the west and plateaus of Andhra Pradesh, Karnataka and Tamil Nadu in south. Leading producers of this crop are Maharashtra, Gujarat, Andhra Pradesh, Punjab and Haryana. Jute: Jute is a cash crop in West Bengal and adjoining eastern parts of the country. West Bengal accounts for about three-fourth of the production in the country. Bihar and Assam are other jute growing areas. Ideal growing condition include temperature in range of 24°C – 35°C and rainfall of 120- 150cm. Sugarcane: Sugarcane is a crop of tropical areas. Under rainfed conditions, it is cultivated in subhumid and humid climates. It requires hot and humid climate with average temperature of 21°C27°C and 75-100 cm rainfall. In IndoGangetic plain, its cultivation is largely concentrated in Uttar Pradesh. Sugarcane growing area in western India is spread over Maharashtra and Gujarat. In southern India, it is cultivated in irrigated tracts of Karnataka, Tamil Nadu and Andhra Pradesh. Uttar Pradesh produces about twofifth of sugarcane of the country. Maharashtra, Karnataka, Tamil Nadu and Andhra Pradesh are other leading producers of this crop. Tea: Tea is a plantation crop used as beverage. It is grown over undulating topography of hilly areas and well drained soils in humid and sub-humid tropics and sub-tropics. The ideal temperature for growth is 20°C – 30°C and rainfall around 150-300cm. In India, tea plantation is done in Brahmaputra valley of Assam, sub-Himalayan region of West Bengal (Darjiling, Jalpaiguri and Cooch Bihar districts) and lower slopes of Nilgiris and Cardamom hills of Western Ghats.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 15

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Coffee: Coffee is a tropical plantation crop. There are three varieties of coffee i.e. arabica, robusta and liberica. Coffee is cultivated in the highlands of Western Ghats in Karnataka, Kerala and Tamil Nadu. The ideal temperature for growth is between 15°C and 28°C and rainfall from 150 cm to 250cm. Tabular Representation of Various Crop Requirements in India Crop Rice

Wheat

Jowar

Bajra

Maize

Climatic Conditions Temp: Higher than 22°C Rain: More than 100cm

Soil Requirements

Area of Cultivation

Fertile clayey or loamy soil of the river valleys, flood plains, coastal plains and deltas capable of holding water Well-drained fertile silt and clayey loams

Lower and middle Ganga Plains, the east and west coastal plains, the Brahmaputra Valley and parts of the Deccan Plateau. Punjab, Haryana, Uttar Pradesh, Rajasthan and Madhya Pradesh

Temp: Winter 10°C -15°C Summer 21°C26°C Rain: 50-75 cm Temp: 26°C – 33°C Clayey, regur and alluvium Rain: About 30 cm

Temp: 25°C – 30 °C Rain: 40 -50 cm Temp: 21°C – 27°C Rain: 50 -100 cm

Sandy loams, black and red soils

Maharashtra, Karnataka, Madhya Pradesh, Andhra Pradesh, Tamil Nadu, Uttar Pradesh, Rajasthan and Gujarat Maharashtra, Gujarat, Uttar Pradesh, Rajasthan and Haryana. Madhya Pradesh, Andhra Pradesh, Karnataka, Rajasthan and Uttar Pradesh

Deep fertile well drained soil rich in organic matter with good water holding capacity Ragi Temp: 20°C – 30°C Red, light black sandy Karnataka, Tamil Nadu, Rain: 50 -100 cm loams Andhra Pradesh, Orissa, Bihar, Gujarat and Maharashtra Gram Temp: 20°C – 25°C Well-drained fertile silt and Madhya Pradesh, Uttar Rain: 40 -50 cm clayey loams Pradesh, Rajasthan, Haryana and Maharashtra Tur (Arhar) Temp: Winter Sandy loam to clayey loam, Uttar Pradesh, Madhya 15°C -18°C Deep well drained soil Pradesh, Maharashtra, Summer 30°CGujarat, Andhra Pradesh, 35°C Odisha, Karnataka and Tamil Rain: 50-70 cm Nadu Groundnut Temp: 20°C – 30°C Sandy loams and black soil Andhra Pradesh, Tamil Nadu, Rain: 50 -80 cm Karnataka, Gujarat & Maharashtra. Rapeseed Temp: 10°C – 20°C Alluvial soil Uttar Pradesh, Rajasthan, & Mustard Rain: 50 -100 cm Punjab, Haryana, Madhya Pradesh and Chhattisgarh Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 16

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Sesamum (Til)

Temp: 20°C – 25°C Well-drained light loamy Orissa, Rajasthan, Gujarat, Rain: About 50 soils Tamil Nadu, Maharashtra, cm West Bengal and Madhya Pradesh.

Sunflower

Temp: 15°C – 25°C Well-drained loamy soil Rain: About 50 cm Temp: 15°C – 25°C Friable loamy soils can Rain: 40-60 cm retain moisture.

Soyabean

Linseed

Temp: 10°C – 20°C Rain: 50 -75 cm

Clay loams, deep black soils and alluvial soils

Cotton

Temp: 21°C – 30°C Rain: 50 -100 cm Temp: 24°C – 35°C Rain: 120 -150 cm Temp: 21°C – 27°C Rain: 75 -100 cm

Black soil, Alluvial soil and Red soil Light sandy or clayey loam with annual water supply Deep, well-drained, rich loamy soil with moisture retaining capacity

Jute Sugarcane

Coconut

Tea

Coffee Rubber

Temp: 20°C – 25°C Rain: Above150 cm Temp: 20°C – 30°C Rain: 150 -300 cm

Karnataka, Maharashtra, Andhra Pradesh, Haryana, Bihar and Uttar Pradesh Maharashtra, Uttar Pradesh, Uttarakhand, Madhya Pradesh, Gujarat and Chhattisgarh. Madhya Pradesh, Uttar Pradesh, Bihar, Chhattisgarh and Maharashtra Punjab, Maharashtra, Gujarat and Haryana West Bengal, Assam, Bihar and Orissa Uttar Pradesh, Maharashtra, Tamil Nadu, Karnataka, Andhra Pradesh, Bihar and Punjab Kerala, Tamil Nadu and Karnataka

Loose porous or sandy along sea shores Well-drained deep fertile Brahmaputra & Surma valleys sandy loams of Assam, Darjeeling and Jalpaiguri districts of northern West Bengal and Nilgiris, Palnis and Annamalai hills in South India Temp: 15°C – 28°C Well-drained loamy soils, Karnataka , Kerala and Tamil Rain: 150 -250 cm rich in humus and minerals Nadu Temp: 25°C – 35°C Deep, rich and well- Kerala, Tamil Nadu, Rain: Above drained loamy soil, at an Karnataka and Andaman and 300cm elevation of about 400 Nicobar Islands metres

Agricultural Development in India Agriculture continues to be an important sector of Indian economy. The importance of agricultural sector in India can be gauged from the fact that about 57 per cent of its land is devoted to crop cultivation, whereas, in the world, the corresponding share is only about 12 per cent. Indian agricultural economy has been largely subsistence in nature. After Independence, the immediate goal of the Government was to increase food grains production by (i) switching over from cash crops to food crops; (ii) intensification of cropping over already cultivated land; and (iii) increasing cultivated area by bringing cultivable and fallow land under Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 17

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

plough. Intensive Agricultural District Programme (IADP) and Intensive Agricultural Area Programme (IAAP) were launched in 1950s to improve production. New seed varieties of wheat (Mexico) and rice (Philippines) known as high yielding varieties (HYVs) were available for cultivation by mid-1960s and India took advantage by introducing package technology comprising HYVs, along with chemical fertilizers in irrigated areas of Punjab, Haryana, and Western Uttar Pradesh. This strategy of agricultural development increased the food production at very vast rate; this growth came to be known as Green Revol ution. This strategy of agricultural development made the country self-reliant in food grain production. But green revolution was initially confined to irrigated areas only. This led to regional disparities in agricultural development in the country. Agro-climatic planning was introduced in 1988 to induce regionally balanced agricultural development in the country. It also emphasised the need for diversification of agriculture and harnessing of resources for development of dairy farming, poultry, horticulture, livestock rearing and aquaculture. However, lack of development of rural infrastructure, withdrawal of subsidies and price support, and impediments in availing of the rural credits may lead to inter-regional and inter-personal disparities in rural areas. Improvement in technology, better yield crops, expansion in irrigation, improved fertilizers and use of pesticides has significantly improved the agricultural productivity in the country. Government initiated schemes like Rashtriya Krishi Vikas Yojana, Rainfed Farming Systems, National Horticulture mission etc along with National Mission on Oilseeds and Oil palms and Technology Mission on Oilseed, Pulses and Maize has led to improvement in agricultural produce in India. Indian Council of Agricultural Research (ICAR) - The Indian Council of Agricultural Research (ICAR) is an autonomous organisation under the Department of Agricultural Research and Education (DARE), Ministry of Agriculture, Government of India. It was formerly known as Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 18

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Imperial Council of Agricultural Research and it was established on 16 July 1929. The Council is the apex body for co-ordinating, guiding and managing research and education in agriculture including horticulture, fisheries and animal sciences in the entire country. The ICAR has played a pioneering role in ushering Green Revolution and subsequent developments in agriculture in India through its research and technology development that has enabled the country to increase the production of foodgrains by 4 times, horticultural crops by 6 times, fish by 9 times (marine 5 times and inland 17 times),milk 6 times and eggs 27 times since 1950-51, thus making a visible impact on the national food and nutritional security. The mandates for the ICAR are to – 









To plan, undertake, aid, promote and co-ordinate education, research and its application in agriculture, agro forestry, animal husbandry, fisheries, home science and allied sciences. To act as a clearing house of research and general information relating to agriculture, animal husbandry, home science and allied sciences, and fisheries through its publications and information system; and instituting and promoting transfer of technology programmes. To provide, undertake and promote consultancy services in the fields of education, research, training and dissemination of information in agriculture, agro forestry, animal husbandry, fisheries, home science and allied sciences. To look into the problems relating to broader areas of rural development concerning agriculture, including postharvest technology by developing co-operative programmes with other organizations such as the Indian Council of Social Science Research, Council of Scientific and Industrial Research, Bhabha Atomic Research Centre and the universities To do other things considered necessary to attain the objectives of the Society.

Government Steps to Enhance Agricultural Inputs Government has taken many steps to improve the yield of agriculture in the country. Various steps have been taken to promote efficient use of seeds, fertilizers, pesticides, micronutrients and irrigation. Each of these plays a role in determining yield level and in turn augmentation in level of production. Seeds Seeds are a critical input for agricultural crops. In India, farmers typically rely on farm-saved seeds, overuse of which leads to a low seed replacement rate and poor yield. An Indian Seed Programme for encouraging the development of new varieties and protecting the rights of farmers and plant breeders has been put in place with the participation of central and state governments, the Indian Council of Agricultural Research (ICAR), state agricultural universities, seed cooperatives, and private sectors. A central-sector Scheme for development and strengthening of infrastructure facilities for production and distribution of quality seeds, with the aim of making quality seeds of various crops available to farmers at affordable price, is under implementation since 2005-06. A Sub-Mission on Seed and Planting Material under the National Mission for Agricultural Extension and Technology has been approved for the Twelfth Five Year Plan. Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 19

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

Mechanization and Technology Tractors are the main power source for various farm operations. With adoption of appropriate mechanization of farm operations, we can increase production and farm productivity by 10-15 per cent. Steps are taken for setting up of custom-hiring centres/high-tech machinery banks so that small and marginal farmers can reap the benefits of farm mechanization. The government has initiated a Sub-Mission on Agriculture Mechanization in the Twelfth Five year Plan, with a focus on custom hiring. Integrated Nutrient Management Over 80% of India’s Urea requirements are met from domestic production but we are largely dependent on foreign imports for meeting requirements of potassic (K) and phosphatic (P) fertilizers. Over-use of nitrogenous and limited use of P and K fertilizers are matters of great concern and need appropriate price incentives by reducing fertilizer subsidies so that sustainable practices are encouraged. The government has notified the New Investment Policy 2012 (NIP-2012) in the urea sector which will encourage investments leading to increase in indigenous capacities, reduction in import dependence and savings in subsidy due to import substitution at prices below import parity price. Under the Nutrient Based Subsidy (NBS) scheme for phosphatic and potassic (P&K) fertilizers implemented in 2010, a fixed amount of subsidy, decided on annual basis, is provided to each grade of P&K fertilizer, depending upon its nutrient content. An additional subsidy is also provided to secondary and micro-nutrients. Under this scheme, manufacturers/marketers are allowed to fix the maximum retail price (MRP). Irrigation Although India has made considerable progress in developing irrigation infrastructure, irrigation efficiency is low for both surface and ground waters. In order to help the rainfed farmers improve productivity and profitability, in situ soil and water conservation practices are developed for different agro-climatic regions with special emphasis on effective rainwater management. The central government initiated the Accelerated Irrigation Benefit Programme (AIBP) in 1996-7 for extending assistance for the completion of incomplete irrigation schemes. Besides, the Command Area Development Programme has also been amalgamated with the AIBP to reduce the gap between irrigation potential that has created and that is utilized.

Major Schemes / Programmes for the Agricultural Sector The central government has undertaken many schemes for enhancing productivity and exploring untapped potential of the agricultural sector. The central government supplements the efforts of state governments through centrally sponsored and central-sector schemes. National Mission on Agricultural Extension and Technology (NMAET) Agricultural productivity has a positive correlation with level of farm mechanization. For accelerated growth in farm mechanization in the current decade, there is a need to include the large community of small and marginal farmers into the fold of cost effective and remunerative Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 20

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

mechanized farming, to help sustain desired agricultural growth and to enhance agricultural productivity. Agricultural Technology, including the adoption/ promotion of critical inputs, and improved agronomic practices were being disseminated under 17 different schemes of the Department of Agriculture & Cooperation during the 11th Plan. The Modified Extension Reforms Scheme was introduced in 2010 with the objective of strengthening extension machinery and utilizing it for synergizing interventions under these schemes under the umbrella of the Agriculture Technology Management Agency (ATMA). The NMAET has been envisaged as the next step towards this objective through the amalgamation of these schemes. NMAET consists of 4 Sub Missions: (i) (ii) (iii) (iv)

Sub Mission on Agricultural Extension (SMAE) Sub-Mission on Seed and Planting Material (SMSP) Sub Mission on Agricultural Mechanization (SMAM) Sub Mission on Plant Protection and Plant Quarantine (SMPP)

The common threads running across all 4 Sub-Missions in NMAET are Extension and Technology. Therefore, while 4 separate Sub-Missions are being proposed for administrative convenience, these are inextricably linked to each other at the field level and most components thereof have to be disseminated among farmers and other stakeholders through a strong extension network. The aim of the Mission is to restructure and strengthen agricultural extension to enable delivery of appropriate technology and improved agronomic practices to farmers. This is envisaged to be achieved by a judicious mix of extensive physical outreach and interactive methods of information dissemination, use of ICT, popularisation of modern and appropriate technologies, capacity building and institution strengthening to promote mechanisation, availability of quality seeds, plant protection etc. and encourage aggregation of Farmers into Interest Groups (FIGs) to form Farmer Producer Organisations (FPOs). National Food Security Mission With an aim to enhance the production of rice, wheat, and pulses by 10, 8, and 2 million tonnes respectively, government had launched NFSM-Rice, NFSM-Wheat and NFSM-Pulses in 2007-08. During 2012-13, a Special Plan to achieve 19+ million tonnes of pulses production during Kharif 2012 was launched by the government. The programme also aimed at area expansion and productivity enhancement; restoring soil fertility and productivity; creating employment opportunities; and enhancing farm-level economy to restore the confidence of farmers of targeted districts. Rashtriya Krishi Vikas Yojana The Rashtriya Krishi Vikas Yojana (RKVY) was launched in 2007-8 for incentivizing states to enhance public investment. It permits taking up national priorities as sub-schemes, allowing the states flexibility in project selection and implementation for increased public investment in Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 21

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

agriculture by incorporating information on local requirements, geographical/climatic conditions, available natural resources/ technology and cropping patterns. It aims to significantly increase the productivity of agriculture and its allied sectors and eventually maximize the returns of farmers in agriculture and its allied sectors. National Mission for Sustainable Agriculture Climate change poses a major challenge to agricultural production and productivity. National Mission for Sustainable Agriculture (NMSA), under the aegis of the National Action Plan on Climate Change (NAPCC), seeks to transform Indian agriculture into a climate resilient production system through suitable adaptation and mitigation measures in domains of both crops and animal husbandry. NMSA as a programmatic intervention focuses on promotion of location specific integrated/composite farming systems; resource conservation technologies; comprehensive soil health management; efficient on-farm water management and mainstreaming rainfed technologies. NMSA identifies 10 key dimensions namely seed & culture water, pest, nutrient, farming practices, credit, insurance, market, information and livelihood diversification for promoting suitable agricultural practices that covers both adaption and mitigation measures through four functional areas, namely, Research and Development, Technologies, Products and Practices, Infrastructure and Capacity building. During XII Five Year Plan, these dimensions have been embedded and mainstreamed into Missions/Programmes/Schemes of Ministry of Agriculture including NMSA through a process of restructuring of various schemes/missions implemented during XI Five Year Plan and convergence with other related programmes of Central/State Governments. Bringing Green Revolution to Eastern India(BGREI) Bringing Green Revolution to Eastern India, initiated in 2010-11, intends to address the constraints limiting the productivity of 'rice based cropping systems'7 in eastern India comprising seven states, viz. Assam, Bihar, Chhattisgarh, Jharkhand, Odisha, Eastern Uttar Pradesh, and West Bengal. The BGREI is a subscheme of the Rashtriya Krishi Vikas Yojna (RKVYJ). The following strategies are being adopted, in general, for maximising productivity and production of crops in the eastern region – i.

In situ water harvesting/conservation through adoption of cultural practices like bed furrow in deep black cotton uplands and flat sowing & ridging later in red soils. ii. Reclamation of soil salinity through application of gypsum particularly in oilseed crops along with micro-nutrients like zinc, iron & sulphur in deficient soils. iii. Reclamation of acidic soils through liming/paper mills sludge/application of organic manures/green manures to improve physical condition of the soil iv. Promotion of Integrated Nutrient Management to ensure balanced use of fertilizers/organic manures/bio-fertilizers.

7

Current focus is on rice and wheat only.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 22

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

v. Adoption of soil & water conservation practices namely; summer ploughing, broad bed furrow, compartmental bunding, pre-monsoon sowing and rain water harvesting (Farm ponds) to check soil erosion and recycling runoff. vi. Enhancement of irrigation Water Use Efficiency through adoption of micro-irrigation system (Sprinkler & Drip). vii. Promotion of high value crops namely; sweet sorghum, maize, pulses and oilseeds in addition to hybrid rice in the region. Outcome: Eastern region hitherto known as food deficit region, has with the help of the programme, turned food surplus region. The rice production from the region is estimated at 562.6 lakh tons an increase of 19.8% over last year against an all India increase of 7%. And the foodgrain production from the region is estimated at 1032 tons an increase of 11.9% against an all India increase of 2.2%. The increased productivity/ production was optimized due to resource allocation and utilization. The significant increase in production of food grains in the region not only offset the decline in production in central and peninsular India but also contributed significantly to the highest ever production of food grains. The growth in food grains i.e. rice and wheat provides an opportunity to procure and create food grain reserves locally reducing the pressure on Punjab and Haryana, and cutting costs on transport and other logistics. The focus will now be to consolidate the gains with continued emphasis during the 12th Plan. Further steps will be taken to improve the infrastructure for procurement and storage of the produce and to ensure a reasonable price for the farmers. Evergreen Revolution The architect of the country’s green revolution, M.S. Swaminathan, gave a clarion call for taking up an ‘evergreen revolution’ that “increases productivity in perpetuity without causing any ecological harm and without using chemical inputs”. “I am against a second green revolution, but I am very much for an evergreen revolution,” he said. Pointing out that a majority of food production comes from farmers with small holdings, he said it was essential to increase their income through higher productivity. But it should be done without harming ecological interests, he noted. Swaminathan is an advocate of moving India to sustainable development, especially using environmentally sustainable agriculture, sustainable food security and the preservation of biodiversity, which he calls an "evergreen revolution."

Integrated Scheme Of Oilseeds, Pulses, Oilpalm & Maize (ISOPOM) National Mission on Oilseeds and Oil Palm (NMOOP) envisages increase in production of vegetable oils sourced from oilseeds, oil palm and TBOs from 7.06 million tonnes (average of 2007-08 to 2011-12) to 9.51 million tonnes by the end of Twelfth Plan (2016-17). The Mission is proposed to be implemented through three Mini Missions with specific target as detailed below: Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 23

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

MM I on Oilseeds

Achieve production of 35.51 million tones and productivity of 1328 kg/ha of oilseeds from the present average production & productivity of 28.93 million tonnes and 1081 kg/ha during the 11th Plan period respectively.

MM II on Oil Palm

Bring additional 1.25 lakh hectare area under oil palm cultivation through area expansion approach in the States including utilization of wastelands with increase in productivity of fresh fruit brunches (FFBs) from 4927 kg per ha to 15000 kg per ha.

MM III on TBOs

Enhance seed collection of TBOs from 9 lakh tonnes to 14lakh tonnes and to augment elite planting materials for area expansion under waste land.

The strategy to implement the proposed Mission includes       

increasing Seed Replacement Ratio (SRR) with focus on Varietal Replacement; increasing irrigation coverage under oilseeds from 26% to 36%; diversification of area from low yielding cereals crops to oilseeds crops; inter-cropping of oilseeds with cereals/ pulses/ sugarcane; use of fallow land after paddy /potato cultivation; expansion of cultivation of Oil Palm and tree borne oilseeds in watersheds and wastelands; increasing availability of quality planting material enhancing procurement of oilseeds and collection; and processing of tree borne oilseeds.

Inter-cropping during gestation period of oil palm and tree borne oilseeds would provide economic return to the farmers when there is no production. The scheme would be implemented in mission mode through active involvement of all the stakeholders. The Centre and States will bear costs in the ratio of 75:25. Fund flow would be strictly monitored to ensure that benefit of the Mission reaches the targeted beneficiaries in time to achieve the results. NEED FOR MISSION APPROACH India is among major oilseed growers and edible oil importers. India’s vegetable oil economy is world’s fourth largest after USA, China and Brazil. The oilseed accounts for 13% of the gross cropped area, 3% of the Gross National Product and 10% value of all agricultural commodities. The diverse agro-ecological conditions in the country are favourable for growing 9 annual oilseed crops, which include 7 edible oilseeds (groundnut, rapeseed & mustard, soybean, sunflower, sesame, safflower and niger) and two non-edible oilseeds (castor and linseed). Oilseeds cultivation is undertaken across the country in about 27 million hectares mainly on marginal lands, of which 72% in confined to rainfed farming.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 24

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

During the last few years, the domestic consumption of edible oils has increased substantially and has touched the level of 18.90 million tonnes in 2011-12 and is likely to increase further. With per capita consumption of vegetable oils at the rate of 16 kg/year/person for a projected population of 1276 million, the total vegetable oils demand is likely to touch 20.4 million tonnes by 2017. A substantial portion of our requirement of edible oil is met through import of palm oil from Indonesia and Malaysia. It is, therefore, necessary to exploit domestic resources to maximize production to ensure edible oil security for the country. Oil palm is a comparatively new crop in India and is the highest vegetable oil yielding perennial crop. With quality planting materials, irrigation and proper management, there is potential of achieving 20-30 MT Fresh Fruit Bunches per ha after attaining age of 5 years. Therefore, there is an urgent need to intensify efforts for area expansion under oil palm to enhance palm oil production in the country. Tree-borne oilseeds (TBOs), like sal, mahua, simarouba, kokum, olive, karanja, jatropha, neem, jojoba, cheura, wild apricot, walnut, tung etc. are cultivated or grow wild in the country under different agro-climatic conditions. These TBOs are also good source of vegetable oil and therefore need to be supported for cultivation. Background: In order to provide flexibility to the States in implementation based on regionally differentiated approach, to promote crop diversification and to provide focused approach to the programmes, the four erstwhile schemes of OPP, OPDP, NPDP and AMDP were merged into one Centrally Sponsored Integrated Scheme of Oilseeds, Pulses, Oil palm and Maize (ISOPOM) in 2004. Now ISOPOM is replaced with National Mission on Oilseeds and Oil Palm (NMOOP) to be implemented during the 12th Plan Period as NFSM absorbed pulses and maize component from the ISOPOM scheme.

Problems of Indian Agriculture The nature of problems faced by Indian agriculture varies according to agro-ecological and historical experiences of its different regions. Many of the problems are common to the nation and range from physical constraints to institutional hindrances. 1. Dependence on erratic Monsoon is one of the major problems in India. Irrigation covers only about 33 per cent of the cultivated area in India. Hence, the crop production in rest of the cultivated land directly depends on rainfall. Since, rainfall is very fluctuating; the areas are vulnerable to both droughts and floods. Drought is a common phenomenon in the low rainfall areas which may also experience occasional floods. 2. Low Productivity is another major concern. Per hectare output of most of the crops such as rice, wheat, cotton and oilseeds in India is much lower than that of other countries in the world. Because of the very high pressure on the land resources, the labour productivity in Indian agriculture is also very low in comparison to international level.

Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 25

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF Student Notes:

3. The farmers use outdated techniques. Most of the agricultural operations are carried out manually using simple and conventional tools. This hampers the production potential of the farmers. 4. Constraints on financial resources and indebtedness also make agriculture unmanageable for small and marginal farmers with very meagre or no savings. Crop failures and low returns from agriculture have forced them to fall in the trap of indebtedness. 5. Lack of land reforms has led to exploitation of Indian farmers for long time. There are no proper land records which make them susceptible to exploitation. 6. Besides, small size farms and fragmentation of land holdings also reduces the productivity and production of the farms. More than 60 per cent of the ownership holdings have a size smaller than one hectare (ha). Furthermore, about 40 per cent of the farmers have operational holding size smaller than 0.5 hectare (ha). The small size fragmented landholdings are uneconomic. A large number of farmers produce crops for self-consumption. These farmers do not have enough land resources to produce more than their requirement. Most of the small and marginal farmers grow food grains, which are meant for their own family consumption. 7. There is a massive problem of under-employment in the agricultural sector in India, particularly in the un-irrigated tracts. In these areas, there is a seasonal unemployment ranging from 4 to 8 months. 8. Another serious problem that arises out of faulty strategy of irrigation and agricultural development is degradation of land resources. Large tracts of fertile lands suffer from soil erosion due to wind, deforestation, overgrazing and occasional heavy rainfall. Soil's fertility should be conserved at any cost. This is serious because it may lead to depletion of soil fertility. The situation is particularly alarming in irrigated areas. A large tract of agricultural land has lost its fertility due to alkalisation and salinisation of soils and water logging. 9. Besides, the marketing of agricultural products, especially in rural India, is neither adequate nor standardised. Thus, many farmers have to sell their products at low prices through local traders and middle-men.

UPSC Questions Covered 1. “Small-holder farms need to be strengthened to achieve national food security.” Do you agree with this assessment? Substantiate. (UPSC 2010/12 Marks) 2. Assess the contributions made by the Indian Council of Agricultural Research (ICAR) in agricultural development. (UPSC 2010/12 Marks) 3. Write about Organic Farming in 20 words. (UPSC 2008/2 Marks) 4. Agricultural Productivity in India remains low. Explain the reasons for this situation. (UPSC 2008/15 Marks) 5. Write note on Negative impacts of shifting cultivation. (UPSC 2005/2 Marks) 6. Write short notes on Jhum cultivation – process and consequences. (UPSC 2002/2 Marks) 7. Give an account of the tea plantations of Assam and West Bengal and state the economic significance of these plantations. (UPSC 2002/10 Marks) 8. What is dry farming? Discuss the relevance in augmenting the food supply in India. (UPSC 1999/15 Marks) 9. What is shifting cultivation? Describe its salient characteristics with reference to India? (UPSC 1996/15 Marks) Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 26

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF Student Notes:

10. What is dryland agriculture? Discuss its importance to India? (UPSC 1994/15 Marks) 11. Briefly explain the use of various chemical fertilizers in India agriculture. (UPSC 1992/15 Marks) 12. Mention the states where shifting cultivation is still practiced in India. (UPSC 1990/3 Marks) 13. What are the important wheat growing regions in India and why? Are we now growing enough wheat in India to meet our own demand for it? (UPSC 1985/20 Marks) 14. Government of India has given high priority to Oilseeds Development Programme. What strategy has been adopted to accelerate the efforts for increasing their production? Name important oilseeds cultivated in India with their distribution. (UPSC 1984/15 Marks) 15. Name the cotton growing areas of India. Describe the various factors which favour its cultivation in these areas. What part does cotton play in the present day economy of India? (UPCS 1983/15 Marks) 16. Discuss the geographical conditions favouring the cultivation of wheat or rice in India and describe the steps taken for improving its productivity. (UPCS 1982/30 Marks) 17. What is shifting cultivation? Where in India has this been resorted do? Consider its consequences and examine the steps taken by Government to prevent this practice. (UPCS 1981/20 Marks) 18. Which are the States in India that produce: (i) groundnut, (ii) tea, (iii) tobacco, and (iv) pepper? (UPCS 1980/20 Marks) 19. Can be agricultural development, we have achieved so far, be considered adequate? If so, why? If not, why not?

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS Rajinder Nagar: 1/8-B, 2nd Floor, Apsara Arcade, Near Gate 6, Karol Bagh Metro, Delhi Mukherjee Nagar: 103, 1st Floor, B/1-2, Ansal Building, Behind UCO Bank, Delhi-9

09650617807, 09968029039, 09717162595 27

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS www.visionias.in GEOGRAPHY: 19

Distribution of Key Natural Resources Across the World (Including South Asia and the Indian Sub-Continent

Contents 1

Introduction ........................................................................................................................................................ 2 1.1

Uneven Distribution of Resources .............................................................................................................. 2

2

Classification of Resources ................................................................................................................................. 2

3

Energy Resources ............................................................................................................................................... 2 3.1

Coal ............................................................................................................................................................. 3

3.1.1 3.2

Petroleum ................................................................................................................................................... 6

3.3

Natural Gas ................................................................................................................................................. 8

3.3.1

Shalegas .............................................................................................................................................. 9

3.3.2

Coalbed Methane (CBM) .................................................................................................................. 10

3.4

India – Petroleum – Petroleum and Natural Gas ..................................................................................... 11

3.5

Nuclear ..................................................................................................................................................... 15

3.5.1

1

Coal in India ........................................................................................................................................ 4

India .................................................................................................................................................. 17

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1 Introduction Natural resources which satisfy the material and spiritual needs of humans are the free gifts of the nature. In other words, any material or energy derived from the nature that is used by humans called a natural resource. These resources include land, water, minerals, vegetation, wildlife etc. In fact every material has some utility for human beings but its utilisation is possible on the availability of appropriate technology. Distribution of natural resource refers to the geographic occurrence or spatial arrangement of resources on earth. In other words, where resources are located. Any one place may be rich in the resources people desire and poor in others.

1.1 Uneven Distribution of Resources Low latitudes (latitudes close to the equator) receive more of the sun's energy and much precipitation, while higher latitudes (latitudes closer to the poles) receive less of the sun's energy and too little precipitation. The temperate deciduous forest biome provides a more moderate climate, along with fertile soil, timber, and abundant wildlife. The plains offers flat landscapes and fertile soil for growing crops, while steep mountains and dry deserts are more challenging. Metallic minerals are most abundant in areas with strong tectonic activity, while fossil fuels are found in rocks formed by deposition (sedimentary rocks). However, uneven distribution of natural resources have their own consequences on human settlement, economic activities, trade and even on conflict and war. Human settlement has been found near the natural resources in pre-historic time. Natural resources form the backbone of the economy of a nation. Without land, water, forest, mineral one cannot develop agriculture and industry. By utilising natural resources, humans created their own world of houses, buildings, means of transport and communication, industries etc.

2 Classification of Resources Resources can be classified in several ways: one the bases of (i) renewability, (ii) origin and (iii) utility. The objective of classification would primarily decide how we put a resource under a particular category.

Figure 1: Classification of Resources

3 Energy Resources Energy is an essential input for economic development and improving the quality of life. It is required for generation of power, required by agriculture, industry, transport and other sectors of the economy. Energy may be classified into two categories, namely: 2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF  

www.UPSCPDF.com

https://t.me/UPSC_PDF

Conventional – Coal, Petroleum, Natural gas and electricity Non-conventional – solar, wind, tidal, geothermal, and biogas energy

Other classification can be made between –  

Non-renewable resources – which when exhausted are exhausted forever such as coal etc. Renewable resources – which are inexhaustible such as wind energy, solar energy etc.

3.1 Coal Coal is a one of the important minerals which is mainly used in the generation of thermal power and smelting of iron ore. It is the one of the most mined mineral from the earth. According to one estimate, proven coal reserves are 860, 938 million tonnes. Of the three fossil fuels (Petroleum, natural gas and coal), coal has the most widely distributed reserves; coal is mined in over 100 countries, and on all continents except Antarctica. The largest proved reserves are found in the United States, Russia, China, Australia and India (figure 2). A proved recoverable reserve is the tonnage of coal that has been proved by drilling etc. and is economically and technically extractable. Coal is found majorly in forms of Lignite [1] and Anthracite. Distribution of coal across the world is shown in figure 3.

Figure 2: Global share of recoverable coal reserves

Figure 3: coal deposits of the world 3

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

In terms of production, China is the top coal producer since 1983. In 2011 China produced 3,520 millions of tonnes (mt) of coal – 49.5% of 7,695 million tonnes world coal production. In 2011 other large producers were United States (993 mt), India (589 mt), European Union (576 mt) and Australia (416 mt). Top coal exporting countries are Australia with 27% and Indonesia with 26% of total world coal export in 2010. Japan is the largest coal importer with 17% of total world coal import seconded by China having share of 16% in 2010. Major coalfields of the world are listed in the table 1. North America

Europe

             

Asia

    

Africa

         

South America

Pennsylvania anthracite field Appalachian bituminous field Eastern Illinois field – Illinois, Indiana and Kentucky Western interior field – Iowa, Missouri, Oklahoma Gulf province – Texas, Alabama and Arkansas Rocky mountain province – Utah, Colorado, Wyoming, Montana, new Mexico Canada – Prairies, British Columbia coalfields, Nova Scotia Coal fields Donetz coal basin (anthracite and high grade bituminous coal) Moscow-Tula coalfields Kuznetsk coal basin Karaganda field Silesia coal fields Ruhr area of Germany Other coal fields in Urals, Taimyr fields of the Arctic, deposits of the Caucasus mountains China – Shanxi, Fushun, Inner Mongolia, Kansu Japan – Chikugo coalfield, Ishikari coalfield India – Damodar valley, Raniganj, Bokaro, Jharia, Singareni. Pakistan - Quetta, Kalabagh and Thar coalfields Australia – Bowen Basin coalfield, Galilee Basin coalfield, South Maitland coalfield, Sydney Basin coalfield, and Latrobe valley coalfield Transvaal and Natal – Middleburg, Vereeniging and Witbank Zimbabwe – Wankie Zaire – Luena Mozambique – Maniamba Zambia – Nkandabwe and Mamba Nigeria – Enugu Brazil – Santa Catarine and Rio grande de sul Chile – Concepcion Columbia – Cauca valley coalfield Mexico – Piedras Negras, Sabinas and Lampazos Table 1 – Distribution of coal across continents

3.1.1 Coal in India Coal is the most important and abundant fossil fuel in India. It accounts for 55% of the country's energy need. Hard coal deposit spread over 27 major coalfields, are mainly confined to eastern and south central parts of the country. A cumulative total of 2,93,497 million tonnes of geological resources of Coal upto depth of 1200 meters have so far been estimated in the country as on 1.4.2012. The lignite reserves stand at a level of 41.96 billion tones as on 1.4.2012, of which 90% occur in the southern State of Tamil Nadu. Other states where lignite deposits have been located are Rajasthan, Gujarat, Kerala, Jammu & Kashmir, and union territory of Puducherry The coal resources of India are available in older Gondwana (570 million years to 245 million years ago) formations of peninsular India and younger tertiary (60 to 15 million years ago) formations of north-eastern region. Formation-wise coal resources of India as on 1.4.2012 are given in table 2 below: 4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

Formation Gondwana coals Tertiary coals Total

Proved (million tonnes) 117551.01 593.81 118114.82

https://t.me/UPSC_PDF Total (million tonnes) 292004.51 1492.64 293497

Table 2: Estimations for different types of coal based on formation The Gondwana coal belongs to the carboniferous period. It is found in the Damodar, Mahanadi, Godavari, and Narmada valleys. Raniganj, Jharia, Bokaro, Ramgarh, Giridih, Chandrapur, Karanpura, Tatapani, Talcher, Himgiri, Korba, Penchgati, Sarguja, Kamthi, Wardha valley, Singreni (A.P.) and Singrauli are some of the important coal mines of the Gondwana formations. The Jharguda coal mine (Chhattisgarh) is the thickest coal seam 132 meters of the Gondwana period, followed by the Kargali seam near Bokaro belong to the Gondwana period. The detail of state-wise geological resources of Gondwana coal is given below in table 3. State Andhra Pradesh Chhattisgarh Jharkhand Madhya Pradesh Maharashtra Odisha Uttar Pradesh West Bengal Total

Proved (million tonnes) 9566.61 13987.85 40163.22 9308.70 5667.48 25547.66 884.04 12425.44 117551.01

Total (million tonnes) 22154.86 50846.15 80356.2 24376.26 10882.09 71447.41 1061.80 30615.72 292004.51

Table 3: Gondwana coalfields

Figure 4: Major coalfields of India 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Tertiary coal is found in the rocks of the Tertiary era. It is about 15 to 60 million years old. The Tertiary coal is also known as the ‘brown coal’. The Tertiary coal contributes only about two per cent of the total coal production of the country. It is an inferior type of coal in which the carbon varies between 30 per cent in Gujarat and Rajasthan to 50 per cent in Assam. Lignite coal is found in Arunachal Pradesh and West Bengal (Darjeeling District). The largest lignite deposits of the country are at Neyveli in the state of Tamil Nadu. The detail of statewise geological resources of tertiary coal is given below in table 4. State Arunachal Pradesh Assam Meghalaya Nagaland Total

Proved (million tonnes) 31.23 464.78 89.04 8.76 593.81

Total (million tonnes) 90.23 510.52 576.48 315.41 1492.64

Table 4: Tertiary coalfields

3.2 Petroleum Petroleum is also called ‘black gold’ or ‘liquid gold’. It is second to coal in terms of sources of energy. It is an essential source of energy for all internal combustion engines in automobiles, railways and aircraft. Crude petroleum occurs in sedimentary rocks of the tertiary period. It is formed when large quantities of dead organisms, usually zooplankton and algae, are buried underneath sedimentary rock and subjected to intense heat and pressure. Petroleum (and natural gas) are born and accumulate in the sedimentary mantle of the Earth. Small amounts of these hydrocarbons are present throughout the mantle, but large accumulations are encountered less frequently. About 600 sedimentary basins, characterized by oil and gas occurrence, are found on the Earth. Unlike coal, Petroleum is not distributed evenly around the world. More than half of the world’s proven oil reserves are located in the Middle East (figure 5). Following the Middle East are Canada and the United States, Latin America, Africa, and the region occupied by the former Soviet Union. Each of those regions contains less than 15 percent of the world’s proven reserves [2].

6

www.visionias.in

Figure 5: Worldwide Oil Distribution ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Since exploration for oil began during the early 1860s, some 50,000 oil fields have been discovered. More than 90 percent of these fields are insignificant in their impact on world oil production. The two largest classes of fields are the super-giants, fields with 5 billion or more barrels of ultimately recoverable oil, and world-class giants, fields with 500 million to 5 billion barrels of ultimately recoverable oil. Fewer than 40 supergiant oil fields have been found worldwide. The Arabian-Iranian sedimentary basin in the Persian Gulf region contains twothirds of these supergiant fields. The remaining super-giants are distributed as follows: two in the United States, two in Russia, two in Mexico, one in Libya, one in Algeria, one in Venezuela, and two in China. The nearly 280 world-class giant fields thus far discovered, plus the super-giants, account for about 80 percent of the world’s known recoverable oil. There are, in addition, approximately 1,000 known large oil fields that initially contained between 50 million and 500 million barrels. These fields account for some 14 to 16 percent of the world’s known oil. Major oil fields are listed below:        

Ghawar field – Saudi Arabia Burgan field – Kuwait Azeri-Chirag-Guneshli – Caspian Sea, Azerbaijan Ku-Maloob-Zaap – Mexico Zakum - UAE Ferdows field – Iran Sugar Loaf field – Brazil Bolivar Coastal field – Venezuela

World’s five largest offshore oilfields:     

Safaniya oilfield – Persian Gulf, Saudi Arabia Upper Zakum oilfield – Persian Gulf, UAE Manifa oilfield – Persian Gulf, Saudi Arabia Kashgan oilfield – Caspian Sea, Kazakhstan Lula Oilfield - Brazil

According to current estimates, more than 81% of the world's proven oil reserves are located in OPEC Member Countries, with the bulk of OPEC oil reserves in the Middle East (figure 6). OPEC Member Countries have made significant additions to their oil reserves in recent years. As a result, OPEC's proven oil reserves currently stand at 1,200.83 billion barrels.

7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 6: Share of Organization of the Petroleum Exporting Countries (OPEC) in world crude oil reserves 2012 Classification of crude oil Crude oil may be referred to as sweet if it contains relatively little sulfur (0.5%) or sour if it contains substantial amounts of sulfur. Sweet crude requires less energy to be extracted and once extracted, yields higher quality gasoline as well as larger quantities of it. Iraq is one of the leading producers of sweet crude. Major locations where sweet crude is found include the Appalachian Basin in Eastern North America, Western Texas, the Bakken Formation of North Dakota and Saskatchewan, the North Sea of Europe, North Africa, Australia, and the Far East including Indonesia. Sour crude, on the other hand, has a high level of impurities in it, namely sulfur, which must first be removed before being processed into gas and other petroleum based products. Venezuela is a leading producer of sour crude oil. Sour crude is more common in the Gulf of Mexico, Mexico, South America, and Canada. Crude produced by OPEC Member Nations also tends to be relatively sour, with an average sulfur content of 1.77%. According to IEA top 10 oil producer countries produced over 64 % of the world oil production in 2012. In 2012 total oil production was 4,142 Mt. The top oil producers in 2012 were:          

Russia - 544 Mt (13 %) Saudi Arabia - 520 Mt (13 %) United States - 387 Mt (9 %) China - 206 Mt (5%) Iran - 186 Mt (4 %) Canada - 182 Mt (4 %) United Arab Emirates (UAE) - 163 Mt (4 %) Venezuela - 162 Mt (4 %) Kuwait - 152 Mt (4 %) Iraq - 148 Mt (4 %).

3.3 Natural Gas Natural gas is a fossil fuel formed when layers of buried plants, gases, and animals are exposed to intense heat and pressure over thousands of years. The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in natural gas. Natural gas, a nonrenewable energy resource, is found in deep underground rock formations or associated with other hydrocarbon reservoirs in coal beds and as methane clathrates. Petroleum is another resource and fossil fuel found in close proximity to, and with natural gas. Like Petroleum, natural gas is not distributed evenly around the world. More than three-fourth of the world’s proved natural gas reserves are located in top ten countries (figure 7). Following the Russia are Iran and Qatar, Turkmenistan, USA. Small gas fields are located in various parts of the world. [2]. Unconventional sources of natural gas are:   

8

Shale gas Coalbed methane (CBM) methane hydrates

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Figure 7: Countries with largest proved natural gas reserves Some of the largest gas fields are listed below:          

South Pars/North Dome – Persian Gulf, Iran and Qatar Urengoy – Siberian Basin, Russia Yamburg – Arctic circle, Russia Hassi R’Mel – Algeria Shtokman – Barents Sea, Russia South lolotan-Osman – Turkmenistan Zapolyarnoye – Russia Hugoton – USA Groningen – Netherlands Bovanenko – Russia

As measured by the International Energy Agency, the top 10 natural gas producers in 2011 were (66.7% of total):          

Russia (20.0%) United States (19.2%) Canada (4.7%) Qatar (4.5%) Iran (4.4%) Norway (3.1%) China (3.0%) Saudi Arabia (2.7%) Indonesia (2.7%) Netherlands (2.4%)

3.3.1 Shalegas Shale gas is a natural gas produced from shale, a type of sedimentary rock. Due to constant announcements of shale gas recoverable reserves, as well as drilling in Central Asia, South America and Africa, deepwater drilling, estimates are undergoing frequent updates, mostly increasing. Since 2000, some countries, notably the US and Canada, have seen large increases in proved gas reserves due to development of shale gas, but shale gas deposits in most countries are yet to be added to reserve calculations. Some analysts expect that shale gas will 9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

greatly expand worldwide energy supply. Figure 8 shows the major shale gas fields of the word. China is estimated to have the world's largest shale gas reserves followed by USA, Argentina, Mexico, South Africa, Australia, and Canada (table 5).

Figure 8: World Shale Gas The United States and Canada are the major producers of commercially viable natural gas from shale formations in the world, even though about a dozen other countries have conducted exploratory test wells. China is the only nation outside of North America that has registered commercially viable production of shale gas, although the volumes contribute less than 1% of the total natural gas production in that country. In comparison, shale gas as a share of total natural gas production in 2012 was 39% in the United States and 15% in Canada. Country

China USA Argentina Mexico South Africa Australia Canada Libya Algeria Brazil

Estimated recoverable reserves (trillion cubic feet) 1, 275 862 774 681 485 396 388 290 231 226

Proven gas reserves(trillion cubic feet) 107 272.5 13.4 12 110 62 54.7 159 12.9

Table 5: List of top 10 countries by recoverable shale gas 3.3.2 Coalbed Methane (CBM) CBM is generated by the conversion of plant material to coal through burial and heating. As “coalification” progresses, increasingly dense coal is formed. Coal serves as both the source rock and the reservoir rock. Coal is extremely porous but has low permeability (connected openings). Much of the methane generated by the coalification process escapes to the surface or migrates into adjacent reservoir or other rocks, but a significant volume remains trapped within the coal itself. 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 9: Major coalbed Methane reserves CBM can be found almost anywhere there is coal. Figure 9 shows CBM resources by top countries. Deep coal seams beyond the reach of mining operations present opportunities for development of CBM. The largest proven recoverable coal reserves, according to the latest published data, are in the USA (28.6%), followed by Russia (18.5%), China (13.5%), Australia (9.0%) and India (6.7%). Indonesia has highly prospective CBM potential, with an estimated 453 Tcf of in-place resources located mainly in Sumatra and Kalimantan provinces. Depending on the source, Russia’s resource estimates range from 600 to 2,825 Tcf. Global CBM production totals 5.8 Bcfd (billion cubif feet per day) from 15 basins in the USA, Canada, Australia, China, and India. The USA still dominates with nearly 5 Bcfd of production and about 20 Tcf produced to date, but production there is expected to fall going forward because of resource maturity and depletion. Australia may well displace the USA as the top-ranked producer, making a projected 6 Bcfd by 2020 once its LNG export plants are fully operational. CBM production in China (150 MMcfd) and India (10 MMcfd) is struggling due to more challenging geologic conditions and low well productivity.

3.4 India – Petroleum – Petroleum and Natural Gas Oil exploration and production was systematically taken up after the Oil and Natural Gas Commission was set up in 1956. Till then, the Digboi in Assam was the only oil producing region but the scenario has changed after 1956. Mumbai High which lies 160 km off Mumbai was discovered in 1973 and production commenced in 1976. In recent years, new oil deposits have been found at the extreme western and eastern parts of the country. State/region

Reserves in million metric tonnes Gujarat 136.73 Assam (includes north eastern reserves) 178.07 Andhra Pradesh 7.42 Tamil Nadu 9.21 Western Offshore (includes Bombay High, 396.41 Rajasthan) Eastern Offshore 30.43 Total 758.27 Table 6: Reserves of Crude Oil in India (2013) 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

India has total reserves (proved & indicated) of 758 million metric tonnes of crude oil (table 6) and 1355 billion cubic meters of natural gas (table 7) as on 1.4.2013. Onshore and offshore crude oil constitutes 398 million metric tonnes and 360 million metric tonnes respectively. Geographical distribution of crude oil indicates that the maximum reserves are in the western offshore including Bombay High and Rajasthan (52%) followed by Assam (23%) whereas maximum reserves of natural gas are in the Eastern offshore including CBM in West Bengal (38%) followed by western offshore including Bombay High, Rajasthan, Madhya Pradesh and Jharkhand (36%). The increase in the estimated natural gas reserves is largely from CBM. State/region Gujarat Assam (includes north eastern reserves) Andhra Pradesh Tamil Nadu Western Offshore (includes Bombay High, Rajasthan, Madhya Pradesh and Jharkhand) Eastern Offshore (Includes CBM in West Bengal) Total

Reserves in billion cubic meters 77.53 181.77 48.21 45.83 488.20 513.22 1354.76

Table 7: Reserves of Natural Gas in India (2013) The 15 basins out of a total 26 sedimentary basins (figure 10) in India have prognosticated hydrocarbon resources of about 206 Billion barrels of oil equivalent spread across onland, offshore and deepwater areas. Total area under these basins is 3 million sq. km. Over the last twelve years, there have been significant forward steps in exploring the hydrocarbon potential of the sedimentary basins of India. The unexplored area has come down to 15% which was 50% in 1995-96.

Figure 10: sedimentary Basin of India Oil and natural gas have been found in exploratory wells in Krishna-Godavari and Kaveri basin on the east coast. Largest natural gas discovery has been made in Krishna-Godavari deep waters. Similarly, largest oil discovery after Bombay High has been made in the Barmer oil fields of Rajasthan. In Assam, Digboi, Naharkatiya and Moran are important oil producing areas. The major oil fields of Gujarat are Ankaleshwar, Kalol, Mehsana, Nawagam, Kosamba and Lunej. Exclusive reserves of natural gas are located along the eastern coast as well as Tripura, Rajasthan and off-shore wells in Gujarat and Maharashtra. Some of the major oil and gas discoveries in 21st century are shown in figure 11.

12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 11: Major Oil and Gas discoveries after 2000 Coalbed Methane (CBM) India has substantial coal reserves and most are suitable for CBM development. Deep coal deposits, not accessible by conventional mining operations, also offer CBM development opportunities. In 1997, India’s government formulated a CBM policy and allotted a number of blocks for exploration. Commercial production of CBM began in 2007. The first CBM production started in 2007 from Raniganj in West Bengal. Government aims to offer up to 90% of total coal bearing area by the end of 2016-17 for exploration and production of CBM. The CBM reserves as per Directorate General of Hydrocarbons is tabulated here under: State West Bengal Jharkhand Madhya Pradesh Gujarat Total

Coalfields/block North Raniganj, Eastern Raniganj and Birbhum Jharia, East and West Bokaro, North Karanpura Sohagpur, Satpura Cambay Basin

Reserves in billion cubic metres 109.87 174.93 114.11 311-549 (advance estimates) 710 - 948

Table 8: CBM reserves of India Shale gas Shale gas has reduced America’s dependence on oil imports, leading other countries to look for such reserves. India, too, has potential to reduce its dependence on imports by tapping the potential of shale gas. Six onshore basins — Cambay, Krishna-Godavari, Cauvery, Assam-Arakan, Ganga and Gondwana/Damodar—have been identified for shale exploration (figure 12). The Indian Government entered into a MoU with the United States Geological Survey (USGS) to conduct an assessment of the shale gas resources. According to the US Energy Information Administration, India could be sitting on as much as 96 TCF of recoverable shale gas reserves, equivalent to about 26 years of its gas demand, compared with its 43.8 TCF of natural gas reserves at the end of 2012. Another estimate, by Schlumberger Company, has indicated a shale gas resource base of between 600 Tcf and 2,000 Tcf.

13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 12: Shale oil and gas basins of India Krishna Godavari basin, located in eastern India, is considered to hold the largest shale gas reserves in the country. The basin is estimated to have around 27 Tcf of technically recoverable gas. The Cauvery basin in Tamil Nadu state is estimated to have recoverable shale gas reserves of 7 Tcf. The Cambay basin in Gujarat is the largest basin in the country, spread across 51,800 sq km. As per the initial studies, around 20 Tcf of gas is estimated as technically recoverable reserves in the Cambay basin. ONGC had drilled the country’s first shale gas well in Jambusar in the October in 2013 to exploit the natural gas trapped within the shale formations located in Cambay basin. Methane Hydrate Methane Hydrate is a cage-like lattice of ice inside of which are trapped molecules of methane, the chief constituent of natural gas. It is found in sea-bed that forms at low temperatures and high pressure. It is also found in onshore deposits in the permafrost of northern Canada and Russia. Heating the deposits or lowering the pressure will release gas from the solid. One litre of solid hydrate releases around 165 litres of gas.

Figure 13: Potential Gas Hydrate reserves of India 14

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

India has some of the biggest methane hydrate reserves in the world. These are tentatively estimated at 1,890 trillion cubic metres. An Indo-US scientific joint venture in 2006 explored four areas: the Kerala-Konkan basin, the Krishna-Godavari basin, the Mahanadi basin and the seas off the Andaman Islands (figure 13). The deposits in the Krishna Godavari basin turned out to be among the richest and biggest in the world. The Andamans yielded the thickest-ever deposits 600 metres below the seabed in volcanic ash sediments.

3.5 Nuclear Nuclear energy has emerged as a viable source in recent times. Important minerals used for the generation of nuclear energy are uranium and thorium. Uranium is a relatively common element in the crust of the Earth. It is a metal approximately as common as tin or zinc, and it is a constituent of most rocks and even of the sea. The table 14 gives some idea of our present knowledge of uranium resources. It can be seen that Australia has a substantial part (about 31 percent) of the world's uranium, Kazakhstan 12 percent, and Canada and Russia 9 percent each. Known uranium resources have increased almost threefold since 1975. Recycled uranium and plutonium is another source for Uranium fuel, and currently saves 1500-2000 tU per year of primary supply, depending on whether just the plutonium or also the uranium is considered. In fact, plutonium is quickly recycled as MOX fuel, whereas the reprocessed uranium (RepU) is mostly stockpiled. Re-enrichment of depleted uranium (DU, enrichment tails) is another secondary source. There is about 1.5 million tonnes of depleted uranium available, from both military and civil enrichment activity since the 1940s, most at tails assay of 0.25 - 0.35% U-235. Russian enrichment plants have treated 10-15,000 tonnes per year of DU producing a few thousand tonnes per year of natural uranium equivalent.

tonnes U percentage of world Australia 1,661,000 31% Kazakhstan 629,000 12% Russia 487,200 9% Canada 468,700 9% Niger 421,000 8% South Africa 279,100 5% Brazil 276,700 5% Namibia 261,000 5% USA 207,400 4% China 166,100 3% Ukraine 119,600 2% Uzbekistan 96,200 2% Mongolia 55,700 1% Jordan 33,800 1% other 164,000 3% World total

5,327,200

Figure 14: Known Recoverable Resources of Uranium 2011 Global uranium mine production increased by over 25% between 2008 and 2010 because of significantly increased production in Kazakhstan, currently the world's leading producer. Global uranium production trend is shown in figure 15. Demand for uranium is expected to continue to rise for the foreseeable future. Although the Fukushima Daiichi nuclear accident has affected nuclear power projects and policies in some countries, nuclear power remains a key part of the global energy mix.

15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 15: Top 10 Uranium producing countries (2010) Current usage of Uranium is about 68,000 tU/yr. Thus, the world's present measured resources of uranium (5.3 Mt) in the cost category around present spot prices and used only in conventional reactors, are enough to last for about 80 years. Thorium as a nuclear fuel Today uranium is the only fuel supplied for nuclear reactors. However, thorium can also be utilised as a fuel for CANDU (CANada Deuterium Uranium) reactors or in reactors specially designed for this purpose. Neutron efficient reactors, such as CANDU, are capable of operating on a thorium fuel cycle, once they are started using a fissile material such as U-235 or Pu-239. Then the thorium (Th-232) atom captures a neutron in the reactor to become fissile uranium (U-233), which continues the reaction. Thorium is about 3.5 times more common than uranium in the Earth's crust. Present knowledge of the distribution of thorium resources is poor because of the relatively low-key exploration efforts arising out of insignificant demand. World distribution of Thorium reserves is shown in figure 16. India and Australia are believed to possess about 300,000 tonnes each; i.e. each country possessing 25% of the world's thorium reserves.

16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 16: World Thorium reserves (in tonnes) (2005) 3.5.1 India India has relatively modest reserves of uranium. India's uranium resources are modest, with 102,600 tonnes U (tU) as reasonably assured resources (RAR) and 37,200 tonnes as inferred resources in situ at January 2011. However, department of atomic energy claims to have reserves of 1, 86, 653 tU in 2013. Andhra Pradesh followed by Jharkhand and Meghalaya in that order is top state with largest uranium reserves. With rise in number of reactors, India expects to import an increasing proportion of its uranium fuel needs. In 2013, India imported about 40% of her uranium requirements from France, Russia and Kazakhstan. India’s Uranium mines are shown in figure 17. Ministry of Environment and Forest rejected the proposal of uranium mining in Mehgalaya keeping in view of the sentiments of the local people and a number of representations received from local civil society group. Following are the uranium mines in Jharkhand’s Singhbhum zone:         

Jaduguda Mine Bhatin Mine Turamdih Mine Bagjata Mine Narwapahar Mine Banduhurang Mine Jaduguda Mill Turamdih Mill Mohuldih Mine

Major areas which are currently under survey and exploration to augment uranium reserves in India include:       

17

Tummalapalle-Rachakuntapalle, Kadappa district, Andhra Pradesh Koppunuru and adjoining areas, Guntur district, Andhra Pradesh Rohil and adjoining areas, Sikar district, Rajasthan Wahkut and Umthongkut areas of West Khasi Hills district, Meghalaya Gogi, Yadgir district, Karnataka Singridungri-Banadungri, East Singhbhum district, Jharkhand and Bangurdih, Seraikela-Kharsawan district, Jharkhand.

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 17: Uranium occurrence and production centres in India Indian interest in thorium is motivated by their substantial reserves. Department of Atomic Energy has established the presence of 10.70 million tonnes of Monazite ore, found in beach and river sand in the country, which contains 9,63,000 tonnes of Thorium Oxide (ThO2) in 2009. India Monazite contains about 9-10% of ThO2 and about 8,46,477 tonnes of thorium Metal can be obtained from 9,63,000 tonnes. In 2013, total Monazite reserves are estimated to be 11.93 million tonnes. Following is the state wise distribution: State Odisha Andhra Pradesh Tamil Nadu Kerala West Bengal Jharkhand Total

Monazite (million tonne) 2.41 3.72 2.46 1.90 1.22 0.22 11.93

Thorium is mainly obtained from monazite and ilmenite in the beach sands along the coast of Kerala and Tamil Nadu (figure 18). World’s richest monazite deposits occur in Palakkad and Kollam districts of Kerala, near Vishakhapatnam in Andhra Pradesh and Mahanadi river delta in Odisha.

18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 18: Thorium deposits, India References: [1] Types of coal 





Lignite - often referred to as brown coal, is a soft brown combustible sedimentary rock that is formed from naturally compressed peat. It is considered the lowest rank of coal due to its relatively low heat content. It has a carbon content of around 25-35%, a high inherent moisture content sometimes as high as 66%, and an ash content ranging from 6% to 19%. It is mined in Bulgaria, Kosovo, Greece, Germany, Poland, Serbia, Russia, Turkey, the United States, Canada, India, Australia and many other parts of Europe and it is used almost exclusively as a fuel for steam-electric power generation. Bituminous coal or black coal is a relatively soft coal containing a tarlike substance called bitumen. It is of higher quality than lignite coal but of poorer quality than anthracite. The carbon content of bituminous coal is around 60-80%; the rest is composed of water, air, hydrogen, and sulphur. Anthracite is a hard, compact variety of mineral coal that has a high luster. It has the highest carbon content, the fewest impurities, and the highest calorific content of all types of coal. The carbon content is between 92.1% and 98%. It is used mainly in power generation, in the metallurgy sector. Anthracite accounts for about 1% of global coal reserves,[4] and is mined in only a few countries around the world. China accounts for the majority of global production; other producers are Russia, Ukraine, North Korea, Vietnam, the UK, Australia and the US.

[2] Reserves are identified quantities of “in-place” minerals that are considered recoverable under current economic and technological conditions.

19

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Sources: 1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11. 12. 13. 14.

NCERT class XIl – India people and economy Geography of India by Majid Hussain Wikipedia http://www.portal.gsi.gov.in/portal/page?_pageid=127,721708&_dad=portal&_schema=PORTAL http://www.geologydata.info/coal_02.htm http://www.coal.nic.in/reserve2.htm http://www.britannica.com/EBchecked/topic/454269/petroleum/50722/Status-of-the-world-oil-supply http://www.petroleum.co.uk/sweet-vs-sour http://www.forbes.com/sites/williampentland/2013/09/07/worlds-five-largest-offshore-oil-fields/ http://www.gazprominfo.com/articles/prospecting/ http://www.eia.gov/todayinenergy/detail.cfm?id=13491 http://www.britannica.com http://www.cbmasia.ca/CBM-In-Indonesia http://www.thehindubusinessline.com/industry-and-economy/between-a-rock-and-a-hardplace/article5335576.ece 15. http://indiatogether.org/shale-environment 16. http://www.epmag.com/Technology-Operations/ONGC-Readies-Shale-Gas-Play_121525 17. http://www.dghindia.org/SedimentaryBasins.aspx# 18. http://petroleum.nic.in/kelkar.pdf 19. http://petroleum.nic.in/stratreport.pdf 20. http://petroleum.nic.in/pngstat.pdf 21. http://www.cmpdi.co.in/cbm.php 22. http://articles.economictimes.indiatimes.com/2013-03-17/news/37787191_1_hydrate-reservesmethane-hydrate-japan-oil-gas 23. http://www.naturalgasasia.com/ngri-finds-gas-hydrate-reserves-along-east-coast-of-india-3638 24. http://www.dghindia.org/NonConventionalEnergy.aspx?tab=0 25. http://www.thehindu.com/business/Industry/shale-gas-oncg-to-drill-more-wells-incambay/article5526061.ece 26. http://pib.nic.in/newsite/erelease.aspx?relid=74293 27. http://www.downtoearth.org.in/content/india-set-new-nuclear-age 28. http://www.ucil.gov.in/web/ucil_operetions_in_jharkhand.html 29. http://moef.nic.in/downloads/public-information/Ur_report.pdf 30. http://dae.nic.in/?q=node/660 31. http://thoriumforum.com/reserve-estimates-thorium-around-world 32. http://www.world-nuclear.org/info/Country-Profiles/Countries-G-N/India/ 33. http://www.mapsofworld.com/thematic-maps/natural-resources-maps/ 34. http://notesforupsc.blogspot.in/2014/01/gs-2-distribution-of-key-natural.html 35. https://drive.google.com/folderview?id=0Bz1txbcKwYPXdEQ0QzJOdDkxbTg&usp=sharing 36. http://notesforupsc.blogspot.in/2014/01/gs-2-distribution-of-key-natural.html 37. http://notesforupsc.blogspot.in/2014/01/gs-2-distribution-of-key-natural.html

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 20

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS www.visionias.in GEOGRAPHY: 20

Mineral Resources & Manufacturing Industries 1. Mineral and Energy Resources 1.1 Types of Mineral Resources 1.2 Distribution of Minerals in India 1.2.1 The North-Eastern Plateau Region 1.2.2 The Central belt 1.2.3 The South-Western Plateau Region 1.2.4 The North-Western Region 1.3 Ferrous Minerals 1.3.1 Iron Ore 1.3.2 Manganese 1.4 Non-Ferrous Minerals 1.4.1 Copper 1.4.2 Bauxite 1.4.3 Lead 1.4.4 Zinc 1.4.5 Gold: 1.4.6 Silver 1.5 Non- Metallic Minerals 1.5.1 Mica 1.5.2 Limestone 1.5.3 Dolomite 1.6 Atomic Minerals 2. Energy Resources 2.1 Conventional Energy Sources 2.1.1 Coal: 2.1.2 Petroleum 2.1.3 Natural Gas 2.2 Non Conventional energy Sources 1

2.2.1 Solar Energy www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

2.2.2 Wind Energy 2.2.3 Tidal and Wave Energy 2.2.4 Geothermal Energy 2.2.5 Bio-energy 3. Manufacturing Industries 3.1 Types of Industries 3.2 Location of Industries 3.2.1 Geographical Factors 3.2.2 Non – Geographical Factors 3.3 Major Industries 3.3.1 Iron & Steel Industry 3.3.2 Cotton textile Industry 3.3.3 Sugar Industry 3.3.4 Petrochemical Industries 3.3.5 Machine Tools 3.3.6 Automobile Industry 3.3.7 Electronic Industry 3.3.8 Knowledge based Industries 3.4 Liberalisation, Privatisation, Globalisation (LPG) and Industrial Development in India 3.5 Industrial Regions 4. UPSC Questions Covered Sources:

2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1. Mineral and Energy Resources India is endowed with a rich variety of minerals. Large size and diverse geological formations have favoured India in providing a wide variety of minerals. It has been estimated that nearly 100 minerals are known to be produced and worked in India. The country has fairly abundant reserves of coal, iron and mica, adequate supplies of manganese ore, titanium and aluminium, raw materials for refractory and limestone; but there is deficiency in ores of copper, lead and zinc. There are workable deposits of tin and nickel. India earns a lot of foreign exchange via export of a large variety of minerals such as iron ore, titanium, manganese, granite etc. while at the same time India has to depend upon imports to meet her requirements of some other mineral sources such as copper, silver, nickel, cobalt, zinc, lead, tin, mercury etc. The mineral resources in India are present in the peninsular part of the country. The vast alluvial plain tract of north India is devoid of minerals of economic use. The mineral resources provide the country with the necessary base for industrial development.

1.1 Types of Mineral Resources On the basis of chemical and physical properties, minerals may be grouped under two main categories of metallic and non-metallic minerals. Metallic minerals are the sources of metals. Metallic minerals can be further divided into two class- ferrous minerals (which have iron content) like iron, nickel, cobalt, tungsten, manganese etc. and non-ferrous minerals (which don’t have iron content) like copper, bauxite, silver, gold etc. Non-metallic minerals can be divided into fuel minerals (which are organic in origin) like coal, petroleum etc. and other non-metallic minerals like limestone, graphite etc. Minerals have certain characteristics. These are unevenly distributed over space. There is inverse relationship in quality and quantity of minerals i.e. good quality minerals are less in quantity as compared to low quality minerals. All minerals are exhaustible over time and it takes long to develop geologically and they cannot be replenished immediately at the time of need.

1.2 Distribution of Minerals in India Most of the metallic minerals in India occur in the peninsular plateau region in the old crystalline rocks. Minerals are generally concentrated in three major belts in India. There are some sporadic occurrences here and there in isolated pockets. These belts are: 1.2.1 The North-Eastern Plateau Region: This belt covers Chota Nagpur (Jharkhand), Odisha Plateau, West Bengal and parts of Chhattisgarh. It is the richest mineral belt in India. It has variety of minerals viz. iron ore, coal, manganese, bauxite, mica. The Chota Nagpur plateau is also known as mineral heart land of India. 1.2.2 The Central belt: This belt encompassing parts of Chhattisgarh, Madhya Pradesh, Andhra Pradesh and Maharashtra is the second largest mineral belt in the country. Large deposits of manganese, bauxite, limestone, marble, coal, mica, iron ore are available here. 1.2.3 The South-Western Plateau Region: This belt extends over Karnataka, Goa and contiguous Tamil Nadu uplands and Kerala. This belt is rich in ferrous metals and bauxite. It also contains high grade iron ore, manganese and limestone. This belt packs in coal deposits except Neyveli lignite. It does not have mica and copper deposits. 1.2.4 The North-Western Region: This belt extends along Aravali in Rajasthan and part of Gujarat and minerals are associated with Dharwar system of rocks. This belt has developed recently and is gradually becoming a productive region holding great promise for mining of the nonferrous metals. Copper, zinc has been major minerals. Rajasthan is rich in building stones i.e. sandstone, granite, marble. Gypsum and Fuller’s earth deposits are also extensive. Dolomite and limestone provide raw materials for cement industry.

1.3 Ferrous Minerals Ferrous minerals form an important part of mining activity in India and provide base to metallurgical industries in India. Our country is well-placed in respect of ferrous minerals both in reserves and production. 1.3.1 Iron Ore: Iron is a metal of universal use. India has the largest reserve of iron ore in Asia. It is used for manufacturing articles from safety pins to ships. It is a durable and cheap metal which can be moulded in different forms and can be mixed with other metals to form alloys. Iron is not found in pure form. It is often 3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

mixed with lime, magnesium, phosphorous, silicon, etc. In India, we get four main types of iron ore, which are as under: Haematite: It is also known as red-ochre, as it is reddish in colour. The iron contents in this type ranges from about 60 to 70 per cent. Most of the iron ore reserves in India belong to this type. Magnetite: It is the best quality of iron ore and contains more than 70 per cent of the iron contents. The colour of the ore is dark brown to blackish and is known as black ore. It has magnetic properties. Limonite: It is yellow or light brown in colour and the iron contents ranges from about 40 to 60 per cent. It is called hydrated iron oxide, when the iron ore in mixed with oxygen and water. Its mining is easier and cheaper. Siderite: It is an inferior variety of iron ore and has many impurities. The iron contents ranges from about 20 to 40 per cent. It is also called iron carbonate.

4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

About 95 per cent of total reserves of iron ore are located in the States of Odisha, Jharkhand, Chhattisgarh, Karnataka, Goa, Andhra Pradesh and Tamil Nadu. In Odisha, iron ore occurs in a series of hill ranges in Sundergarh, Mayurbhanj and Jhar. The important mines are Gurumahisani, Sulaipet, Badampahar (Mayurbhaj), Kiruburu (Kendujhar) and Bonai (Sundergarh). In Jharkhand has some of the oldest iron ore mines and most of the iron and steel plants are located around them. Important mines such as Noamundi and Gua are located in Poorbi and Pashchimi Singhbhum districts. Dalli, and Rajhara in Durg are other important mines of iron ore. In Karnataka, iron ore deposits occur in Sandur-Hospet area of Bellary district, Baba Budan hills and Kudremukh in Chikmagalur district and parts of Shimoga, Chitradurg and Tumkur districts. The districts of Chandrapur, Bhandara and Ratnagiri in Maharashtra, Karimnagar, Warangal, Kurnool, Cuddapah and Anantapur districts of Andhra Pradesh, Salem and Nilgiris districts of Tamil Nadu are other iron mining regions. Goa has also emerged as an important producer of iron ore.

India is the fifth largest exporter of iron in the world. Increasing demand of iron ore in domestic market has adversely affected the export performance of the sector. About half of the total production of iron ore is exported to Japan, South Korea, East European Countries and the Gulf region. Some iron ore is also exported to 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

USA and China. The main ports handling the export are Marmagao, Vishakhapatnam, Paradip, Mangalore, Haldia and Chennai. Japan is the most important buyer of Indian iron ore. 1.3.2 Manganese: Manganese is a black hard iron like metal and is an important raw material for smelting of iron ore and also used for manufacturing ferrous alloys. It is also used for the manufacture of bleaching powder, insecticides, paints, glazed pottery, matches, batteries and china-clay. India has second largest ore reserves in the world after Zimbabwe. Manganese deposits are found in almost all geological formations; however, it is mainly associated with Dharwar system. Odisha is the leading producer of Manganese. Major mines in Odisha are located in the central part of the iron ore belt of India, particularly in Bonai, Kendujhar, Sundergarh, Gangpur, Koraput, Kalahandi and Bolangir. Karnataka is another major producer and here the mines are located in Dharwar, Bellary, Belgaum, North Canara, Chikmagalur, Shimoga, Chitradurg and Tumkur. Maharashtra, Madhya Pradesh, Andhra Pradesh, Goa and Jharkhand are minor producers of manganese. India is the world’s fifth largest producer of manganese ore as over four-fifth of the total produce of manganese is consumed within the country. Japan is the largest buyer of Indian manganese accounting for about two-third of the total export.

1.4 Non-Ferrous Minerals India has limited reserves of non-ferrous minerals except bauxite. Copper, bauxite, gold, silver, tungsten, nickel, cobalt are major non-ferrous minerals. 1.4.1 Copper: Copper has been used for making utensils and coins since long. Also, Copper is an indispensable metal in the electrical industry for making wires, electric motors, transformers and generators. It is alloyable, malleable and ductile. It is a good conductor of electricity and it is used in making electrical wires, equipments and utensils. India has limited reserves of copper. The Copper deposits mainly occur in Singhbhum district in Jharkhand, Balaghat district in Madhya Pradesh and Jhunjhunu and Alwar districts in Rajasthan. Minor producers of Copper are Agnigundala in Guntur District (Andhra Pradesh), Chitradurg and Hasan districts (Karnataka) and South Arcot district (Tamil Nadu). Mining of copper is a costly and tedious affair as copper ores contain small percentage of metal. The production of copper ore in the country always fall short of our requirements and India has to import copper from other countries, mainly USA, Canada, Zimbabwe, Mexico. 1.4.2 Bauxite: Bauxite is an important ore and is used in making aluminium. Due to its lightness, strength, malleability, ductility, heat and electrical conductivity and resistance to atmospheric corrosion, aluminium has become one of the most useful metals in the present age. It is not specifically a mineral but a rock consisting mainly of hydrated aluminium oxides. Bauxite is found mainly in tertiary deposits and is associated with Laterite rocks occurring extensively either on the plateau or hill ranges of peninsular India and also in the coastal tracts of the country. India is self-sufficient in bauxite reserves. Kalahandi and Sambalpur in Odisha are the leading producers in the country. Jharkhand, Gujarat, Chhattisgarh, Madhya Pradesh and Maharashtra are other major producers. Bhavanagar, Jamnagar in Gujarat have the major deposits. Chhattisgarh has bauxite deposits in Amarkantak plateau while Katni-Jabalpur area and Balaghat in M.P. have important deposits of bauxite. 1.4.3 Lead: Lead is a widely used material mainly due to its malleability, softness, heaviness and bad conductivity of heat. Important use of lead is as a constituent in alloys such as type metal, bronze and antifriction metal. It doesn’t occur free in nature and occurs as a cubic sulphide known as Galena. Lead ores occur in India in the Himalayas, Tamil Nadu, Rajasthan, Andhra Pradesh and Jharkhand. Rajasthan is the leading producer of lead. Udaipur (Zawar, Rikhabdeo), Dungarpur (Ghughra and Mando) and Alwar are the main producing districts. About 75% of Indian requirements are met by imports mainly from Australia, Canada and Myanmar.

6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.4.4 Zinc: Zinc is a mixed ore containing lead and zinc and is mainly used for alloying and manufacturing galvanized sheets. It is also used for dry batteries, white pigments, electrodes, textiles etc. Known reserves of zinc in India are very limited. More than 99% of zinc in India is produced in Zawar area in Udaipur district of Rajasthan. Most of the industrial needs are met via imports from Zaire, Canada, Australia and Russia. 1.4.5 Gold: Gold is a valuable material which occurs in auriferous lodes and in sands of several rivers. It is known for making ornaments and usage as international currency. India’s contribution to global gold production is very small. There are three main gold fields in India namely, Kolar Gold Field, Hutti Gold field in Raichur district of Karnataka and Ramgiri Gold field in Anantpur district of Andhra Pradesh. Kolar is the largest mine and one of the deepest mines in the world. Alluvial gold is obtained from the sands of the Subarnarekha River in Jharkhand. Such deposits are called placer deposits and the process of recovering gold from these sources is called panning. 1.4.6 Silver: Silver is a precious metal valued next only to gold in making ornaments due to its softness and attractive white colour. It is also used in manufacture of chemicals, electroplating, photography, for colouring glasses etc. The chief ore minerals of silver are agentine, stephanite, pyrargyrite and proustite. India has limited resources of silver ore and majority of production comes from Zawar mines in Udaipur district of Rajasthan. 7 www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.5 Non- Metallic Minerals Among the non-metallic minerals produced in India, mica is the important one. The other minerals extracted for local consumption are limestone, dolomite and phosphate. They are used in a large variety of industries; the major industries being cement, fertilizers, electrical, etc. 1.5.1 Mica: Mica is mainly used in the electrical and electronic industries as it can be split into very thin sheets which are tough and flexible. It has also been used in India since ancient times as a medicinal item in Ayurveda and is known as Abhrak. Three major types of mica found in India are- Muscovite, Phlogopite and Biotite. Rajasthan have the largest deposits of mica. Mica in India is produced in Hazaribagh plateau of Jharkhand, Nellore district of Andhra Pradesh, Bhilwara and Udaipur in Rajasthan followed by Tamil Nadu, Karnataka, West Bengal and Madhya Pradesh. India has near monopoly in the production of mica, producing about 60% of the world’s total production. 1.5.2 Limestone: Limestone is associated with rocks either composed of calcium carbonate or a mixture of calcium carbonate and magnesium carbonate. It is used for large variety of purposes like cement industry, iron and steel industry, chemical industry etc. Of the total consumption,. 75 per cent is used in cement industry, 16 per cent in iron and steel industry, 4 per cent in chemical industry and the rest in paper, sugar, fertilizers, Ferromanganese, glass and rubber industries. Limestone is produced in the states of Madhya Pradesh, Rajasthan, Andhra Pradesh, Gujarat, Chhattisgarh and Tamil Nadu. Madhya Pradesh is the largest producer of limestone in India where large deposits occur in the districts of Jabalpur, Satna, Betul, Rewa. 1.5.3 Dolomite: Limestone with more than 10% of magnesium is called dolomite, when percentage rises to about 45%, it is called true dolomite. Dolomite is chiefly used in metallurgical activities; as refractories; as blast furnace flux; as a source of magnesium salts and in fertilizer and salt industry. Odisha, Chhattisgarh, Andhra Pradesh, Jharkhand, Rajasthan and Karnataka are the major producers of Dolomite in India. Orissa is the largest producer of dolomite in the country with major deposits in Sundargarh, Sambhalpur and Koraput districts.

1.6 Atomic Minerals Uranium and thorium are the main atomic minerals; Beryllium, Lithium and Zirconium are the other minerals. Uranium deposits occur in Singhbhum and Hazaribagh districts of Jharkhand, Gaya district of Bihar, and in the sedimentary rocks in Saharanpur district of Uttar Pradesh. But the largest source of uranium comprise the monazite sands, both beach and alluvial. The largest concentration of monazite sand is on the Kerala coast. Some uranium is found in the copper mines of Udaipur in Rajasthan. India produces about 2% of world’s uranium reserves. Thorium is also derived from monazite which contains 10% thorium. Other mineral carrying thorium is thorianite. Kerala, Bihar, Jharkhand, Tamil Nadu and Rajasthan are the main producers.

8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

2. Energy Resources

Depending upon its source and utilization, energy can be divided into two major classifications viz. (i) Traditional or non-commercial, and (ii) Commercial Energy. Examples of non-commercial energy resources are firewood, charcoal, cow dung and agricultural wastes. The commercial sources of energy comprise coal, oil, natural gas, hydro-electricity, natural gas, nuclear power as well as wind and solar power. Another important classification based on the nature of energy is conventional energy source and nonconventional energy source. Coal, Petroleum, Natural Gas and electricity are the main sources of conventional energy while solar, wind, tidal, geothermal etc are example of non-conventional source of energy.

2.1 Conventional Energy Sources The conventional sources are exhaustible resources. Major conventional sources of energy are discussed below:

9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

2.1.1 Coal: Coal is a one of the important minerals which is mainly used in the generation of thermal power and smelting of iron ore. Coal occurs in rock sequences mainly of two geological ages, namely Gondwana and tertiary deposits. Most of the coal deposits are about 300 million years old. About 65 per cent of the total coal production is consumed for generating electricity. It is also used as a basic fuel in many industries. Entire process of steel making is based on metallurgical coal. Cement industry consumes about five per cent of the total production. Coal is also an important source of naphtha and ammonia, which are widely used for making chemical fertilizers, tar, benzene, carbon black, etc. Soft coke is used as fuel in the kitchen. Depending upon the percentage of carbon present, the coal can be grouped in four types, such as peat, lignite, bituminous and anthracite. Peat- It represents the first stage of coal formation, i.e. from wood to coal, today; peat is being formed at many places. It has a high percentage of moisture and volatile matter. The carbon content in peat is less than 40 per cent. It burns like wood and gives more smoke and less heat. It leaves a large amount of ash after burning. Its low heating capacity reduces its value as an industrial fuel. Lignite- It is generally regarded as the next stage of coal formation after peat. It is also known as the brown coal. Lignite is soft, but more compact than peat. The carbon contents vary from 40 per cent to 60 per cent. Lignite has large percentage of moisture and less amount of combustible matter. The increasing demand for coal has enhanced its use in thermal power stations and in some industries. In India, lignite is mostly found in Rajasthan, Tamil Nadu, Assam and Jammu and Kashmir states. Bituminous -It is the hard and compact variety of coal. The carbon content varies from about 60 per cent to 80 per cent. Almost 80 per cent of the world's total output of coal is of the bituminous type. The moisture and the volatile contents are also less. Coke is mainly used in the iron and steel industry for smelting iron ore in blast furnaces. Bituminous coal is found in Jharkhand, Orissa, West-Bengal, Madhya Pradesh and Chhattisgarh. Anthracite - It is the hardest and the best quality of coal. The carbon content varies from about 80 per cent to 90 per cent. Anthracite, practically, has no volatile matter. It does not ignite easily, but once lighted, it has the highest heating capacity. It burns for a long time and leaves very little ash behind. Only about 5 per cent of the world's total coal is anthracite. In India this type of coal is found only in Jammu and Kashmir and that too in very small quantity. About 80 per cent of the coal deposits in India is of bituminous type and is of non-coking grade. The most important Gondwana coal fields of India are located in Damodar Valley. They lie in Jharkhand-Bengal coal belt and the important coal fields in this region are Raniganj, Jharia, Bokaro, Giridih, Karanpura. The other river valleys associated with coal are Godavari, Mahanadi and Son. The most important coal mining centres are Singrauli in Madhya Pradesh (part of Singrauli coal field lies in Uttar Pradesh), Korba in Chhattisgarh, Talcher and Rampur in Odisha, Chanda–Wardha, Kamptee and Bander in Maharashtra and Singareni and Pandur in Andhra Pradesh. Coal mining industry is facing a lot of problems in India. Some of the major problems are – i. ii. iii. iv.

The distribution of coal is uneven; this involves high transport cost to carry heavy commodity like coal over long distance. Consequently, the coal consuming industries have to pay much higher prices. Indian coal has high ash content and low calorific value. The ash content varies about 20-30 percent which significantly reduces the calorific value of the product. A large percentage of the coal is taken out from underground mines where the productivity of the labour and machinery is quite low. Besides the problem of pilferage and fire in mines, mining industry is also suffering from problems of environmental pollution.

2.1.2 Petroleum: Crude petroleum consists of hydrocarbons of liquid and gaseous states varying in chemical composition, colour and specific gravity. It is an essential source of energy for all internal combustion engines in automobiles, railways and aircraft. Its numerous by-products are processed in petrochemical industries such as fertiliser, synthetic rubber, synthetic fibre, medicines, Vaseline, lubricants, wax, soap and cosmetics.

10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The crude petroleum deposits are found only in the sedimentary rock basins of marine origin. But all sedimentary rocks do not contain mineral oil. Petroleum has an organic origin and is formed by the gradual decay and compression of various marine deposits. They remain buried for millions of years and the decomposition of the organic matter has led to the formation of mineral oil. According to latest estimates the total reserves of crude oil are about 500 crore tons on land and in off-shore regions. There are three main areas of potential petroleum reserves. These are: 1. The Terai zone running parallel to the Himalayas from Jammu and Kashmir to Assam; 2. River basins of Ganga, Satluj, etc. including deltaic tracts of Ganga, Mahanadi, Godavari, Krishna and Kaveri; 3.The continental shelf along the Western Coast, Gulf of Cambay, and the islands in the Arabian Sea and the Bay of Bengal. Oil and natural gas have been recently found in exploratory wells in Krishna-Godavari and Kaveri basin on the east coast. India is not self-sufficient in respect of crude oil and has to import huge quantities from abroad. At present, India has to import about 55 per cent of its needs of petroleum and its products. The imports are mainly from the Middle East countries (Iraq, Iran, Kuwait, Saudi Arabia, Bahrain), Russia, Indonesia, Malaysia and Kazakhstan. Pipelines are most convenient, efficient and economical mode of transporting liquids like petroleum, petroleum products, natural gas, water, milk etc. India has a pipeline network exceeding 7000 km in the country.

11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Advantages of Pipeline: 1. Pipeline are ideally suited to transport the liquids and gases. 2. Pipelines can be laid through difficult terrains as well as under water. 3. It involves low energy consumption. 4. It needs little maintenance. 5. They are safe, accident-free and environmental friendly. Disadvantages of Pipelines: 1. They are not flexible i.e. they can be used only for a few fixed points. 2. The capacity cannot be increased once laid down. 3. It is difficult to maintain security arrangements for the pipelines. 4. Underground pipelines cannot be easily repaired and detection of leakage is also difficult. Important Pipelines in India: 1. 2. 3. 4. 5. 6.

Naharkatia- Nunmati – Barauni Pipeline Mumbai High – Mumbai – Ankaleshwar – Kayoli Pipeline Salaya- Koyali – Mathura Pipeline Hajira – Bijapur – Jagdishpur (HBJ) Gas Pipeline Jamnagar – Loni LPG Pipeline Kandla – Bhatinda Pipeline

2.1.3 Natural Gas: Natural gas is obtained along with oil in all the oil fields. Whenever a well for oil is drilled, it is natural gas which is available before oil is struck. But exclusive reserves have been located along the eastern coast (Tamil Nadu, Odisha and Andhra Pradesh) as well as in Tripura, Rajasthan and off-shore wells in Gujarat and Maharashtra. With fast expanding transport network, the consumption level is increasing day by day. Oil products constitute nearly 80% of the total commercial energy used in transport. As these energy sources are limited in quantity, so the need of the hour is to develop and implement energy conservation programme in transport sector. The Petroleum Conservation Research Association (PCRA) under the Ministry of Petroleum and Natural Gas has been taking various steps to increase awareness and promote conservation of petroleum products.

2.2 Non Conventional energy Sources With increasing demand for energy and with fast depleting conventional source of energy such as coal, petroleum and natural gas, the non-conventional sources of energy such as energy from sun, wind, bio-mass, tidal , geo-thermal energy are gaining importance. This energy is abundant, pollution-free, renewable and ecofriendly. Besides, it can be supplied evenly to urban, rural and even remote areas. The non-conventional energy sources are cost intensive at the initial stages but will provide more sustained, eco-friendly cheaper energy after the initial cost is taken care of. 2.2.1 Solar Energy: Sun rays tapped in photovoltaic cells can be converted into energy, known as solar energy. The two effective processes considered to be very effective to tap solar energy are photovoltaic and solar thermal technology. Solar thermal technology has some relative advantages over all other non-renewable energy sources. It is cost competitive, environment friendly and easy to construct. It is generally used more in appliances like heaters, crop dryers, cookers, etc. The western part of India has greater potential for the development of solar energy in Gujarat and Rajasthan. 2.2.2 Wind Energy: Wind energy is absolutely pollution free, inexhaustible source of energy. The mechanism of energy conversion from blowing wind is simple. The kinetic energy of wind, through turbines is converted into electrical energy. The Ministry of non-conventional sources of energy is developing wind energy in India to lessen the burden of oil import bill. The country’s potential of wind power generation exceeds 50,000 megawatts, of which one fourth can be easily harnessed. In Rajasthan, Gujarat, Maharashtra and Karnataka, favourable conditions for wind energy exist. Wind power plant at Lamba in Gujarat in Kachchh is the largest in Asia. Another, wind power plant is located at Tuticorin in Tamil Nadu. 2.2.3 Tidal and Wave Energy: Ocean currents are the store-house of infinite energy. For the past few centuries, persistent efforts were made to create a more efficient energy system from the ceaseless tidal waves and ocean current. India has great potential for the development of tidal energy as large tidal waves are known to occur along the west coast of India but so far these have not yet been utilised. 2.2.4 Geothermal Energy: There are vast possibilities of developing and exploiting geothermal energy in India. Lots of hot spring localities have been found in the country. Many potential sites have been identified in Jammu & Kashmir, Himachal Pradesh, Uttarakhand, Jharkhand and Chhattisgarh. A geothermal energy plant has been commissioned at Manikaran in Himachal Pradesh. 12 www.visionias.in ©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

2.2.5 Bio-energy: Bio-energy refers to energy derived from biological products which includes agricultural residues, municipal, industrial and other wastes. Bio energy is a potential source of energy conversion. It can be converted into electrical energy, heat energy or gas for cooking. It will also process the waste and garbage and produce energy. The technique is based on the decomposition of organic matter in the absence of air to yield gas consisting of methane and carbon dioxide which can be used as a source of energy. This will improve economic life of rural areas in developing countries, reduce environmental pollution, enhance self-reliance and reduce pressure on fuel wood. 2.3 Conservation of Natural Resources In order to promote sustainable development, we need to integrate economic development with environmental concerns. In method of conventional usage of natural resources, there has been large amount of wastage and many environmental problems. Hence, for sustainable development, there is an urgent need to conserve the resources. The alternative energy sources like solar power, wind, wave, geothermal energy are inexhaustible resource and should be developed to replace the exhaustible resources.

3. Manufacturing Industries Manufacturing is the processing of primary products into more refined and more usable products. Many of the natural products cannot be used directly without processing. It is because of this reason that we manufacture cloth from cotton, sugar from sugarcane, paper from wood pulp etc. By doing so, we make the primary products more valuable and usable. Thus, manufacturing means transformation of natural material endowments into commodities of utility by processing, assembling and repairing.

3.1 Types of Industries Industries are classified in a number of ways.  

 



On the basis of size, capital investment and labour force employed, industries are classified as large, medium, small scale, and cottage industries. On the basis of ownership, industries are categorised as : (i) public sector, (ii) private sector, and (iii) joint and cooperative sector, Public sector enterprises are government/state controlled companies or corporations funded by governments. Industries of strategic and national importance are usually in the public sector. Industries are also classified on the basis of the use of their products such as: (i) basic goods industries, (ii) capital goods industries (iii) intermediate goods industries, and (iv) consumer goods industries. Another method of classifying industries is on the basis of raw materials used by them. Accordingly, these can be: (i) agriculture based industries, (ii) forest-based industries, (iii) mineral-based industries, and (iv) industrially processed raw material based industries. Another common classification of industries is based on the nature of the manufactured products. Eight classes of industries, thus identified are: (1) Metallurgical Industries, (2) Mechanical Engineering Industries, (3) Chemical and Allied Industries, (4) Textile Industries, (5) Food Processing Industries, (6) Electricity Generation, (7) Electronics and (8) Communication Industries.

Sr. No.

Basis

1

Source of Raw (i)Agro-based Material industries

(i) Agricultural products used as (i) Cotton, textile, jute, sugar raw materials and paper industry (ii) Iron and steel, chemical and cement (ii) Minerals used as raw industry (iii) Matchsticks and materials (iii) Raw materials Bidi industries (iv) Motor used from forests (iv) Finished industries use manufactured products are used as raw iron and steel. materials for other industries.

2

Ownership

(i) Operated and controlled by (i)

13

Types Industries

(i) Public Sector

www.visionias.in

of Chief Characterises

Examples

Bokaro

©Vision IAS

Steel

Plant,

www.UPSCPDF.com

https://t.me/UPSC_PDF

(ii) Private Sector

government

https://t.me/UPSC_PDF Chittaranjan Locomotive works;

(iii) Mixed Sector

(ii) Operated and controlled by (ii) Tata Iron & Steel, Birla an individual or a group as a Cement; (iv) Cooperative company; Sector (iii)Maruti Udyog; (iii) Established jointly by public (v) Multinational (iv) Sugar Industry and private sector; (iv)Industry Companies (Maharashtra), Amul (Gujarat); established by a co-operative society of raw material (v)BMW car manufacturer of producers (v)Foreign Germany companies established their companies with Indian companies 3

Major Functions

(i) Basic Industry

(i) Their finished product is (i) Iron & steel Industry used as raw material for other (ii) Consumer (ii) Toothpaste, Soap, Sugar industries Goods Industry Industries (ii) Their finished produce is (iii) Capital Goods (iii) Produce machines for sugar directly consumed; Industry and cotton mills (iii)Such machines are made (iv) Half (iv) Plastic grains industries which can be used to produce Manufacturer other goods. Industry (iv) Raw materials produced for other industries

4

Knowledge Based Industries

5

Manufactured (i) Metallurgical Goods (ii) Mechanical Engineering

-

Application of special Software Industry knowledge of manufacturing Hi-tech expertise, engineering and management, Fast growth rate -

-

(iii) Chemical and Related Activities (iv)Textiles (v) Fertiliser (vi) Electronics and Electricals

3.2 Location of Industries Location of industries is influenced by several factors like access to raw materials power, market, capital, transport and labour, etc. Relative significance of these factors varies with time and place. The factors affecting the location of industry can be divided into two broad categories: a) Geographical Factors and b) NonGeographical Factors. 3.2.1 Geographical Factors Following are the important geographical factors influencing the location of industries. Raw Materials: Location of industries is often governed by the location of raw materials. Industries using weightlosing raw materials are located in the regions where raw materials are located. For raw materials which lose weight in process of manufacture or which cannot bear high transport cost or cannot be transported over a long 14

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

distance because of their perishable nature, industries are often located near the supply of raw materials. Examples of this type of industry are sugar mills, pulp industry, copper smelting and pig iron industries. Power: Regular supply of power is a pre-requisite for the location of industries. Coal, mineral oil and hydro electricity are the three important conventional sources of power. Most of the industries tend to concentrate around the source of power. Certain industries, like aluminium and synthetic nitrogen manufacturing industries tend to be located near sources of power because they are power intensive and require huge quantum of electricity. Labour: Availability of cheap labour is a prerequisite for many industries which are labour intensive in nature. Labour supply should be available in large numbers and also they should have skill or technical expertise as needed. Light consumer goods and agro-based industries need plentiful of labour supplies. Transport: Transport by land or water is necessary for the assembly of raw material and for the marketing of finished goods. Thus, for proper industrial development, we need to have well developed transport facilities. Market: The process of manufacturing requires that the finished goods do reach the market. Nearness to market is essential for quick disposal of manufactured goods. It helps in reducing the transport cost and enables the consumers to get products at reasonable prices. Similarly heavy machine, machine tools, heavy chemicals are located near the high demand areas as these are market orientated. Cotton textile industry uses a non-weightlosing raw material and is generally located in large urban centre, e.g. Mumbai, Ahmadabad, Surat, etc. Petroleum refineries are also located near the markets as the transport of crude oil is easier and several products derived from them are used as raw material in other industries. Site: Site requirements for industrial development are of considerable significance. Sites, generally, should be flat and well served by adequate transport facilities. Large areas are required to build factories. Now, there is tendency to set up industries in rural areas as cost of land has shot up in urban areas. 3.2.2 Non – Geographical Factors Apart from the geographical factors, there are various other factors which decide the location of industries in the country. Following are some of the important non-geographical factors which influence the location of industries in the countryCapital: Modern industries are capital intensive and require huge investments which are generally available in urban centres. Hence, many urban cities have become hub for major industries in the country. Government Policies: Government activity in planning the future distribution of industries, for reducing regional disparities, elimination of pollution of air and water and for avoiding their heavy clustering in big cities has become an important factor. There is an increasing trend to set up industries in an area where the government policies are favourable and promote industry friendly policies. Industrial Inertia: Industries tend to develop at the place of their original establishment, though the original cause may have disappeared. This phenomenon is known as geographical inertia or industrial inertia. Banking Facilities: Establishment of industries involves daily exchange of Crores of rupees which is possible through banking facilities only. So areas with better banking facilities are better suited to the establishment of industries.

3.3 Major Industries Major industries in India can be studied under the following headings: 3.3.1 Iron & Steel Industry The development of the iron and steel industry opened the doors to rapid industrial development in India. Almost all sectors of the Indian industry depend heavily on the iron and steel industry for their basic infrastructure. The other raw materials besides iron ore and coking coal, essential for iron and steel industry are limestone, dolomite, manganese and fire clay. All these raw materials are gross (weight losing), therefore, the best location for the iron and steel plants is near the source of raw materials. In India, there is a crescent shaped region comprising parts of Chhattisgarh, Northern Odisha, Jharkhand and western West Bengal, which is extremely rich in high grade iron ore, good quality coking coal and other 15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

supplementing raw materials. India has 11 integrated steel plants, 150 mini steel plants and a large number of rolling, re-rolling mills and foundries. Except TISCO now Tata Steels Ltd., all the big steel plants are managed by SAIL. The list of integrated iron and steel plants is1. 2. 3. 4. 5. 6. 7. 8. 9. 10. 11.

Rashtriya Ispat Nigam Ltd. (Vishakhapatnam, Andhra Pradesh) Jindal Steel & Power Ltd. (Raigarh, Chhattisgarh) Bhilai Steel Plant (Bhilai, Chhattisgarh) Boakro Steel Plant (Bokaro, Jharkhand) Tata Steels Ltd. (Jamshedpur, Jharkhand) JSW Steel Ltd. (Bellary, Karnataka) Tata Sponge Iron Limited (Keonjhar, Odisha) Rourkela Steel Plant (Rourkela, Odisha) Salem Steel Plant (Salem, Tamil Nadu) Durgapur Steel Plant (Durgapur, West Bengal) Indian Iron & Steel Company Ltd. (Burnpur, West Bengal)

Details of some of the important iron and steel plant are as follows: Tata Steel Ltd.: It is the oldest and the largest integrated iron and steel plant in India located at Jamshedpur in Jharkhand. TSL is most ideally located in respect to iron are, coking coal and flux supplies. The plant started producing pig iron in 1908 and steel in 1911. This plant enjoys the following advantages: (1) Iron ore is obtained from the Noamundi mines of Singhbhum district in Jharkhand and the Guruma-hisani mines in Mayurbhanj district of Orissa. (2) Joda mines of Keonjhar(Kendujhar) district of Orissa supply manganese. (3) Dolomite, limestone and fire clay are obtained from Sundargarh district of Orissa. (4) Large requirement of water for cooling purposes is met from the Subernarekha and Kharkai rivers. (5) Labour: Labour is available locally from the Santhal tribe and from Bihar, Uttar Pradesh and Madhya Pradesh. (6) Coal: It is available from the mines of Jharia and West Bokaro (Jharkhand).

16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Indian Iron and Steel Company (IISCO): The three steel plants at Kulti, Burnpur and Hirapur are located near Asansol in West Bengal. They have merged together to form the Indian Iron and Steel Company (IISCO). Pig iron is produced at Hirapur plant and sent to Kulti for making steel. The rolling mills are in Burnpur. The IISCO plants have the following geographical advantages: (1) Iron ore is brought from Singhbhum (Jharkhand) and Mayurbhanj (Orissa). (2) Coking coal is available from Jharia and cheap electricity from the Damodar Valley Corporation. (3) Manganese is supplied by Jharkhand, Bihar, Orissa and Madhya Pradesh. (4) Dolomite and limestone are obtained from Sundargarh (Orissa) (5) Cheap labour is ready available from the adjoining thickly populated states. (6)Water is readily available from the Damodar river. 17

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Visvesvaraya Iron and Steel ltd. (VISL): It was established as Mysore Iron and Steel Works in 1923 by the princely state of Mysore. It is located at Bhadravati. This plant is one of the major producers of alloy and special steel in the country.(1) High grade iron ore is available from Chikmaglur district; (2) Manganese is available from Shimoga and Ghitradurga; (3) it uses hydroelectric power from Sharavali project. Hindustan Steel Ltd (HSL)-Bhilai: The Bhilai Steel plant is located in the Durg district of Chhattisgarh and was built with the Russian collaboration. Bhilai steel plant has the following geographical advantages; (1) Rich iron ore is available from Dalli-Rajhara mines; (2) Coal is obtained from Korba and Kargali fields in Madhya Pradesh.(3) Limestone from Nandini mines (4) Manganese is obtained from Bhandara (Maharashtra) and Ballaghat (Madhya Pradesh)mines (5) Dolomite comes from Bilaspur. 3.3.2 Cotton textile Industry The cotton textile industry is one of the traditional industries of India. The development of this industry in India was due to several factors. One, it is a tropical country and cotton is the most comfortable fabric for a hot and humid climate. Second, large quantity of cotton was grown in India. Abundant skilled labour required for this industry was available in this country. The first modern cotton mill was established in Mumbai in 1854. By 1947, the number of mills in India went up to 423 but the scenario changed after partition when large number of mills had gone to West Pakistan. The cotton textile industry in India can be broadly divided into two sectors, the organised sector and the decentralised sector. The decentralised sector includes cloth produced in handlooms (including Khadi) and power looms.

18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Cotton is a “pure” raw material which does not lose weight in the manufacturing process. So other factors, like, power to drive the looms, labour, capital or market may determine the location of the industry. At present the trend is to locate the industry at or close to markets, as it is the market that decides what kind of cloth is to be produced. Also the market for the finished products is extremely variable; therefore, it becomes important to locate the mills close to the market. In the second half of the nineteenth century, the cotton textile industry expanded very rapidly throughout the country. Thus, the cotton textile industry is located in almost every state in India, where one or more of the locational factors have been favourable. Presently Maharashtra, Gujarat and Tamil Nadu are the leading cotton producing states. West Bengal, Uttar Pradesh, Karnataka, and Punjab are the other important cotton textile producers. Tamil Nadu has the largest number of mills and most of them produce yarn rather than cloth. Although cotton textile is one of the most important industries of India, it suffers from many problems. Some of the burning problems include- (1) Scarcity of raw materials; (2) Obsolete Machinery; (3) Erratic power supply; (4) Low productivity of labour; (5) Labour strikes; (6) Stiff Competition in domestic and international market; (7) Sick Mills; (8) Lack of finance. 19

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3.3.3 Sugar Industry The sugar industry is the second most important agro-based industry in the country. India is the largest producer of both sugarcane and cane sugar. The industry provides employment for more than 4 lakh persons directly and a large number of farmers indirectly. Sugar industry is a seasonal industry because of the seasonality of raw materials. As Sugarcane is a weight-losing crop, Sugar factories hence, are located within the cane producing regions. Maharashtra is the leading sugar producer in the country and produces more than one-third of the total production of the sugar in the country. Uttar Pradesh is the second largest producer of sugar. The sugar factories are concentrated in two belts – the Ganga-Yamuna doab and the tarai region. In the southern India, sugar mills are located in Tamil Nadu, Karnataka and Andhra Pradesh. The other States which produce sugar are Bihar, Punjab, Haryana, Madhya Pradesh and Gujarat. Sugar Industry is a highly localized industry. The salient features for its localized nature are- (1) Sugar cane is the chief raw material used for making sugar. (2) Sugar cane dries up quickly after harvesting. It can neither be stored nor kept in the field after the crop matures. (3) There should be no gap between harvesting and crushing of sugar cane. (4) Sugar cane is a bulky raw material and only about 9 to 12 tonnes of sugar is produced from 100 tonnes of cane (5) Transportation of sugar cane is costly. To reduce this cost sugar mills are established in sugar cane growing areas. (6) Sugar cane is generally transported through animal driven transport or tractor trailers. Therefore most of the sugar mills are installed within 20 km from the cane growing area. (7) Sugar mills have no problem of fuel because the bagasse of sugar cane can be used for heating the juice or for generating electricity. The entire energy requirements of a sugar mill are met through electricity generated with using bagasse as fuel. 3.3.4 Petrochemical Industries Petrochemical industries are one of the fastest growing industries in India. A variety of products come under this category of industries. Many items are derived from crude petroleum, which provide raw materials for many new industries; these are collectively known as petrochemical industries. This group of industries is divided into four sub-groups: (i) polymers, (ii) synthetic fibres, (iii) elastomers, and (iv) surfactant intermediate. Mumbai is the hub of the petrochemical industries. Cracker units are also located in Auraiya (Uttar Pradesh), Jamnagar, Gandhinagar and Hajira (Gujarat), Nagothane, Ratnagiri (Maharashtra), Haldia (West Bengal) and Vishakhapatnam (Andhra Pradesh). 3.3.5 Machine Tools It is a core industry and provides mother machines to all sectors of the economy. There are about 200 units manufacturing various types of machine tools and hand tools. The Kirloskar Brothers ltd was the pioneer company, which started production in 1930s. The Hindustan Machine Tools (HMT), Bangalore, a public sector unit, is the first large scale modern machine tools factory in India. These factories produce a large variety of machine tools, such as lathes, radial drilling machines, grinding machines, gear hobbling machines, lamp making machines, etc. Besides machine tools, HMT also produces watches, tractors and printing machinery. 3.3.6 Automobile Industry Before independence, assembling of foreign made vehicles was done in India. The real development of the industry began with the setting up of two auto mobile units: (I) Premier Automobiles (Mumbai) in 1947, and (ii) Hindustan Motors Ltd. (Kolkata), in 1948. As steel is the basic raw material for this industry, it tends to be located near iron and steel producing; centres. Port cities are preferred due to import and export facilities. The centres producing tyres, tubes, batteries, paints, etc. provide an added advantage. Recently, the trend has been to locate the automobile manufacturing units near the market.

20

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3.3.7 Electronic Industry

The electronics industry has developed mainly after independence. It covers a wide range of products including transistor sets, televisions, telephone exchanges, telecommunication, computers and various equipments for posts and telegraph, defence, railway and meteorological departments. The setting up of the Indian Telephone Industry (ITI) in 1950 at Bangalore gave a boost to this industry. The software has emerged as a major industry in the field of electronics. The computer industry made a modest beginning in the: mid 1970s. Now it has achieved a major breakthrough. The main reason for its rapid growth is a big bank of technically competent manpower. Bangalore is the largest centre of: electronics goods production and is rightly called the 'Electronic Capital of India’. 3.3.8 Knowledge based Industries The advancement in information technology has significantly increased the knowledge based industries in India. The Information Technology (IT) revolution opened up new possibilities of economic and social transformation. The IT and IT enabled business process outsourcing (ITES BPO) services continue to be on a robust growth path. The IT software and services industry accounts for almost 2 per cent of India’s GDP.

21

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3.4 Liberalisation, Privatisation, Globalisation (LPG) and Industrial Development in India After the new Industrial Policy was announced in 1991, the major objectives of the policy were to build on the gains already made, correct the distortions or weaknesses that have crept in, to maintain a sustained growth in productivity and gainful employment and attain international competitiveness. Within this policy, measures initiated are: (1) abolition of industrial licensing, (2) free entry to foreign technology, (3) foreign investment policy, (4) access to capital market, (5) open trade, (6) abolition of phased manufacturing programme, and (7) liberalised industrial location programme. The industrial licensing system was abolished for all except six industries related to security, strategic or environmental concerns. The government also decided to offer a part of the shareholdings in the public enterprises to financial institutions, general public and workers. The threshold limits of assets have been scrapped and no industry requires prior approval for investing in the delicensed sector. In the new industrial policy, Foreign Direct Investment (FDI) has been seen as a supplement to the domestic investment for achieving a higher level of economic development. Government has permitted access to automatic route for Foreign Direct Investment under various sectors and respective limits have been setup for various fields. Besides, the industrial policy has been liberalised to attract private investor both domestic and multi-nationals. New sectors like, mining, telecommunications, highway construction and management have been thrown open to private companies. Still there has been a big gap between approved and actual foreign direct investment, even though the numbers of foreign collaborations are increasing. The thrust of globalisation has been to increase the domestic and external competition through extensive application of market mechanism and facilitating dynamic relationship with the foreign investors and suppliers of technology. On the whole, it has been seen that the major share went to core, priority sectors while infrastructural sector was untouched. Further, the gap between developed and developing states has become wider. Major share of both domestic investment as well as foreign direct investment went to already developed states. In fact, economically weaker states could not compete with the developed states in open market in attracting industrial investment proposals and hence they are likely to suffer from these processes. Thus, we need to look ahead at balancing the act and provide initiatives for the weaker states to reap benefits of the policies of liberalisation, privatisation and globalisation.

3.5 Industrial Regions Industries are distributed unevenly in India because the factors affecting industrial locations are not the same everywhere. Industries tend to concentrate in few pockets because of certain favourable factors. These pockets of high concentration of industries are known as industrial regions. Several indices are used to identify the clustering of industries, important among them are : (i) the number of industrial units, (ii) number of industrial workers, (iii) quantum of power used for industrial purposes, (iv) total industrial output, and (v) value added manufacturing, etc. Industrial regions have been classified into three categories: Major Industrial region is identified on the basis of a minimum daily factory working force of 1.5 lakh; Minor industrial region must have a minimum working force of 25000 labours; industrial district has a working labour force of less than 25000. Following are the eight major industrial regions of India: 1. Mumbai-Pune Industrial Region: Location and Extent: This region extends along the coast of the Arabian Sea in Maharashtra. It extends up to Pune to the southeast of Mumbai. Advantages and Factors of Development: (i) Raw material: A lot of cotton is produced in the area around Mumbai. Before independence, however, cotton used to be imported through Mumbai port. (ii) Sources of energy: This region is situated at a long distance from the coal producing regions. But electricity is easily available from the Tata Hydro-electric power houses and the Tarapur Nuclear Power Station. (iii) Climate: Humid climate of this region is suitable for cotton textile industry. Due to humid climate, thread does not snap while spinning.

22

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

(iv) Capital and banking facilities: Mumbai is a major trading metropolis. Capital and banking facilities are, therefore, easily available. (v) Port facilities: The British purchased the Island of Mumbai in 1774 and built a port here. A railway line had been laid in 1853 connecting Mumbai with Thane. Mumbai port is connected to Pune through Bhorghat Pass and to Nasik through Thalghat Pass. Mumbai port developed rapidly after the opening of the Suez Canal in 1869 .Its hinterland has a dense network of railways and roads. It is a point of convergence of international air routes also. (vi) Market: This region is prosperous economically and the people here have a high purchasing power. Therefore, there is a large demand of industrial goods in the domestic market. The region has easy access to international markets also. (vii) Labour: Skilled and unskilled labour is easily available. Services of foreign experts are also utilised these days. Important Industries: Cotton textiles, woollen, silk and synthetic fibres and textile printing are the chief industries in this region. It is the largest cotton textile producing region in Asia. Manufacturing vegetable oils, rubber goods, soaps and detergents, electrical goods, engineering goods, automobiles, cycles, etc. and oil refining are also important industries of this region. Chief Industrial Centres: Mumbai, the neighbouring suburbs of Thane, Lalganj, Parel, Worli, Mahi, Dadar, etc. and Pune are the chief industrial centres of this region. 2. Hugli Industrial Region: Location and Extent: This region extends on both sides of the Hooghly river from Bansberia to the north of Kolkata to Birlanagar to the south. Advantages and Factors of Development (i) Raw material: Enough raw materials are available locally for jute, paper, chemical, silk, leather and engineering industries, (ii) Port facilities: Kolkata and Haldia ports facilitate import of necessary inputs and export of finished products. (iii) Sources of energy: Coal and electricity are available from Damodar Valley nearby. (iv) Water: Enough water is available from Hooghly and groundwater sources for industries such as jute and paper mills. (v) Capital and banking facilities: Kolkata being a major trade centre, capital and banking services are easily available. (vi) Transport: Railways and roads link this region with all parts of the country. Rivers Damodar and Hooghly are navigable. Before independence this region was linked with Assam and the other parts of northeast through Brahmaputra waterway. (vii) Labour: This region is surrounded by areas of high density of population. Therefore, there is no shortage of labour. Trained manpower is also available around Kolkata. Important Industries: Important industries of this region are jute, paper, cotton textiles, automobiles, engineering, electrical goods, chemicals, drugs and pharmaceuticals, diesel engines, machinery for textile and sugar mills, cycles, paints, rubber goods, pottery, silk textiles, vegetable oil and match industries. Chief Industrial Centres: Haldia, Serampur, Rishra, Howrah, Kolkata, Sibpur, Naihati, Kakinara, Titagarh, Birianagar, Bansberia, etc. are the important industrial centres in this region. Silt deposition in Hooghly poses problems to navigation. Farakka Barrage has been built to regulate the flow in the Ganga to solve this problem. Special ships are used for de silting the Hooghly River. Haldia port on the coast of the Bay of Bengal has been developed to reduce pressure on Kolkata port.

23

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3. Bangalore-Chennai Industrial Region: Location and Extent: This region lies in the two states of Karnataka and Tamil Nadu. Madurai is situated in its southern part while Bangalore is situated in the north. Advantages and Factors of Development (i) Raw material: This region is an important producer of cotton and sugar cane providing raw material for cotton textile and sugar industries. Minerals like iron ore, gold, bauxite, magnetite, etc. are also found here. They serve as raw materials for a number of industries. (ii) Climate: This region has a mild climate which is suitable for hard work round the year. (iii) Research institutions: Research institutions like Central Sugar cane Research Institute, Coimbatore, and Indian Institute of Sciences, Bangalore, situated in this region provide skilled workers and technical support. (iv) Transport: This region has a dense network of railways and roads and connected to Chennai, Mumbai and Mangalore ports 24

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

(v) Sources of energy: This region does not have coal reserves but hydroelectricity is available. This region has taken advantage of Mettur, Shivasamudram, Papanasam, Pykara and Sharavati hydroelectric power projects. Important Industries: This region has a variety of industries. Industries like cotton textiles, silk textiles, sugar, leather goods, chemicals, and machine tools have developed here. A number of large public sector industries like Hindustan Machine Tools Ltd.; Indian Telephone Industries, Bharat Electronics and Hindustan Aeronautics are situated in this region. Bhadravati Steel Plant under the management control of SAIL is also situated in this region. Chief Industrial Centres: Madurai, Sivakasi, Tiruchirapalli, Coimbatore, Madukottai, Mettur, Bangalore, Mysore and Mandya are the important industrial centres. Coimbatore (Tamil Nadu) and Bangalore (Karnataka) have witnessed a rapid industrial development during the last some years. 4. Gujarat Industrial Region: Location and Extent: This region extends around the Gulf of Khambhat. Gujarat is situated in its northern part and Bharuch in its southern part. Advantages and Factors of Development (i) Raw material: Area around this region produces large amount of cotton. Mineral oil and natural gas for petrochemical industries are also locally available. (ii) Cheap land: Land is cheap and abundant here in comparison to Mumbai. (iii) Labour: This region has an old tradition of cloth weaving. Therefore, skilled cheap labour for cotton textile industry is easily available. (iv) Transport: Industrial centres of this region are connected with each other and other cities with railways and roads. There are pipelines for transport of gas and oil. [t has given impetus to the development of petrochemical industries. (v) Capital: Ahmadabad and Vadodara are cities of rich people. Therefore capital for industry is easily available. (vi) Port Facilities: This region is served by the new port of Kandla. This port is relatively closer to Europe, Africa and Central Asia. Important Industries: Cotton textile is the chief industry of this region. Chemical, drugs and pharmaceuticals, woollen and silk textiles, paper, milk products, match and machinery for textile industries are the other important industries. India's famous Amul Milk Industry is in this region. For the past some years, petrochemical industry using mineral oil and natural gas has been making rapid progress. Chief Industrial Centres: Ahmadabad, Vadodara, Koyali, Bharuch, Surat, Anand, Kheda, Gandhar, etc. are the chief industrial centres. 5. Chhotanagpur Region: Location and Extent: This region extends over West Bengal, Bihar and Orissa. The Damodar and the Subernarekha rivers flow through this region. Advantages and Factors of Development (i) Raw material: This region is rich in mineral resources and has large reserves of iron ore, copper, mica, bauxite, fire clay, coal, manganese, dolomite, limestone, etc. (ii) Labour: Cheap workers from Bihar and Uttar Pradesh are easily available. Trained and skilled workers are also available. (iii) Sources of energy: The well-known coal deposits of Damodar valley lay in this region. Electricity is also available from Damodar valley project. (iv) Transport: This region is connected to the Kolkata port and other parts of India with roads and railways. The canal waterways of Damodar Project are also used. Important Industries and Chief Industrial Centres: A variety of industries including iron and steel, paper, chemicals, heavy engineering, cycles, aluminium, fertilisers, cement, locomotive and railway wagons, etc. have 25

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

developed in this region. Iron and steel is the most important industry of Chhotanagpur region. The public sector steel plants of Bokaro, Durgapur, Kulti and Burnpur and the private sector iron and steel plant of Jamshedpur are situated in this very region. Sindri, Chittaranjan, Dhanbad, Ranchi, Chaibasa, Hazaribagh, Daltonganj, Garwa and Japla are the chief industrial centres. 6. Vishakhapatnam-Guntur Region: Location and Extent: This region extends from Vishakhapatnam in Andhra Pradesh to Prakashan and Kurnool districts in the south. Facilities available and Reasons for Development (i) Raw materials: This area is also agriculturally prosperous. The raw materials like sugar cane, cotton and jute are locally available. Iron ore is available nearby from Bailadila mines and bauxite reserves are also found in the area. Limestone is also available locally, (ii) Power resources: Coal available from Godavari valley and power generated from coal is also available in the region. The benefit of oil and natural gas reserves in Krishna-Godavari basin also accrue to this region. (iii) Port facilities: For import and export trade port facilities are available at Vishakhapatnam and Machilipatnam. It also takes advantage of Chennai and a new port at Ennore. (iv) Water: The surface water of Krishna and Godavari rivers and coastal waters as well as groundwater in coastal areas is adequately available to industries in the region. (v) Capital and banking: Finance and banking facilities are available from Vishakhapatnam, Vijayawada and other cities. (vi) Transport: A network of railways and road transport is found in the area. Many principal railway routes and national highways pass through the region. In this industrial region density of population is also high. There is thus no shortage of labour. There are many higher technical institutions in the cities of Andhra Pradesh. Therefore, trained engineers and workers are also available. (vii) Major industries: In this region chiefly the following industries have developed petrochemicals, sugar, cotton clothes, jute, paper, fertilisers, cement, aluminium, iron and steel, lead, zinc smelting, etc. (viii) Chief industrial centres: The chief industrial centres of the region are Vishakhapatnam, Vijayawada, Vijayanagar, Rajahmundri, Guntur, Eeuru, and Kurnool. 7. Gurgaon-Delhi-Meerut Region: Location and Extent: The industrial region is spread over the states of Delhi, Haryana, Uttar Pradesh and Union Territory of Delhi. The region extends from Agra to Ambala. Facilities Available and Reason for Development (i) Raw materials: This region is away from mining and power resources region. It is, however, agriculturally prosperous region. Sugar cane is the chief crop. It supplies raw materials to a large number of sugar mills in the area. The region is also well developed in milk production. (ii) Power resources: Two main sources are hydel and thermal power. There are many thermal power stations in the region. It gets electricity from Northern Grid of Bhakra-Nangal project. (iii) Transport: There is a vast rail-road network in the region. There are no problems in respect of availability of raw materials, labour, capital and other facilities. (iv) Labour: There is no shortage of trained and skilled labour because of the existence of a large number of educational and training institutions in the area. (v) Principal industries: The industries manufacturing light engineering and consumer durables are found in the area. Chief industries are cotton, woollen and silk mills, instruments and tools, tractors, cycles and car manufacturing units, electronics and vegetable oils, electrical instruments, domestic appliances, agricultural tools, etc. Software and hardware and glass industries are also found. There are also two large oil refineries at Panipat and Mathura in this region. 26

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

8. Kollam-Tiruvanantapuram Region: Location and Extent: The region extends from Trichurnagar of Kerala state to Thiruvananthapuram in the South. Five districts of Kerala namely: Trichur, Ernakulam, Allappuzha, Kollam and Thiruvananthapuram districts are located in this region. Facilities Available and Reasons for Development (i) Raw materials: Almonite, rutoite, zercon, and mononite sands are found in adequate quantities. Plantation, agriculture like tea, coffee, spices, etc supply raw materials to industries. (ii) Sources of power: Hydroelectric power stations found in the region are the main sources of supply of electricity in the region. These power sources are chiefly responsible for industrialisation of the region. (iii) Transport: The principal rail routes and national highway linking coastal regions pass through the area. Even roads are found in hilly regions. This wide network of roads and railways has helped in movement of raw materials and goods. Therefore, distribution of manufactured goods also does not face any problems. (iv) Ports: A chief port in the area namely Kochi has many facilities available. (v) Chief industries: Agricultural products processing related industries such as cotton textiles, sugar, rubber, matches, and fish, mineral-based industries like glass, chemical fertilisers, petroleum and its products, paperboard and coir products, fine instruments, machinery and tools, etc. are found in the area. (vi) Principal industrial centres: The principal industrial centres of the region are Thiruvananthapuram, Kollam, Allappuzha, Kochi, Alwaye and Trichur. There are thirteen Minor Industrial Regions in the country. They are Ambala-Amritsar, SaharanpurMuzaffarnagar-Bijnor, Indore-Dewas-Uijjain, Jaipur-Ajmer, Kolhapur-South Kannada, Northern Malabar, Middle Malabar, Adilabad-Nizamabad, Allahabad-Varanasi-Mirzapur, Bhojpur-Munger, Durg-Raipur, Bilaspur-Korba, and Brahmaputra valley. Also, there are fifteen industrial districts which are Kanpur, Hyderabad, Agra, Nagpur, Gwalior, Bhopal, Lucknow, Jalpaiguri, Cuttack, Gorakhpur, Aligarh, Kota, Purnia, Jabalpur and Bareilly.

4. UPSC Questions Covered Sources: a) b) c) d)

NCERT – India People and Economy ICSE Geography- Class X - -R K Jain Geography Class XII – Yashpal Singh India- A Comprehensive Geography – D.R. Khullar

e) http://pib.nic.in/feature/feyr2000/fmar2000/f060320002.html f) http://www.preservearticles.com/2011101215197/brief-notes-on-the-major-industrial-regionsof-india.html g) http://hbswk.hbs.edu/industries/

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 27

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS www.visionias.in GEOGRAPHY: 21

Transport & Communication and International Trade 1. Transport 1.1 Land Transport 1.1.1 Road Transport 1.1.1.1 Advantages of Roads 1.1.1.2 Distribution of Roads in the World 1.1.1.3 Distribution of Roads in India 1.1.1.3.1National Highways 1.1.1.3.2 The State Highways 1.1.1.3.3 The District Roads 1.1.1.3.4 The Village Roads 1.1.1.3.5 The Border Roads 1.1.1.3.6 Expressways 1.1.1.3.7 The Asian Highway (AH) 1.1.1.4 Road Density 1.1.1.5 Problems of Road Transport 1.1.2 Rail Transport 1.1.2.1 Advantages of Rail Transport 1.1.2.2 Limitations of Rail Transport 1.1.2.3 Distribution of Railways in the World 1.1.2.4 Distribution of Railways in India 1.1.2.5 Problems of Railways in India 1.2 Water Transport 1.2.1 Inland Waterways 1.2.1.1 Necessary Conditions for Inland Waterways 1.2.1.2 Advantages of Inland Waterways 1.2.1.3 Limitations of Inland Waterways 1.2.1.4 Distribution of Inland Waterways in the World 1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.2.1.5 Distribution of Inland Waterways in India 1.2.2 Oceanic Routes 1.2.2.1 Main Ocean Routes of the World 1.2.2.2 Main Shipping Canals 1.2.2.3 Oceanic Routes in India 1.2.2.3.1 Problems of Shipping in India 1.2.3. Major Ports in India 1.2.4 Types of Port 1.2.5 Types of port on the basis of location 1.2.6 Types of port on the basis of specialised functions 1.3 Air Transport 1.3.1 Important Air Routes of the World 1.3.2 Air Transport in India 1.4 Pipeline Transport 1.4.1 Advantages of Pipeline Transport 1.4.2 Limitations of Pipeline Transport 1.4.3 Distribution of Pipelines in the World 1.4.4 Pipeline Transport in India 2. Communication 2.1 Personal Communication System 2.2 Mass Communication System 2.2.1 Radio 2.2.2 Television (T.V.) 2.2.3 Satellite Communication 3. International Trade 3.1 Factors influencing International Trade 3.2 Components of International Trade 3.3 Types of International Trade 3.4 International Pattern of Trade 3.5 Regional Trade Blocs and World Trade Organisation (WTO) 3.6 Balance of Trade 3.7 Concerns Related to International Trade 3.8 Limitations of International Trade 3.9 India’s Foreign Trade 3.10 Challenges in International Trade for India 4. Sources

2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1. Transport Transport provides services of carrying men and materials from one place to another. It links all the spheres of earth, land, air and water. Development of cheap and efficient means of transport is necessary for the progress of a country. Transport routes serve as basic economic arteries of the country and provide important link between production and consumption. Density of transport network and its modernity is the index of economic development of any country. Transport system can be broadly classified into four distinct ways i.e. land transport, water transport, air transport and pipeline transport. Land transport can be taken by man himself or through animal transport, road transport or rail transport. Water transport can be classified in inland transport systems and oceanic waterway transport systems.

1.1 Land Transport Man has been using footpaths for transport since prehistorical times. After the invention of wheel, when manmade carts, driven by oxen, horse and camel and made use of unsurfaced roads; with the invention of steam engine need was felt for providing rail lines. First such rail line was, perhaps, from Stockton and Darlington in northern England opened in 1825. Soon the first public railway system became very popular as it was very convenient and fastest mode of transport. The networks of road and rail transport threw open remote interior parts of continents to human settlements, grain farming and industrialisation. 1.1.1 Road Transport Pt. Jawaharlal Nehru said, ''The path of development goes to villages through roads". This is true to other fields too. The roads are harbingers of economic development. Only 20 per cent population of the world lives in developed countries, but it has 72 per cent cars, buses, trucks, etc of the world. Road networks are found in high density in areas with higher population density round the world. With the advancement in technology, metalled roads are reaching the countryside and helping in connecting people. 1.1.1.1 Advantages of Roads The major advantages of road transport over other means of transport are as follows: 1) Road transport is cheaper than rail transport. Its cost of construction, repair and maintenance is comparatively less than railway transport. 2) Roads are available up to the house of consumer. The producer and trader prefer roads only because there arise no need of loading and unloading of their goods at different places. The raw material and the machines reach the factory directly and the products to the consumers safely. 3) Road transport is the best for short and medium distances. People and goods take less time in reaching their destination. 4) Roads are highly useful for transporting ephemeral goods such as green vegetables, fruits and milk. The roads are basis of truck farming. 5) Anytime, anywhere no problem of time and travel. 6) Regular expenditure on roads is very low as compared to rail transport which is high on maintenance of stations, platforms, rail-routes and on employing large number of employees for running the railways. 7) The construction and usage of roads in inaccessible hilly areas with steep slopes and forested areas is difficult but possible. 8) Packing of goods is not always necessary in road transport. Sometimes, fruits and vegetables are loaded without packing. 9) Roads can negotiate steep slopes and sharp turns and are more flexible means of transport. 3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.1.1.2 Distribution of Roads in the World The road network is not evenly spread throughout the world; the density of roads is not the same everywhere nor is there any system of distribution of roads between small towns and cities. City roads suffer from chronic traffic congestion. There are peaks (high points) and troughs (low points) of traffic flow between certain hours of the day. It is estimated that total length of roads in the world is three crore nine lakh km. Out of this only 1.5 crore km roads can be used in all seasons. The North American continent alone has 35 per cent of world's good roads. The economically and industrially advanced countries have generally a good road network whereas developing and poor countries cannot cope with the demands of traffic. The United States of America has also highest road density. Having consideration for safety on roads, many theories of transportation or traffic-flows have been put forward. These seek to describe in a precise mathematical way the interactions among vehicles, drivers, and the infrastructure. It has been found that there is some kind of relationship between these elements which if studied properly could help in planning, design, and operations of roadway facilities. Particular attention is paid in respect of flow, density and velocity. In most cities of the world there is chronic traffic congestion. Many suggestions have been made for urban transport solutions. Among these suggestions include: (i) Higher Parking Fee (ii) Mass Rapid Transit (MRT) (iii) Improved Public Bus Service (iv) Expressways / Toll Roads 1.1.1.3 Distribution of Roads in India India has one of the largest road networks in the world with a total length of 46.9 lakh km (2013). About 65% of freight and 80% passenger traffic is carried by the roads. National Highways in India constitute only about 1.7% of the road network but carry about 40% of the total road traffic. Number of vehicles has been growing at an average pace of 10.16% per annum over the last five years. India has a long tradition of building roads since the times of Chandragupta Maurya and Asoka. The real progress was made during Mughal period, when Sher Shah Suri constructed a road between Peshawar and Kolkata. It is now called Grand Trunk (G.T.) Road. Road transport in modern sense was very limited in India before World War-II. The first serious attempt was made in 1943 when ‘Nagpur Plan’ was drawn. This plan could not be implemented due to lack of coordination among the princely states and British India. After Independence, twenty-year road plan (1961) was introduced to improve the conditions of roads in India. However, roads continue to concentrate in and around urban centres. Rural and remote areas had the least connectivity by road. Currently, the Indian road network consists of National Highways, State Highways, District roads and Village roads. Besides these, there are International highways and the Expressways, which are of recent development.

1.1.1.3.1NATIONAL HIGHWAYS These are the main roads, which are constructed and maintained by the Central Government through National Highway Authority of India (NHAI)1, which was established in 1995. These roads are meant for interstate movement and connect the state capitals, important ports, major cities and railway junctions. The total length of the National Highways was about 19,700 km in 1951. It has increased to about 70,934 km in 2012. The National Highways are only 2 per cent of the total road length in India, but these roads carry about 40 per cent of the total road traffic of India. 1

The National Highways Authority of India (NHAI) was formed in 1995. It is an autonomous body under the Ministry of Surface Transport. It is entrusted with the responsibility of development, maintenance and operation of National Highways. This is also the apex body to improve the quality of the roads designated as National Highways.

4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

As of now about 26 per cent (18,350 km) of the total length of National Highways (NHs) is single lane/intermediate lane, about 51 per cent (36,031 km )is two-lane standard, and the balance 23 per cent (16,553 km)is four-lane standard or more. The NHDP project is composed of the following phases: Phase I: The Golden Quadrilateral (GQ) connecting the four major cities of Delhi, Mumbai, Chennai and Kolkata. This project connecting four metro cities would be 5,846 km (3,633 mi). Total cost of the project is Rs.300 billion (US$6.8 billion), funded largely by the government’s special petroleum product tax revenues and government borrowing. In January 2012, India announced the four lane GQ highway network as complete. Phase II: North-South and East-West corridors comprising national highways connecting four extreme points of the country. The North-South and East-West Corridor (NS-EW; 7,300 km) connecting Srinagar in the north to Kanyakumari in the south, including spur from Salem to Kanyakumari (Via Coimbatore and Kochi) and Silchar in the east to Porbandar in the west. Total length of the network is 7,300 km (4,500 mi). The Golden Quadrilateral and the corridors will also be connected to 10 major ports of India, namely Kandla, Jawaharlal Nehru Port, Marmagao, New Mangalore, Kochi, Tuticorin, Ennore, Vishakhapatnam, Paradip and Haldia, through a road length of 363 km. Phase III: The government recently approved NHDP-III to upgrade 12,109 km (7,524 mi) of national highways on a Build, Operate and Transfer (BOT) basis, which takes into account high-density traffic, connectivity of state capitals via NHDP Phase I and II, and connectivity to centres of economic importance. Phase IV: The government is considering widening 20,000 km (12,000 mi) of highway that were not part of Phase I, II, or III. Phase IV will convert existing single lane highways into two lanes with paved shoulders. The plan will soon be presented to the government for approval. Phase V: As road traffic increases over time, a number of four lane highways will need to be upgraded/ expanded to six lanes. The current plan calls for upgrade of about 5,000 km (3,100 mi) of four-lane roads, although the government has not yet identified the stretches. Phase VI: The government is working on constructing expressways that would connect major commercial and industrial townships. It has already identified 400 km (250 mi) of Vadodara (earlier Baroda)-Mumbai section that would connect to the existing Vadodara (earlier Baroda)-Ahmadabad section. The World Bank is studying this project. The project will be funded on BOT basis. The 334 km (208 mi) Expressway between Chennai—Bangalore and 277 km (172 mi) Expressway between Kolkata—Dhanbad has been identified and feasibility study and DPR contract has been awarded by NHAI. Phase VII: This phase calls for improvements to city road networks by adding ring roads to enable easier connectivity with national highways to important cities. In addition, improvements will be made to stretches of national highways that require additional flyovers and bypasses given population and housing growth along the highways and increasing traffic. The government has not yet identified a firm investment plan for this phase.

1.1.1.3.2 THE STATE HIGHWAYS These highways are constructed and maintained by the State Governments through their respective Public Works Departments (PWD). The State Highways provide linkages with the National Highways, district headquarters, important towns, tourist centres and minor ports and carry the traffic along major centres within the state. These arterial routes provide connectivity to important towns and cities within the state with National Highways or State Highways of the neighbouring states. Their total length is about 137,712 km. These constitute 4 per cent of total road length in the country. 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.1.1.3.3 THE DISTRICT ROADS These roads are constructed and maintained by Zila Parishads and the Public Works Departments. The district roads mostly connect the district headquarters with the main towns and large villages within the districts. Now most of these roads are metalled roads and provide accessibility to the rural areas. The total length is about 4,70,000 km. They account for 14 per cent of the total road length of the country.

1.1.1.3.4 THE VILLAGE ROADS These roads are constructed and maintained by the Village Panchayat. They connect the villages with the neighbouring towns and cities. These roads made great progress under the Pradhan Mantri Grameen Sadak Yojana (PMGSY). Under this scheme, the all weather roads are constructed to provide easy access to the villages. Their total length in 2005 was 26,50,000 km, which was about 80 per cent of all types of roads in India.

1.1.1.3.5 THE BORDER ROADS The Border Roads Organisation (BRO) was established in 1960. Its main aim was to plan and construct roads of strategic importance in the northern and north-eastern border areas of the country. BRO has constructed roads in high altitude mountainous areas. Apart from this main work, the BRO also undertakes snow clearance in high altitude areas.

1.1.1.3.6 EXPRESSWAYS Expressways are the highest class of roads in the Indian Road Network. An expressway is a controlled-access highway; it is a highway that controls entrances to it and exits from it by incorporating the design of the slip roads for entry and exit into the design of the highway itself. Expressways make up approximately 1,208 km (751 mi) of India's road network, as of 2013. The expressways in use are:

6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

7

www.UPSCPDF.com

www.visionias.in

https://t.me/UPSC_PDF

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

National Highway NH-1

https://t.me/UPSC_PDF

Route

Distance

Jalandhar – Uri

663

New Delhi-Ambala-Jalandhar-Amritsar

456

NH-2

Delhi-Mathura-Agra-Kanpur-Allahabad-Varanasi-Kolkata

1465

NH-3

Agra-Gwalior-Nasik-Mumbai

1161

NH-4

Thane and Chennai via Pune and Belgaum

1235

NH-5

Kolkata - Chennai

1533

NH-6

Kolkata – Dhule

1949

NH-7

Varanasi – Kanyakumari

2369

NH-8

Delhi-Mumbai-(via Jaipur, Baroda and Ahmedabad)

1428

NH-9

Mumbai-Vijayawada

841

NH-10

Delhi-Fazilka

403

NH-11

Agra- Bikaner

582

NH-12

Jabalpur-Jaipur

890

NH-13

Sholapur-Mangalore

691

NH-15

Pathankot-Samakhiali

1526

NH-17

Panvel-Edapally

1269

NH-22

Ambala-Shipkitr

459

NH-28

Lucknow-Barauni

570

NH-1A

List of Main National Highways in India 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12) 13) 14) 15) 16) 8

Greater Noida – Agra Yamuna Expressway (165 kilometres) Ahmadabad Vadodara Expressway (95 kilometres) Mumbai-Pune Expressway (93 kilometres) Jaipur-Kishangarh Expressway (90 kilometres) Allahabad Bypass Expressway (86 kilometres) Durgapur Expressway (65 kilometres) Ambala Chandigarh Expressway (35 kilometres) Chennai Bypass Expressway (32 kilometres) Delhi-Gurgaon Expressway (28 kilometres) NOIDA-Greater NOIDA Expressway (24 kilometres) Delhi-NOIDA Flyway (23 kilometres) Mumbai Nasik Expressway (150 kilometres) PVNR Hyderabad Airport Expressway (12 kilometres) Hyderabad ORR Expressway (150 kilometres) Guntur-Vijayawada Outer ring road Expressway (46 Kilometres) Outer Ring Road, Guntur & Vijayawada Coimbatore Bypass expressway(28 kilometres) www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.1.1.3.7 THE ASIAN HIGHWAY (AH) The Asian Highway (AH) project, also known as the Great Asian Highway, is a cooperative project among countries in Asia and Europe and the United Nations Economic and Social Commission for Asia and the Pacific (ESCAP), to improve the highway systems in Asia. It is one of the three pillars of the Asian Land Transport Infrastructure Development (ALTID) project, endorsed by the ESCAP commission at its 48th session in 1992, comprising Asian Highway, Trans-Asian Railway (TAR) and facilitation of land transport projects. Agreements have been signed by 32 countries to allow the highway to cross the continent and also reach to Europe. Some of the countries taking part in the highway project are India, Sri Lanka, Pakistan, China, Japan, South Korea and Bangladesh. Most of the funding comes from the larger, more advanced Asian nations like Japan, India and China as well as international agencies such as the Asian Development Bank. The following are the routes which pass through India – 1) 2) 3) 4) 5) 6)

AH1; Petrapole to Atari via NH 1 & 2 AH42, 3,754 km (2346 miles); Lanzhou, China (on AH5) to Barhi, India (on AH1) AH43, 3,024 km (1892 miles); Agra, India (on AH1) to Matara, Sri Lanka AH44, 107 km (67 miles); Dambulla, Sri Lanka (on AH43) to Trincomalee, Sri Lanka AH45, 2,030 km (1269 miles); Kolkata, India (on AH1) to Bangalore, India (on AH43/AH47) AH46, 1,967 km (1,222 miles); named Great Eastern Highway within India from its East Coast to West Coast - Hazirah-Surat-Jalgaon-Howrah(Kolkata) till AH2. 7) AH47, 2,057 km (1286 miles); Gwalior, India (on AH43) to Bangalore, India (on AH43/AH45) 8) AH48, 1 km (.625 miles); Phuentsholing, Bhutan to border between Bhutan and India 1.1.1.4 Road Density The distribution of roads in India is highly uneven. The density of roads (length of roads per 100 sq km of area) varies from only about 10.5 km in Jammu and Kashmir to about 400 km in Kerala. The national average of road density is about 75 km per 100 sq km. The density of roads is generally high in most of Northern and Southern states. It is low in the Himalayan region, Madhya Pradesh and Rajasthan. This is due to the topography and the level of economic development of the areas. The construction of roads is easy and cheaper in plain areas than in the hilly and plateau regions. Keeping in view the volume of goods traffic and passengers, the road network is not only insufficient, but also inefficient. About 45 per cent of the roads in India are unmetalled and this restricts their use during the rainy season and also for heavy vehicles. 1.1.1.5 Problems of Road Transport The road transport in India is facing a number of problems. Some of them are as under: 1) About half of the Indian roads are unsurfaced. These can be used only in fair weather and becomes muddy and unfit during the rainy season. 2) Most of the National Highways suffer from inadequate capacity, weak pavements, old and broken bridges, unbridged level crossings, lack of by-pass roads and lack of amenities and safety measures. The mixing of traffic by high speed cars, trucks, buses, tractors, two wheelers, animal driven vehicles, cyclists, etc. increases traffic time, congestion, pollution and road accidents. 3) The existence of multiple check posts, toll tax, and octroi duties collection points on roads waste time and retards the traffic movement and speed. 4) Important amenities, such as repair shops, first aid centres, telephones, clean toilets, food outlets, rest places are lacking along the roads.

9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

State wise Length of Roads in India

5) The rules of road safety and traffic are wilfully violated by the drivers and there is no efficient system of checking. 6) The road engineering and construction techniques are out-dated and are not able to meet the challenges of the future. 7) The participation of private sector in road development is very little due to high investments and low returns. 8) The policy relating to highway development is not stable, as it changes with the change of government. 9) The multiplicity of agencies involved in the planning, construction and maintenance of different types of roads. 10 www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

10) There is a shortage of funds for the construction and maintenance of roads, even for highways, in India. 1.1.2 Rail Transport The first train of the world started in 1825 A.D. between Stockholm to Darlington in northern England. Since then, railways became an important means of land transport. Railroad is normally called a track. Distance between two parallel rails is known as gauge. Over sixty percents of world's rail routes are of standard gauge of 1435 mm. Rail gauge larger than standard gauge is called broad gauge and smaller than standard gauge is called narrow gauge. The measurements of narrow and broad gauges slightly varies from country to country – narrow gauge between 914 mm and 1067 mm and broad gauge between 1520 mm and 1676 mm [as in India]. Further many countries have 1,000 mm gauge, also known as metre gauge. 1.1.2.1 Advantages of Rail Transport The major advantages of the rail transport are as follows: 1) It is a cheap means of transport for long distance journeys of people and goods. 2) It is a fast transport for long distances. 3) Due to development of new technology in railway lines, wagons and coaches, engines and operation system, the speed of trains has become more than 300 km per hour. The fast running trains are in vogue in Japan, France and Germany. 4) On account of air-conditioned coaches, excellent arrangement in sleeper coaches and catering travel by trains has become very comfortable. 5) Trains transport heavy and bulky goods over long distances. 6) Trains are convenient mode of transport for sending agro-products to consumers and raw materials to factories. 7) After introduction of big containers, trains and trucks together help the goods to reach at the doorstep of the consumers. 8) Provision of container services has considerably reduced expenses on packing, loading and unloading. 9) Perishable goods are transported in refrigerated wagons. 10) Railways contribute greatly to economic development of a region. 1.1.2.2 Limitations of Rail Transport Some of the limitations of the modern rail transport are1) Huge capital investment is imperative in constructing railway track, stations, platforms and manufacturing wagons and coaches, etc. 2) It is difficult to construct and maintain rail routes in hilly terrains with steep slopes and deserts. 3) Rail transport is generally impossible in areas of heavy rainfall and snowfall. 4) Sending of goods through rail transport becomes difficult due to different gauge of railway lines i.e. broad, metre and narrow. This increases the expenditure on loading and unloading. 1.1.2.3 Distribution of Railways in the World The network of rail routes is unevenly distributed across the world. The economically developed countries of the world have more railways. Railways have played an important role in the industrialisation of these countries. The colonial rulers of Europe connected the interior parts of their colonies in Asia and Africa to the ports. The main purpose of this was to bring the raw material from the interior of these colonies to the ports, which was later shipped to European countries. This was the main purpose behind connecting Delhi to Kolkata, Mumbai and Chennai. Similar course was followed in Africa by the French, Italians and other colonial powers.

11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Later, most of the cities were connected by the railway networks. Parts of Europe have great density of railway network. It is said that Belgium has the world's densest rail route network It has 1 km railway lines for every 6.5sq km area. In Asia the countries of Japan, China and India are densely populated. They have also dense network of railways. In other countries railways are not widespread. West Asia is least developed in rail networks because of existence of vast deserts and thinly populated regions. Very recently China has constructed railway line up to Lhasa in Tibet. The Qinghai-Tibet railway is the highest altitude railways of the world. Another project, Trans-Asian Railway (TAR) undertaken by the United Nations Economic and Social Commission for Asia and Pacific [UNESCAP] integrates freight railway networks across Europe and Asia. North America has the densest rail route network in the world. About 40 per cent rail routes of the world are found in this continent. Very heavy load like minerals, food grains, logs of timber etc. are transported by railways. Passengers, however, prefer air journey or road journey. Intercontinental rail routes connect two ends of a continent. These rail routes are constructed from the political, economic and military points of view. Important among these routes are given below: (i) Trans-Siberian Railway: This route was constructed for connecting European Russia to Siberia or Asian Russia and runs from St. Petersburg in the west to Vladivostok on the Pacific Coast in the east passing through Moscow, Ufa, Novosibirsk, Irkutsk, Chita and Khabarovsk. It is the most important route in Asia and the longest (9,332 km) double-tracked and electrified trans– continental railway in the world. It has helped in opening up its Asian region to West European markets. Its development is on account of economic, political and defence reasons. (ii) Canadian Pacific Railway: This 7,050 km long rail-line in Canada runs from Halifax in the east to Vancouver on the Pacific Coast passing through Montreal, Ottawa, Winnipeg and Calgary. This was constructed for connecting British Columbia (an eastern Province) to other states of Canada. Later on, it gained economic significance because it connected the Quebec-Montreal Industrial Region with the wheat belt of the Prairie Region and the Coniferous Forest region in the north. Thus each of these regions became complementary to the other. (iii) Australian Intercontinental Rail Route: The main purpose of constructing this was to connect the Western Australia to east Australian states so as to keep it within the union. (iv) The Union and Pacific Railway: This rail-line connects New York on the Atlantic Coast to San Francisco on the Pacific Coast passing through Cleveland, Chicago, Omaha, Evans, Ogden and Sacramento. The most valuable exports on this route are ores, grain, paper, chemicals and machinery. (v)Trans-Asiatic Railway: A UN assisted rail project for linking Istanbul with Bangkok via Iran, Pakistan, India, Bangladesh and Myanmar has been pending since a very long time. 1.1.2.4 Distribution of Railways in India The network of the Indian Railways is the largest in Asia and fourth largest in the world. It is the life-line of the country catering to its need for large-scale movement of traffic, both passengers and freight. Mahatma Gandhi said, the Indian railways “brought people of diverse cultures together to contribute to India’s freedom struggle.” Indian Railway was introduced in 1853, when a line was constructed from Bombay to Thane covering a distance of 34 km. Indian Railways is the largest government undertaking in the country. The length of Indian Railways network is about 64,000 km. It’s very large size puts lots of pressure on a centralised railway management system. Thus, in India, the railway system has been divided into sixteen zones. On the basis of width of the track of Indian Railways, three categories have been made: Broad Gauge: The distance between the rails in the broad gauge is 1.676 metres. The total length of broad gauge line is about 46,800 km, which accounts for about 74 per cent of the total length of rail routes in the country.

12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Metre Gauge: The distance between the rails in the metre gauge is one metre. The total length of the metre gauge line is about 13,300 km, which accounts for about 21 per cent of the total length of rail routes in the country. Narrow Gauge: The distance between the rails in the narrow gauge is 0.762 metre or 0.610 metre. The total length of the narrow gauge is about 3,124 km, which accounts for about 5 per cent of the total length of rail routes in the country. The narrow gauge is generally confined to hilly areas. The Government of India has nationalised the railways and adopted a policy of gauge conversion, mainly from metre gauge to broad gauge. The unigauge system of railways will assure larger capacity, higher speed and consequently cheaper transportation. The process of gauge conversion is very slow due to the shortage of funds and it will take many more years to bring the total railway system under single gauge. The distribution of Indian Railway network has been influenced by the geographical, economical and political factors. The Northern Plains of India with level land, high density of population, fertile soils and intense agriculture activities presents the most favourable environment for the development of railways. The relief of Himalayas and the plateaus is not suitable for the large scale development of railway network. The development of railways is more in economically active areas. Railways also bring economic development and prosperity to those regions through which they pass. Due to this economic link, we find the highest density of railways near big urban and industrial centres, and also in areas which are rich in minerals and agricultural resources. The present railway system in India is the legacy of British Rule. They planned the pattern of the railway network according to their needs. 1.1.2.5 Problems of Railways in India Railways being the largest public sector undertaking has varied and complex problems. Some of them are as under: 1) Its present railway network is overburdened and inadequate to meet the new challenges of a fast developing economy. 2) Some regions are beyond the reach of railways due to unfavourable geographical conditions. These areas need to be opened to railways for removing regional inequalities in economic growth. 3) Railways are facing stiff competition from road transport and thus its share in passenger and goods traffic is declining. 4) Railways are overburdened with surplus staff on its regular pay roles. This burden hinders the further development of railways. 5) The railways have to develop uneconomic projects due to political pressures and interferences. 6) Railways have huge outstanding payments to diesel and electric power supply companies. 7) The State Electricity Boards and NTPC increase the tariffs arbitrarily and thus add to the burden of railways. 8) Railways are the largest consumer of diesel. Any increase in the rates of diesel, adversely affect the financial resources. 9) Most of the equipment used by the railways are now obsolete and need immediate replacements. 10) There is mounting deficit due to non increase in fares and tariffs by the Government due to political reasons. Despite these problems and shortcomings, there is no other substitute for railways, as these are 5 times more energy efficient and four times more economical than road transport. In the last few years, some administrative changes have been implemented to reduce the deficit. As a result of consistent efforts, the Indian Railways are now generating surplus funds. Some of the measures taken include sharpening of marketing capability; Strengthening of high density network; Cutting down of unnecessary overheads; Commercial exploitation of railway lands; Participation by the private sector; and Effective and efficient use of available financial resources. 13 www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.2 Water Transport Man has been using water transport since ancient times. Waterways were being used mainly for transporting goods for the last few years. But now, big passenger ships are moving from one corner of the world to another with the load of thousands of tourists. Water transport is the cheapest as compared to other means of transport because no cost is involved in constructing the roads or on their maintenance. Waterways are highly suitable for heavy and bulky materials. Waterways are of two types: (i) Inland Waterways, and (ii) Ocean Waterways. 1.2.1 Inland Waterways The rivers, lakes and canal used for transporting goods or people are called inland waterways. The inland waterways were very important before the invention of trains and motor vehicles. They were very much in use for transporting passengers and goods. But, rail routes and roads have reduced their importance to some extent. 1.2.1.1 Necessary Conditions for Inland Waterways The following are the necessary conditions which need to be met for successful inland water transport in the country. 1) Rivers should be perennial or water should flow in sufficient quantity throughout the year. Seasonal rivers are unsuitable for navigation. 2) Water transport cannot take place in river having rapids or waterfalls. 3) The water in rivers, lakes and canals should not freeze during winter season. 4) Soil or sand should not be deposited on the mouth of rivers. The deposition of sand or soil reduces the depth of water. 5) The course of rivers should not be full of curves. These curves increase the time of transportation. 6) Rivers should not change their courses during floods. 1.2.1.2 Advantages of Inland Waterways Inland waterways are advantageous in many ways. These can be summarised as – 1) Transportation of heavy and bulky goods is easy and cheap. Coal, different ores, wood and big size manufactured goods are suitable for water transport. 2) Rivers and lakes are natural routes. Expenditure on their construction and maintenance is not required. 3) Waterways experience comparatively few accidents. 4) Rivers are the only means of transport in thick forested lands of heavy rainfall. 1.2.1.3 Limitations of Inland Waterways In spite of the above mentioned advantages, the inland waterways have following limitations1) Time is lost due to slow speed. Hence, they are not suitable for transporting perishable goods such as fruits, vegetables and milk and their by products. 2) Most of the rivers flow far away from the densely populated areas where demand for transportation is more. Hence, this mode of transportation presents difficulties. 3) Seasonal change in the flow and depth of water creates problem in transportation 4) For keeping desired depth in the rivers, lakes and canals, silting of sand and soil is to be removed regularly. This involves expenditure and the navigation is halted during such an exercise. 1.2.1.4 Distribution of Inland Waterways in the World All the rivers and lakes of the world are more or less used for transportation. But, navigable rivers which pass through densely populated areas are more used for navigation. The major inland water ways used extensively round the globe can be studied as follows-

14

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Rhine Waterway: Rhine River flows through industrial The Rhine flows through industrially advanced nations of Switzerland, Germany, France, Belgium and the Netherlands. The Rhine River is navigable from Rotterdam for about 870 km. At its source in Switzerland, it flows along boundary of France and Germany and drains Germany and the Netherlands and has its mouth near North Sea. On its banks are located main cities of Europe like Strasbourg {France}, Bonn, Cologne, Dusseldorf and Rotterdam. The vessel take the cargo of industrial products, coal food grains in addition to passengers and tourists which have seen considerable rise in the past few decades. For the benefit of tourists, the vessels are fitted with modern conveniences and sail in both directions of the rift valley. One can enjoy the scenic beauty of the Vossages of France and Black Forest of Germany. Each year more than 20,000 ocean-going ships and 2, 00,000 inland vessels sail in this waterway. Danube Waterway: It is an important inland waterway of Eastern Europe. The Danube rises in the Black Forest of Germany and flows eastwards through Austria, Slovak Republic, Hungary Croatia, Bulgaria, Romania and other countries and then joins the landlocked Black Sea. It is 2,850 km long. In 1992, a 171 km canal was constructed linking it with Kohlheim. Now Danube covers a distance of 3,500 km to fall into Black Sea. Cargoes carrying export items are wheat, maize, timber, and machinery sail in the river. The waterway is also gaining importance on account of rising tourism. Great Lakes· St. Lawrence Seaway: This waterway flows through the industrially advanced region and estuary St. Lawrence River of the United States and Canada. It is therefore the longest and busiest inland waterway of the world. Ships can ply up to a distance of 3760 km in it. The ships plying on this route are long and narrow and are capable of transporting 45,000 tonnes of freight. Agro-products, machines, iron ore, coal, petroleum, limestone, etc. are mainly transported from the ports like Duluth and Buffalo, which are equipped with all modern facilities. The Great Lakes region of North America consists of Lakes Superior, Michigan, Huron, Erie and Ontario. Mississippi Waterway: Mississippi River is one of the main rivers of North America. It has its source in Lake Itasca in Minnesota and flow 3,718 km draining fertile lands of interior parts of North America. It then joins the Gulf of Mexico. This waterway has become more important these days. About 16 km north its tributary Saint Louis Missouri joins it. Together with Missouri, its total length is 6238 km. For greater part it is navigable. Steamers can ply in this river up to Minneapolis some distance away from Lake Superior. The Mississippi-Ohio waterway connects the interior part of U.5.A with the Gulf of Mexico in the south. Volga Waterway: Volga is Europe's biggest river and has large number of developed waterways. After rising from in the Valdai Hills north-west of Moscow, it flows for about 3689 km before draining into Caspian Sea. Oaka River is its major right bank tributary. The river is connected to river Don by a canal which flows into the Black Sea. 1.2.1.5 Distribution of Inland Waterways in India The inland waterways refer to using inland water bodies, such as rivers, canals, creeks, backwaters, etc. for transporting goods and people from one place to another. A number of rivers, like Ganga, Brahmaputra Yamuna, Mahanadi, Godavari, Krishna, Kaveri, Narmada, Tapi, etc. were the main arteries of inland waterways in India. At present, the inland waterways in India are about 14,500 km in length, contributing about 1% to the country’s transportation. Out of this about 3,700 km are navigable by mechanised boats. In order to increase the significance of inland waterways and to improve their efficiency, the Inland Waterways Authority of India (IWAI) was set up in 1986. The following inland waterways have been declared is the National Waterways by the IWAI. There are six identified national waterways in India. National waterway-1: Allahabad–Haldia stretch of the Ganges–Bhagirathi–Hooghly River of total length 1620 km was declared as National Waterway-1 (NW-1) in the year 1986. The Hooghly river portion of the waterway from Haldia to Nabadwip is tidal. Sea going vessels navigate up to Calcutta (140 km) and the fairway up to Calcutta is maintained by the Calcutta Port Trust. From Calcutta up to Tribeni there are no restrictions for navigation by inland vessels of a loaded draft up to 4m.From Farakka upstream the navigable route is through the main Ganga 15 www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

River. The Feeder Canal and the navigation lock at Farakka become the link between the Bhagirathi and main Ganga upstream Farakka Barrage. The large variation in discharge along with unstable morphological condition of bank and bed, heavy sediment load, continuous braiding and meandering make development of navigational channel a complex task. National Waterway-2: Sadiya–Dhubri stretch of the Brahmaputra River of total length 891 km was declared as National Waterway-2 (NW-2) in the year 1988. The river Brahmaputra flows down the centre of Assam Valley. It receives a number of tributaries like Subansiri,Jia Bharali, Dihing, Burhi Dihing, Disang, Dhansiri and Kopili. National Waterway-3: Kollam–Kottapuram stretch of West Coast Canal and Champakara and Udyogmandal canals of total length 205 km was declared as National Waterway-3 (NW-3) in the year 1993. This waterway comprises of natural lakes, back-waters, river sections and man-made canal sections. The Champakara and Udyogmandal canals link industrial centres of Ambalamugal and Udyogmandal with the Kochi port. National Waterway- 4: Kakinada–Pondicherry stretch of canals and Kaluvelly tank, Bhadrachalam–Rajahmundry stretch of River Godavari and Wazirabad–Vijayawada stretch of River Krishna of total length 1095 km was declared as National Waterway-4 (NW-4) in the year 2008.

16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

National Waterway-5: Talcher–Dhamra stretch of rivers, Geonkhali–Charbatia stretch of East Coast Canal, Charbatia–Dhamra stretch of Matai river and Mahanadi delta rivers of total length 620 km was declared as National Waterway-5 (NW-5) in the year 2008. National Waterway-6: Lakhipur-Bhanga stretch of 121 km of the Barak River is the 6th waterway. It will result in unified development of the waterways for shipping and navigation and transportation of cargo to the North Eastern Region particularly in the states of Assam, Nagaland, Mizoram, Manipur, Tripura and Arunachal Pradesh. It was accepted as National Waterway in January 2013 by Union Cabinet. Uttar Pradesh has the highest length of inland waterways, followed by West Bengal, Andhra Pradesh, Assam, Kerala and Bihar.

17

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.2.2 Oceanic Routes The oceans are linked with each other and are for most parts negotiable. Ocean transport plays a significant role in international trade. Most of the crude oil from the oil producing countries of the world is exported through oil tankers. The transportation of agro-products, processed foods and manufactured goods including all heavy and bulky goods are moved through ocean routes. 1.2.2.1 Main Ocean Routes of the World North Atlantic Ocean Route: It is one of the busiest sea routes in the world. It is also known as Big Trunk Route. Approx 25 per cent of the ships of the world ply on this route. The main ports of Western Europe are Glasgow and London (U.K.), Rotterdam (Netherlands), Antwerp (Belgium), Ie Havre and Bordeaux (France).Main ports of North America are: Quebec and Montreal (Canada); Boston, New York and Baltimore (U.S.A.). Goods shipped from Europe to Canada and the U.S.A includes manufactured goods like clothes, chemicals, fertilisers, wines etc. From Canada and the U.S.A to Europe, items include food grains, iron and steel, transport equipment etc. Mediterranean-Red Sea-Indian Ocean Route: This route connects Eastern Africa, Southern Asia and countries of Far East to West European countries. This is a very important ocean route of the world. It passes through North Sea, Atlantic Ocean Mediterranean Sea, Red Sea, Arabian Sea, Indian Ocean and South China Sea. The Suez Canal route has reduced the distance 6,400 km. Main Ports include Port Said, Aden, Karachi, Mumbai, Kochi, Colombo, Singapore and Bangkok. Materials moving towards East constitute mainly machines and industrial products etc. while materials moving towards West are raw materials, cotton, tea, coffee, sugar, rubber, petroleum, etc. Cape Ocean Route (Cape of Good Hope Route): Before the opening of Suez Canal Route, Europeans used to pass through this route while visiting India, China and Australia. Still, this route connects Western Africa, South Africa, Australia and New Zealand to Western Europe for trade, these days. Main Ports in this route are London, Lisbon, Cape Town, Adelaide, Melbourne, Sydney, Wellington (New Zealand). Palm-oil, wood, almond and copper are sent to Europe from Africa while wheat, maize, wool, etc. are sent to Africa from Australia. Industrial products are sent from Europe to Africa and Australia. South Atlantic Route: The trade between the countries of South America and Europe is being carried out through this route. Brazil, Argentina, Uruguay are the main countries of South America benefitted by this route. This route is comparatively less important. Quantity of trade is less because of the underdeveloped West African countries. Main Ports on this route include London, Liverpool, Hamburg (Europe) Kingston, Havana (West Indies) Rio-de Janeiro (Brazil, Buenos Aires (Argentina), Montevideo (Uruguay). Materials transported include coffee, rubber, sugar, meat, wool, wheat, are sent from countries of South America and West Indies to Europe. Coal, machines and industrial products are sent from Europe to these countries. North Pacific Ocean Route: This route is used for trade between western regions of North America and Japan; and China and Far East Asia. These ocean routes are lengthy route and lack facilities of harbours and refilling fuels. Main Ports include Yokohama, Tokyo, Shanghai and Manila in East Asia and San Francisco, Seattle and Los Angeles in Western North America. Goods Transported are silk and tea from Japan, wool and different minerals from Australia are sent through this route to North America. In return, North America sends wood, cereals, petroleum and finished goods to Australia, Japan and New Zealand.

18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Major Sea Routes round the world

1.2.2.2 Main Shipping Canals Shipping canals are canals especially intended to accommodate ships used on the oceans, seas or lakes to which it is connected. As opposed to it, a barge canal is intended to carry barges and other vessels specifically designed for river and/or canal navigation. Because of the constraints of accommodating vessels capable of navigating large bodies of open water, a ship canal typically offers deeper water. Ship canals are constructed for a number of reasons which include creating a shortcut and avoiding lengthy detours; to create a navigable shipping link between two land-locked seas or lakes; to provide inland cities with a direct shipping link to the sea; and to provide an economical alternative to other options. List of Important Shipping Canals in the World Canal

Length

Lock depth

Dimension

White Sea – 141 mi Baltic Canal (227 km)

3.5 m (11 ft)

135m × 14.3 m × 3.5m

Rhine-MainDanube Canal

106 mi (171 km)

4m (13 ft)

lock dimensions: 190m x 11.45m x 4m

Suez Canal

120.11 mi (193.30 km)

No locks, 205 m but 24 m (673 ft) wide (79 ft) deep.

19

www.visionias.in

Location

Russia

Germany

Egypt

Notes Opened in 1933, is partly a canalised river, partly an artificial canal, and partly some natural lakes. Shallow depth limits modern vessels from using the canal. Opened in 1992, links the large rivers Rhine and Danube, and thus also the North Sea and the Black Sea. Opened in 1869, links the Mediterranean Sea to the Red Sea. ©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

Volga-Don Canal

62 mi (100 km)

3.5 m (11 ft)

lock dimensions: 140m x 16.6m x 3.5m

Kiel Canal

60 mi (97 km)

14 m (46 ft)

lock dimensions: 310m x 42m x 14m

Houston Ship 56 mi Channel (90 km)

14 m (46 ft)

161 m (528 ft) wide

Panama Canal

25.9 m (85 ft)

lock dimensions: 320m x 33.53m x 25.9 m

Danube40 mi Black Sea (64 km) Canal

5.5 m (18 ft)

lock dimensions: 138m x 16.8m x 5.5m

Manchester Ship Canal

36 mi (58 km)

8.78 m (28.8 ft)

lock dimensions: 170.68m x 21.94m x 8.78m

Welland Canal

43.4 km (27.0 mi)

8.2 m (27 ft)

lock dimensions: 225.5m x 23.8m x 8.2 m

8.2 m (27 ft)

lock Canada dimensions: USA 225.5m x 2.3m x 8.2 m

Saint Lawrence Seaway

51 mi (82 km)

https://t.me/UPSC_PDF

Russia

Opened in 1952, connects the Black, Azov, and Caspian Seas.

Germany

Opened in 1895. Shortens the passage between the North Sea and the Baltic Sea.

USA

Connects Houston, the Gulf of Mexico.

Texas to

Panama

Opened in 1914. Links the Caribbean Sea to the Pacific Ocean, creating a shortcut.

Romania

Opened in 1984. Links the Danube to the Black Sea.

UK

Canada

Opened in 1894. Links the in-land city of Manchester to Irish Sea.

Opened in 1931. Links Lake Erie to Lake Ontario and is part of the Saint Lawrence Seaway.

Links Montreal with Lake Superior.

1.2.2.3 Oceanic Routes in India The coastline of the mainland of India and of the islands is about 7,517 km long. India had a flourishing maritime trade even during the ancient days with East Indies and Middle East countries. The shipping got a setback with the arrival of European companies during the colonial rule. India has 13 major ports and 176 non-major ones. The major ports carry about 3/4th of the total traffic. Despite adequate capacity and handling facilities the average turnaround time of major Indian ports is less than 4 days which is very high compared to the average turnaround time of about 10 hrs in Hong Kong. This undermines the competitiveness of Indian ports. Since the ports are not adequately linked to the Hinterland, the evacuation of CARGO is slow leading to congestion. To this end, all ports trust have set up groups with representatives from the National Highway Authority of India(NHAI), Railways and State Governments to prepare comprehensive plans aimed at improving road-rail connectivity of ports. The NHAI has taken up port connectivity as major component of the National Highways Development Project (NHDP). 20

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.2.2.3.1 PROBLEMS OF SHIPPING IN INDIA The Indian shipping industry is facing a number of problems. Some of them are as under: 1) 2) 3) 4) 5) 6)

Inadequacy of tonnage capacity. Shortage of container fleet. Over-aged vessels resulting in high operation costs. Stiff competition with foreign shipping companies which provide better and cheaper service. Congestion at the major ports, and Inadequate infra-structural support like ship-repair facility, dry-docking and cargo handling.

1.2.3. Major Ports in India The 13 major ports of India handle more than 95 per cent of our foreign trade by volume and 70 per cent by value. The major ports are Kandla, Mumbai, Jawaharlal Nehru (Nhava Sheva), Mormugao, New Mangalore, Kochi, Tuticorin, Chennai, Vishakhapatnam, Paradip, Haldia, Kolkata and Port Blair. Details of some of these ports are as follows1) Kandla: Kandla port was developed soon after independence to make up the loss of Karachi to Pakistan. It is a tidal port and is located at the eastern end of the Rann of Kachchh. It handles the exports and imports for Jammu and Kashmir, Himachal Pradesh, Punjab, Haryana, Delhi, Rajasthan and Gujarat. It handles crude oil, petroleum products, cotton, fertilizers, food grains, cement, sugar, edible oils, scrap, etc. 2) Mumbai: It is the biggest natural harbour on the west coast of India. The opening of Suez Canal in 1869 brought it much closer to the European countries. A new port Nhava Sheva has been developed near Mumbai port. It has decongested traffic at Mumbai port. It handles a large variety of cargo from Middle-East and European countries. It serves as a hub port in this region. 3) Mormugao: Mormugao port is an important port of Goa and handles the iron ore export from India. It is located on the entrance of the Zuari estuary. With the opening of Konkan Railway, its importance has been enhanced and it is working as a multi-commodity port. 4) New Mangalore: It is a new port developed about 9 km north of the old port. The port is well linked with Mumbai and Kanyakumari. The main items of cargo from this port are iron ore, manganese ore, fertilizers, tiles, cement, coffee, cashew nuts, forest products, food grains, etc. 5) Kochi: It is a natural port located along the coast of Kerala and is popularly known as “Queen of the Arabian Sea”. Kochi has sheltered backwater bay, and is open to traffic throughout the year. The main items of export and import are coir goods, copra, coconut oil, tea, rubber, spices, cashew kernels, sea food, chemical fertilizers, etc. The Kochi Oil Refinery receives crude oil from this port. 6) Tuticorin: It has been recently developed along the south-eastern coast of Tamil Nadu. It has an artificial deep sea harbour and is well connected with railways and roads. Main exports and imports are tea, spices, cotton textiles, hides and skins, edible oils, sugar, petroleum products, etc. 7) Chennai: It is the oldest artificial harbour on the east coast of India. It is often hit by cyclones in October and November, making the shipping difficult. It is not suited for large ships due to lesser depth of water. This port mainly handles petroleum products, fertilizers, iron ore, coal, edible oils, machinery, cotton, metals, etc. 8) Vishakhapatnam: It is the deepest, land-locked, protected and the best natural harbour of India. An outer harbour has been developed to handle iron ore and petroleum. It also has the shipbuilding and ship-repair industry. Its main imports and exports are petroleum, fertilizers, chemical, machinery, metals, iron ore, timber, leather goods and food grains. 9) Paradip: It is deep water and all weather port, located about 100 km east of Cuttack. It has the deepest harbour in the country. This port handles iron ore and coal along with some dry cargo. The port is well connected through rail and road with different parts of Orissa. 10) Kolkata-Haldia: It is situated along the Hugli River about 148 km away from sea shore. It is one of the leading ports of India. Its importance has slightly declined due to the development of Paradip and Vishakhapatnam ports. Kolkata is a truncated port and has two dock systems-Kidderpore Docks and Netaji Subhash docks. Recently in 1978, another port Haldia (90 km downstream from Kolkata) has been 21

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

developed, for handling the bulk cargo, and to relieve pressure on the old port. The port handles petroleum, chemicals, edible oils, railway equipment, machinery, tea, sugar, gunnies, leather goods, lac, mica, scrap, etc. 1.2.4 Types of Port Generally, ports are classified according to the types of traffic which they handle. Types of port according to cargo handled: (i) Industrial Ports: These ports specialise in bulk cargo-like grain, sugar, ore, oil, chemicals and similar materials. (ii) Commercial Ports: These ports handle general cargo-packaged products and manufactured goods. These ports also handle passenger traffic. (iii) Comprehensive Ports: Such ports handle bulk and general cargo in large volumes. Most of the world’s great ports are classified as comprehensive ports. 1.2.5 Types of port on the basis of location (i) Inland Ports: These ports are located away from the sea coast. They are linked to the sea through a river or a canal. Such ports are accessible to flat bottom ships or barges. For example, Manchester is linked with a canal; Memphis is located on the river Mississippi; Rhine has several ports like Mannheim and Duisburg; and Kolkata is located on the river Hooghly, a branch of the river Ganga. (ii) Out Ports: These are deep water ports built away from the actual ports. These serve the parent ports by receiving those ships which are unable to approach them due to their large size. Classic combination, for example, is Athens and its out port Piraeus in Greece. 1.2.6 Types of port on the basis of specialised functions (i) Oil Ports: These ports deal in the processing and shipping of oil. Some of these are tanker ports and some are refinery ports. Maracaibo in Venezuela, Esskhira in Tunisia, and Tripoli in Lebanon are tanker ports. Abadan on the Gulf of Persia is a refinery port.

22

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

(ii) Ports of Call: These are the ports which originally developed as calling points on main sea routes where ships used to anchor for refuelling, watering and taking food items. Later on, they developed into commercial ports. Aden, Honolulu and Singapore are good examples. (iii) Packet Station: These are also known as ferry ports. These packet stations are exclusively concerned with the transportation of passengers and mail across water bodies covering short distances. These stations occur in pairs located in such a way that they face each other across the water body, e.g. Dover in England and Calais in France across the English Channel. (iv) Entrepot Ports: These are collection centres where the goods are brought from different countries for export. Singapore is an entrepot for Asia. For e.g. Rotterdam for Europe, and Copenhagen for the Baltic region (v) Naval Ports: These are ports which have only strategic importance. These ports serve warships and have repair workshops for them. Kochi and Karwar are examples of such ports in India. 23

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.3 Air Transport Air transport is the fastest means of movement from one place to the other. It has reduced distances by minimising the travel time. It is very essential for a vast country like India, where distances are large and the terrain and climatic conditions are diverse. Air services can be further classified into two type’s i.e. (i) domestic air services; and (ii) international services. The domestic air services provide air services by transporting passengers and goods from one part to another part within the same country; whereas international services provide connection between two or more countries. 1.3.1 Important Air Routes of the World Generally, all the countries of the world have their own airways. But, air routes are well developed in industrially advanced countries because aeroplanes get more passengers and goods for air transport in these countries. Airlines earn a lot of profit in such countries. Areas of Dense Air routes cover Western Europe, South Eastern Canada and Eastern United States of America and South and South East Asia. Air services for different directions are available at many cities of the world. 1.3.2 Air Transport in India Air transport in India made a beginning in 1911 when airmail operation commenced over a little distance of 10 km between Allahabad and Naini. But its real development took place in post-Independent period. In 1947, there were four companies, namely 1 Indian National Airways; 2 Tata Sons Limited, 3 Air Services of India, and 4 Deccan Airways. The Airport Authority of India is responsible for providing safe, efficient air traffic and aeronautical communication services in the Indian Air Space. The authority manages 125 airports including 11 international, 86 domestic and 29 civil enclaves at defence air fields. To enhance airport infrastructure in India, modernization of existing airport infrastructure in metro and non-metro cities and construction of Greenfield airports were contemplated. The Twelfth Five Year Plan (2012-17) envisages an investment of Rs. 65,000 crore at Indian airports, of which a contribution of about Rs. 50,000 crore is expected from the private sector. The air transport in India was managed by two corporations, Air India and Indian Airlines after nationalisation. Now many private companies have also started passenger services. Air India provides International Air Services for both passengers and cargo traffic. It connects all the continents of the world through its services. Domestic passenger traffic handled at Indian airports reached 106 million during January to November 2012; while the International passenger traffic handled at Indian airports was placed at 37.8 million during JanuaryNovember 2012. International cargo throughput at Indian airports during January-November 2012 was 1.30 MMT as compared to 1.37 MMT during the previous year. Domestic cargo throughput during JanuaryNovember 2012 stood at 0.73 MMT. The Government of India approved a Turn Around Plan (TAP) and a Financial Restructuring Plan (FRP) for improving the operational and financial performance of Air India (AI) in April 2012. The company has taken several initiatives towards cost cutting and revenue enhancement during the year 2011-12, covering route rationalization, phasing out and grounding of old fleet, freezing of employment in non-operational areas, leveraging assets of the company to increase MRO (maintenance, repair, and overhaul) revenue and revenue from the company's real estate properties. The TAP also included operationalization of subsidiary companies in ground handling and MRO and transfer of manpower and equipment so that these could be treated as independent profit centres.

24

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1.4 Pipeline Transport Pipelines were used to supply water cities, factories, etc. till recently. But, nowadays, pipelines are used in transporting liquid materials mainly petroleum and its products, natural gas, slurry of iron ore and coal and even milk. 1.4.1 Advantages of Pipeline Transport The pipeline transport provides many advantages in transport of fluid products across various centres for trade. Their salient features include1) 2) 3) 4) 5)

It is a cheap means of transport for liquid goods. Maintenance expenditure is less as compared to other modes of transport after they are laid. It is possible to lay pipelines even in inaccessible and undulating areas. This mode of transport is not affected by bad weather conditions. There is no problem of leakage, damage and accidents in pipeline transport.

1.4.2 Limitations of Pipeline Transport Following are the main disadvantages of pipeline transport: 1) 2) 3) 4)

It is not flexible, i.e., it can be used only for a few fixed points. Its capacity cannot be increased once it is laid. It is difficult to make security arrangements for pipelines. Underground pipelines cannot be easily repaired and detection of leakage is also difficult.

1.4.3 Distribution of Pipelines in the World The areas of the world with dense network of pipelines are as under: (i) United States of America has dense network of pipelines. Most of the pipelines transport petroleum products and natural gas from the coastal areas like Gulf of Mexico to the consuming areas of north east. The total length of pipelines in USA in 2007 was 8,00,000 km. In Canada (1, 00,000 km) and Mexico (40,016 km), pipelines are also important means of transport. The most famous pipeline of the United States is called 'Big Inch'. It carries mineral oil from oil wells of Gulf of Mexico to north-eastern parts. (ii) In many European countries, petroleum products and natural gas is transported through pipelines. The oil of North Sea is distributed through pipelines on the main land of the continent. Russia in 2007, alone has 2, 44,000 km long pipelines. Pipeline transport is also important in Germany and France. COMECON, 4800 km long is the longest pipeline of the world. It transports mineral oil from Volga and Ural in Russia to East European countries. (iii) Middle East Asia: Oil is transported through pipelines from Saudi Arabia (6550 km), Iraq and other countries to refineries located on the Mediterranean coast. In Iran 9,800 km long pipeline exists. (iv) Central Asia: The oil producing countries of central Asia i.e. Azerbaijan, Turkmenistan and Kazakhstan supply petroleum and natural gas through many pipelines to Turkey and Russia. Thousand kilometres long pipelines are under construction in this region. 1.4.4 Pipeline Transport in India Pipeline transport in India dates back to 1959 when Oil India Limited (OIL) was incorporated as a company. Asia’s first cross country pipeline covering a distance of 1,157 km was constructed by OIL from Naharkatiya oilfield in Assam to Barauni refinery in Bihar. Other extensive network of pipelines has been constructed in the western region of India of which Ankleshwar-Koyali, Mumbai High- Koyali and Hazira-Vijaipur-Jagdishpur (HVJ) are most important. Recently, a 1256 km long pipeline connecting Salaya (Gujarat) with Mathura (U.P.) has been constructed. It supplies crude oil from Gujarat to Punjab (Jalandhar) via Mathura. Some of the important pipelines are briefly described as under: 25

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1. Naharkatia-Nunmati-Barauni Pipeline: This was the first pipeline constructed in India to bring crude oil from Naharkatia oilfield to Nunmati. It was later extended to transport crude oil to refinery at Barauni in Bihar. It is 1,167 km long. It is now extended to Kanpur in U.P. 2. Mumbai High-Mumbai-Ankleshwar-Koyali Pipeline: This pipeline connects oilfields of Mumbai High and Gujarat with oil refinery at Koyali. A 210 km long double pipeline connects Mumbai with Mumbai High. It provides facilities for transporting crude oil and natural gas. Ankleshwar-Koyali pipeline was completed in 1965. It transports crude oil from Ankleshwar oilfield to Koyali refinery. 3. Salaya-Koyali-Mathura Pipeline: An important pipeline has been laid from Salaya in Gujarat to Mathura in U.P. via Viramgram. This is 1,256 km long pipeline which supplies crude oil to refineries at Koyali and Mathura. From Mathura, it has been extended to the oil refinery at Panipat in Haryana and further to Jalandhar in Punjab. It has an offshore terminal for imported crude oil. 4. Hajira-Vijapur-Jagdishpur (HVJ) Gas Pipeline: This pipeline has been constructed by Gas Authority of India Limited (GAIL) to transport gas. It is 1,750 km long and connects Hazira in Maharashtra to Vijapur in M.P. and Jagdishpur in U.P. It carries 18 million cubic metres of gas everyday to three power houses at Kawas (Gujarat), Anta (Rajasthan) and Auraiya (U.P.) and to six fertilizer plants at Bijapur, Sawai Madhopur,. Jagdishpur, Shahjahanpur, Aonla and Babrala. 5. Jamnagar-Loni LPG Pipeline: This 1,269 km long pipeline has been constructed by Gas Authority of India Limited (GAIL) at the cost of Rs. 1,250 crore. It connects Jamnagar in Gujarat to Loni near Delhi in U.P. and passes through the states of Gujarat, Rajasthan, Haryana and U.P. This is the longest LPG pipeline of the world. It is equivalent to transporting 3.5 lakh LPG gas cylinders across 1,269 km every day and its capacity is being increased to 5.0 lakh cylinder per day. 6. Kandla-Bhatinda Pipeline: This 1,331 km long pipeline is proposed to be constructed for transporting crude oil to the proposed refinery at Bhatinda. It is to be constructed by IOC at the estimated cost of Rs. 690 crore.

2. Communication Earlier, means of transport and communication were the same. Transfer of information was done by man or animals or birds. Inventions of telegraph and telephone have given a new shape to communication system. But the revolution in the field of communication came after the invention of radio and television. This has made impossible things possible. Major revolution in communication came when Samuel Morse invented telegraph in 1844. It played a significant role in colonisation of Western America in the 19th century. Invention of telephone in 1975 by Graham Bell and radio in 1894 by Marconi gave new direction to communication. The news was transmitted throughout the world with the help of radio and without using wire. Marconi sent the message across the Atlantic Ocean in 1901. After the fully developed television in 1945, transmission of picture becomes possible. Modern information technology has given many forms to communication. Now, the whole world has come closer together with the help of these communication aids such as cellular phone, E-mail, Fax, Internet, etc. Compared to means of transport, the means of communication have transformed the world into a 'global village'. Internet is today the world's most important means of communication. It has added new dimensions to international trade, banking, remote sensing and other aspects. Today, the Internet is used in a variety of fields like, education, trade, banking, management, industry, communication, health and surgery, scientific research, meteorology, administration and in hundreds of other fields. Internet is a huge reservoir of knowledge. According to one estimate, almost half of the world's population will be connected by internet by 2020. On the basis of scale and quality, the mode of communication can be divided into following categories: a) Personal Communication System and b) Mass Communication System. 26

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

2.1 Personal Communication System Personal Communication System includes use of letters, telephones, telegrams, fax, emails, internet etc. Among the above means, internet is the most widely used and most effective means of communication in urban areas. The network through internet and e-mail provides an efficient access to information at a comparatively low cost. It enables us with the basic facilities of direct communication. In the rural areas, telephones and letters play the role of bridging the people. With the development of technology, internet is expected to soon penetrate in the rural areas too.

2.2 Mass Communication System Mass communication system includes usage of radio, television, cinema, satellite, newspaper, magazine and book, public meetings, seminars and conferences etc. It focuses on a single source transmitting information to a large group of receivers. 2.2.1 Radio Radio broadcasting started in India in 1923 by the Radio Club of Bombay. Since then, it gained immense popularity and changed the socio-cultural life of people. Government brought Radio Broadcasting under its control in 1930 under the Indian Broadcasting System. It was changed to All India Radio in 1936 and to Akashwani in 1957. All India Radio broadcasts a variety of programmes related to information, education and entertainment. With the start of FM radio services in the country, radio has reached new standards in the country. FM broadcasting began on 23 July 1977 in Chennai, then Madras, and was expanded during the 1990s. Times FM (now Radio Mirchi) began operations in 1993 in Ahmedabad. Until 1993, All India Radio or AIR, a government undertaking, was the only radio broadcaster in India. Indian policy currently states that these broadcasters are assessed a One-Time Entry Fee (OTEF), for the entire license period of 10 years. Under the Indian accounting system, this amount is amortised over the 10 year period at 10% per annum. Annual license fee for private players is either 4% of revenue share or 10% of Reserve Price, whichever is higher. 2.2.2 Television (T.V.) Television broadcasting has emerged as the most effective audio-visual medium for disseminating information and educating masses. Initially, the T.V. services were limited Television (T.V.) Television broadcasting has emerged as the most effective audio-visual medium for disseminating information and educating masses. Initially, the T.V. services were limited only to the National Capital where it began in 1959. After 1972, several other centres became operational. In 1976, TV was delinked from All India Radio (AIR) and got a separate identity as Doordarshan (DD). After INSAT-IA (National Television-DD1) became operational, Common National Programmes (CNP) was started for the entire network and its services were extended to the backward and remote rural areas. Asianet was the first private channel in India and also most popular in India. The central government launched a series of economic and social reforms in 1991 under Prime Minister Narasimha Rao. Under the new policies the government allowed private and foreign broadcasters to engage in limited operations in India. This process has been pursued consistently by all subsequent federal administrations. Foreign channels like CNN, STAR TV and private domestic channels such as Zee TV, ETV and Sun TV started satellite broadcasts. Starting with 41 sets in 1992 and one channel, by 1995, TV in India covered more than 70 million homes giving a viewing population of more than 400 million individuals through more than 100 channels.

27

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

There are five basic types of television in India: broadcast or "over-the-air" television, unencrypted satellite or "free-to-air", Direct-to-Home (DTH), cable television, and IPTV. Over-the-air and free-to-air TV is free with no monthly payments while Cable, DTH, and IPTV require a monthly payment that varies depending on how many channels a subscriber chooses to pay for. Channels are usually sold in groups or a la carte. All television service providers are required by law to provide a la carte selection of channels. 2.2.3 Satellite Communication The beginning of era of space in the world took place with the sending of artificial satellite-Sputnik in the space on 4th October, 1957. India has placed its own satellites in orbit for communication and surveying of national resources through remote sensing techniques. This has helped in giving telephone connections to each village. Now, a resident of a small village of India can talk via mobile or satellite phone from his home to his relative or friend sitting in anywhere in the world. Artificial satellites, now, are successfully deployed in the earth’s orbit to connect even the remote corners of the globe with limited onsite verification. These have rendered the unit cost and time of communication invariant in terms of distance. This means it costs the same to communicate over 500 km as it does over 5,000 km via satellite On the basis of configuration and purposes, satellite system in India can be grouped into two: Indian National Satellite System (INSAT) and Indian Remote Sensing Satellite System (IRS). The INSAT is a multipurpose satellite system for telecommunication, meteorological observation and for various other data and programmes. Established in 1983 with commissioning of INSAT-1B, it initiated a major revolution in India’s communications sector and sustained the same later. INSAT space segment consists of 24 satellites out of which 10 are in service (INSAT-3A, INSAT-4B, INSAT-3C, INSAT-3E, KALPANA-1, INSAT-4A, INSAT-4CR,GSAT-8, GSAT-12 and GSAT-10).The system with a total of 168 transponders in the C, Extended C and Ku-bands provides services to telecommunications, television broadcasting, weather forecasting, disaster warning and Search and Rescue operations2. The IRS satellite system became operational with the launching of IRS-IA in March 1988 from Vaikanour in Russia. India has also developed her own Launching Vehicle PSLV (Polar Satellite Launch Vehicle). These satellites collect data in several spectral bands and transmit them to the ground stations for various uses. The National Remote Sensing Agency (NRSA) at Hyderabad provides facilities for acquisition of data and its processing. These are very useful in the management of natural resources.

3. International Trade A transaction of any kind between two or more parties is called trade. It may takes place at two main levels international and national. International trade is the exchange of goods and services among two or more countries of the world. There are various reasons although economic causes like availability and lower price are generally the main cause for international trade to take place. The initial form of trade in primitive societies was the barter system, where direct exchange of goods took place. It was the system prevailing in the beginning and is considered the forerunner of modern trade. The barter system of exchange was a difficult and cumbersome process. One had not only to search for sellers and buyers but also carry a lot of weight amid any season of the year. There were other difficulties as well like making enquiries to find out what was required and what not. All this was overcome with the introduction of money. In the olden times, before paper and coin currency came into being, rare objects with very high intrinsic value

2

For complete list of Indian Communication Satellites, please visit http://en.wikipedia.org/wiki/List_of_Indian_satellites and http://www.isro.org/satellites/allsatellites.aspx

28

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

served as money, like, flint stones, obsidian, cowrie shells, tiger’s paws, whale’s teeth, dogs teeth, skins, furs, cattle, rice, peppercorns, salt, small tools, copper, silver and gold. The Silk Route was an excellent example of early organised international trade between distant lands. The 6,000 km long Silk Route linked Rome to China with other connecting points like India, Persia and Central Asia. The traders transported through this route Chinese silk, Roman wool and precious metals and many other high value commodities. After disintegration of Roman Empire, ascendancy of Europe began in 12th and 13th centuries. Trade flourished along with naval warfare. There was considerable rise in Asian and European trade which helped the discovery of new land including Americas. Fifteenth century onwards, the European colonialism began and along with trade of exotic commodities, a new form of trade emerged which was called slave trade. The Portuguese, Dutch, Spaniards, and British captured African natives and forcefully transported them to the newly discovered Americas for their labour in the plantations. After the Industrial Revolution the demand for raw materials like grains, meat and wool also expanded, but their monetary value declined in relation to the manufactured goods. The industrialised nations imported primary products as raw materials and exported the value added finished products back to the non-industrialised nations. In the later half of the nineteenth century, regions producing primary goods were no more important, and industrial nations became each other’s principle customers. During the World Wars I and II, there were concerns about security, taxes and quantitative restrictions imposed by many countries for the first time. As a result of these concerns organisations like General Agreement for Tariffs and Trade (GATT) later christened the World Trade Organisation (WTO) came into being. Their first task was to work towards reducing tariff, which many countries had imposed. International trade is the result of specialisation in production. It benefits the world economy if different countries practise specialisation and division of labour in the production of commodities or provision of services. Thus, international trade is based on the principle of comparative advantage, complimentarity and transferability of goods and services and in principle, should be mutually beneficial to the trading partners. Trends in Growth in Trade Volumes

3.1 Factors influencing International Trade There are many factors which influence the international trade. Important among these are described below: Inequality in Natural Resources: The distribution of natural resources is uneven in the world. Due to diversity in geological structure, climate, natural vegetation, soil, etc., different types of natural resources are found in different countries. Some countries possess some resources more than their requirement. These countries 29

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

export their products to the countries which are either poor in reserves or do not have any reserve. Hence, inequality in natural resources is the main base of international trade. This inequality is on account of three important reasons: 1) Geological structure: The diversity of relief is influenced by geological structure which is turn determines mineral resources base and diversity of agriculture and crops as well animals raised. For e.g. Lowlands have greater agricultural potential. Mountains attract tourists and promote tourism. 2) Mineral resources: They are unevenly distributed the world over. The availability of mineral resources provides the basis for industrial development. 3) Climate: It influences the type of flora and fauna that can survive in a given region. It also ensures diversity in the range of various products, e.g. wool production can take place in cold regions, bananas, rubber and cocoa can grow in tropical regions. Population factors: Population size, distribution, diversity as well as people's tastes, likes and dislikes determine the type and volume of goods traded. Two important population factors are: a) Cultural factors: Distinctive forms of art and craft develop in certain cultures which are valued the world over, e.g. China produces the finest porcelains and brocades. Carpets of Iran are famous while North African leather work and Indonesian batik cloth are prized handicrafts. b) Size of population: Densely populated countries have large volume of internal trade but little external trade because most of the agricultural and industrial production is consumed in the local markets. Standard of living of the population determines the demand for better quality imported products because with low standard of living only a few people can afford to buy costly imported goods. Stage of Economic Development: At different stages of economic development of countries, the nature of items traded undergoes changes. In agriculturally important countries, agro products are exchanged for manufactured goods whereas industrialised nations export machinery and finished products and import food grains and other raw materials. Extent of foreign investment: Foreign investment can boost trade in developing countries which lack in capital required for the development of mining, oil drilling, heavy engineering, and lumbering and plantation agriculture. By developing such capital intensive industries in developing countries, the industrial nations ensure import of food stuffs, minerals and create markets for their finished products. This entire cycle steps up the volume of trade between nations. Production more than Requirement: Some countries produce more than their requirement because of their favourable environment conditions, technological efficiency and skilled labour. Hence, these countries export their surplus products to other countries. Shortage of Goods: No country is independent in all its requirement of goods. There exists shortage of some or the other goods. For example, Japan has technology for producing best quality steel and other means, but it lacks iron ore and coal. Hence, it overcomes the shortage of raw materials by importing them from India and Australia. Development of Transport and Communication: Transport and communication are the main bases of international trade. Surface, water, air and pipeline transport are required for transferring goods from surplus producing countries to the countries of shortage. Technological Inequality: Some countries have developed some specific type of technology which could not be developed by other countries. For example, United States of America and France have high level technology for building passenger aeroplanes. Other countries of the world purchase aeroplanes from these countries so as to meet their demand. 30

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Trade Policies: Developing countries provide some concessions to exporters for boosting their export e.g. tax concessions, economic aid, etc. Such policies of the government aim to balance the trade in the country's favour or to enhance the foreign currency reserve, because export help to earn more foreign money. Many countries levy heavy taxes on goods of import so as to check their import and promote their local industries. Economic Demand: Notwithstanding these bases, if there is no economic demand of goods, its international trade is impossible in such a situation. A country may have any quantity of surplus production but without demand, it cannot be goods of trade. When it becomes an economic demand, the country tries to procure it.

3.2 Components of International Trade International trade has three very important aspects. These are volume, sectoral composition and direction of trade. Volume of Trade: Volume of trade can be measured in three different ways: (a) Actual tonnage of goods traded; (b) Total volume and value of goods and; (c) Value on per capita basis. However, services traded cannot be measured in tonnage. Therefore, the total value of goods and services traded is considered to be the volume of trade. Composition of Trade: The nature of goods and services imported and exported by countries have undergone changes during the last century. There has been a steady rise in the volume and prices of manufactured goods. On account of rapid growth of trade of manufactured goods there has been rapid growth of manufacturing industries. Thus, the prices of manufactured goods on account of large supplies are coming down. The trend of decrease in prices of manufactured goods is also on account of decrease in tariff barriers under the World Trade Organisation (WTO). Direction of International Trade: Historically, the developing countries of the present used to export valuable goods and artefacts, etc. which were exported to European countries. During the nineteenth century there was a reversal in the direction of trade. European countries started exporting manufactured goods for exchange of foodstuffs and raw materials from their colonies. However, during the second half of the twentieth century, Europe lost its colonies while India, China and other developing countries started competing with developed countries. The nature of the goods traded has also changed.

3.3 Types of International Trade International trade may be categorised into two types: (a) Bilateral trade: Bilateral trade is done by two countries with each other. They enter into agreement to trade specified commodities amongst them. For example, country A may agree to trade some raw material with agreement to purchase some other specified item to country B or vice versa. (b) Multi-lateral trade: As the term suggests multi-lateral trade is conducted with many trading countries. The same country can trade with a number of other countries. The country may also grant the status of the “Most Favoured Nation” (MFN) on some of the trading partners.

3.4 International Pattern of Trade 1) On account of globalisation of agricultural and industrial products, the international trade become highly complex. 2) Fast Growth Rate: The volume of trade is growing very fast. 3) The rate of growth of export trade is almost double that of production rate. 4) The rate of growth of export trade is many times more than the rate of growth of world population. 5) About 25 per cent of world production has now entered international trade.

31

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3.5 Regional Trade Blocs and World Trade Organisation (WTO) In1948, to liberalise the world from high customs tariffs and various other types of restrictions, General Agreement for Tariffs and Trade (GATT) was formed by some countries. In 1994, it was decided by the member countries to set up a permanent institution for looking after the promotion of free and fair trade amongst nation and the GATT was transformed into the World Trade Organisation from 1st January 1995. WTO is the only international organisation dealing with the global rules of trade between nations. It sets the rules for the global trading system and resolves disputes between its member nations. WTO also covers trade in services, such as telecommunication and banking, and others issues such as intellectual rights. Regional Trade Blocs have come up in order to encourage trade between countries with geographical proximity, similarity and complementarities in trading items and to curb restrictions on trade of the developing world. Today, 120 regional trade blocs generate 52 per cent of the world trade. These trading blocs developed as a response to the failure of the global organisations to speed up intra-regional trade. Though, these regional blocs remove trade tariffs within the member nations and encourage free trade, in the future it could get increasingly difficult for free trade to take place between different trading blocs. Major Regional Trade Blocs Regional Blocs ASEAN (Association of South East Asian Nations)

Head Quarters Jakarta, Indonesia

Member Nations

Origin

Commodities

Brunei, Indonesia, Malaysia, Singapore, Thailand, Vietnam, Philippines, Myanmar, Cambodia, Laos

Aug, 1967

Armenia, Azerbaijan, Belarus, Georgia, Kazakhstan, Kyrgyzstan, Moldova, Russia, Tajikistan, Turkmenistan, Ukraine and Uzbekistan. Brussels, Austria, Belgium, Belgium Denmark, France, Finland, Ireland, Italy, the Netherlands, Luxemburg, Portugal, Spain, Sweden and U.K. Montevideo, Argentina, Bolivia, Uruguay Brazil, Columbia, Ecuador, Mexico, Paraguay, Peru, Uruguay and

-

Agro products, rubber, palm oil, rice, copra, coffee, minerals – copper, coal, nickel and tungsten; Energy – petroleum and natural gas and Software products Crude oil, natural gas, gold, cotton, fibre, aluminium

CIS Minsk, (Commonwealth Belarus of Independent States)

EU (European Union)

LAIA (Latin American Integration Association) 32

www.visionias.in

EEC - Agro products, March minerals, 1957 chemicals, wood, EU - paper, transport Feb. vehicles, optical 1992 instruments, clocks - works of art, antiques 1960 -

©Vision IAS

Other areas of co-operation Accelerate economic growth, Cultural development, Peace and regional stability Integration and cooperation on matters of economics, defence and foreign policy

Single market with single currency

-

www.UPSCPDF.com

https://t.me/UPSC_PDF

Venezuela U.S.A., Canada and Mexico

NAFTA (North American Free Trade Association) OPEC (Organisation of Petroleum Exporting Countries)

Vienna, Austria

1994

Algeria, Indonesia, Iran, Iraq, Kuwait, Libya, Nigeria, Qatar, Saudi Arabia, U.A.E. and Venezuela Bangladesh, Maldives, Bhutan, Nepal, India, Pakistan and Sri Lanka

SAFTA (South Asian Free Trade Agreement)

1949

https://t.me/UPSC_PDF

Agro products, motor vehicles, automotive parts, computers, textiles Crude petroleum

Jan2006

-

Coordinate and unify petroleum policies

-

Reduce tariffs on interregional trade

3.6 Balance of Trade Balance of Trade includes all transactions in goods and services including international aid and investments appearing in the current account of a country. By balances of trade we are able to compare the import-export of goods and services into a country. When the value of exported goods of a country exceeds the value of imported goods, it is called positive balance of trade. Contrary to this, if the value of imported goods exceeds the value of exported goods, it is called negative trade balance. Global Top 10 Trading Countries3 Rank

Exporter

Value

Share

1 2 3 4 5 6 7 8 9 10

China USA Germany Japan Netherland France S.Korea Russia Italy Hong Kong

2049 1546 1407 799 656 569 548 528 501 493

11.1 8.4 7.6 4.3 3.6 3.1 3.0 2.9 2.7 2.7

Annual Percentage Change 8 4 -5 -3 -2 -5 -1 1 -4 8

Rank

Importers

Value

Share

1 2 3 4 5 6 7 8 9 10

USA China Germany Japan UK France Netherland Hong Kong S. Korea India

2336 1818 1167 886 690 674 591 553 520 490

12.6 9.8 6.3 4.8 3.7 3.6 3.2 3.0 2.8 2.6

Annual Percentage Change 3 4 -7 4 2 -6 -1 8 -1 5

Values in Billion Dollar and Percentage

3.7 Concerns Related to International Trade International trade is mutually beneficial to nations provided the following conditions are met: 1) 2) 3) 4) 3

It leads to domestic competitiveness and enhances regional specialisation. Increases sales and organisations achieve higher level of production Improves standard of living both through income and employment opportunities. It makes goods and services available globally.

Leading exporters and importers in World merchandise trade, 2012

33

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

5) Through enhancing sales potential there is equalisation of prices and wages. 6) International trade technology leads to diffusion of knowledge and culture.

3.8 Limitations of International Trade The limitations and demerits of the international trade can be studied as follows: 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 12)

It creates a scenario dependence on other countries. More inequalities and uneven levels of development are created. International trade promoted exploitation, and commercial rivalry leading to wars Global trade affects many aspects of life. Through rapid changes in consumption and production pattern, international trade impacts everything from the environment to health and well-being of the people around the world. International trade works to economy's and a company's advantage and leads to more, production and the use of natural resources. It is detrimental to resources' consumption. Resources get used up at a faster rate than they can be replenished. Through increased shipping on account of increase in tourism and trade marine life depletes fast. As a result of exploitation of natural resources forests are being cut down. The river basins and underground water are used sold off to private drinking water companies. There is more pollution on account of expanding business especially by multinational corporations trading in oil, gas mining, pharmaceuticals and agri-business. The norms of sustainable development are neglected as there is more profit maximisation.

3.9 India’s Foreign Trade After moderating in the two years following the global economic crisis, world trade in both goods and services in the financial year 2013-14 reached and surpassed pre-crisis levels in 2011. However, the deceleration in world growth and trade in 2012 and forecast of only a gradual upturn in global growth by international institutions portend a weak and slow recovery for world trade. India's merchandise trade increased exponentially in the 2000s decade from US$ 95.1 billion in 2000-1 to US$ 620.9 billion in 2010-11 and further to US$ 793.8 billion in 2011-12. India's share in

34

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Commodity Composition of India’s Imports

global exports and imports also increased from 0.7 per cent and 0.8 per cent respectively in 2000 to 1.7 per cent and 2.5 per cent in 2011 as per the WTO. Bolstered by the measures taken by the government to help exports in the aftermath of the world recession of 2008 and the low base effect, India's export growth in 2010-11 reached an all time high since Independence of 40.5 per cent. Though it decelerated in 2011-12 to 21.3 per cent, it was still above 20 per cent and higher than the compound annual growth rate (CAGR) of 20.3 per cent for the period 2004-5 to 2011-12. India faced serious food shortage during 1950s and 1960s. The major item of import at that time was food grain, capital goods, machinery and equipments. The balance of payment was adverse as imports were more than export in spite of all the efforts of import substitution. After 1970s, food grain import was discontinued due to the success of green revolution but the energy crisis of 1973 pushed the prices of petroleum, and import budget was also pushed up. Food grain import was replaced by fertilisers and petroleum. Machine and equipment, special steel, edible oil and chemicals largely make the import basket. The export-import ratio highlights the direction of trade between the two countries. Most of the countries want to maintain this ratio greater than one in order to boost their exports and reduce dependency on imports. A look at the trade share and export-import ratio of India with its major trading partners is as follows:

35

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

3.10 Challenges in International Trade for India The challenges for India on the trade front are many. While India has successfully diversified its export basket, more needs to be done on the product diversification front. It also has to reposition itself in its traditional areas of strength like textiles and leather & leather manufactures where it has lost considerable ground, while at the same time making forays into new areas. With multilateral trade negotiations stalled, and RTAs on the rise, India also has to follow a strategic regional trading policy focusing on the potential technology-intensive items in the more important RTAs. Though geopolitical considerations are important, India may have to bargain more in its regional trade negotiations, particularly in cases where livelihood concerns of large pockets of the population are involved, There is also need to address the inverted duty structure in sectors like electronics, textiles, and chemicals and the artificial inverted duty structure caused by some FTAs/RTAs. On the services front, a gold mine of opportunity in sectors like tourism including health tourism is waiting to be tapped. Thus there are many micro, port-specific and sector-specific issues that need urgent attention. These are related to infrastructure, trade facilitation, tax and tariffs, and credit, and can realistically be addressed in the short and medium term. Addressing these issues, as is currently being done by the government, can exponentially promote India's export growth.

36

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

4. Sources i. ii. iii. iv. v. vi. vii. viii. ix. x. xi. xii. xiii.

http://www.nhai.org/roadnetwork.htm Annual Report 2010–11" (PDF). Ministry of Road Transport and Highways, Government of India. p. 1. Retrieved 3 April 2013. http://www.nhai.org/WHATITIS.asp https://sites.google.com/site/roadnumberingsystems/home/route-lists/asian-highways http://en.wikipedia.org/wiki/Asian_Highway_Network http://iwai.nic.in/index1.php?lang=1&level=2&sublinkid=145&lid=164 https://www.un.org/en/development/desa/policy/wesp/wesp_archive/2012chap2.pdf http://www.wto.org/english/res_e/statis_e/its2013_e/its13_toc_e.htm http://comtrade.un.org/db/mr/daYearsGraph.aspx http://en.wikipedia.org/wiki/Association_of_Southeast_Asian_Nations http://en.wikipedia.org/wiki/FM_broadcasting_in_India Economic Survey 2013 NCERT – India People and Economy

xiv. xv. xvi. xvii.

ICSE Geography- Class X - -R K Jain Geography Class XII – Yashpal Singh India- A Comprehensive Geography – D.R. Khullar NCERT – Fundamentals of Human Geography

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 37

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS www.visionias.in GEOGRAPHY: 22

Location of Industries

Contents Factors affecting Location of Industries ..................................................................................................................... 3 Access to Market .................................................................................................................................................... 3 Access to Raw Material .......................................................................................................................................... 3 Access to Labour Supply ......................................................................................................................................... 3 Access to Sources of Energy ................................................................................................................................... 4 Access to Transportation and Communication Facilities........................................................................................ 4 Government Policy ................................................................................................................................................. 4 Access to Agglomeration Economies/Links between Industries ............................................................................ 4 Other miscellaneous factors................................................................................................................................... 4 Primary Activities ........................................................................................................................................................ 5 Hunting and Gathering ........................................................................................................................................... 5 Pastoralism or Animal Rearing ............................................................................................................................... 6 Nomadic Herding ................................................................................................................................................ 6 Commercial Livestock Rearing............................................................................................................................ 6 Agriculture .............................................................................................................................................................. 8 Subsistence Agriculture ...................................................................................................................................... 8 Plantation Agriculture ........................................................................................................................................ 9 Extensive Commercial Grain Cultivation ............................................................................................................ 9 Mixed Farming .................................................................................................................................................. 10 Dairy Farming ................................................................................................................................................... 10 Mediterranean Agriculture ............................................................................................................................... 12 Market Gardening and Horticulture ................................................................................................................. 12 Co-operative Farming ....................................................................................................................................... 12 Collective Farming ............................................................................................................................................ 12 Mining................................................................................................................................................................... 12 1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Manufacturing Activities .......................................................................................................................................... 13 Iron and Steel Industry ......................................................................................................................................... 13 America............................................................................................................................................................. 13 Europe .............................................................................................................................................................. 13 Asia ................................................................................................................................................................... 14 Australia ............................................................................................................................................................ 15 Africa................................................................................................................................................................. 15 Chemical Industry with Special Reference to Petro-chemicals ............................................................................ 15 America............................................................................................................................................................. 16 Europe .............................................................................................................................................................. 16 West Asia .......................................................................................................................................................... 16 India .................................................................................................................................................................. 17 Textile Industry ..................................................................................................................................................... 17

2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Factors affecting Location of Industries The location of industry at a particular place is the result of a number of decisions taken at various levels. There are certain geographical factors which facilitate this decision making. There are other factors which fall outside the subject matter of geography. The validity or importance of a factor also changes with time and space. Industries maximise profits by reducing costs. Therefore, industries should be located at points where the production costs are minimum. Some of the factors influencing industrial locations are as under:

Access to Market The existence of a market for manufactured goods is the most important factor in the location of industries. ‘Market’ means people who have a demand for these goods and also have the purchasing power (ability to purchase) to be able to purchase from the sellers at a place. Many industries are located near large urban centres because the concentration of population in those areas ensures readily available market. Remote areas inhabited by a few people offer small markets. The developed regions of Europe, North America, Japan and Australia provide large global markets as the purchasing power of the people is very high. The densely populated regions of South and South-east Asia also provide large markets. Some industries, such as aircraft manufacturing, have a global market. The arms industry also has global markets.

Access to Raw Material Raw material used by industries should be cheap and easy to transport. Raw materials are the basic requirements for manufacturing industry. Some raw materials lose weight during processing but others do not. Industries based on cheap, bulky and weight-losing material (ores) are located close to the sources of raw material such as steel, sugar, and cement industries. Perishability is a vital factor for the industry to be located closer to the source of the raw material. Agro-processing and dairy products are processed close to the sources of farm produce or milk supply respectively. Many industries do not require much of raw materials and these can be located anywhere independent of raw material sources such as garment and electronic industries. There are some industries which are not wedded to any particular raw material. Such industries are known as foot-loose industries. With the expansion and development of means of transportation the role of raw materials in location of industries has almost lost its significance. The establishment of iron and steel industry in Japan and cotton textile industry in Liverpool prove the fact that the multi-nationals and countries with sufficient capital can manipulate the means of transportation in their favour and obtain raw materials.

Access to Labour Supply Labour supply is an important factor in the location of industries. Two aspects of labour are important for the location of industry. First, the availability of cheap labour in large numbers and second, the level of their skills. For labour intensive industries, cheap labour should be available. Skilled labour is costly but their efficiency and skill compensate for the higher wages. Some industries are located at a particular place due to the availability of skilled labour like electronic industry in Japan, glass industry in Ferozabad (Uttar Pradesh) and utensil industry in Jagadhari and Moradabad.

3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Labour is more mobile than other factors of production. It can be moved from villages to towns, from towns to metropolis, from one industry or place to another or even from one country to the other country. This mobility is namely ascribed to differential wage rates in different situations.

Access to Sources of Energy In the earlier phase of the industrial revolution, the industries were generally located near the source of energy as they have fixed locations. Now, large scale generation of hydroelectric power and ability to transmit at high voltage to far off places and proper distribution over larger areas through grid system have made it possible to take the energy to any location. Thus the dependence of industries for their location on energy resources has considerably reduced. However, some energy intensive industries such as aluminium industry are still located near the energy sources.

Access to Transportation and Communication Facilities Speedy and efficient transport facilities to carry raw materials to the factory and to move finished goods to the market are essential for the development of industries. The cost of transport plays an important role in the location of industrial units. Modern industry is inseparably tied to transportation systems. Improvements in transportation led to integrated economic development and regional specialisation of manufacturing. The means of transportation help in the development of industry. At the same time, after the location of industries at a place, the means of transportation also develop very fast. The concentration of large industries in the Great Lakes region has been caused by cheap means of water transportation provided by the lakes. Almost all large industrial towns in Japan are ports. The cheap water transport has facilitated the development and concentration of Jute mills in the Hoogly valley in India and large industrial towns in the Rhine valley of Europe.

Government Policy Sometimes Government adopt ‘regional policies’ to promote ‘balanced’ economic development and hence set up industries in particular areas.

Access to Agglomeration Economies/Links between Industries Many industries benefit from nearness to a leader-industry and other industries. These benefits are termed as agglomeration economies. Savings are derived from the linkages which exist between different industries.

Other miscellaneous factors Some other factors are crucial for the location of certain industries, for example, the cotton mills were established earlier in the hinterland of Bombay because coastal location provided high humidity in the air. It prevented the yarn from breaking. Now it is possible to maintain the required amount of humidity in the mills with technological intervention. It is therefore, possible to establish spinning mills away from the coast. Water is an important factor in industrial location. It is required in large quantities in cotton textile industry for bleaching and in Iron and steel industry for cooling. It is possible, now, to carry water from one place to the other through pipelines. In certain situations the demand of water is so large that it cannot be met through transportation of water and such establishments are taken to the sources of water such as nuclear reactors. The location of some industries is decided by institutional factors like historical, social and political decisions. Location of industries in backward regions in order to reduce economic disparity and shifting of industries to the

4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

interior parts of a country due to strategic reasons during war are examples of institutional decisions in the location of industries. So, the location of modem industries is not guided by a single factor due to its complex nature. All aspects have to be considered and analysed before deciding location of industries.

Primary Activities Primary activities are directly dependent on environment as these refer to utilisation of earth’s resources such as land, water, vegetation, building materials and minerals. It, thus includes, hunting and gathering, pastoral activities, fishing, forestry, agriculture, and mining and quarrying.

Hunting and Gathering The earliest human beings depended on their immediate environment for their sustenance. They subsisted on: (a) animals which they hunted; and (b) the edible plants which they gathered from forests in the vicinity.

Fig 1. Areas of Gathering Gathering is practised in regions with harsh climatic conditions. It often involves primitive societies, which extract, both plants and animals to satisfy their needs for food, shelter and clothing. This type of activity requires a small amount of capital investment and operates at very low level of technology. The yield per person is very low and little or no surplus is produced. Gathering is practised in:  5

High latitude zones which include northern Canada, northern Eurasia and southern Chile; www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 

www.UPSCPDF.com

https://t.me/UPSC_PDF

Low latitude zones such as the Amazon Basin, tropical Africa, Northern fringe of Australia and the interior parts of Southeast Asia.

In modern times some gathering is market oriented and has become commercial. Gatherers collect valuable plants such as leaves, barks of trees and medicinal plants and after simple processing sell the products in the market.

Pastoralism or Animal Rearing At some stage in history, with the realisation that hunting is an unsustainable activity, human beings thought of domestication of animals. People living in different climatic conditions selected and domesticated animals found in those regions. Depending on the geographical factors, and technological development, animal rearing today is practised either at the subsistence or at the commercial level. Nomadic Herding Nomadic herding or pastoral nomadism is a primitive subsistence activity, in which the herders rely on animals for food, clothing, shelter, tools and transport. They move from one place to another along with their livestock, depending on the amount and quality of pastures and water. A wide variety of animals is kept in different regions. In tropical Africa, cattle are the most important livestock, while in Sahara and Asiatic deserts, sheep, goats and camel are reared. In the mountainous areas of Tibet and Andes, yak and llamas and in the Arctic and sub-Arctic areas, reindeer are the most important animals. Pastoral nomadism is associated with three important regions. The core region extends from the Atlantic shores of North Africa eastwards across the Arabian peninsula into Mongolia and Central China. The second region extends over the tundra region of Eurasia. In the southern hemisphere there are small areas in South-West Africa and on the island of Madagascar. Commercial Livestock Rearing Unlike nomadic herding, commercial livestock rearing is more organised and capital intensive. Commercial livestock ranching is essentially associated with western cultures and is practised on permanent ranches. These ranches cover large areas and are divided into a number of parcels, which are fenced to regulate the grazing. When the grass of one parcel is grazed, animals are moved to another parcel. The number of animals in a pasture is kept according to the carrying capacity of the pasture. New Zealand, Australia, Argentina, Uruguay and United States of America are important countries where commercial livestock rearing is practised.

6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Fig. 2 Areas of Nomadic Herding

Fig. 3 Areas of Commercial Livestock Rearing

7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Agriculture Agriculture is practised under multiple combinations of physical and socio-economic conditions, which gives rise to different types of agricultural systems. The following are the main agricultural systems: Subsistence Agriculture Subsistence agriculture is one in which the farming areas consume all, or nearly so, of the products locally grown. It can be grouped in two categories — Primitive Subsistence Agriculture and Intensive Subsistence Agriculture. Primitive Subsistence Agriculture Primitive subsistence agriculture or shifting cultivation is widely practised by many tribes in the tropics, especially in Africa, south and Central America and South East Asia. The vegetation is usually cleared by fire, and the ashes add to the fertility of the soil. Shifting cultivation is thus, also called slash and burn agriculture. It is prevalent in tropical region in different names, e.g. Jhuming in North eastern states of India, Milpa in Central America and Mexico and Ladang in Indonesia and Malaysia.

Fig. 4 Areas of Primitive Subsistence Agriculture Intensive Subsistence Agriculture This type of agriculture is largely found in densely populated regions of monsoon Asia. There are two types of intensive subsistence agriculture: 1. Intensive subsistence agriculture dominated by wet paddy cultivation: This type of agriculture is characterised by dominance of the rice crop. Land holdings are very small due to the high density of population. 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

2. Intensive subsidence agriculture dominated by crops other than paddy: Due to the difference in relief, climate, soil and some of the other geographical factors, it is not practical to grow paddy in many parts of monsoon Asia. Wheat, soyabean, barley and sorghum are grown in northern China, Manchuria, North Korea and North Japan. In India wheat is grown in western parts of the Indo-Gangetic plains and millets are grown in dry parts of western and southern India.

Fig. 5 Areas of Intensive Subsistence Agriculture Plantation Agriculture Plantation agriculture as mentioned above was introduced by the Europeans in colonies situated in the tropics. Some of the important plantation crops are tea, coffee, cocoa, rubber, cotton, oil palm, sugarcane, bananas and pineapples. The characteristic features of this type of farming are large estates or plantations, large capital investment, managerial and technical support, scientific methods of cultivation, single crop specialisation, cheap labour, and a good system of transportation which links the estates to the factories and markets for the export of the products. The French established cocoa and coffee plantations in west Africa. The British set up large tea gardens in India and Sri Lanka, rubber plantations in Malaysia and sugarcane and banana plantations in West Indies. Spanish and Americans invested heavily in coconut and sugarcane plantations in the Philippines. The Dutch once had monopoly over sugarcane plantation in Indonesia. Extensive Commercial Grain Cultivation Commercial grain cultivation is practised in the interior parts of semi-arid lands of the mid-latitudes. Wheat is the principal crop, though other crops like corn, barley, oats and rye are also grown. This type of agriculture is best developed in Eurasian steppes, the Canadian and American Prairies, the Pampas of Argentina, the Velds of South Africa, the Australian Downs and the Canterbury Plains of New Zealand. 9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Fig 6. Areas of Extensive Commercial Grain Cultivation Mixed Farming Mixed farms are moderate in size and usually the crops associated with it are wheat, barley, oats, rye, maize, fodder and root crops. Fodder crops are an important component of mixed farming. Equal emphasis is laid on crop cultivation and animal husbandry. Animals like cattle, sheep, pigs and poultry provide the main income along with crops. This form of agriculture is found in the highly developed parts of the world, e.g. North-western Europe, Eastern North America, parts of Eurasia and the temperate latitudes of Southern continents. Dairy Farming It is practised mainly near urban and industrial centres which provide neighbourhood market for fresh milk and dairy products. The development of transportation, refrigeration, pasteurisation and other preservation processes have increased the duration of storage of various dairy products. There are three main regions of commercial dairy farming. The largest is North Western Europe the second is Canada and the third belt includes South Eastern Australia, New Zealand and Tasmania.

10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Fig. 7 Areas of Mixed Farming

Fig. 8 Areas of Dairy Farming 11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Mediterranean Agriculture Mediterranean agriculture is highly specialised commercial agriculture. It is practised in the countries on either side of the Mediterranean Sea in Europe and in north Africa from Tunisia to Atlantic coast, southern California, central Chile, south western parts of South Africa and south and south western parts of Australia. This region is an important supplier of citrus fruits. Viticulture or grape cultivation is a speciality of the Mediterranean region. Best quality wines in the world with distinctive flavours are produced from high quality grapes in various countries of this region. Market Gardening and Horticulture Market gardening and horticulture specialise in the cultivation of high value crops such as vegetables, fruits and flowers, solely for the urban markets. Farms are small and are located where there are good transportation links with the urban centre where high income group of consumers is located. This type of agriculture is well developed in densely populated industrial districts of north west Europe, north eastern United States of America and the Mediterranean regions. The Netherlands specialises in growing flowers and horticultural crops especially tulips, which are flown to all major cities of Europe. Co-operative Farming Co-operative societies help farmers, to procure all important inputs of farming, sell the products at the most favourable terms and help in processing of quality products at cheaper rates. Co-operative movement originated over a century ago and has been successful in many western European countries like Denmark, Netherlands, Belgium, Sweden, Italy etc. In Denmark, the movement has been so successful that practically every farmer is a member of a co-operative. Collective Farming The basic principal behind this type of farming is based on social ownership of the means of production and collective labour. Collective farming or the model of Kolkhoz was introduced in erstwhile Soviet Union to improve upon the inefficiency of the previous methods of agriculture and to boost agricultural production for self-sufficiency. The farmers pool in all their resources like land, livestock and labour. However, they are allowed to retain very small plots to grow crops in order to meet their daily requirements. Yearly targets are set by the government and the produce is also sold to the state at fixed prices. Produce in excess of the fixed amount is distributed among the members or sold in the market. The farmers have to pay taxes on the farm produces, hired machinery etc. This type of farming was introduced in former Soviet Union under the socialist regime which was adopted by the socialist countries. After its collapse, these have already been modified.

Mining The use of minerals in ancient times was largely confined to the making of tools, utensils and weapons. The actual development of mining began with the industrial revolution and its importance is continuously increasing. The profitability of mining operations depends on two main factors: 1. Physical factors include the size, grade and the mode of occurrence of the deposits. 2. Economic factors such as the demand for the mineral, technology available and used, capital to develop infrastructure and the labour and transport costs.

12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The developed economies are retreating from mining, processing and refining stages of production due to high labour costs, while the developing countries with large labour force and striving for higher standard of living are becoming more important. Several countries of Africa and few of South America and Asia have over fifty per cent of the earnings from minerals alone.

Manufacturing Activities Manufacturing activities add value to natural resources by transforming raw materials into valuable products. Manufacturing involves the application of power, mass production of identical products and specialised labour in factory settings for the production of standardised commodities. Manufacturing may be done with modern power and machinery or it may still be very primitive. Some of the major manufacturing industries and their locations are discussed below.

Iron and Steel Industry Iron and steel industry is Important in United States of America, Soviet Union, European countries, Australia and India. Japan, South Africa, Brazil and Colombia are other Iron and steel producing countries. Continent wise distribution can be discussed as under: America The Great Lakes region in United States of America is the leading iron and steel producing region. The good quality coke is available from Pennsylvania. Iron ore is brought from the mines of Lake Superior region. Limestone is obtained from the neighbourhood of Alpena located on the western coast of Lake Huron. Water is available in plenty from the local rivers and lakes for cooling. This part of United States is densely populated which ensures large supply of labour. The high density of population and development of iron and steel based industries have created large market in this region. Pittsburgh and Youngtown to the east of the Great Lakes and Chicago and Gary to its west are the major centres of iron and steel industries. There is a great demand for iron and steel in the industrial complexes of Detroit, Toledo and Cleveland as well as the rail industry of Chicago. The demand for iron ore is high in the industries located on the coasts of Lake Erie. It is met from the mines of Lake Superior region and the Labrador mines. They are brought by ships through St. Lawrence Seaway. Iron and steel Industry has also developed in the Atlantic coastal region. Iron ore is imported from Venezuela, Labrador and Chile as the coast location has facilitated the oceanic transport. Alabama is the third important Iron and steel producing region. Birmingham is the most important iron and steel centre of this region. The iron and steel industry in South America is located in Colombia, Venezuela and Brazil. In Colombia, coal is available from Tunza district located north of Bogota, iron ore and limestone is available locally and hydroelectric power is obtained from Toba Lake. In Venezuela, the iron and steel industry is based on the iron ore from El Pao, Serra Bolivar and Dagiana Hills, coal and limestone from Nankol and hydroelectric power from Caroni river. The iron and steel industry in Brazil developed after the Second World War. The main steel plants in Brazil are located are located at Volta Redona, Montevarde and Santos. Chile is also an important steel producing country of South America. Europe The Second World War created a situation before west European nations that they had to turn towards cooperation rather than competing with each other. Six countries joined together to form a cooperative community in 1952. France, Germany, Netherlands, Belgium, Luxembourg and Italy became its members. In 13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

1973, United Kingdom, Ireland and Denmark also joined it. It is known as European Coal and Steel Community. The major objective of the community is to provide facilities for the supply of iron ore and coal to the members of the community without any hindrance. Earlier, iron and steel industry in Europe was closely linked with coal mines but now some industries have moved to the port towns and some have been established near the iron ore mines. The iron and steel industry in Europe has developed in France-Belgium, Loraine (France) – Luxembourg – Saar (Germany), Ruhr (Germany) and north, north-eastern and central parts of United Kingdom. Loraine has the largest iron-ore reserve in Europe. Ruhr region has high quality coking coal. Rhine River and the canal network developed in the region provide cheap water transport. Demand for iron and steel in the local industries is large as most of the west European countries have high level of industrialisation. In United Kingdom some iron and steel industries are located near the coal mines such as Birmingham. Some are located near the iron ore mines such as Fordingham and some are located near the ports like Talbot. Other iron and steel producing countries of Europe are Sweden, Poland and Czechoslovakia. Iron and steel industry has developed in southern Ukraine which is based on the iron ore from Krivoy Rog and Kerch peninsula, coal from Donetsk Basin (Donbas) and local manganese. The Ural region is another important steel producing region of Russia. Iron ore in this region is obtained from Magnet Mountains, coal from Kuznetsk Basin (Kuzbas) and Karaganda basin. Trans-Siberian railway provides surface transport. Sverdlovsk, Magnitogorsk and Nizhny Tagil are major iron and steel centres. Besides these major regions, Iron and steel industry has also been located in Kuzbas and Caucasus region. Asia In Asia, iron and steel industry has developed in Japan, China and India. The iron and steel industry in Japan developed in response to the large demand in engineering, and ship-building industry. This demand accounts for the rapid development of iron and steel industry in Japan in spite of the fact that she neither had large Iron ore deposits nor coal reserves. Kyushu island of Japan has very limited coal reserves. Japan imports large quantities of coke, iron ore, pig iron as well as scrap iron. The iron and steel industry has been located in southern Honshu and northern Kyushu Islands. The history of the development of iron and steel industry in China started in the post revolution period i.e. after 1949, though Japanese had established it at Anshan and Fushan in Manchuria earlier. Besides Manchuria, Shanxi, Shenxi, Hobei and Shandong are the major iron and steel producing provinces.

14

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Fig. 9 World- Iron and Steel industry Three iron and steel plants were established in India before Independence. Two of these were located at Jamshedpur and Kulti -Burnpur based on the iron ore, coal and manganese resources of Bihar, West Bengal and Orissa. Mysore Steel Works at Bhadravati was established by exploiting the iron ore resources of Karnataka. In India, iron ore reserves are located in Keonjhar, Mayurbhanj, Guru Mahisani, Badam Pahar, Bonai and Noamundi. Coal is available from Jharia, Raniganj, Karnpura, Giridhih, Talchir, Singrauli and Korba. Manganese is obtained from Bonai and limestone from Birmitrapur. The high density of population in eastern India provides cheap labour. There is a dense network of rail and roads. Water is available from rivers. The industrial hinterland of Calcutta has large demand for Iron and steel. This is why three Iron and steel plants i.e. Durgapur, Rourkela and Bokaro, have been established in this region after independence. Bhilai was located in backward tribal region in order to reduce the regional imbalance in economic development.. Australia Australian Iron and steel industry is based on the coal found in the Hunter valley of New Castle. It is located on the eastern coast. There is an iron and steel plant at Port Kembla in the south of Sydney. Africa Iron and steel industry has developed in Algeria, Egypt, Zimbabwe and South Africa. South Africa is the major steel producing country in Africa. The industry at Vereeniging utilizes scrap iron and pig iron from Natal.

Chemical Industry with Special Reference to Petro-chemicals Chemical industry is based on two types of raw materials: natural like minerals, coal, petroleum, salts, potash, sulphur, limestone, gypsum and vegetable products and by products of other industries such as paper and pulp industry, iron and steel industry and gas manufacturing industry. Major factor for the location of chemical industry are availability of raw materials, cheaper means of transport for bulky materials, water supply, sources for energy and demand of chemicals in other industries.

15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The major industry based on mineral oil is its refining. The oil refining technology was developed in United States of America, Europe and former USSR. Earlier the refineries were generally located near the oil wells. The petrochemical industry developed in Europe and United States of America after the Second World War. The development of large tankers and pipelines facilitated the transportation of petroleum in bulk and this provided favourable conditions for locating the refineries and petro-chemical industries near the markets as well as ports. America Most of the petro-chemical complexes in North-America are located in the coastal regions. About 30 per cent of the oil in United States of America is refined along the Gulf of Mexico coast and another 15 per cent is refined on the Pacific Coast. The refineries located on the East Coast get crude oil from Venezuela and West Asia. The refined oil is transported from the Gulf Coast to the eastern region through pipelines and to the west by tankers. Petro-chemical complexes have developed in Philadelphia and Delaware in the eastern region and at Chicago and Toledo in the Great Lakes region. Los Angeles has a big petrochemical complex on the western coast of United States. In Canada, Montreal has a large petro-chemical industry. The crude oil is brought from Portland and Maine through pipelines and by tankers from Venezuela. The other important petrochemical complex in Canada is located at Sarnia in Ontario province. After the Second Wold War, a refinery was constructed in the Paraguayan Peninsula of Venezuela which receives crude oil through pipelines from the wells located near Maracaibo Lake. Europe The petro-chemical complexes in Europe are located near the markets where these products are demanded. The major complexes are located on the coasts of Southern North Sea and English Channel. Main centres are Antwerp, Rotterdam, Southampton and the cities located in the lower Sein Valley. The petro-chemical complexes of Germany are located in Ruhr region. The French refineries and petro-chemical complexes are concentrated between Le Havre-Roven and Marseilles including Paris and Lyons. The first petro-chemical complex in former Soviet Union was located at Baku and Grozny because the mineral oil was available from the Caucasian oil fields. New petro - chemical complexes are generally located near the consumption centres. Moscow, Volga, Ural and Soviet Central Asia are the main regions where new petro-chemical complexes have been recently located. West Asia The largest refinery in West Asia is located at Abadan (Iran). West Asia is a large producer of petroleum but there is little demand because the region is not industrially developed. Thus, most of the petrochemical complexes are located on the coasts in order to facilitate export. Saudi Arabia has a large petro-chemical complex at Ras Tanura while Mina-el-Ahmadi is the largest petro-chemical complex of Kuwait.

16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Fig. 10 World-chemical and petrochemical industries India The largest petro-chemical complex In India was established by Union Carbide at Trombay (Mumbai). A petrochemical complex has been developed along with refinery at Koeli in Vadodra. Indian Petro Chemical Corporation has been established under public sector. It has started a petrochemical complex at Jawahar Nagar near Vadodara. Bongaigaon in Assam is another petro-chemical complex under the public sector. Haldia (West Bengal) and Barauni (Bihar) have been established for petro-chemical processing. Three large fertiliser complexes are being developed at Bijaipur, Sawai Madhopur and Jagdishpur by utilising the gas brought through HBJ (Hazira-Bijaipur-Jagdishpur) pipelines. The Mathura refinery has started diversification of products besides refining the oil.

Textile Industry History of industrial development in Japan, India, Brazil and Egypt started with the development of the textile industry. The raw material for textile industry is obtained from hair of animals and vegetation. Wool, silk, cotton and flax etc. are raw materials derived from natural sources. Some raw materials for textile industry have been developed by man using his technological and scientific knowledge e.g. nylon, rayon, terelene, terewool, etc. The technology for manufacturing synthetic fibres has been developed by economically developed countries and therefore, they have monopolised the production of these fibres. United States of America is an important producer of synthetic fibres. Here this industry is located in eastern Pennsylvania and mid-eastern Atlantic coastal region. Recently it has been developed in Virginia and Tennessee states as they have plenty of water and energy resources, besides the reserves of coal. The major synthetic fibre producing countries in Europe are Germany, United Kingdom, Italy, France, Netherlands, Switzerland and Spain. These countries import the pulp from Norway, Sweden and Finland. Japan like United States of America is an important producer of synthetic fibre. This industry is concentrated along with the chemical industry in southern Honshu, Kyushu and Shikoku islands. The softwood from the 17

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Taiga conical forest belt in Russia is an asset to the synthetic fibre industry. This industry is concentrated in the western and mid-northern parts of Ural industrial region because this region lies at the meeting point of chemical industry and the conical forest belt.

Fig. 11 World-textile industry

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS www.visionias.in GEOGRAPHY: 23

Human Development Contents Human Development ................................................................................................................................................. 2 Concept of Development and Indian aspects ........................................................................................................ 2 Measuring Human Development ........................................................................................................................... 2 Human Development Index (HDI) ...................................................................................................................... 2 Other Multi-dimensional measures of Human Development ................................................................................ 3 Inequality adjusted HDI (IHDI) ........................................................................................................................... 3 Gender Inequality Index (GII) ............................................................................................................................. 4 Multi-Dimensional Poverty Index (MPI) ............................................................................................................. 4 Human Development in India................................................................................................................................. 5 India Human Development Report 2011................................................................................................................ 6 Human Development Index................................................................................................................................ 6 Income Index ...................................................................................................................................................... 7 Education Index .................................................................................................................................................. 8 Health Index ....................................................................................................................................................... 9 Planning and Development .................................................................................................................................. 11

1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Human Development Human development is a process of enlarging the range of people’s choices, increasing their opportunities for education, health care, income and empowerment and covering the full range of human choices from a sound physical environment to economic, social and political freedom. Thus, enlarging the range of people’s choices is the most significant aspect of human development. People’s choices may involve a host of other issues, but, living a long and healthy life, to be educated and have access to resources needed for a decent standard of living including political freedom, guaranteed human rights and personal self-respect, etc. are considered some of the non-negotiable aspects of the human development.

Concept of Development and Indian aspects It is believed that “Development is freedom” which is often associated with modernisation, leisure, comfort and affluence. In the present context, computerisation, industrialisation, efficient transport and communication network, large education system, advanced and modern medical facilities, safety and security of individuals, etc. are considered as the symbols of development. Every individual, community and government measures its performance or levels of development in relation to the availability and access to some of these things. But, this may be partial and one-sided view of development. It is often called the western or euro-centric view of development. For a postcolonial country like India, colonisation, marginalisation, social discrimination and regional disparity, etc. show the other face of development. Thus, for India, development is a mixed bag of opportunities as well as neglect and deprivations. There are a few areas like the metropolitan centres and other developed enclaves that have all the modern facilities available to a small section of its population. At the other extreme of it, there are large rural areas and the slums in the urban areas that do not have basic amenities like potable water, education and health infrastructure available to majority of this population. The situation is more alarming if one looks at the distribution of the development opportunities among different sections of our society. It is a well-established fact that majority of the scheduled castes, scheduled tribes, landless agricultural labourers, poor farmers and slums dwellers, etc. are the most marginalised lot. A large segment of female population is the worst sufferers among all. It is also equally true that the relative as well as absolute conditions of the majority of these marginalised sections have worsened with the development happening over the years. Consequently, vast majority of people are compelled to live under abject poverty and subhuman conditions.

Measuring Human Development Most systematic effort towards measuring Human Development was the publication of the First Human Development Report by United Nations Development Programme (UNDP) in 1990. Since then, UNDP has been bringing out World Human Development Report every year. This report does not only define human development, make amendments and changes its indicators but also ranks all the countries of the world based on the calculated scores. Human Development Index (HDI) The first Human Development Report introduced a new way of measuring development by combining indicators of life expectancy, educational attainment and income into a composite human development index, the HDI. The breakthrough for the HDI was the creation of a single statistic which was to serve as a frame of reference for both social and economic development. The HDI sets a minimum and a maximum for each dimension, called

2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

goalposts, and then shows where each country stands in relation to these goalposts, expressed as a value between 0 and 1.

Figure 1. Components of HDI The education component of the HDI is measured by mean of years of schooling for adults aged 25 years and expected years of schooling for children of school entering age. Mean years of schooling is estimated based on educational attainment data from censuses and surveys available in the UNESCO Institute for Statistics database and Barro and Lee (2010) methodology. Expected years of schooling estimates are based on enrolment by age at all levels of education and population of official school age for each level of education. Expected years of schooling is capped at 18 years. The education index is the geometric mean of two indices. The decent standard of living component is measured by GNI per capita (PPP$). The HDI uses the logarithm of income, to reflect the diminishing importance of income with increasing GNI. The life expectancy at birth component of the HDI is calculated using a minimum value of 20 years and maximum value of 83.57 years. The scores for the three HDI dimension indices are then aggregated into a composite index using geometric mean. Given the imperfect nature of wealth as gauge of human development, the HDI offers a powerful alternative to GDP and GNI for measuring the relative socio-economic progress at national and sub-national levels. Comparing HDI and per capita income ranks of countries, regions or ethnic groups within countries highlights the relationship between their material wealth on the one hand and their human development on the other.

Other Multi-dimensional measures of Human Development To obtain a full picture of the evolution of human development, one must go beyond the dimensions in the HDI. Significant aggregate progress in health, education and income is qualified by high and persistent inequality, unsustainable production patterns and disempowerment of large groups of people around the world. In the most notable innovations in the 20th anniversary year of Human Development Report, three new multidimensional measures of inequality and poverty were introduced. Inequality adjusted HDI (IHDI) The 2010 Report introduced the Inequality-adjusted HDI (IHDI), a measure of the level of human development of people in a society that accounts for inequality. Under perfect equality the IHDI is equal to the HDI, but falls below the HDI when inequality rises. In this sense, the IHDI is the actual level of human development (taking into account inequality), while the HDI can be viewed as an index of the potential human development that could be achieved if there is no inequality. 3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The IHDI takes into account not only a country’s average human development, as measured by health, education and income indicators, but also how it is distributed. IHDI accounts for inequalities in life expectancy, schooling and income, by “discounting” each dimension’s average value according to its level of inequality. The difference between the HDI and the IHDI measures the “loss” in potential human development due to inequality. Gender Inequality Index (GII) The disadvantages facing women and girls are a major source of inequality. All too often, women and girls are discriminated against in health, education and the labour market — with negative repercussions for their freedoms. The GII is unique in including educational attainment, economic and political participation and femalespecific health issues and in accounting for overlapping inequalities at the national level.

Figure 2. Components of GII Like the IHDI, the GII captures the loss of achievement in key dimensions due to gender inequality. It ranges from 0 (no inequality in the included dimensions) to 1 (complete inequality). The GII increases when disadvantages across dimensions are associated—that is, the more correlated the disparities between genders across dimensions, the higher the index. Multi-Dimensional Poverty Index (MPI) The dimensions of poverty go far beyond inadequate income—to poor health and nutrition, low education and skills, inadequate livelihoods, bad housing conditions, social exclusion and lack of participation. The Multidimensional Poverty Index (MPI) complements money-based measures by considering multiple deprivations and their overlap. The index identifies deprivations across the same three dimensions as the HDI and shows the number of people who are multi-dimensionally poor and the number of deprivations with which poor households typically contend.

4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 3. Dimensions of MPI

Human Development in India The Human Development Report of the United Nations Development Programme (UNDP) for 2013, released on Thursday, puts India’s HDI value for the last year at 0.554, placing it in the medium human development category. India has been ranked 136 among 187 countries evaluated for human development index (HDI).

Figure 4. HDI progress of India On the positive side, India’s HDI value went up from 0.345 to 0.554 between 1980 and 2012, an increase of 61 per cent or an average annual increase of 1.5 per cent. Life expectancy at birth increased by 10.5 years, mean years of schooling by 2.5 years and expected years of schooling by 4.4 years. Importantly, the gross national income (GNI) per capita went up 273 per cent, the report says. There is a word of appreciation for India for its policies on internal conflicts. “India has shown that while policing may be more effective in curbing violence in the short term, redistribution and overall development are better strategies to prevent and contain civil unrest in the medium term,” the report says, referring to Operation Green Hunt launched against Maoists, which has come under sharp criticism from human rights activists within the country. The other initiatives that have been lauded are the right to education and the rural employment guarantee scheme that provides up to 100 days of unskilled manual labour to eligible poor at a statutory minimum wage. “This initiative [the job guarantee scheme] is promising because it provides access to income 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

and some insurance for the poor against the vagaries of seasonal work and affords individual the self-respect and empowerment associated with work.” Despite India’s progress, its HDI of 0.554 is below the average of 0.64 for countries in the medium human development group, and of 0.558 for countries in South Asia. From South Asia, countries which are close to India’s HDI rank and population size are Bangladesh and Pakistan with HDIs ranked 146 each. But the report points out that the ranking masks inequality in the distribution of human development across the population. Even on the Gender Inequality Index — India has been ranked 132nd among the 148 countries for which data is available. In India, only 10.9 per cent of the parliamentary seats are held by women, and 26.6 per cent of adult women have reached a secondary or higher level of education, compared with 50.4 per cent of their male counterparts. For every 100,000 live births, 200 women die of causes related to pregnancy, and female participation in the labour market is 29 per cent, compared with 80.7 per cent for men. As for the Multidimensional Poverty Index (MPI), India’s value averages out at 0.283, a little above Bangladesh’s and Pakistan’s. The figures for evaluating MPI have been drawn from the 2005-06 survey, according to which 53.7 per cent of the population lived in multidimensional poverty, while an additional 16.4 per cent were vulnerable to multiple deprivations. The values of various indicators for India are: 1. 2. 3. 4. 5. 6.

Life expectancy at birth (Health) – 65.8 years Mean years of schooling (Education) – 4.4 years GNI per capita in PPP terms (Income) – 3285 dollars Inequality adjusted HDI – 0.392 Gender Inequality Index – 0.610 Multi-Dimensional Poverty Index – 0.283

India Human Development Report 2011 The purpose of this report is to capture the progress in human development at the state level in India. In order to do this, three indices are constructed—the Health Index, the Education Index, and the Income Index. The Health Index is constructed using life expectancy at birth, which is indicative of a long and healthy life and is the most comprehensive indicator of the state of health of the population. To construct the Education Index, the two indicators used are ‘adjusted mean years of schooling’ and ‘literacy rate for population 7 years and above’. These indicators are expected to reflect people’s ability to acquire education and knowledge, which are important components of human development. To construct the Income Index, the mean per capita expenditure (at 1999–2000 prices) weighted by the Gini coefficient of inequality of consumption expenditure is taken for each state. The findings of the report for different indicators are discussed as under: Human Development Index The states that perform better on health and education outcomes are also the states with higher HDI and thus higher per capita income. Most of the states that are performing low on human development outcomes are concentrated in the northern and central belt.

6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 5. HDI across states (2007-08) The highest HDI (0.79) is for Kerala, followed by Delhi and Himachal Pradesh. Fourteen states and the northeastern states (excluding Assam) have an HDI higher than the national average, that is, Andhra Pradesh, Uttarakhand, West Bengal, Karnataka, Gujarat, Jammu & Kashmir, Haryana, Tamil Nadu, Maharashtra, the northeastern states excluding Assam, Punjab, Goa, Himachal Pradesh, Delhi, and Kerala. Eight states (Chhattisgarh, Orissa, Bihar, Madhya Pradesh, Jharkhand, Uttar Pradesh, Rajasthan, and Assam), again listed in ascending order, have an HDI value below the national average of 0.47. Except for Rajasthan, these are also the states with a low Income Index reflecting a lower standard of living. Income Index The lowest standard of living as highlighted by the Income Index is evident in the poorer states like Assam, Bihar, Chhattisgarh, Jharkhand, Madhya Pradesh, Orissa, and Uttar Pradesh . These are also the states that have high concentrations of the marginalized groups like SCs, STs, and Muslims.

7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 6. Income Index across various states (2007-08) These states have incomes below the national average, with Bihar having the lowest income per capita. This is also reflected in the lowest monthly per capita consumption expenditure (MPCE) adjusted for inflation and inequality for the state. Yet, what is worth highlighting is that these poorer states, despite low absolute incomes, have witnessed high Net State Domestic Product (NSDP) growth rates (especially Bihar, Chhattisgarh, Orissa, and Uttarakhand which had growth rates above 10 per cent per annum). The change in the Income Index between 1999–2000 and 2007–8 is almost the same as the change in the HDI over the same period for India (that is, 21 per cent). Education Index The Education Index, defined as the arithmetic mean of adjusted mean years of schooling index and literacy rate index, has seen a very impressive improvement for all states. Education Index for India has improved by 28 per cent between 1999 and 2000 and 2007–8, that is, much more than the Income Index..

8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 6. Education Index across states Even in the relatively poorer states like Assam, Chhattisgarh, Orissa, Madhya Pradesh, and Uttarakhand the Education Index is above 0.5. The north-eastern states have been good performers despite low levels of income. This highlights the fact that income is not a necessary condition for improvement in educational outcomes The improvement of 28.5 per cent in the Education Index during the period 1999–2000 to 2007–8 has driven the HDI for the country upwards. Again, as with the Income Index, the improvement in the Education Index has been the greatest in the educationally backward and poorer states of India—Uttar Pradesh, Rajasthan, Orissa, Madhya Pradesh, Andhra Pradesh, Chhattisgarh, Bihar, Uttarakhand, and Jharkhand— listed here in ascending order of the improvement in the Education Index. The improvement in the educationally backward states suggests a strong trend of convergence across the states in terms of outputs and outcomes. Health Index The Health Index is defined in terms of life expectancy at birth since a higher life expectancy at birth reflects better health outcomes for an individual.

9

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Figure 7. Health Index across states The improvement in the Health Index for India between 1999–2000 and 2007–8 was much lower than both the Income Index and the Education Index. The improvement in the Health Index during the period 1999–2000 to 2007–8 (13 per cent) is well below the improvement in the overall HDI of the country. In other words, while the Income Index has improved at the same rate as the HDI, and the Education Index by much more than the improvement in the HDI, the Health Index has not shown any significant change. There are already well-known cases of success in building an effective public health system in several states of India (for example, Kerala and Tamil Nadu). With the best public health system in the country Kerala has the highest life expectancy at birth. What is worth mentioning is that Bihar, the state that ranks the lowest in terms of almost all human development indicators, has a life expectancy at birth at par with the national average. Similarly, the relatively poorer state of Rajasthan performs marginally better than the national average. The north-eastern states, excluding Assam, have a higher life expectancy at birth compared to the national average. It is the states with the most serious health outcome indicators and the worst health process/input indicators, which have shown the most improvement over this period, namely, Madhya Pradesh, Uttar Pradesh, Orissa, and Assam. Overall the states’ policies play a crucial role in shaping the nature of the development process. How inclusive the development process is for all the social groups residing in the state is a reflection of the state’s commitment 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

towards various dimensions of human welfare. This is supported by the success of social mobilization states like Tamil Nadu, Kerala, and the north-eastern states, where strong state commitment resulted in the upliftment of the backward castes such that their performance in health and education indicators is even better than the upper castes in most of the other states.

Planning and Development There are two approaches to planning, i.e. sectoral planning and regional planning. The sectoral planning means formulation and implementation of the sets of schemes or programmes aimed at development of various sectors of the economy such as agriculture, irrigation, manufacturing, power, construction, transport, communication, social infrastructure and services. There is no uniform economic development over space in any country. Some areas are more developed and some lag behind. This uneven pattern of development over space necessitates that the planners have a spatial perspective and draw the plans to reduce regional imbalance in development. This type of planning is termed as regional planning. In order to arrest the accentuation of regional and social disparities, the Planning Commission introduced the ‘target area’ and target group approaches to planning. Some of the examples of programmes directed towards the development of target areas are Command Area Development Programme, Drought Prone Area Development Programme, Desert Development Programme, Hill Area Development Programme, etc.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 11

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

VISIONIAS www.visionias.in GEOGRAPHY: 24

Summary: Human Development Report – 2014 Theme: 2013 The Rise of the South: Human Progress in a Diverse World 2014 Sustaining Human Progress: Reducing Vulnerability and Building Resilience “Human progress is neither automatic nor inevitable”- Martin Luther King

What is HDR? The Human Development Report (HDR) published by the United Nations Development Programme (UNDP), is an annual report which measures of human development across the globe.

How is human development measured? Human development is measured in terms of 5 indices: 1. 2. 3. 4. 5.

Human Development Index Inequality adjusted Human Development Index Gender Inequality Index Gender Development index Multi-dimensional Poverty Index

Each Index has been explained as follows.

1. Human Development Index Calculated in terms of 3 parameters: 1. To live a long and healthy life (Life expectancy at birth) 2. To be educated and knowledgeable (Mean years of schooling + Expected years of schooling) 3. To enjoy a decent standard of living (Per capita Gross National Income, Purchasing Power Parity adjusted) =

(



×

×

)

HDI of some countries: 1

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF Very High Ranking countries (≥0.800)

High Ranking countries (≥0.700)

1. Norway 2. Australia 47. Croatia 49. Argentina

57. Russia 73. Sri Lanka 79. Brazil 83. Ukraine 91. China

https://t.me/UPSC_PDF

Medium Ranking countries (>0.550) 107. Palestine 118. South Africa 135. India 136. Bhutan 142. Bangladesh

Low Ranking countries

146. Pakistan 169. Afghanistan 186. Congo 187. Niger

2014 vs 2013- A comparison for India: Parameters (India) HDI HDI Ranking Life expectancy at birth Mean years of schooling GNI per capita $ Points to note:     

2013 data 0.586 135 66.4 4.4 years 5150

2012 data 0.554 136 65.8 years 3285

Global (2013) 0.702 70.8 years 7.7 years 13723

India’s ranking has improved by 1. All other BRICS countries fare better than India Neighbours like Sri Lanka and Bangladesh, as well as a war-torn state like Palestine fare better than India. A total of 187 countries have been ranked. Some countries have not been included In HDI report 2014- Somalia, North Korea are among them

Related Terms explained: Life expectancy at birth: Number of years a newborn infant could expect to live if prevailing patterns of agespecific mortality rates at the time of birth stay the same throughout the infant’s life. Mean years of schooling: Average number of years of education received by people ages 25 and older, converted from education attainment levels using official durations of each level. Expected years of schooling: Number of years of schooling that a child of school entrance age can expect to receive if prevailing patterns of age-specific enrolment rates persist throughout the child’s life. Gross national income (GNI) per capita: Aggregate income of an economy generated by its production and its ownership of factors of production, less the incomes paid for the use of factors of production owned by the rest of the world, converted to international dollars using PPP rates, divided by midyear population

2. Inequality adjusted HDI HDI value adjusted for inequalities in the three basic dimensions of human development India’s ranking: Same rank, but HDI value is 0.418 (% difference over HDI=28.6) Gini coefficient for India= 33.9 Related Terms explained: Quintile ratio: Ratio of the average income of the richest 20% of the population to the average income of the poorest 20% of the population.

2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Palma ratio: Ratio of the richest 10% of the population’s share of gross national income (GNI) divided by the poorest 40%’s share. Middle class incomes almost always account for about half of GNI and that the other half is split between the richest 10% and poorest 40%, though their shares vary considerably across countries. Gini coefficient: Measure of the deviation of the distribution of income among individuals or households within a country from a perfectly equal distribution. A value of 0 represents absolute equality, a value of 100 absolute inequality.

3. Gender Development Index A composite measure reflecting disparity in human development achievements between women and men in three dimensions—health, education and living standards =



∶



Ranks of some countries: 1. Slovakia (GDI= 1.00) 2. Argentina 132. India (GDI= 0.828) 148. Afghanistan (lowest rank) Points to note: 

    

It is distribution sensitive. Distribution sensitive means that the GDI takes into account not only the average or general level of well-being and wealth within a given country, but focuses also on how this wealth and well-being is distributed between different groups within society. The GDI cannot be used independently from the Human Development Index (HDI) score and so, it cannot be used on its own as an indicator of gender-gaps. Introduced this year for the first time BRICS ranking- Russia> Brazil> China> South Africa> India While the overall gender gap is an 8% deficit for women, the income gap is shockingly high — per capita income for men is more than double that for women. There are 16 countries where the female HDI is ≥ male HDI (includes Russian federation, Uruguay, Ukraine)

4. Gender Inequality Index A composite measure reflecting inequality in achievement between women and men in three dimensions: reproductive health, empowerment and the labour market. Range= 0-1 [0= zero inequality; 1=100% inequality] Ranks of some countries: 1. Slovenia (0.021) 2. Switzerland 127. India 127. Pakistan

3

www.visionias.in

©Vision IAS

www.UPSCPDF.com

https://t.me/UPSC_PDF

https://t.me/UPSC_PDF

Related Terms explained: Maternal mortality ratio: Number of deaths due to pregnancy-related causes per 100,000 live births. Adolescent birth rate: Number of births to women ages 15–19 per 1,000 women ages 15–19. Labour force participation rate: Proportion of a country’s working-age population (ages 15 and older) that engages in the labour market, either by working or actively looking for work, expressed as a percentage of the working-age population. Points to be noted:  

China> Russia> Brazil> South Africa In the 2010 Human Development Report, another alternative to the Gender-related Development Index (GDI), namely, the Gender Inequality Index (GII) was proposed in order to address some of the shortcomings of the GDI.

5. Multidimensional Poverty Index Percentage of the population that is multi-dimensionally poor adjusted by the intensity of the deprivations. MPI was developed in 2010 by Oxford Poverty & Human Development Initiative and the UNDP. It uses different factors to determine poverty beyond income-based lists. It replaced the previous Human Poverty Index. The index uses the same 3 dimensions as the HDI: health, education, and standard of living. These are measured using ten indicators.

Dimension

Indicators 1. 2.

Health Education

Child Mortality Nutrition Years of school Children enrolled

3. 4.

Cooking fuel Toilet Water Electricity Floor Assets

5. 6. 7. Living Standards 8. 9. 10.

=

×

H: Percentage of people who are MPI poor (incidence of poverty) A: Average intensity of MPI poverty across the poor (%) Country India China Brazil

% population living in multidimensional poverty 55.3 6 3.1

Points to be noted:  4

Overall 2.2 billion people are either near or living in multi-dimensional poverty (suffering deprivations in 33.33% of weighted indicators). www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF  

www.UPSCPDF.com

https://t.me/UPSC_PDF

MPI is calculated for only 104 countries Both HDI and MPI has been criticized by economist such as Ratan Lal Basu for lack of "Moral/Emotional/Spiritual Dimensions" of poverty. The same has been captured by "Global Happiness Index" in which a country like Bhutan (which has dismal performance on other indicators) has been ranked no.1.

Overall: Slowdown in human development- Though human development levels continue to rise across the world, the rate of this growth has slowed and the spread has been very uneven. It is a result of the lingering global economic crisis that has caused a dip in income growth in Europe, Arab countries, and Central Asia. HDI parameters- Life expectancy at birth has increased due to lower IMR and child mortality, fewer deaths due to HIV/AIDS and better nutrition. Education levels have risen on stronger investments and political commitment. Multidimensional poverty has been considerably reduced, though wide variation across countries and regions remains. Nearly 80% of the global population lack social protection, while 12% (842 million people) suffer from chronic hunger – and nearly half of all workers across the world are in informal or precarious employment. Inequality has declined in health access, remained constant in education but increased by two percentage points with respect to income. Vulnerability- “Vulnerability is not the same as poverty. It means not lack or want but defencelessness, insecurity and exposure to risks, shocks and stress.” —Robert Chambers The Report considers the way in which vulnerabilities change during our lives—by taking a ‘life cycle approach’. Unlike more static models, this analysis suggests that children, adolescents and the elderly each face different sets of risks which require targeted responses. Some periods of life are identified as particularly important: for example, the first 1,000 days of a child’s life or the transition from school to work or from work to retirement. Setbacks at these points can be particularly difficult to overcome and may have prolonged impacts.

Who is vulnerable to what and why?

To what

Who Thepoor, informal workers, socially excluded

Economic shocks, health shocks

Limited capabilities

Women, people with disabilities, migrants, minorities, children, the elderly, youth

Natural disasters, climate change, industrial hazards

Location, position in society, sensitive periods in the life cycle

Conflict, civil unrest

Low social cohesion, unresponsive institutions, poor governance

Whole communities, regions

5

Why

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Although poverty is declining overall, almost 800 million people are at risk of falling back into poverty if setbacks occur. The report notes that threats such as financial crises, fluctuations in food prices, natural disasters and violent conflict significantly impede progress. Resilience- At its core, resilience is about ensuring that state, community and global institutions work to empower and protect people. The report advocates for the universal provision of basic social services to enhance resilience. It refutes the notion that only wealthy countries can afford to do this. Countries such as Republic of Korea, and developing countries such as Costa Rica started putting in place measures of social insurance when their Gross Domestic Product (GDP) per capita was lower than India’s and Pakistan’s now.

6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Responsive and accountable institutions of governance are critical to overcoming the sense of injustice, vulnerability and exclusion that can fuel social discontent. The report calls for “an international consensus on universal social protection” to be included in the post-2015 development goals agenda. The idea that everyone has the universal right to education and healthcare! The report urges a three-fold policy path to get the world out of the morass it is stuck in: universal provision of social services, stronger social protection and a return to 100% employment policies. All these would require a strong and active role of the state.

With respect to India: India has worked towards disaster management is reflected when cyclone Phailin struck in Oct 2013 and advanced evacuation was possible. Thus reducing vulnerability due to natural disasters. In 2013, India witnessed a historic transition from the famine conditions of 1943 to a legal commitment to provide, at a very low cost, the minimum essential calories to over 75 percent of the population from home grown food. India’s MGNREGA is a promising employment initiative. A rarely heard criticism of the NREGA is that the easy availability of work may discourage workers from moving to more-productive sectors of the economy, thus harming longer term growth prospects. Improving accountability through transparency measures such as India’s Right to Information Act can expose corruption and graft and boost efficiency. Persistent vulnerability is rooted in historic exclusions—women in patriarchal societies, Dalits in India encounter discrimination and exclusion. India’s failure to transition from primary to industry has to be remedied—jobs in business process outsourcing are a boon for the balance of payments but hardly for mass employment.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 7

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

VISIONIAS z™ www.visionias.in www.visionias.wordpress.com GEOGRAPHY: 25

G. S. III – ECONOMIC GEOGRAPHY

 Agricultural Marketing: Issues and Related Constraints  Agricultural Transportation: Issues and Related Constraints  e-Agriculture : e-Technology in The Aid of Farmers

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 1

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Agricultural Marketing: Issues and Related Constraints Contents          

  

Introduction Characteristics of Agricultural Product Importance and Objectives of Agricultural Marketing Facilities Needed for Farmer in Marketing Methods of Sale and Marketing Agencies Existing Systems of Agricultural Marketing in India Ideal Marketing System Principles of Scientific Marketing for Farmers Impact of Globalization: Contract Marketing Government Measures to Improve Agricultural Marketing ◦ Marketing surveys ◦ Rural Godown Scheme ◦ Grading and Standardization ◦ Marketing Research & Information Network ◦ AgmarkNet ◦ National Agricultural Market Atlas (NAMA) ◦ CCS National Institute Of Agricultural Marketing, Jaipur ◦ Terminal Market Complexes ◦ Organization of Regulated Markets ◦ Central Warehousing Corporation ◦ Directorate of Marketing and Inspection ◦ Government Purchases and Fixation of Support Prices Problems in Agricultural Marketing Suggestions to Improve Agricultural Marketing Conclusion

Introduction The term agricultural marketing is composed of two words -agriculture and marketing. Agriculture, in the broadest sense means activities aimed at the use of natural rural resources for human welfare, and marketing connotes a series of activities involved in moving the goods from the point of production to the point of consumption. Specification, the subject of agricultural marketing includes marketing functions, agencies, channels, efficiency and cost, price spread and market integration, producer’s surplus etc. The agricultural marketing system is a link between the farm and the non-farm sectors. In India Agriculture was practiced formerly on a subsistence basis; the villages were self sufficient, people exchanged their goods, and services within the village on a barter basis. With the development of means of transport and storage facilities, agriculture has become commercial in character; the farmer grows those crops that fetch a better price. Marketing of agricultural produce is considered as an integral part of agriculture, since an agriculturist is encouraged to make more investment and to increase production. Thus there is an increasing awareness that it is not enough to produce a crop or animal product; it must be marketed as well. Agricultural marketing involves in its simplest form the buying and selling of agricultural produce. But, in modem times, marketing of agricultural produce is different from that of olden days. In modem marketing, agricultural produce has to undergo a series of transfers or exchanges from one hand to another before it finally reaches the consumer. 2

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

The National Commission on Agriculture defined agricultural marketing as a process which starts with a decision to produce a saleable farm commodity and it involves all aspects of market structure of system, both functional and institutional, based on technical and economic considerations and includes pre and post- harvest operations, assembling, grading, storage, transportation and distribution. The Indian council of Agricultural Research defined involvement of three important functions, namely (a) assembling (concentration) (b) preparation for consumption (processing) and (c) distribution. Characteristics of Agricultural Product Agricultural products differ in nature and contents from industrial goods in the following respects.  Agricultural products tend to be bulky and their weight and volume are great for their value in comparison with many industrial goods.  The demand on storage and transport facilities is heavier, and more specialized in case of agricultural products than in the case of manufactured commodities.  Agricultural commodities are comparatively more perishable than industrial goods. Although some crops such as rice and paddy retain their quality for long time, most of the farm products are perishable and cannot remain long on the way to the final consumer without suffering loss and deterioration in quality.  There are certain agricultural products such as mangoes and grapes which are available only in their seasons but this condition of seasonal availability is not found in the case of industrial goods.  Agricultural produce is to be found scattered over a vast geographical area and as such its collection poses a serious problem. But such is not condition in the case of industrial goods.  There are various kinds and varieties in farm produce and so it is difficult to grade them.  The farmers especially in countries like India have low holding-back. Therefore he has to sell his produce immediately after the harvest at whatever price he can fetch because of his pressing needs.  Finally, both demand and supply of agricultural products are inelastic. A bumper crop, without any minimum guaranteed support price from the government may spell disaster for the farmer. Similarly the farmer may not really be in a position to take advantage of shortages or deficit crop. These benefits may pass on only to the middleman. Importance and Objectives of Agricultural Marketing The farmer has realized the importance of adopting new techniques of production and is making efforts for more income and higher standards of living. As a consequence, the cropping pattern is no longer dictated by what he needs for his own personal consumption but what is responsive to the market in terms of prices received by him. While the trade is much organized the farmers are not Farmer is not conversant with the complexities of the marketing system which is becoming more and more complicated. The cultivator is handicapped by several disabilities as a seller. He sells his produce at an unfavourable place, time and price. The objectives of an efficient marketing system are:  To enable the primary producers to get the best possible returns,  To provide facilities for lifting all produce, the farmers are willing, to sell at an incentive price,  To reduce the price difference between the primary producer and ultimate consumer, and  To make available all products of farm origin to consumers at reasonable price without impairing on the quality of the produce. Facilities Needed for Farmer in Marketing In order to have best advantage in marketing of his agricultural produce the farmer should enjoy certain basic facilities.  He should have proper facilities for storing his goods.  He should have holding capacity, in the sense, that he should be able to wait for times when he could get better prices for his produce and not dispose of his stocks immediately after the harvest when the prices are very low.  He should have adequate and cheap transport facilities which could enable him to take his surplus produce to the mandi rather than dispose it of in the village itself to the village money-lender-cum-merchant at low prices. 3

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 



www.UPSCPDF.com

https://t.me/UPSC_PDF

He should have clear information regarding the market conditions as well as about the ruling prices, otherwise may be cheated. There should be organized and regulated markets where the farmer will not be cheated by the "dalals" and "arhatiyas". The number of intermediaries should be as small as possible, so that the middleman's profits are reduced. This increases the returns to the farmers.

Methods of Sale and Marketing Agencies The marketing of agricultural produce is generally transacted in one of the following ways.  Under cover or the Hatta System: - Under this system, the sale is effected by twisting or clasping the fingers of the sellers agent under cover of a cloth. The cultivator is not taken into confidence until the final bid is cleared.  Open auction syste: - Under this system the agent invites bids for the produce and to the highest bidder the produce is sold.  Dara system:- Another related system is to keep the heaps of grains of different quantities and sell them at fiat rates without indulging in weightment etc.  Moghum sale:- Under this system, sale is based on the verbal understanding between buyers and sellers and without mentioning the rate as it is understood that the buyers will pay the prevailing rate.  Private agreement: - The seller may invite offers for his produce and may sell to one who might have offered the highest price for the produce.  Government purchase: - The government agencies lay down fixed prices for different qualities of agriculture commodities. The sale is affected after a gradual processing for gradation and proper weightment. This practice is also followed in co-operative and regulated markets.  Marketing agencies:- The various agencies engaged in the marketing of agricultural produce can be classified into two categories, viz., (i) government and quasi private agencies like the co-operative societies and (ii) private agencies. A chain of middlemen may be found operating both in Government and private agencies. Existing Systems of Agricultural Marketing in India The existing systems of agricultural marketing in India are as briefly described here:  Sale to moneylenders and traders:- A considerable part of the total produce is sold by the farmers to the village traders and moneylenders. According to an estimate 85% of wheat, 75% of oil seeds in U.P., 90% of jute in West Bengal and 60% of wheat, 70% of oil seeds and 35% of cotton in Punjab are sold by the farmers in the villages themselves. Often the money lenders act as a commission agent of the wholesale trader.  Hats and shanties:- Hats are village markets often held once or twice a week, while shanties are also village markets held at longer intervals or on special occasions. The agents of the wholesale merchants, operating in different mandies also visit these markets. Most of "hats" are very poorly equipped, are uncovered and lack storage, drainage, and other facilities. It is important to observe that only small and marginal farmers sell their produce in such markets. The big farmers with large surplus go to the larger wholesale markets.  Mandies or wholesale markets:- One wholesale market often serves a number of villages and is generally located in a city. In such mandies, business is carried on by arhatiyas. The farmers sell their produce to these arhatiyas with the help of brokers, who are generally the agents of arhatiyas. Because of the malpractices of these middlemen, problems of transporting the produce from villages to mandies, the small and marginal farmers are hesitant of coming to these mandies. The arhatiyas of these mandies sell off the produce to the retail merchants. However, paddy, cotton and oilseeds are sold off to the mills for processing. The marketing system for sugarcane is different. The farmers sell their produce directly to the sugar mills.  Co-operative marketing:- To improve the efficiency of the agricultural marketing and to save farmers from the exploitation and malpractices of middlemen, emphasis has been laid on the development of co-operative marketing societies. Such societies are formed by farmers to take advantage of collective bargaining. A marketing society collects surplus from it members and sell it in the mandi collectively. This improves the bargaining power of the members and they are able to obtain a better price for the produce. In addition to the sale of produce, these societies also serve the members in a number of other ways.

4

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Ideal Marketing System The ideal marketing system is one that maximizes the long run welfare of society. To do this, it must be physically efficient, otherwise the same output could be produced with fewer resources, and it must be electively efficient, otherwise a change in allocation could increase the total welfare and where income distribution is not a consideration. For maximum physical efficiency, such basic physical functions as transportation, storage, and processing should be carried on in such a way so as to achieve the highest output per unit of cost incurred on them. Similarly an ideal marketing system must allocate agricultural products in time, space and form to intermediaries and consumers in such proportions and at such prices as to ensure that no other allocation would make consumers better off. To achieve this condition, prices throughout the marketing system must be efficient and must at the same time be equal to the marginal costs of production and marginal consumer utility. The following characteristics should exist in a good marketing system.  There should not be any government interference in free and market transactions. The method of intervention include, restrictions on food grain movements, restrictions on the quantity to be processed, or on the construction of processing plant, price supports, rationing, price ceiling, entry of persons in the trade, etc. When these conditions are violated, the inefficiency in the market system creeps in and commodities pass into the black market. They are not then easily available at the fair prices.  The marketing system should operate on the basis of the independent, but systematic and orderly, decisions of the millions of the individual consumer and producers whose lives are affected by it.  The marketing system should be capable of developing into an intricate and far-flung marketing system in view of the rapid development of the urban industrial economy.  The marketing system should bring demand and supply together and should establish equilibrium between the two.  The marketing system should be able to generate employment by ensuring the development of processing industries and convincing the people to consume more processed foods, consistent with their tastes, habits and income levels. Principles of Scientific Marketing for Farmers The tendency among the farmers to market their produce has been increasing. Production is complete only when the produce is marketed at a price remunerative to the farmer. Increasing specialization in production of higher marketable/ marketed surplus of the produce and alternative channels of marketing has increased the importance of the marketing activity for the farmers. However, marketing activity should be guided by certain basic principles which are briefly explained. The farmers can gain more if they follow the following principles of scientific marketing:  Always bring the produce for sale after cleaning it: - Impurities, when present, lower the price offered by the traders-buyers in the market. The fall in price is more than the extent of impurity present in the produce would warrant. Clean produce attracts more buyers.  Sell different qualities of products separately: - The produce of different varieties should be marketed separately. It has been observed that when different varieties of products are marketed separately, the farmers get a higher price because of the buyer’s preference for specific varieties.  Sell the produce after grading it: - Graded produce is sold off quickly. The additional income generated by the adoption of grading and standardization is more than the cost incurred in the process of grading and standardization. This shows that there is an incentive for the farmers for the production of good quality products.  Keep abreast of market information: - Price information helps him to take decisions about when and where to sell the produce, so that a better price may be obtained.  Carry bags/packs of standard weights: - Farmers should weigh their produce and fill each bag with a fixed quantity. Majority of the farmers do not weigh their produce before taking it for sale and suffer loss by way of a possible malpractice in weighing, or they may have to make excess payments in transit (octroi, transport costs, etc.).  Avoid immediate post-harvest sales:- The prices of the produce touch the lowest level in the peak marketing season. Farmers can get better prices by availing of warehouses facilities existing in their areas. Farmers can meet their cash needs by pledging the warehouse receipt to nationalized banks. 5

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 



www.UPSCPDF.com

https://t.me/UPSC_PDF

Patronize co-operative marketing societies:- Farmers can get better prices by sales through a cooperative and marketing society and can avoid the possibility of being cheated. The cost of marketing particularly the transportation cost for farmers having a small quantity of marketable surplus is minimized, for transportation is arranged co-operatively by the society and the profit earned by the society is shared among its members. Sell the produce in regulated markets:- The farmers should take their produce for sale to the nearly regulated markets rather than sell them in village or unregulated markets. In regulated markets marketing charges are on very few items. They get the sales slips in the regulated markets, which show the quantity of the produce marketed and the amount of charges deducted from the values of the produce. Sales slips protect farmers against the malpractices of deliberate erroneous accounting or unauthorized deductions.

Impact of Globalization: Contract Marketing The macro level changes due to the New Economic Policy have had a direct impact in the field of agricultural marketing. So the impact of globalization has been highlighted here. As a result of globalization substantial investments in new ventures are being made by national as well as international corporations. A number of foreign companies are slated to enter the Indian market through collaborations with the well known Indian companies like Eagle Agro-farms, Maxworth Orchards, etc. It is clear that the wholesaler in the fresh products market as well as the processor will prefer contract marketing tie-ups with the farmers for sourcing his supply requirements. The concept of contract farming is not new to India. Several years back, contract marketing was successfully tried in respect of "Hima peas". 'MARKFED' of Punjab also operated a scheme of contract marketing for green peas, Agrecotec proposes to setup country-wide retail network of shops for fresh fruit vegetable marketing. Direct marketing to consumer is already being done by the Mother Dairy through its outlets in Delhi. The successful integration of production and marketing under Apni mandi scheme in Punjab and the marketing managements of 'FRESH' in Hyderabad are clear signs that contract marketing is going to be increasingly resorted to in the years to come. “Pepsi Foods" also an another example of contract farming of potatoes and tomatoes. Under this farming farmers will be producing specific varieties or qualities tailored to meet the requirements of the processor or the fresh produce market. The potential benefits of the contract marketing are: Producers can reduce the market risk,  Post harvest losses can be reduced,  Technology can be transferred to the producers,  Contract serve as a security for increased access to credit by both producers and processors,  Contract may create a greater sense of common interest among the producers and induce greater involvement in group activities etc. Common problems may be:  Volatility in market price,  There is risk that the processors may manipulate the quality standards,  Coordination problems may be there regarding delivery of inputs or produce,  Processors may lack the competence or capacity to deliver the require technical assistance,  Producers may become tied to a contract relationship by virtue of debt, specialization, or the disappearance of other markets and may be unable to adjust their production activities to changing conditions etc. Many of these problems of contract farming will not arise where goodwill and credibility exist between the farmers and the concerned company. Government Measures to Improve Agricultural Marketing Government of India has adopted a number of measures to improve agricultural marketing, the important ones being - establishment of regulated markets, construction of warehouses, provision for grading, and standardization of produce, Standardization of weight and measures, daily broadcasting of market prices of agricultural crops on All India Radio, improvement of transport facilities, etc. These are as briefly described here :  Marketing surveys: - In the first place the government has undertaken marketing surveys of various 6

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF













7

www.UPSCPDF.com

https://t.me/UPSC_PDF

goods and has published these surveys. These surveys have brought out the various problems connected with the marketing of goods and have made suggestions for their removal. Rural Godown Scheme: - The scheme of Rural Godowns has been formulated for creation of scientific storage capacity with allied facilities in rural areas by encouraging private and cooperative sector to invest in the creation of storage infrastructure in the country. The eligible promoters for construction of rural godowns are individual farmers, group of farmers/ growers, partnership/ proprietary firms, NGO, companies, corporations, cooperatives, Agricultural Produce Marketing Committees, Marketing Boards and Agro Processing Corporations. Godowns built under the scheme should be structurally sound on account of engineering considerations and functionally suitable to store the agricultural produce. The general conditions for scientific construction will be as follows: ◦ The construction of godown should be as per Central Public Works Department/State Public Works Department specifications or any other standard specifications laid down in this behalf. ◦ The godown should be properly ventilated, should have well fitted doors, windows and ventilators and should be waterproof (control of moisture from floor, walls and roof etc.) ◦ The godown structure should have protection from rodents. ◦ The godown should have protection from birds (windows / ventilators with jali). ◦ The openings of godown such as doors, windows etc. should be designed in such a manner that the godown can be sealed for effective fumigation etc. ◦ The godown complex should have an easy approach road, pucca internal roads, proper drainage, arrangements for effective control against fire and theft and also have arrangements for easy loading and unloading of stocks. Grading and Standardization: - The government has done much to grade and standardize many agricultural goods. Under the Agricultural Produce (Grading and Marketing) Act the Government has set up grading stations for commodities like ghee, flour, eggs, etc. The graded goods are stamped with the seal of the Agricultural Marketing Department -AGMARK. The "Agmark" goods have a wider market and command better prices. Marketing Research & Information Network: - This Central Sector Scheme was sanctioned by the Ministry Of Agriculture in March, 2000. The objective of the scheme is to establish a nationwide information network for speedy collection and dissemination of market data for its efficient and timely utilization; to ensure flow of regular and reliable data to the producers, traders and consumers to derive maximum advantage out of their sales and purchases, and to increase efficiency in marketing by effective improvement in the existing market information system.The AGMARKNET portal is continuously being enriched with other information related to agricultural marketing for the benefit of farmers and other market users. AgmarkNet: - Agricultural Marketing ‘AgmarkNet’ is a unique live portal on agricultural commodities anywhere in the world, technically supported by a high capacity Central server and the programming capabilities of the NIC and the data is fed into the system in a decentralized mode through the voluntary cooperation of mandi staff. This is acceptable since the aim of the network is to keep farmers and other market functionaries informed of price and market related information. The portal is in public domain and anybody can access information from the portal as per their requirement. The portal is becoming popular as the information related to different aspects of marketing. The market information from the portal is being broadcasted by various Television News Channels and published in News Papers for benefits of farmers and other stakeholders. Efforts are also being made for dissemination of market information in association with other service providers like IKSL, NOKIA and IIT, Kanpur (BSNL Telecom Center of Excellence)etc. through SMS and voice mode to the farmers and other beneficiaries. National Agricultural Market Atlas (NAMA): - National Agricultural Market Atlas (NAMA) is an offshoot of the AGMARKNET with an additional component of spatial data. It provides GIS web interface to visualize the daily market scenario on National Map. Overlaying the above information with the Road/Rail network makes it more meaningful and strengthens the decisions taken by the planner as well as the farmer. It provides details about market functionaries, market infrastructure, etc. in the form of map. The geographical distribution of the markets in conjunction with market parameters will be of immense help both the monitoring authorities and the farming community. CCS National Institute Of Agricultural Marketing, Jaipur: - The National Institute of Agricultural Marketing (NIAM) is a premier National level Institute set up by the Government of India in August 1988 to offer specialized Training, Research, Education and Consultancy in the field of Agricultural Marketing. NIAM has been involved in collecting market based data for the project of National Agricultural www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF











www.UPSCPDF.com

https://t.me/UPSC_PDF

Marketing Atlas (NAMA) from different states by providing training, creating database of various markets. The data has been collected with the co-operation of Officers and Staff of State Agricultural Marketing Boards, Directorate of Agricultural Marketing, Department of Agriculture, Department of Horticulture of various States. Terminal Market Complexes: - To encourage private sector investment in agriculture, the Union ministry of agriculture is setting up terminal market complexes (TMCs), which are reducing wastage of farm produce and thereby boosting supply. It provides facilities such as cleaning, sorting, packing, storage, cold chain and transportation. It encourages participation of private enterprises which are selected as promoters in the TMC project through competitive bidding and are eligible for subsidy. Private enterprise can be any individual or consortium, while producers’ association can be farmer societies, registered NGOs, etc and the TMC project are being implemented as a separate company to be registered under the Companies Act, 1956. Organization of Regulated Markets: - Regulated markets have been organized with a view to protect the farmers from the malpractices of sellers and brokers. The management of such markets is done by a market committee which has nominees of the State Government, local bodies, arhatiyas, brokers and farmers. Thus all interests are represented on the committee. These committees are appointed by the Government for a specified period of time. Important functions performed by the committees can be summarized as follows. ▪ Fixation of charges for weighing, brokerages etc., ▪ Prevention of unauthorized deductions, underhand dealings, and wrong practices by the arhatiyas, ▪ Enforcing the use of standardized weights, ▪ Providing up to date and reliable market information to the farmers, and ▪ Settling of disputes among the parties arising out of market operations. Central Warehousing Corporation: - The Central Warehousing Corporation was set up in 1957 with the purpose of constructing and running godowns and warehouses for the storage of agricultural produce. The states has set-up the State Warehousing Corporations with the same purpose. At present the Food Corporation is constructing its own network of godowns in different parts of the country. Directorate of Marketing and Inspection: - The directorate was set up by the Government of India to co-ordinate the agricultural marketing of various agencies and to advise the Central and State Governments on the problems of agricultural marketing. Activities of this directorate includes the following:▪ Promotion of grading and standardization of agricultural and allied commodities; ▪ Statutory regulation of markets and market practices; ▪ Training of personnel; ▪ Market extension; ▪ Market research, survey and planning and ▪ Administration of old storage order, 1980 and meat food products order, 1973. Government Purchases and Fixation of Support Prices:- In addition to the measures mentioned above, the Government also announces minimum support price for various agricultural commodities from time to time in a bid to ensure fair returns to the farmers. These prices are fixed in accordance with the recommendations of the Agricultural, Price Commission. If the prices start falling below the declared level (say, as a result of glut in the market), the Government agencies like the Food Corporation of India intervene in the market to make direct purchase from the farmers at the support prices. These purchases are sold off by the Government at reasonable price through the public distribution system.

Problems in Agricultural Marketing Indian system of agricultural marketing suffers from a number of defects. As a consequence, the Indian farmer is deprived of a fair price for his produce. The main defects of the agricultural marketing system are discussed here: Improper warehouses: - There is an absence of proper warehousing facilities in the villages. Therefore, the farmer is compelled to store his products in pits, mud-vessels, "Kutcha" storehouses, etc. These unscientific methods of storing lead to considerable wastage. Approximately 1.5% of the produce gets rotten and becomes unfit for human consumption. Due to this reason supply in the village market increases substantially and the farmers are not able to get a fair price for their produce. The setting up of Central Warehousing Corporation and State Warehousing Corporation has improved the situation to some extent. 8

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 



















9

www.UPSCPDF.com

https://t.me/UPSC_PDF

Lack of grading and standardization: - Different varieties of agricultural produce are still not graded properly. The practice usually prevalent is the one known as "dara" sales wherein heap of all qualities of produce are sold in one common lot thus the farmer producing better qualities is not assured of a better price. Hence there is no incentive to use better seeds and produce better varieties. Inadequate transport facilities: - Transport facilities are highly inadequate in India. Only a small number of villages are joined by railways and pucca roads to mandies. Produce has to be carried on slow moving transport vehicles like bullock carts. Obviously such means of transport cannot be used to carry produce to far-off places and the farmer has to dump his produce in nearby markets even if the price obtained in these markets is considerably low. This is even truer with perishable commodities. Presence of a large number of middlemen: - The field of agricultural marketing is viewed as a complex process and it involves a large number of intermediaries handling a variety of agricultural commodities, which are characterized by seasonality, bulkiness, perishability, etc. The prevalence of these intermediaries varies with the commodities and the marketing channels of the products. Because of the intervention of many middlemen, the producer’s share in consumer’s area is reduced. Malpractices in unregulated markets: - Even now the number of unregulated markets in the country is substantially large. Arhatiyas and brokers, taking advantage of the ignorance, and illiteracy of the farmers, use unfair means to cheat them. The farmers are required to pay arhat (pledging charge) to the arhatiyas, "tulaii" (weight charge) for weighing the produce, "palledari" to unload the bullock-carts and for doing other miscellaneous types of allied works, "garda" for impurities in the produce, and a number of other undefined and unspecified charges. Another malpractice in the mandies relates to the use of wrong weights and measures in the regulated markets. Wrong weights continue to be used in some unregulated markets with the object of cheating the farmers. Inadequate market information: - It is often not possible for the farmers to obtain information on exact market prices in different markets. So, they accept whatever price the traders offer to them. With a view to tackle this problem the government is using the radio and television media to broadcast market prices regularly. The news papers also keep the farmers posted with the latest changes in prices. However the price quotations are sometimes not reliable and sometimes have a great time-lag. The trader generally offers less than the price quoted by the government news media. Inadequate credit facilities: - Indian farmer, being poor, tries to sell off the produce immediately after the crop is harvested though prices at that time are very low. The safeguard of the farmer from such "forced sales" is to provide him credit so that he can wait for better times and better prices. Since such credit facilities are not available, the farmers are forced to take loans from money lenders, while agreeing to pledge their produce to them at less than market prices. The co-operative marketing societies have generally catered to the needs of the large farmers and the small farmers are left at the mercy of the money lenders. Small and scattered holding: - The agricultural holdings are very small and scattered throughout the country, as a result of which the marketable surplus generated is very meagre. It is not an easy task organizing how the goods can be assembled for efficient marketing. Moreover there are many varieties of particular crops and this poses problems in pricing. Forced sales: - The financial obligations committed during production force farmers to dispose the commodity immediately after the harvest though the prices are very low. Such forced sales or distress sales will keep the farmer in vicious cycle of poverty. Report has it that the farmer, in general, sells his produce at an unfavourable place and at an unfavourable time and usually he gets unfavourable terms. Technological development problems in farm production: - Evidence has it that technological change in performing certain farm operations brought in new problems in agricultural marketing. For example, paddy harvesters are identified to increase the moisture content problem in paddy; mechanical picking of cotton associated with the problem of mixing trash with cotton; potato diggers are found to cause cuts on the potato; sugarcane harvesters effects the problem of trash mix with the cane, etc. These problems lead to the reduction of price for the farm products. Unless corrective measures are affected, the production technologies accentuate the marketing problems. Poor handling, packing, packaging, and processing facilities: - For efficient and orderly marketing of agricultural products, careful handling and packing are required. Present packing and handling are inadequate. For instance, many times we see rough and careless treatment in the packing and initial handling of fruits and vegetables. Green vegetables are packed in heavy sacks which will be heated up quickly at the centre, wilt and rot soon. Workers or passengers are allowed to ride on top of a load of vegetables, which will result in physical damage. Careless handling of fruits and insanitary handling of the produce are other problems. Poor handling and packing expose the products to substantial physical www.visionias.in ©Vision IAS

https://t.me/UPSC_PDF

 







www.UPSCPDF.com

https://t.me/UPSC_PDF

damage and quality deterioration. If there are no processing facilities, say, for tomatoes, it means all the harvested crops must be sold within a given time and because there are packaging problems, quite a substantial part of the produce may be lost before getting to the market. Not only do these losses cut down the supply of products reaching the consumers, but also raise the price of the remaining portion, which must bear all costs. Growth of urban centres: - The growth of urban centres creates more marketing problems, concerned with inadequate supply to meet the increase in size; the need to create new markets and storage problems. Communication problem: - One of the key elements of efficient agricultural marketing system is the availability of proper communication infrastructure. Rural areas are inadequately placed with reference to posts, telegraphs and telephone. The literacy rate being low among the farmers, it poses difficulty of the communication tasks. Lack of farmer's organization: - The farmers are scattered over a wide area without any common organization. In the absence of such organization, farmers do not get anybody to guide them and protect their interests. On the other hand, traders are an organized body. Thus, the marketing system, therefore, constitutes unorganized farming community on one side and organized and powerful traders on the other side. Under such situations, farmers will be generally exploited and do not get remunerative prices for their produce. Inadequate research on marketing: - Until recently, all efforts have been geared towards producing more without thinking about how to market them. There is need to know about new technologies in food storage and preservation. There is also need for research on consumer demands and preferences, handling and packaging. Problems caused by Globalization: - The globalization has brought drastic changes in India across all sectors and it is more so on agriculture, farmers and made a deep impact on agricultural marketing. It is basically because of majority of Indians are farmers. It has brought several challenges and threats like uncertainty, turbulence, competitiveness, apart from compelling them to adapt to changes arising out of technologies. If it is the dark cloud there is silver lining like having excellent export opportunities for our agricultural products to the outside world.

Suggestions to Improve Agricultural Marketing Improving the marketing system of agricultural products would help the farmer to better his economy. The following are suggested measures that could reflect an improved agricultural marketing system:  Establishment of More Regulated Markets: - A regulated market is one, which aims at the elimination of the unhealthy and unscrupulous practices, reducing marketing charges and providing facilities to producers. Under the regulated markets, its management should be vested with market committees in which the members would be producers, traders, officials of the marketing societies, officials of agricultural and animal husbandry etc. The institute should be self-financed, statutory and autonomous. Funds would be raised through licensing fees and market fees on the notified agricultural produce transacted in the premises of the market yard. The regulated market however has the following benefits: ◦ Farmers are encouraged to bring their produce directly to the markets. ◦ Farmers are protected from the exploitation of market functionaries. ◦ Farmers are ensured better prices for their produce. ◦ Farmers have access to up-to-date market information. ◦ The marketable surplus of the farmers will be increased. ◦ Marketing costs are lowered and producers share will be increased.  Improvement in Standardization and Grading: - Standard specifications and grading should be designed to be useful to as many producers, traders and consumers as possible i.e., standards should reflect market needs and wants. One grade should have the same implications to producers, traders and consumers in the quality of the product. It must have mutually acceptable description. They should reflect commodity characteristics that all types of buyers recognize. The grading should be simple, clear and easy to understand.  Improvement in Handling and Packing: - This refers to the adoption of new techniques for the physical handling of commodities throughout the various phases of marketing, for instance, the use of cold storage (mechanical refrigeration) in handling of perishables, new methods of packing etc. The most appropriate handling and suitable containers among the available ones are meant to use against dust, heat, rain, flies etc., to prevent considerable physical losses and quality deterioration. 10

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 













www.UPSCPDF.com

https://t.me/UPSC_PDF

Provision of Storage Facilities: - Reduction of physical damage and quality deterioration in the products can be brought about through the application of the scientific techniques and provision of appropriate storage facilities depending on the nature and characteristics of products and the climatic conditions of an area. To this effect, more licensed warehouse are required. A licensed warehouse has the following benefits: ◦ Reduces the wastage in storage of various commodities by providing scientific storage facilities ◦ Assists the government in orderly marketing of agricultural commodities by introducing standard grade and specifications ◦ Issues warehouse receipts, a negotiable instrument in which commercial banks advance finance to the producers and dealers ◦ Assists government in the scheme of price support operations. However, there would be procedures for storage which are not too bureaucratic. The depositor intending to store the produce in the warehouse would have to present a written requisition in the application prescribed by the warehouse. The commodity meant for storage will be properly packed and delivered at the warehouse. The depositor would have to disclose all details of the commodity including the market value in the application form. The commodity brought for storage will be graded and weighed by trained technical personnel before the commodity can be stored. Different storage charges would also apply for different commodities and the stocks offered for storage will be insured against possible risks of fire, theft and floods, strikes and civil commotion. Improvement in Transport Facilities: - Link-up and associated road development is sine qua non for the success of market structure. The availability of efficient transportation encourages the farmers to the markets of their option to derive the price benefits. Rural roads particularly are in bad state during all seasons and more so during rainy season. Investment on roads should be given top priority. Also another problem is that perishables cannot be transported in closed wagons hence there is a need to provide necessary ventilation in whichever means they are to be transported. Market Information: - As such we have newspapers, price bulletins, reports of the government agencies etc., which provide market information. This information would be much more useful if an educational programme is made available to analyse and interpret the information at the markets. The raw data no doubt provides valuable information but skilful interpretation makes it useful to the farmers. Market Research: - Market research can be defined as the study of consumer demand by a firm so that it may expand its output and market its product. It centres on consumer's needs, preferences, impressions of a product, accessibility of markets, efficiency of marketing etc. Marketing research needs to be given top priority to improve up on the marketing system. Market Extension: - This involves the dissemination of needed information on marketing to producers. The farmers will be advised on consumer preferences, grading, packaging, transport, etc., in order to help them to secure better returns. Provision of Agricultural Marketing Training to Farmers: - Provision of training is of utmost importance in view of the malpractices resorted to by various market functionaries. The farmer needs to be trained in product planning i.e. crops and varieties to be grown, preparation of produce of produce for marketing, malpractices and rules and regulations, market information, promotion of group marketing, etc. Promoting Cooperative Marketing: - Cooperative marketing is the organized sale of farm products on a non-profit basis in the interests of the individual producer. Cooperative marketing are organized by farmers themselves and the profits are distributed among the farmer-members based on the quantity of the produce marketed by them. The agricultural marketing system should basically ensure that the producer is encouraged to increase production, besides assuring the farmer remunerative prices for his produce and supplying the commodities to the customers at reasonable prices. In view of this, cooperative marketing societies should be established for meeting the requirements of the farmer. The benefits of cooperative marketing include: ▪ Make arrangement for the sale of produce of the members ▪ Provides credit facilities to the members on the security of agricultural produce ▪ Provide grading facilities, which would result in better price ▪ Make arrangement for scientific storage of the member’s produce ▪ Arrange the supply off inputs required by the farmers ▪ Undertake the system of pooling the produce of the members to enhance the bargaining power

11

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF





www.UPSCPDF.com

https://t.me/UPSC_PDF

through unity of action ▪ Arrange for the export of the produce to enable the farmers get better returns ▪ Act as an agent of the government in procurement of food-grains, etc. Provisions for Cold Storage Facilities and Refrigerated Transport: - For perishable commodities like fruits and vegetables, quality losses are enormous and hence it would be necessary to take measures and devise means or methods of controlling and minimizing losses. Preservation is, thus, a necessary adjunct of production and a vital link between production and consumption. Cold storage is the most important for the proper marketing of horticultural produce, because it had a definite season of production and the quality of the produce deteriorates quickly after harvest. Most fruits and vegetables losses moisture to the surrounding air almost any time in the humidity of the air is less than saturated. It is possible to maintain high humidity of the 80 – 95 per cent in proper cold storages and hence refrigeration is also beneficial in reducing moisture losses. Refrigerated transport for perishables needs to be provided during their movement in marketing channels. Besides road transport, railway wagons should also be suitably modified for transportation of perishables. Development of Physical Market: - Physical markets handling fruits and vegetables suffer from operational and management inadequacies. A country level plan to identify markets of national importance for fruits and vegetables and provision of need-based infrastructure from export point of view in all these markets is imperative.

Conclusion There is no doubt that in any marketing there is a motive towards profit involved and at the same time the marketing is to be based on certain values, principles and philosophies such as offering just and fair prices to the farmers who toil hard to till. Bringing necessary reforms coupled with proper price discovery mechanism through regulated market system will help streamline and strengthen the agricultural marketing. In order to avoid isolation of small-scale farmers from the benefits of agricultural produce they need to be integrated and informed with the market knowledge like fluctuations, demand and supply concepts which are the core of economy. Marketing of agriculture can be made effective if it is looked from the collective and integrative efforts from various quarters by addressing to farmers, middlemen, researchers and administrators. It is high time we brought out significant strategies in agricultural marketing with innovative and creative approaches to bring fruits of labour to the farmers.

Agricultural Transportation: Issues and Related Constraints Contents  Introduction  Role of Intermediate Means of Transport in Agriculture  Effect of Markets and Storage Facilities on Agricultural Transportation  Transportation Cost of Agricultural Produce and Farmer's Income  Transportation Problems and Road Network  Problems of Road Transport in India  Special Problems in the Construction of Rural Roads  Measures Taken for Improving Rural Road Infrastructure by Government  Suggestions for Better Rural Road Network  Conclusion Introduction An efficient transport system is critically important to efficient agricultural marketing. If transport services are infrequent, of poor quality or are expensive then farmers will be at disadvantage when they attempt to sell their crops. An expensive service will naturally lead to low farm gate prices (the net price the farmer receives from selling his produce). Seasonally impassable roads or slow and infrequent transport services, coupled with poor 12

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

storage, can lead to losses as certain crops (e.g. milk, fresh vegetables, tea) deteriorate quickly over time. If the journey to market is made over rough roads then other crops (e.g. bananas, mangoes) may also suffer losses from bruising; this will also result in lower prices to the farmer. Agriculture is best served by consistent high urban, and international, demand. This is best brought about by an efficient, high volume, transport and marketing system where the transporting and marketing unit costs are low. If the margin between what the farmer receives from the sale of his produce and what the urban consumer pays for his produce is high then the effective demand transferred to the farmer will be correspondingly be reduced. Similarly if internal transport costs in a country are particularly high then the scope for agricultural exports will also suffer in comparison with other more efficient countries. The pattern of agricultural marketing is strongly influenced by the nature of transport services. Many developing countries suffer from monopolistic, low volume and high cost transport and marketing systems. Economies of scale are present in both transport and marketing operations. In the following we will consider transport costs, the impact of roads on rural development, access to markets and the potential use of intermediate means of transport. Role of Intermediate Means of Transport in Agriculture Intermediate Means of Transport or IMTs includes wheelbarrows, bicycles, rickshaws, various animal carts and wagons, motorcycles, motorized three-wheelers, and two-wheel tractors that fill the gap between more expensive motor vehicles and tedious human effort. Intermediate means of transport IMTs can play a useful role in agricultural marketing. Walking, the dominant mode of on-farm transport, can restrict any increase in agricultural production. IMT can improve the efficiency of on-farm agricultural transports by reducing transport costs and time. The effects on agricultural production can be manifold:  Cultivation of bigger areas  Utilization of more fertile, but remote, soils  Production of heavier corps  Increased utilization of fertilizer and manure  Reduced pest damage and spoilage at crop harvest time  Reduction of transport time, partly used for income generation  Reduced effort and drudgery involved in human porterage  Spill-over effects if animals are used for ploughing and transport Thus, IMT enable the farmers to respond better to markets by augmenting or changing their production. Additionally, they reduce losses, save transport costs and time. If markets are within walking distance then head loading is important. Transport efficiency can be significantly increased by improvement of footpaths or the use of IMT. If markets are more than half a day's non-motorized travel, a multimodal transport system is a cost-effective solution. Trucks are unbeatable on long distances, good roads and fully loaded, and IMT operate more efficiently on short distances with small loads and on bad roads making a multimodal approach the best solution for rural transport problems. Effect of Markets and Storage Facilities on Agricultural Transportation The presence of markets and storage facilities play an important role in affecting choice of vehicle. Markets and storage facilities both provide the same role of acting as a place where agricultural produce can be amalgamated. This may be for the purpose of immediate sale or for transportation to the next destination. Access to markets and storage facilities therefore affect vehicle choice in two main ways. Firstly, the ease of access to these facilities, whether in terms of distance or ability to use the facilities, will dictate the farmer’s decision on which vehicle to use. For example, if the storage facility is close he may decide to buy a 13

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

non-motorised vehicle which would have been of no use if the facility was beyond a certain distance. Similarly, if once the farmer had reached the facility he was unable to use it either because of its expense or because of exclusionist type practises, the need for a vehicle becomes redundant, and the farmer’s produce may as well be sold to the village trader. The farmer will only demand a more advanced vehicle if it is the perception that the vehicle will enable an effective increase in farm gate prices. Secondly, where goods are amalgamated it means that the density of demand for vehicle services increases. The density of demand is of vital importance in determining vehicle choice. The larger the demand the more an efficient and cost effective vehicle can be justified and hence the unitary costs of transport are reduced. The existence of markets and storage facilities are important at any level. For example, at the village level a small grain store may be able to accumulate enough demand from all the farmers to justify the use of a donkey cart for transportation to market. Without the store individual farmers may only be able to justify head loading their surplus produce to market. Similarly, at the district level a market could attract city traders who bring large trucks to transport the produce bought at the market in bulk. The ease with which farmers and traders have access to markets and storage facilities will be reflected in their distribution costs (transport and storage). If distribution costs are low this will effectively increase farm gate prices which will give farmers the incentive to increase production. Transportation Cost of Agricultural Produce and Farmer's Income Cost of transportation of agricultural produce from the farm sites to the market has a great impact on production and income of farmers. This is because transport charges on agricultural produce vary with type of crops, the efficiency of the transport and distance travelled. A significant proportion of the farmer's income had gone to transportation and this is as a result of bad roads in these areas. High cost of transportation would translate to high selling price and if the price is too high when compared with other farmers from other areas, customers will not buy and this may result to selling at a loss. The importance of an efficient and competitive marketing system has been stressed as a complement to rural transport services (RTS) and infrastructure in promoting development. However, the presence of markets in them also constitutes a means by which the effective demand for transport can be increased. A market acts as a point where goods and people are amalgamated together and thereby concentrating the demand for transport. Where populations are dispersed markets are also likely to be dispersed with long average distances to market and people less likely to make the trip. This is an important consideration for the demand for Intermediate means of transports where, if distances become too large, an Intermediate means of transport may not be viable. In addition, one of the most effective ways that farmers have of getting the best price for their produce is for them to sell it themselves directly to final consumers at rural or urban markets, and thus bypass the normal marketing system. Although farmers do not have the economies of scale of travelling wholesalers it is often recognised by urban dwellers that the keenest prices are often provided by the farmers. Farmers bringing their own produce to market represent a very important way of limiting the power of the marketing cartels. Farmers rely on travelling wholesalers, traders, parastatals or large private marketing companies they all reduce the farmers bargaining power, and critically, it reduces demand for transport services and the supply of vehicles available for rural people. There is usually little support by the authorities for ‘unofficial’ trading and farmers are frequently harassed as they attempt to sell. Transportation Problems and Road Network Farmers face various transportation problems in the process of transporting their produce from the farm to their houses and markets. These problems included: 14

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

 Bad roads,  High cost of transportation,  Irregularity of vehicles,  Insufficiency of vehicles,  Insufficient means of transportation and  Long distance from farm to their houses as well as markets. Road network plays main role among them. This is because it is the major means of transporting agricultural produce from the farms to the markets. Road transport has both positive and negative impact on agricultural development in India. The impacts of bad road infrastructure on agricultural output and productivity are following:  The agricultural sector accounts for a large share of gross domestic product. Poverty is concentrated in rural areas. The relatively low levels of road infrastructure and long average travel time’s result in high transaction costs for sales of agricultural inputs and outputs, and this limits agricultural productivity and growth.  Many farmers are reluctant to grow a marketable surplus second crop because it cannot be sold or because the difficulty and expense of transport significantly reduces the returns to labour.  Agricultural productivity will be low and there is a lack of innovation because extension information and inputs do not reach the farmers.  Rural people often are too poor to own their own motorized vehicles and depend on public transport to gain access to locations outside their communities. When rural roads deteriorate public transport becomes more expensive and transport operators eventually decide to stop their business.  Some of the variables that determine the level of development in a given environment are easy accessibility and mobility.  A strong relationship between road transportation, underdevelopment and rurality has been identified by various researches.  When the distance of farm to the market is far and the road is rough perishable crops may be destroyed and farmers may run at a loss.  With improved roads, transport cost savings occur both through lower costs of existing traffic and lower costs of generated and attracted traffic. The assumption is that traffic will grow as a result of road improvements. A deterioration of the road network on the other hand will gradually reduce traffic levels. Moreover the unit transport cost will increase.  When the roads become impassable, there will be a shift to less-effective modes of transport, replacing motorized transport by more costly non-motorized transport. The move to non-motorised transport often implies that a lot of transport simply ceases to take place. If motorised transport is not available, bulky goods can only be transported for short sections.  By the reduction in competition in the transport sector due to lower traffic levels, results in the increased cost of transport and that is passed to the farming households.  A well maintained road network keeps input and transport prices down and, hence, production costs lower and can lead to improved livelihoods through higher incomes.  The quality and density of the rural road network makes a significant difference in the cost of agricultural inputs, the quality and value of outputs as well as the delivery of extension services. Problems of Road Transport in India Road transport of the country is facing a number of problems. Some of these problems are discussed below:  Most of the Indian roads are unsurfaced (42.65%) and are not suitable for use of vehicular traffic. The poor maintenance of the roads aggravates the problem especially in the rainy season. According to one estimate there is about per year loss of Rs. 200 crores on the wear and tear of the vehicles due to poor quality of roads.

15

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF  

  

  

 



www.UPSCPDF.com

https://t.me/UPSC_PDF

Less than 0.1 percent of the national income is spent on the maintenance of roads in India. Sixty percent of villages are without roads in India. It adversely affects our agriculture and rural economy. There is heavy tax burden on motor transport in India. There are multiple check-posts, toll tax and octoroon duties collection points on the roads which bring down the speed of the traffic and waste time. Rate of road taxes vary from state to state and interstate permits are difficult to obtain. Way side amenities like repair shops, first aid centers, telephones, clean toilets, restaurants, rest places are lacking along the Indian roads. There is very little attention on road safety and traffic laws are wilfully violated. There is little co-operation and co- ordination among different states with regard to motor transport. As such, motor transport faces lot of difficulties. According to 'Road Transport Reorganization Committee', 90 per cent of the operators are small operators owning five vehicles or less. Owing to this small number, satisfactory and efficient service is not being provided to the people. Due to high prices of petroleum products and diesel operational costs of road transport are rising and making the mode of transport more costly. Most of the drivers on the roads are unskilled and untrained. One major problem on the Indian roads is the mixing of traffic. Same road is used by high speed cars, trucks, two wheelers, tractors, animal driven carts, cyclists and even by animals. Even highways are not free from this malady. This increases traffic time, congestion and pollution and road accidents. In India, roads are not well-maintained as there are no timely repairs. It causes discomfort and quick depreciation of vehicles. There is very little participation of private sector in road development in India because of long gestation period and low-returns. The legislative framework for private investment in roads is also not satisfactory. The road engineering and construction are yet to gear themselves up to meet the challenges of the future. There has been no stability in policy relating to highway development in the country. It has changed with the change of government. There are a number of agencies which look after the construction and maintenance of different types of roads. Since there is no co-ordination between these agencies their decisions are often conflicting and contradictory.

Special Problems in the Construction of Rural Roads Rural roads constitute a special category of roads as regards the type of materials used and construction techniques employed, as compared with roads forming the highway network. As a result, the construction and maintenance problems involved in keeping the rural road network at a satisfactory level of serviceability are of a different quantum and type. Some of these problems are: Rural roads are generally built up in stages, extending over a number of years. This practice arises from the inadequate availability of finances, as well as from the fact that the traffic is likely to increase after an initial road link is established, thereby necessitating an upgradation of the pavement.  One important and significant feature pertaining to the construction of rural roads is the emphasis placed on the utilisation of the local materials, both soil and stone aggregates in the various layers of the pavement. This necessitates that such materials to be utilized after careful evaluation of their properties and affecting the needed improvements by blending or the use of additives as may be required.  The construction of rural roads is handled by a number of different agencies, varying from state to state. Within the same state different agencies might be building rural roads in different districts.  The level of expertise available shows great variation from department to department, and it is not unusual to find that trained personnel are not available in the executing department to plan, design and construct a rural road that makes optimal use of the material and financial resources available and build a material and financial resources available manual labour is resorted to, to the maximum extent, since providing employment to the local population also forms one of the essential objectives of the various rural development programmes.  Rural labour generally does not have the necessary skills associated with the different phases of road 16

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF



www.UPSCPDF.com

https://t.me/UPSC_PDF

construction, nor is any training imparted to them before inducting them into the construction programme. Employment on such construction works is viewed, rather mistakenly, as a relief measure lesson the problem of rural employment. The consequence of such thinking is a finished product of poor quality, i.e., an improperly built road that has only frittered away the meagre resources. The lack of adequate quality in the inputs, human as well as material, results in a faster deterioration of the serviceability to a lower than the tolerable level. In turn, these results in greater demands on maintenance, viz, more frequent repairs, involving additional deployment of manpower and materials, all adding upto higher spending on maintenance. If money for maintenance is short, final result will be the deterioration of the roadway leading to the loss of initial capital investment itself.

Measures Taken for Improving Rural Road Infrastructure by Government Rural roads connect villages giving access to rural population to the National Highways through Major District Roads and State Highways. Around 59 per cent of the total road length is accounted by rural roads largely built under Jawahar Rojgar Yojna. These roads are of limited value from the point of view of movement of heavy traffic. Some of the government's measures to improve rural road infrastructure are as follows: Pradhan Mantri Gram Sadak Yojana (PMGSY) was launched on 25th December 2000 as a fully funded Centrally Sponsored Scheme to provide all weather road connectivity in rural areas of the country. The programme envisages connecting all habitations with a population of 500 persons and above in the plain areas and 250 persons and above in hill States, the tribal and the desert areas.  The District Rural Roads Plans (DRRPs) have been developed for all the districts of the country and Core Network has been drawn out of the DRRP to provide for at least a single connectivity to every target habitation. This planning exercise has been carried out with full involvement of the three tier Panchayati Raj Institutions.  Large scale revision of Rural Roads Manual were carried out by IRC at the special intervention of Ministry of Rural Development. This Manual has established the standards for construction of Rural Roads.  A three tier quality mechanism has been operationalised to ensure quality of road works during construction.  There is a provision of two bills of quantities, one for construction and another for routine maintenance on lump-sum basis amount every year for 5 years and the contactor is required to offer not only for construction but also for maintenance separately. This helps in delivery of better quality roads because if the quality of road is compromised by the contractor during construction, much more money would be required during the routine maintenance rendering the contract uneconomical for the contractor.  A web based online monitoring, management and accounting system has been developed under the PMGSY. The online system and website is being managed and maintained in collaboration with NIC and CDAC.  The Central Government has created a dedicated fund, called Central Road Fund through collection of cess from petrol and diesel. Presently, Rs. 2/- per litre is collected as cess on petrol and High Speed Diesel (HSD) Oil. The fund is distributed for development and maintenance of National Highways, State Roads and Rural Roads.  Special construction technology to tackle the construction of roads in the hilly regions would be adopted to ensure quality roads within a specific time frame.  Promoting participation of private operators on non viable semi urban/rural routes through favourable policy regime. This could be achieved through following options:◦ Auctioning of combination of routes (which are a mix of profitable and non viable routes) to private operator(s) so as to enable them to compensate their losses on account of operation of non viable routes; ◦ Offering non viable routes to bidder asking for lowest subsidy/financial support; 17

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

◦ Subjecting non viable routes to lower rates of taxation or permit fees and; ◦ Allowing alternate competing modes of passenger road transport. Suggestions for Better Rural Road Network It is essential that for quick development of rural road network concerted effort is required during planning which should begin at gross root level by associating the concerned village folk and by convincing them that appropriate quality of road constructed with appropriate technology would meet their requirement and this would be maintained and upgraded with their association. All possible resources should be mobilized for raising the necessary funds. Some of the possible suggestions are: A feeling has to be created in rural people that they are getting or building an asset for themselves and future generation instead of having a feeling that government is building a road and that the major beneficiaries are the government agencies or the contractor. In other words they should have feeling of belonging instead of detachment.  If Villagers are made aware about their minimum needs and assured that all assistance will be forthcoming for proper maintenance and continuous upgrading of the road with time and need, they will have a cooperative attitude and would assist in many ways during the initial construction, or subsequent maintenance.  Land consolidation work can be taken up simultaneously to planning. The land for access road along with raising of the track and proper drainage of the village should also be considered with other facilities for the village during land consolidation. The land for access road on embankment may be considered similar to land reserved for Panchayat land and other common facilities to the village.  In some cases the village get submerged by the flood of a nearby river. In that case protection of village by bunds/dykes can be considered and these “bunds” will also provide access roads on embankment. But the drainage of village has to be adequately planned in these cases otherwise any opening in the ‘bund’ for cross drainage works, may flood the village by back flow when water level is higher on the other side.  The quality of road to be constructed has to be planned and will depend upon the subgrade soil properties, level of water table, quantity and quality of anticipated traffic and level of maintenance to be provided. The simplest and first stage of road construction is a properly cambered formation, with reasonable shoulder width and drainage system.  The road construction work can be taken up in lean farming period, where by free (if managed) or cheap labour could be available. Similarly the timely maintenance of rural roads is essential. This is from the consideration that once damage starts in rural earthen roads it will develop at a much faster pace compared to higher grade roads. Any neglect will totally undo the assets created in past and instead of upgrading at a later date, only in first stage construction has to be repeated every time afresh. The standard of road should be continuously raised and adequately maintained over the future years.  At least some part of land revenue collected from the villages could be ploughed back for their development and a minimum percentage of land revenue should be earmarked for rural roads also.  Another source of raising fund for the rural road development could be, levying a sort of a cess on the saleable produce. This could be collected from the farmers at the market place, sugar mills, rice mills, etc. Many market places (Mandies) do levy a cess on the parked vehicles and produce sold, for the development of market place and for the facilities provided. Even the private wholesale dealers charge commission over the sale. At present most to the farm produce is purchased by the governmental agencies and the price offered s according to the rates fixed by the government, thus the cess to be collected may form a part of the price offered. The cess collected from market place may be distributed amongst the villages feeding the market place.  Village Panchayats can also collect a type of ‘Road Tax’ from the vehicles in the village. The rates could be different for different types of vehicles.  A toll tax can be collected by panchayat from the vehicles visiting the village. 18

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 



 

www.UPSCPDF.com

https://t.me/UPSC_PDF

Banks can also be asked to liberalize their policy and should consider advancing loans to villages at nominal interest for construction of rural roads providing access to the village which would not involve greater risks than that of existing procedure of advancing loans to artisans, etc. for setting up their shop, workshop etc. for increasing the income. Industrial houses, commercial undertakings, banks etc. can also be asked to adopt villages for upliftment. Villages selected should be similar to selection of poor families in a village or district for their upliftment. These families are given some fund for raising their means of livelihood. The government can also provide matching grant to the funds raised by Panchayat by tax collection, donation, etc. for access road construction to backward villages. By proper training and motivation of the personnel involved in the construction and maintenance of these, as well as increasingly adopting appropriate technological methods that have been developed, better rural roads can be built.

Conclusion Transport plays a significant role in the structure of food production and marketing and that easy transport to market can make all the difference in the level of rural incomes. An improved transportation will encourage farmers to work harder in the rural areas for increased production, add value to their products, reduce spoilage and wastage, empower the farmers as well as having positive impact on the productivity, income, employment level and reduce poverty level in the rural areas. Finally, transport is also seen as a facilitating factor in the mobilisation of the farmers and other allied workers in the overall national development of the nations.

e-Agriculture: e-Technology in The Aid of Farmers Contents

     

  

19

Introduction Information Technology and its Components Role of IT in Agriculture e-Agriculture Ecosystem ICT Initiatives for Agricultural Development in India by Various Agencies Case Studies ◦ Agropedia ◦ e-Choupal ◦ Kissan Kerala ◦ AgmarkNet ◦ eMojani ◦ Agri - Subsidy ◦ Kisan Call Centers ◦ National e-Governance Plan in Agriculture (NeGP-A) ◦ Bhoomi ◦ TARAhaat ◦ Warana Wired Villages ◦ Dairy Information Services Kiosk ◦ GramSampark ◦ Digital Gangetic Plane ◦ Gyandoot IT and Indian Agriculture in the Future Constraints and Remedies for Effective Dissemination Conclusion

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Introduction E-Agriculture is an emerging field for enhancing sustainable agriculture and food security through improved processes for knowledge access and exchange using information and communication technologies (ICT). Agriculture is one of the most important sectors in India, and could benefit tremendously with the applications of ICTs especially in bringing changes to socio-economic conditions of poor in backward areas. Agriculture constitutes a major livelihoods sector and most of the rural poor depend on rain-fed agriculture and fragile forests for their livelihoods. Farmers in rural areas have to deal with failed crops and animal illness frequently and due to limited communication facilities, solutions to their problems remain out of reach. The service role of ICTs can enhance rural community’s opportunities by improving their access to market information and lower transaction costs for poor farmers and traders. Though India has a strong and fast growing IT industry, access to ICTs remains very low particularly in rural areas. The present indicators of IT penetration in Indian society are far from satisfactory. The National Policy for Farmers emphasizes the use of Information and Communication Technology (ICT) at village level for reaching out to the farmers with the correct advisories and requisite information. The available satellite data relating to weather news, long-term and short-term weather forecast, production information, market prices policy developments pertaining to agriculture, apart from the number of advisory services in public or private domain that disseminate information should be utilized adequately. Information Technology and its Components Induction of IT as a strategic tool for agricultural development and welfare of rural India requires that the necessary IT infrastructure is in place. The rapid changes and downward trend in prices in various components of IT makes it feasible to target at a large scale IT penetration into rural India. Some of the broad factors to be noted with respect to various components of IT are listed below:  Input Devices: Radical improvements are witnessed with respect to the means of communication by human beings with computers such as key boards, mouse devices, scanners. The advent of touch screen monitors that allow users to give input to computers by touching on the appropriate location of the monitor has made it possible to develop user-friendly interface for farmers which is easy, intuitive, circumvents language barrier and at the same time provides a relaxed environment to the users. The present day digital cameras make it possible to capture and store good quality graphics and large video clips. The small size and low weight of these digital cameras, which are increasingly becoming affordable, open up the possibilities of providing computer based demonstration clips to educate the farmers. The digital cameras can also be used to upload plant stress related images, movie clips which can facilitate an expert residing at a far of location to quickly recommend a solution.  Output Devices: Monitor screens, printers & plotters, data projectors support high resolution and good quality output. The qualities of these output devices have the potential of generating renewed interest in the farmers in using IT based services. The light weight portable data projectors can be easily carried by the agricultural extension personnel for serving larger audience. Similarly, speakers can also be attached to the computers to incorporate voice based trainings for farmers.  Processors: The processing speeds of computers have gone up. At present high speed processorsare available which makes it possible to undertake substantial processing of data at the client side.  Storage Devices: 80GB and even higher hard disk drives have become common in PC range of computers. This makes it possible to store substantial information at the local level which facilitates faster access. Similarly, high capacity pen drives, CDs make it possible to transfer large volumes of data to locations which cannot be connected to networks immediately. These storage devices are also used for backup of crucial data. As a precaution, many corporate store their backups at locations away from the place of work.  Software: Various operating systems are available which act as interface between the user and the machine. The graphic user interface (GUI) has become an accepted prerequisite for end users. Application software which can support complex user requirements are available. Of the shelf solutions for office automation packages, groupware applications, complex database solutions, communication products, solutions based on remote sensing & geographical information systems are available. In addition, solutions based on some or all of these are also readily available. The present downward trend in the IT industry provides an opportunity get customised application for any specific task developed at an affordable price. Rapid Application Development and Deployment (RADD) is a popular model for quick development and deployment of applications. Development environment itself is simplified with tools that quicken the pace of software specialists. Project management and monitoring software are available that facilitate efficient execution of large and complex applications that are required for rural India.  Networking Devices: The capacity of modems, used to convert the data from digital to analog and vice versa, which are popularly employed to use telephone lines have increased. Internal modems are available integrated into the

20

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF





www.UPSCPDF.com

https://t.me/UPSC_PDF

computer so that they are not exposed to outside environment. The capacities of other networking devices such as routers have also gone up which makes it possible to create large networks with smooth data transmission. Transmission Media: The media through which the data transfer takes place has also undergone revolutionary change. Telephone lines are still the popular source in India although the reliability and low bandwidth are still major issues. High capacity cables, optical fibre, radio, wireless local loops, satellite transmission and various solutions based on a combination of these are already being used in many parts of the country. Other Accessories: Uninterrupted Power Supply (UPS) devices are crucial to ensure the durability of the IT equipment as well as provide backup mechanisms. The potential of solar power packs to provide a feasible solution to shortage of power in the rural areas needs to be exploited.

Role of IT in Agriculture Applications of IT in support of agricultural and rural development fall into five main areas. These are:  Economic development of agricultural producers;  Community development;  Research and education;  Small and medium enterprises development; and  Media networks. Precision farming, popular in developed countries, extensively uses IT to make direct contribution to agricultural productivity. The techniques of remote sensing using satellite technologies, geographical information systems, agronomy and soil sciences are used to increase the agricultural output. This approach is capital intensive and useful where large tracts of land are involved. Consequently it is more suitable for farming taken up on corporate lines. The indirect benefits of IT in empowering Indian farmer are significant and remain to be exploited. The Indian farmer urgently requires timely and reliable sources of information inputs for taking decisions. At present, the farmer depends on trickling down of decision inputs from conventional sources which are slow and unreliable. The changing environment faced by Indian farmers makes information not merely useful, but necessary to remain competitive. Here are some agricultural development services that can be provided in the developing world using ICT:  Online services for information, education and training, monitoring and consultation, diagnosis and monitoring, and transaction and processing;  E-commerce for direct linkages between local producers, traders, retailers and suppliers;  The facilitation of interaction among researchers, extension (knowledge) workers, and farmers;  Question-and-answer services where experts respond to queries on specialised subjects ICT services to block- and district-level developmental officials for greater efficiency in delivering services for overall agricultural development;  Up-to-date information, supplied to farmers as early as possible, about subjects such as packages of practices, market information, weather forecasting, input supplies, credit availability, etc.;  Creation of databases with details of the resources of local villages and villagers, site-specific Information systems, expert systems, etc.;  Provision of early warning systems about disease/ pest problems, information regarding rural development programmes and crop insurances, postharvest technology, etc.;  Facilitation of land records and online registration services;  Improved marketing of milk and milk products;  Services providing information to farmers regarding farm business and management;  Increased efficiency and productivity of cooperative societies through the computer communication network and the latest database technology;  Tele-education for farmers;  Websites established by agricultural research institutes, making the latest information available to extension (knowledge) workers and obtaining their feedback. E-Agriculture Ecosystem E-Agriculture initiatives bring together a wide array of local and regional stakeholders to form a mutually beneficial value chain: Grameen Intel and other social businesses: Information and expertise, consulting services, technology, and programs to reach rural and impoverished markets.  Governments and multilateral development agencies: Program support to enable and increase rural outreach, improve food security, create jobs, and develop partner-ships with local businesses and community organizations.

21

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF     

www.UPSCPDF.com

https://t.me/UPSC_PDF

Banks and other financial institutions: Credit, capital, and other financial instruments (crop insurance, subsidies, etc.) for entrepreneurs and farmers. Universities and agriculture extension systems: Technology to strengthen extension systems; advice and technical support for farming communities; training and capacity-building for entrepreneurs; research and development projects designed to solve problems faced by farming communities. Supply chain (e.g., suppliers, commodity markets, aggregators): Best-of-class products and services for farmers that improve returns to all stakeholders, including farmers. Technology companies: Internet connectivity, hardware, and software solutions that create access to new markets, value chains, and business models. Community organizations (e.g., farmer cooperatives, rural telecenters, government and NGO-run agriculture service centers): Help entrepreneurs; provide grassroots agriculture domain and business support, and enable programs to scale efficiently.

ICT Initiatives for Agricultural Development in India by Various Agencies Some initiatives in India that use ICT for agricultural development are:  Gyandoot project (Madhya Pradesh);  Warana Wired Village project (Maharashtra);  Information Village project of the M S Swaminathan Research Foundation (MSSRF) (Pondicherry);  iKisan project of the Nagarjuna group of companies (Andhra Pradesh);  Automated Milk Collection Centres of Amul dairy cooperatives (Gujarat);  Land Record Computerisation (Bhoomi) (Karnataka);  Computer-Aided Online Registration Department (Andhra Pradesh);  Online Marketing and CAD in Northern Karnataka (Karnataka);  Knowledge Network for Grass Root Innovations-Society for Research and Initiatives (SRISTI) (Gujarat);  Application of Satellite Communication for Training Field Extension Workers in Rural Areas (Indian Space Research Organisation); In addition to the above, a few non-governmental organisations (NGOs) have initiated ICT projects such as:  Tarahaat.com by Development Alternatives (Uttar Pradesh and Punjab);  Mahitiz-samuha (Karnataka);  VOICES – Madhyam Communications (Karnataka);  Centre for Alternative Agriculture Media (CAAM); Some exclusive agricultural portals are also available, such as:  haritgyan.com  krishiworld.net  toeholdindia.com  agriwatch.com  itc's soyachoupal.com  acquachoupal.com  plantersnet.com Case Studies These are some of the few examples of ICT enabled services for Indian farmers:Agropedia  Agropedia is a peer-group tool for interaction among the farmers.  This is a comprehensive, integrated model for digitalized content of agricultural domain. This e-initiative intends to bring together a community through ICT enabled knowledge creating and organising platform with an attempt to leverage the current agricultural extension system.  IIT Kanpur (agropedia platform), IIT Bombay and IIITM Kerala (multi-model delivery) are the three key partner organizations who are in charge of different projects and responsibilities along with ICRISAT- Hyderabad, NAARM- Hyderabad, GBPUAT- Pantnagar, UAS- Raichur under the aegis of the National Agricultural Innovation Project (NAIP).  ICRISAT is the consortium leader, which is responsible for the outputs and deliverables.  Agropedia has been labelled as one stop solution for the Indian agro-sphere. Defining and developing the

22

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

 

www.UPSCPDF.com

https://t.me/UPSC_PDF

Knowledge-Model for understanding of the crop has been done first time ever in the world in order to accumulate codified and approved information about the crops with the support of Food and Agriculture Organisation (FAO), Rome. These models are essentially the structural representation by using symbols for tagging a particular piece of information and relationships between them. Following this, Chickpea, Pigeon pea, Sorghum and Groundnut. Knowledge-Models are developed at ICRISAT, Wheat, Sugarcane, Litchi and Vegetable pea are developed at GBPUAT and Rice is developed at IITK.

e-Choupal  e-Choupal is an initiative from ITC's Agri Business Division to face the challenges of India's agricultural uncertainty.  Indian agriculture is characterised by fragmented farms, weak infrastructure and the involvement of numerous intermediaries. e-Choupal aims at bringing out the Indian farmers from vicious circle of low risk taking ability.  To increase the competitiveness of the Indian agricultural sector and enhance productivity, ITC has developed this market-led business model. It is assumed and expected that a growth in rural incomes will also result in the overall growth of Indian economy.  e-Choupal operates in three layers. This three-layered infrastructure allows ITC to provide a complete end-to-end solution to suit the needs of both the farmers and consumers at village as well as in global level.  The first layer consists of ICT kiosks (Village Level) with internet access, managed by an ITC trained local farmer called the Sancalak. The second layer is known as hubs managed by the traditional intermediary who has local knowledge /skills called Samyojak. The final layer is a network of companies (consumers of farmers products and providers of products and services to the farmers) orchestrated by ITC is known as Choupal Sagar, which has a panIndian presence.  With this model, ITC is able to deliver the same benefits as vertical integration does in matured agricultural economies like USA.  e-Choupal is the largest initiative among all Internet-based programmes in rural India. It reaches to over 4 million farmers of more than 400000 villages through 6500 kiosks. It operates across ten states, namely Madhya Pradesh, Haryana, Uttarakhand, Karnataka, Andhra Pradesh, Uttar Pradesh, Rajasthan, Maharashtra, Kerala and Tamil Nadu in the cultivation of soybeans, coffee, wheat, rice, pulses, and shrimp. Kissan Kerala  Kissan Kerala is an Agriculture Information Services system to provide information and advisory to the farmers of Kerala. This is accessible by all concerned anytime in the day and from any parts of the state.  The objective of this programme is to empower the farmers by providing them useful information and required knowledge; this would lead the farmers to take better decision.  To disseminate the message and to answer farmer’s queries, various channels are used like Television, Internet, Telephone, and Mobile. The farmers are free to choose any medium of their choice.  The quintessential feature of this ICT enabled service delivery model is to ensure that the farmers get the expert's assistance on time and agricultural organisations provide necessary help to the farmers.  This has helped the cultivators to better the crop production, enhanced crop protection, value addition to the existing practices, opening up new avenues and improves the overall life of the farming community.  Children, Youth, women, men and seniors are the target group of this programme, who are somewhat related to the agricultural activities.  Kissan Kerala focuses on five broad areas. ◦ Online Agri advisory service : Portal based online Advisory services for the farmers (www.kissankerala.net) ◦ Kissan Krishideepam : Agriculture based weekly Television program in vernacular language ◦ Online Agri video Channel : In collaboration with the You Tube, online agricultural video channel was brought in the country ◦ Tele Advisory Services : Farmers are just a call away from getting solutions to their problems. AQ dedicated phone number is there to address their need ◦ The mobile based Agri Advisory services: Through text, voice or video message, farmers can get their answers on mobile phones AgmarkNet  In order to bring the farmers in a better bargaining position and to promote a culture of good agricultural marketing practices in the country, Directorate of Marketing and Inspection (DMI) , Ministry of Agriculture has embarked upon an ICT Project – NICNET based Agricultural Marketing Information System Network (AGMARKNET ) as part of the Central Sector Scheme : “Marketing Research and Information Network”.  Objectives:

23

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

◦ To establish a nation-wide information network for speedy collection and dissemination of market information and data for its efficient and timely utilization.

◦ To facilitate collection and dissemination of information related to better price realization by the farmers by



facilitating: ▪ Market related information such as market fee, market charges, costs, method of sale, payment, weighment, handling, market functionaries, development programmes, market laws, dispute settlement mechanism, composition of Market Committees, income and expenditure, etc.; ▪ Price-related information such as minimum, maximum and modal prices of varieties and qualities transacted, total arrivals and dispatches with destination, marketing costs and margins, etc.; ▪ Infrastructure related information comprising facilities and services available to the farmers with regard to storage and warehousing, cold storage, direct markets, contract farming, buy-back arrangements, grading, re-handling and repacking etc.; ▪ Promotion related information covering accepted standards and grades, labelling, sanitary and phytosanitary requirements, pledge finance, marketing credit and new opportunities available in respect of better marketing; ◦ To sensitize and orient farmers to respond to new challenges in agricultural marketing by using ICT as a vehicle of extension. ◦ To improve efficiency in agricultural marketing through regular training and extension for reaching regionspecific farmers in their own language. ◦ To provide assistance for marketing research to generate marketing information for its dissemination to farmers and other marketing functionaries at grass-root level to create an ambience of good marketing practices in the country. Under the project, 199 market nodes are computerized and are reporting daily prices of commodities reaching these markets noted. The training to the officials of the department has been conducted.

eMojani

      

eMojani is a software to distributed to land and city survey offices. One can now apply online for his request for measuring his land. All Fees are calculated and displayed by the application. The application allocates the cases to registered Measurement Surveyors of the department. Now the system decides the Surveyors for doing the measurement and not the individual from the department. The application generates the necessary Challan’s, Receipts and prints the Date of Measurement, Name of Surveyors for doing the measurement along with their contact details. This application has been implemented throughout the state. Department has banned the manual maintenance of Measurement case register. Manual applications are no more accepted. The manual calculation of the fees and assigning the cases to the individual Surveyors has been stopped. The eMojani Application is Integrated with Govt. Receipts and Accounts System (GRAS) for on line transfer and accounting of citizen payments towards various fees. The application has been awarded with the “eGovernance Public Jury Award by the State Government” for the year 2012.

Agri - Subsidy  An online application that automates the subsidy distribution operation under various schemes of Agriculture department.  The application is entered online from block level, forwarded to district office Online & the same is sanctioned at District level Online.  While sanctioning the subsidy, it is taken care that necessary funds are available at district office that was allocated from state level office.  The subsidies are granted for 11 different schemes of central & state.  The details of payment of subsidy are also entered online & SMS is sent to the farmer on every event of his application. Various kinds of reports are available for monitoring and evaluation of the project. Kisan Call Centers  The Kisan Call Centre (KCC) initiative aims to provide information to the farming community through toll-free telephone lines.  Under this project, call centre facilities have been extended to the farmers through call centres located in different states so that farmers can get the information in their own language.  Recently KCCs have been further revamped by consolidation and appointing a new service provider for KCC to set up state of the art KCCs at 14 identified locations.

24

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

National e-Governance Plan in Agriculture (NeGP-A)  The Mission Mode Project has been introduced during last phase of the 11th plan to achieve rapid development of agriculture in India through the use of ICT for ensuring timely access to agriculture related information for the farmers of the country.  There are a number of current IT initiatives/schemes undertaken or implemented by DAC which are aimed at providing information to the farmers on various activities in the agriculture value chain.  These initiatives will be integrated so that farmers would be able to make proper and timely use of the available information.  Such information is intended to be provided to farmers through multiple channels including Common Service Centers, Internet Kiosks and SMSs. 12 clusters of services have been identified and the project has been sanctioned for implementation in 7 States i.e. Assam, Himachal Pradesh, Karnataka, Jharkhand, Kerala, Madhya Pradesh and Maharashtra.  The services include Information on Pesticides, Fertilizers & Seeds, Soil Health; Information on crops, farm machinery, training and Good Agricultural Practices (GAPs); Weather advisories; Information on prices, arrivals, procurement points, and providing interaction platform; Electronic certification for exports & import; Information on marketing infrastructure; Monitoring implementation / evaluation of schemes & program; Information on fishery inputs; Information on irrigation infrastructure; Drought Relief and Management; Livestock Management. Bhoomi

   

The land records management system is the first e-Governance project successfully implemented for the benefits of the common man, jointly by the Government of Karnataka & NIC Karnataka. It has been providing service to more than 70 lakh farmers of Karnataka since the last five years. BHOOMI has become the model for replication in many other States. It has received wide spread recognition from the public and also won the international award, Silver of CAPAM 2002. Salient features are Kiosk setup in each taluk to issue the land records documents to public on demand, Finger print (Bio-metrics) authentication to ensure fool proof system, PKI enabled BHOOMI & integration with Sub-Registrar's data, Mutation requests processed on First-in First-out Basis.

TARAhaat  This project, named "TARAhaat" after the all-purpose haat (meaning a village bazaar), comprises a commercially viable model for bringing relevant information, products and services via the Internet to the unserved rural market of India from which an estimated 50% of the national income is derived.  TARAhaat combines a mother portal, TARAhaat.com, supported by franchised networks of village cybercafes and delivery systems to provide a full range of services its clients. Warana Wired Villages  The key objective of the project has been to utilise IT to increase the efficiency and productivity of the existing sugar cane cooperative enterprises by setting up of a state-of-the-art computer communications network.  This provides agricultural, medical, and educational information in the local language to villages around Warana Nagar in the Kolhapur and Sangli Districts of Maharashtra. Dairy Information Services Kiosk  The DISK application targeted at the booming dairy sector has been tested for two milk collection societies by the Indian Institute of Management Ahmedabad’s e-governance center.  The project consists of two basic components—an application running at the rural milk collection society that could be provided Internet connectivity and a portal at the district level serving transactional and information needs of all members.  DISK has helped in the automation of the milk buying process at 2,500 rural milk collection societies and has been tested in two co-operative villages of Amul dairy in Kheda district.  Software called AkashGanga has been developed with special features to enable speedier collection of milk and faster disbursement of payments to dairy farmers. GramSampark  ‘Gramsampark’ is a flagship ICT product of the state of Madhya Pradesh.  A complete database of available resources, basic amenities, beneficiaries of government programmes and public grievances in all the  51,000 villages of Madhya Pradesh can be obtained by accessing the website.  Gramsampark has three sections-Gram Paridrashya (village scenario), Samasya Nivaran (grievance redress) and Gram Prahari (village sentinel). An eleven-point monitoring system has been put in place whereby programmes are

25

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF 

www.UPSCPDF.com

https://t.me/UPSC_PDF

monitored village-wise every month. Four more programmes are under the monitoring system, which includes untouchability-eradication, women’s empowerment, water conservation and campaigns for sanitation.

Digital Gangetic Plane  One of the first few long-distance Wi-Fi projects in the world, the Digital Gangetic Plane (DGP) connects few villages in Uttar Pradesh to internet using wireless network.  Media Lab Asia (MLA) and Indian Institute of Technology (IIT), Kanpur started creating the DGP wireless network.  The even terrain of Gangetic plain allows unhindered line-of-sight signal transmission for wireless networks despite the presence of tall telecom or power supply towers.  Applications developed intervene on education, health and livelihoods.  Bimari Jankari or disease information portal offers healthcare information in Hindi.  Digital Mandiis a one-stop agro-commodities prices shop for rural farming communities.  The portal serves as agricultural knowledge base in Hindi.  DGP is largely limited by its approach of being a technological research focused on innovation, experimentation and deployment of Wi-Fi enabled internet connectivity. Gyandoot  Gyandoot is a rural infokiosk-based e-governance service delivery model initiated by the state government of Madhya Pradesh in Dhar district.  The project aims to create a cost-effective, sustainable and replicable rural internet delivery model for improving government services for the poor, involving citizen’s cooperatives, government and the community. IT and Indian Agriculture in the Future Technologically it is possible to develop suitable systems, as outlined in the previous sections, to cater to the information needs of Indian farmer. User friendly systems, particularly with content in local languages, can generate interest in the farmers and others working at the grassroots. It is possible to create dedicated networks or harnesses the powers of Internet to make these services are available to all parts of the country. The task of creating application packages and databases to cater to complete spectrum of Indian agriculture is a giant task. The Long Term Agriculture Policy provides an exhaustive list of all the areas that are to be covered. This can be taken as a guiding list to evolve design and develop suitable systems catering to each of the specified areas. Our country has the advantage of having a large number of specialised institutions in place catering to various aspects of Indian agriculture. These institutions can play a crucial role in designing the necessary applications & databases and services. This will facilitate modularisation of the task, better control and help in achieving quick results. As it is, several institutions have already developed systems related to their area of specialisation. For quick results, it may be useful to get the applications outsourced to software companies in India. This will facilitate quick deployment of applications and provide boost to the software industry in India. In order to avoid duplication of efforts, it may be useful to consider promoting a coordinating agency which will have an advisory role to play in evolving standard interface for users, broad design and monitoring of the progress. In the post WTO regime, it is suggested that it is useful to focus more on some agricultural products to maintain an unquestionable competitive advantage for exports. This will call for urgent measures to introduce state of the art technologies such as remote sensing, geographical information systems (GIS), bio-engineering, etc. India has made rapid strides in satellite technologies. It is possible to effectively monitor agricultural performance using remote sensing and GIS applications. This will not only help in planning, advising and monitoring the status of the crops but also will help in responding quickly to crop stress conditions and natural calamities. Challenges of crop stress, soil problems, natural disasters can be tackled effectively through these technologies. A beginning in precision farming can be encouraged in larger tracts of land in which export potential can be tilted in our country’s favour. While developing these systems it is necessary to appreciate that major audience that is targeted is not comfortable with computers. This places premium on user friendliness and it may be useful to consider touch screen technologies to improve user comfort levels. It is often observed that touch screen kiosks, with their intuitive approach, provide a means for quick learning and higher participation. It is also necessary to provide as much content as possible in local languages. Once the required application packages & databases are in place, a major challenge is with respect to dissemination of the information. The Krishi Vigyan Kendras, NGOs and cooperative societies may be used to set up information kiosks. Private enterprise is also required to be drawn into these activities. These kiosks should provide information on other areas of interest such as education, information for which people have to travel distances such as those related to the government, courts, etc.

26

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

Facilities for email, raising queries to experts, uploading digital clips to draw the attention of experts to location specific problems can be envisaged. Constraints and Remedies for Effective Dissemination Educating and catering to the information needs of farmers across nearly seven lakh villages in India indeed sounds unrealistic as this would require immense financial investment. A one-time major investment in establishing communication technologies in the required places restricts the government’s objective of covering more people regularly because of insufficient power availability in rural areas, poor ICT infrastructure, ICT illiteracy, non-availability of timely relevant content, non-integration of services, poor advisory services and lack of localization, and in particular non availability of agricultural information kiosks/ knowledge centers at the grass root level. Some of the major constraints delaying the spread of e-revolution to rural India are listed below:  Haphazard development: It is observed that some initiatives have already been made to provide IT based services to rural community. However, duplication of efforts are witnessed as most of the services revolve around limited subjects. Keeping in view the giant task involved, it is necessary to form a coordination mechanism to strive for a concerted effort to support farming community in the country. Such a coordination agency may only have advisory powers such as user interface, broad design, delivery mechanism of the content and standards for setting up kiosks.  User friendliness: The success of this strategy depends on the ease with which rural population can use the content. This will require intuitive graphics based presentation. Touch screen kiosks are required to be set up to encourage greater participation.  Awareness about the Benefits of ICT: Farmers sometimes become averse to adopting technology as they think that it might result in their losing their traditional methods of cropping practices. They simply do not want to use such systems, even if the cost incurred is negligible. Therefore, the attitude and mindset of farmers needs to be changed first. There is a need to win their confidence and create awareness about the benefits of ICT in agriculture.  Local languages: Regional language fonts and mechanisms for synchronisation of the content provides a challenge that needs to be met with careful planning.  Restrictions: Information content based on remote sensing and geographical information systems can provide timely alerts to the farmers and also improve the efficiency of administration. These applications can have a major impact on the farmers and help them to appreciate the potential of information technology. However, government’s map restriction policies often threaten to stifle the optimal utilisation of these tools.  Power Supply: In most of the rural India, power supply is not available for long hours. This will reduce the usefulness of the intended services. Since almost entire country receives sunshine for most part of the year, it is useful to explore solar power packs for UPS as well as for supply of power. The Ministry of Non-conventional Energy Sources may pay special attention in this area which can be a major contributor to the growth of IT in villages.  Connectivity: Despite the phenomenal progress made in the recent years, the connectivity to rural areas still requires to be improved. Reliable connectivity is a prerequisite for a successful penetration of IT into rural areas. Many private ISPs are setting up large networks connecting many major towns and cities. Since some of these networks pass through rural areas, it is possible to provide connectivity to a large number of villages. Several technologies exist that can be utilised for connecting rural areas. Cable network is a possible medium for providing the last mile connectivity to villages.  Bandwidth: Even in areas where telephone and other communication services exist, the available bandwidth is a major constraint. Since internet based rural services require substantial use of graphics, low bandwidth is one of the major limitations in providing effective e-services to farmers. As already stated, networks with high bandwidth are being set up by several companies passing through rural segments which can be utilised. Until this materialises, a two pronged strategy of storing static information at the kiosks and providing dynamic information from remote locations can be examined. The graphic oriented content which does not change frequently, such as, demonstration clips for farmers, can be stored on the local drives at the kiosks and arrange for periodic updation of this information over the network during non-peak hours. The dynamic information which changes more frequently can be accessed from remote locations to obtain the latest status.  Dissemination Points: Mass deployment of information kiosks is critical for effective use of the Internet based content and services. In order to ensure that the information kiosks are economically feasible, it is necessary to make the proposition sustainable and viable. This requires a major focus on a viable revenue model for such kiosks. In the new information era, the kiosks should be designed to become electronic super markets that can, in addition to being information sources, handle other services of use to the people living in rural areas. The revenue available through such sources can make a kiosk attractive for prospective investors. The Government can provide finance facilities to unemployed rural agricultural graduates who can be expected to have greater commitment and at the same time act as an efficient interface for less educated rural visitors. The objective should be to transform rural information kiosks into ‘clicks and mortar’ gateway to rural India for ‘Bricks and mortar’ industry. Some of the sources that can generate revenue for rural kiosks are : ◦ Distance Education: A large number of people travel substantial distances to attend educational courses. It is

27

www.visionias.in

©Vision IAS

https://t.me/UPSC_PDF

www.UPSCPDF.com

https://t.me/UPSC_PDF

possible to set up virtual classrooms right in their villages.

◦ Training: People living in rural areas require training and a means for upgrading their skills in their area of



work. It is possible to provide quality education right at their door steps with facilities for online interaction with experts. For example, a village teacher or a paramedical staff can keep abreast latest developments without disturbing his/her routine. Similarly, training can be imparted on various aspects of agriculture such as correct practices, irrigation practices, efficient utilisation of tools used in farming such as tractors. ◦ Insurance: The advent of private players into insurance has brought about advanced IT systems that can render services over networks. The kiosks can be insurance agents for insurance firms which, in turn, can compensate the kiosk operators for online transactions for new business as well as maintaining the old. ◦ Local Agent: Many companies have difficulty in working out logistics for their supplies to rural outlets. A rural kiosk can act as conduit for such ‘bricks and mortar’ companies. This has the potential of transforming a rural kiosk into a profitable venture. ◦ Rural Post Office: The kiosks can facilitate sending and receiving emails, facilitate ‘chats’ with experts. Several successful rural kiosks are already available in many states which run essentially on this model. ◦ E-Governance: Rural kiosks are the stepping stones for effective implementation of e-governance. Details related to central / state / local governments, formats and procedures, status verification such as case listings in courts, filing of applications in electronic format where admissible, etc. are some of the areas where kiosks can be of major use. ◦ Online Examinations: Online certification examinations are ‘in things’ with many organisations and certification agencies. Many people are forced to stay at metros to take the examinations. Eventually it should be possible to conduct these examinations through the rural kiosks. Stake Holders: At present, several initiatives have been taken in the form of websites / portals targeting rural India. These are at best sketchy information sources catering to pockets of rural India. It is to be noted that strong interlinkages exist within entire rural India and concerted and coordinated effort is required for carrying the benefits of IT to rural India. The magnitude of the task is such that no single institution or organisation can accomplish it. It is necessary for stake holders in rural India, such as fertiliser industry, to come together to provide adequate thrust to the effort initially. The fertiliser industry distributes more than 15 million tonnes of nutrients per annum in the country involving complex production, logistics and storage operations. A small savings made possible through better management of information up to the point of delivery to farmers can mean significant savings. The success of e-powering Indian agriculture is high if fertiliser industry makes a concerted and coordinated effort to set up Business to Business (B-B) market place with dealer / cooperative networks. The consumer industry also benefits from efficient operations in rural India. The corporate India may be willing to participate in a joint effort that proves beneficial to them as well as the rural India. The Government of India may, as outlined above, initiate a coordinating agency where various stake holders can join hands to spread e-culture to rural India and at the same time benefit from efficient operations.

Conclusion The Indian farmer and those who are working for their welfare need to be e-powered to face the emerging scenario of complete or partial deregulation & reduction in government protection, opening up of agricultural markets, fluctuations in agricultural environment and to exploit possible opportunities for exports. The quality of rural life can also be improved by quality information inputs which provide better decision making abilities. IT can play a major role in facilitating the process of transformation of rural India to meet these challenges and to remove the fast growing digital devides. The rapid changes in the field of information technology make it possible to develop and disseminate required electronic services to rural India. The existing bottlenecks in undertaking the tasks need to be addressed immediately. A national strategy needs to be drawn for spearheading IT penetration to rural India. A national coordinating agency with an advisory role can act as a catalyst in the process. No single institution or organisation alone can succeed in the task of e-powering farmers and rural India. At the same time, scattered and half hearted attempts cannot be successful in meeting the objective. Industries with major stake in villages, such as fertiliser sector, should come together to provide the initial impetus. The success of any IT based service to rural India hinges on evolving a proper revenue model for the dissemination points. The information kiosks can draw revenue from the industry by providing and disseminating required services. Once these dissemination points prove to be economically viable, the IT revolution in rural India will require no crusaders.

Copyright © by Vision IAS All rights are reserved. No part of this document may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, without prior permission of Vision IAS 28

www.visionias.in

©Vision IAS