11 - std'09 - social science - geography - contemporary india part-i

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Page 1: 11 - Std'09 - Social Science - Geography - Contemporary India Part-I
Page 2: 11 - Std'09 - Social Science - Geography - Contemporary India Part-I

iv

CONTENTCONTENTCONTENT

Chapter 1 1-6India – Size and Location

Chapter 2 7-16Physical Features of India

Chapter 3 17-25Drainage

Chapter 4 26-41Climate

Chapter 5 42-51Natural Vegetation and Wild Life

Chapter 6 53-60Population

Glossary 61-62

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The Tropic of Cancer (23° 30'N) divides thecountry into almost two equal parts. To thesoutheast and southwest of the mainland, liethe Andaman and Nicobar islands and theLakshadweep islands in Bay of Bengal andArabian Sea respectively. Find out the extentof these groups of islands from your atlas.

SIZE

The land mass of India has an area of 3.28million square km. India’s total area accountsfor about 2.4 per cent of the total geographical

India is one of the ancient civilisations in theworld. It has achieved multi-faceted socio-economic progress during the last five

decades. It has moved forward displayingremarkable progress in the field ofagriculture, industry, technology and overalleconomic development. India has alsocontributed significantly to the making ofworld history.

LOCATION

India is a vast country. Lying entirely in theNorthern hemisphere (Figure 1.1) the mainland extends between latitudes 8°4'N and37°6'N and longitudes 68°7'E and 97°25'E.

INDIA – SIZE AND LOCATION

Figure 1.1 : India in the World

• The southernmost point ofthe Indian Union– ‘Indira Point’ got submerged underthe sea water in 2004 during the Tsunami.

180°W 150° 120° 90° 60° 30°W 0° 180°E150°120°90°60°30°E

INDIANOCEANINDIANOCEAN

AntarticaAntartica

75°N

60°

30°

15°N

15°S

45°

60°

75°S

PACIFICOCEAN

PACIFICOCEAN

ATLANTICOCEAN

ATLANTICOCEAN

PACIFICOCEAN

PACIFICOCEAN

AfricaAfrica

AsiaAsia 45°EuropeEurope

NorthAmericaNorthAmerica

SouthAmericaSouthAmerica

AustraliaAustralia30°

1

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CONTEMPORARY INDIA2

area of the world. From the Figure 1.2 it isclear that India is the seventh largestcountry of the world. India has a landboundary of about 15,200 km and the totallength of the coast line of the mainlandincluding Andaman and Nicobar andLakshadweep is 7,516.6 km.

India is bounded by the young foldmountains in the northwest, north andnorth east. South of about 22° northlatitude, it begins to taper, and extendstowards the Indian Ocean, dividing it intotwo seas, the Arabian Sea on the west andthe Bay of Bengal on its east.

Look at Figure 1.3 and note that thelatitudinal and longitudinal extent of themainland is about 30°. Despite this fact theeast-west extent appears to be smaller thanthe north-south extent.

From Gujarat to Arunachal Pradeshthere is a time lag of two hours. Hence, timealong the Standard Meridian of India(82°30'E) passing through Mirzapur (inUttar Pradesh) is taken as the standard timefor the whole country. The latitudinal extentinfluences the duration of the day and night,as one moves from south to north.

• Why 82°30'E has been selected as the StandardMeridian of India?

• Why is the difference between the durationsof day and night hardly felt at Kanniyakumaribut not so in Kashmir?

INDIA AND THE WORLD

The Indian landmass has a central locationbetween the East and the West Asia. India is asouthward extension of the Asian Continent.The trans Indian Ocean routes which connectthe countries of Europe in the West and thecountries of East Asia provide a strategic centrallocation to India. Note that the Deccan Peninsulaprotrudes into the Indian Ocean, thus helpingIndia to establish close contact with West Asia,Africa and Europe from the western coast andwith Southeast and East Asia from the easterncoast. No other country has a long coastline onthe Indian Ocean as India has and indeed, it isIndia’s eminent position in the Indian Oceanwhich justifies the naming of an Ocean after it.

Figure 1.2 : Seven Largest Countries of the World

Source : Based on World Population Data Sheet, 2005, Population Reference Bureau, Washington, DC

Since the opening of theSuez Canal in 1869, India’s distance from Europehas been reduced by 7,000 km.

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INDIA – SIZE AND LOCATION 3

Figure 1.3 : India : Extent and Standard Meridian

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CONTEMPORARY INDIA4

Figure 1.4 : India on International Highway of Trade and Commerce

• The number of Union Territoriesalong the western and eastern coasts.• Area-wise which is the smallest and which isthe largest state?• The states which do not have an internationalborder or lie on the coast• Classify the states into four groups eachhaving common frontiers with(i) Pakistan, (ii) China, (iii) Myanmar, and(iv) Bangladesh.

India shares its land boundaries withPakistan and Afghanistan in the northwest,China (Tibet), Nepal and Bhutan in the northand Myanmar and Bangladesh in the east.Our southern neighbours across the seaconsist of the two island countries, namely

India’s contacts with the World havecontinued through the ages but her relationshipsthrough the land routes are much older thanher maritime contacts. The various passes acrossthe mountains in the north have providedpassages to the ancient travellers, while theoceans restricted such interaction for a long time.

These routes have contributed in theexchange of ideas and commodities sinceancient times. The ideas of the Upanishadsand the Ramayana, the stories of Panchtantra,the Indian numerals and the decimal systemthus could reach many parts of the world. Thespices, muslin and other merchandise weretaken from India to different countries. On theother hand, the influence of Greek sculpture,and the architectural styles of dome andminarets from West Asia can be seen indifferent parts of our country.

INDIA’S NEIGHBOURS

India occupies an important strategic positionin South Asia. India has 28 states and 7 UnionTerritories (Figure 1.5).

Before 1947, there were twotypes of states in India – the provinces and thePrincely states. Provinces were ruled directly byBritish officials who were appointed by theViceroy. Princely states were ruled by local,hereditary rulers, who acknowledged sovereignityin return for local autonomy.

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INDIA – SIZE AND LOCATION 5

Figure 1.5 : India and Adjacent Countries

Sri Lanka and Maldives. Sri Lanka isseparated from India by a narrow channelof sea formed by the Palk Strait and the Gulfof Mannar while Maldives Islands are situatedto the south of the Lakshadweep Islands.

India has had strong geographical andhistorical links with her neighbours. Lookat the physical map of Asia in your atlas,and note how India stands apart from therest of Asia.

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CONTEMPORARY INDIA6

1. Choose the right answer from the four alternatives given below.(i) The Tropic of Cancer does not pass through

(a) Rajasthan (c) Chhattisgarh(b) Orissa (d) Tripura

(ii) The easternmost longitude of India is(a) 97° 25' E (c) 77° 6' E(b) 68° 7' E (d) 82° 32' E

(iii) Uttaranchal, Uttar Pradesh, Bihar, West Bengal and Sikkim have commonfrontiers with(a) China (c) Nepal(b) Bhutan (d) Myanmar

(iv) If you intend to visit Kavarati during your summer vacations, which one ofthe following Union Territories of India you will be going to(a) Pondicherry (c) Andaman and Nicobar(b) Lakshadweep (d) Diu and Daman

(v) My friend hails from a country which does not share land boundary withIndia. Identify the country.(a) Bhutan (c) Bangladesh(b) Tajikistan (d) Nepal

2 Answer the following questions briefly.(i) Name the group of islands lying in the Arabian sea.(ii) Name the countries which are larger than India.

(iii) Which island group of India lies to its south-east?(iv) Which island countries are our southern neighbours?

3 The sun rises two hours earlier in Arunachal Pradesh as compared to Gujaratin the west but the watches show the same time. How does this happen?

4 The central location of India at the head of the Indian Ocean is considered ofgreat significance. Why?

MAP SKILLS

1. Identify the following with the help of map reading.(i) The Island groups of India lying in the Arabian Sea and the Bay of Bengal.(ii) The countries constituting Indian Subcontinent.

(iii) The states through which the Tropic of Cancer passes.(iv) The northernmost latitude in degrees.(v) The southernmost latitude of the Indian mainland in degrees.

(vi) The eastern and the western most longitude in degrees.(vii) The place situated on the three seas.

(viii) The strait separating Sri Lanka from India.(ix) The Union Territories of India.

PROJECT/ACTIVITY

(i) Find out the longitudinal and latitudinal extent of your state.(ii) Collect information about the ‘Silk Route’. Also find out the new

developments, which are improving communication routes in the regions ofhigh altitude.

EXERCISE

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You have already learnt earlier that Indiais a vast country with varied landforms.What kind of terrain do you live in? If

you live in the plains you are familiar with thevast stretches of plain land. In contrast, if youlive in hilly region, the rugged terrain withmountains and valleys are common features.In fact, our country has practically all majorphysical features of the earth i.e. mountains,plains, deserts, plateaus and islands. Youmust be wondering how these physicalfeatures have been formed. We will learn moreabout major physical features of India and howthey have been formed.

We find different types of rocks; some arevery hard like marble which has been used formaking the Taj Mahal, and some are very softlike soap stone which is used in making talcumpowder. The colour of soil varies from one placeto the other because soil is formed out ofdifferent types of rocks. Have you ever thoughtabout the causes of these variations? Most ofthese variations are caused due to differencesin rock formations.

India is a large landmass formed duringdifferent geological periods which has influencedher relief. Besides geological formations, anumber of processes such as weathering,erosion and deposition have created andmodified the relief to its present form.

Earth scientists have attempted to explainthe formation of physical features with the helpof some theories based on certain evidences.One such plausible theory is the “Theory of PlateTectonics”. According to this theory, the crust(upper part) of the earth has been formed out ofseven major and some minor plates. (Figure 2.2)

PHYSICAL FEATURES OF INDIA

The movement of the plates results in thebuilding up of stresses within the plates and thecontinental rocks above, leading to folding,faulting and volcanic activity. Broadly, theseplate movements are classified into threetypes(Figure 2.1). While some plates come towardseach other and form convergent boundary. Someplates move away from each other and formdivergent boundary. In the event of two platescoming together they may either collide andcrumble, or one may slide under the other. Attimes, they may also move horizontally past

PLATEPLATEPLATEPLATE

Divergent Boundary

Mantle

Convergent Boundary

PLATEPLATEPLATEPLATE

PLATEPLATE

PLATEPLATE

Mantle

Transform Boundary

Mantle

Mantle

Figure 2.1 : Plate Boundaries

2

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CONTEMPORARY INDIA8

each other and form transform boundary. Themovement of these plates have changed theposition and size of the continents over millionsof years. Such movements have also influencedthe evolution of the present landform featuresrelief of India.

Gondwanaland: It is the southern part of the ancientsuper continent Pangea with Angara Land in thenorthern part.

The Himalayan uplift out of the Tethys seaand subsidence of the northern flank of thepeninsular plateau resulted in the formationof a large basin. In due course of time thisdepression, gradually got filled with depositionof sediments by the rivers flowing from themountains in the north and the peninsularplateau in the south. A flat land of extensivealluvial deposits led to the formation of thenorthern plains of India.

The land of India displays great physicalvariation. Geologically, the Peninsular Plateauconstitutes one of the ancient landmasses onthe earth’s surface. It was supposed to be oneof the most stable land blocks. The Himalayasand the Northern Plains are the most recentlandforms. From the view point of geology,Himalayan mountains form an unstable zone.The whole mountain system of Himalayarepresents a very youthful topography withhigh peaks, deep valleys and fast flowing rivers.The northern plains are formed of alluvial

Most volcanoes andearthquakes in the world are located at platemargins, but some do occur within the plates.

Figure 2.2 : World : Plate Margins

The oldest landmass, (the Peninsula part), wasa part of the Gondwana land. The Gondwanalandincluded India, Australia, South Africa and SouthAmerica as one single land mass. The convectionalcurrents split the crust into a number of pieces,thus leading to the drifting of the Indo-Australianplate after being separated from the Gondwanaland, towards north. The northward drift resultedin the collision of the plate with the much largerEurasian Plate. Due to this collision, thesedimentary rocks which were accumulated inthe geosyncline known as the Tethys were foldedto form the mountain system of western Asia andHimalaya.

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PHYSICAL FEATURES OF INDIA 9

deposits. The peninsular plateau is composedof igneous and metamorphic rocks with gentlyrising hills and wide valleys.

MAJOR PHYSIOGRAPHIC DIVISIONS

The physical features of India can be groupedunder the following physiographic divisions(Figure 2.4):(i) The Himalayan Mountains(ii) The Northern Plains(iii) The Peninsular Plateau(iv) The Indian Desert(v) The Coastal Plains(vi) The Islands

The Himalayan Mountains

The Himalayas, geologically young andstructurally fold mountains stretch over the

Figure 2.3 : Himalayas

northern borders of India. These mountainranges run in a west-east direction from theIndus to the Brahmaputra. The Himalayasrepresent the loftiest and one of the mostrugged mountain barriers of the world. Theyform an arc, which covers a distance of about2,400 Km. Their width varies from 400 Kmin Kashmir to 150 Km in Arunachal Pradesh.The altitudinal variations are greater in theeastern half than those in the western half.The Himalaya consists of three parallelranges in its longitudinal extent. A numberof valleys lie between these ranges. Thenorthern most range is known as the Greator Inner Himalayas or the ‘Himadri’. It is themost continuous range consisting of theloftiest peaks with an average height of 6,000metres. It contains all the prominentHimalayan peaks.

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CONTEMPORARY INDIA10

Figure 2.4 : Relief

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PHYSICAL FEATURES OF INDIA 11

Some Highest Peaks of the Himalayas

Peak Country Heightin metres

Mt. Everest Nepal 8848Kanchenjunga India 8598Makalu Nepal 8481Dhaulagiri Nepal 8172Nanga Parbat India 8126Annapurna Nepal 8078Nanda Devi India 7817Kamet India 7756Namcha Barwa India 7756Gurla Mandhata Nepal 7728

The folds of Great Himalayas areasymmetrical in nature. The core of this partof Himalayas is composed of granite. It isperennially snow bound, and a number ofglaciers descend from this range.

alluvium. The longitudinal valley lyingbetween lesser Himalaya and the Shiwaliks areknown as Duns. Dehra Dun, Kotli Dun andPatli Dun are some of the well-known Duns.

Besides the longitudinal divisions, theHimalayas have been divided on the basis ofregions from west to east. These divisionshave been demarcated by river valleys. Forexample, the part of Himalayas lying betweenIndus and Satluj has been traditionallyknown as Punjab Himalaya but it is alsoknown regionally as Kashmir and HimachalHimalaya from west to east respectively. Thepart of the Himalayas lying between Satlujand Kali rivers is known as KumaonHimalayas. The Kali and Tista riversdemarcate the Nepal Himalayas and the partlying between Tista and Dihang rivers isknown as Assam Himalayas. There areregional names also in these broadcategories. Find out some regional names ofthe Himalayas

The Brahmaputra marks the eastern mostboundary of the Himalayas. Beyond the Dihanggorge, the Himalayas bend sharply to the southand spread along the eastern boundary ofIndia. They are known as the Purvanchal orthe Eastern hills and mountains. These hillsrunning through the north-eastern states aremostly composed of strong sandstones whichare sedimentary rocks. Covered with denseforests, they mostly run as parallel rangesand valleys. The Purvanchal comprises the

• The names of the glaciers and passesthat lie in Great Himalayas• The name of the states where highest peaksare located.

• Location of Mussoorie, Nainital,Ranikhet from your atlas and also name the statewhere they are located.

Figure 2.5 : The Himalayas

The range lying to the south of the Himadriforms the most rugged mountain system andis known as Himachal or lesser Himalaya. Theranges are mainly composed of highlycompressed and altered rocks. The altitudevaries between 3,700 and 4,500 metres andthe average width is of 50 Km. While the PirPanjal range forms the longest and the mostimportant range, the Dhaula Dhar and theMahabharat ranges are also prominent ones.This range consists of the famous valley ofKashmir, the Kangra and Kullu Valley inHimachal Pradesh. This region is well knownfor its hill stations.

The outer most range of the Himalayas iscalled the Shiwaliks. They extend over a widthof 10-50 Km and have an altitude varyingbetween 900 and 1100 metres. These rangesare composed of unconsolidated sedimentsbrought down by rivers from the mainHimalayan ranges located farther north. Thesevalleys are covered with thick gravel and

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CONTEMPORARY INDIA12

Patkai hills, the Naga hills, Manipur hills andthe Mizo hills.

The Northern Plain

The northern plain has been formed by theinterplay of the three major river systems,namely– the Indus, the Ganga and theBrahmaputra along with their tributaries. Thisplain is formed of alluvial soil. The depositionof alluvium in a vast basin lying at the foothillsof the Himalaya over millions of years, formedthis fertile plain. It spreads over an area of 7lakh sq. km. The plain being about 2400 Kmlong and 240 to 320 Km broad, is a denselypopulated physiographic division. With a richsoil cover combined with adequate watersupply and favourable climate it isagriculturally a very productive part of India.

The rivers coming from northernmountains are involved in depositional work.In the lower course, due to gentle slope, thevelocity of the river decreases which results inthe formation of riverine islands.

The rivers in their lower course split intonumerous channels due to the deposition of silt.These channels are known as distributaries.

The Northern Plain is broadly divided intothree sections. The Western part of the NorthernPlain is referred to as the Punjab Plains.Formed by the Indus and its tributaries, thelarger part of this plain lies in Pakistan. TheIndus and its tributaries–the Jhelum, theChenab, the Ravi, the Beas and the Satlujoriginate in the Himalaya. This section of theplain is dominated by the doabs.

Figure 2.7 : The Northern Plains

Majuli, in the BrahmaputraRiver is the largest inhabited riverine island in theworld.

Figure 2.6 : Mizo Hills

‘Doab’ is made up of twowords- ‘do’ meaning two and ‘ab’ meaning water.Similarly ‘Punjab’ is also made up two words- ‘Punj’meaning five and ‘ab’ meaning water.

The Ganga plain extends between Ghaggarand Teesta rivers. It is spread over the states ofNorth India, Haryana, Delhi, U.P., Bihar, partlyJharkhand and West Bengal to its East,particularly in Assam lies the Brahmaputra plain.

The northern plains are generally deseribedas flat land with no variations in its relief. It isnot true. These vast plains also have diverserelief features. According to the variations inrelief features, the Northern plains can bedivided into four regions. The rivers, afterdescending from the mountains depositpebbles in a narrow belt of about 8 to 16 kmin width lying parallel to the slopes of theShiwaliks. It is known as bhabar. All thestreams disappear in this bhabar belt. Southof this belt, the streams and rivers re-emergeand create a wet, swampy and marshy regionknown as terai. This was a thickly forestedregion full of wildlife. The forests have beencleared to create agricultural land and to settlemigrants from Pakistan after partition. LocateDudhwa National Park in this region.

The largest part of the northern plain isformed of older alluvium. They lie above theflood plains of the rivers and present a terracelike feature. This part is known as bhangar.

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PHYSICAL FEATURES OF INDIA 13

The Deccan Plateau is a triangular landmassthat lies to the south of the river Narmada. TheSatpura range flanks its broad base in the northwhile the Mahadev, the Kaimur hills and theMaikal range form its eastern extensions. Locatethese hills and ranges in the physical map ofIndia. The Deccan Plateau is higher in the westand slopes gently eastwards. An extension of thePlateau is also visible in the northeast– locallyknown as the Meghalaya and Karbi-AnglongPlateau. It is separated by a fault from theChotanagpur Plateau. Three Prominent hillranges from the west to east are the Garo, theKhasi and the Jaintia Hills.

The Western Ghats and the Eastern Ghatsmark the western and the eastern edges of theDeccan Plateau respectively. Western ghats lieparallel to the western coast. They are continuousand can be crossed through passes only. Locatethe Thal, Bhor and the Pal Ghats in the Physicalmap of India.

The Western Ghats are higher than theEastern Ghats. Their average elevation is 900–1600 metres as against 600 metres of theEastern Ghats. The Eastern Ghats stretch fromthe Mahanadi Valley to the Nigiris in the south.The Eastern Ghats are discontinuous andirregular and dissected by rivers draining intothe Bay of Bengal. The Western Ghats causeorographic rain by facing the rain bearing moistwinds to rise along the western slopes of theGhats. The Western Ghats are known bydifferent local names. The height of the WesternGhats progressively increases from north tosouth. The highest peaks include the AnaiMudi (2,695metres) and the Doda Betta (2,637metres). Mahendragiri (1,501 metres) is thehighest peak in the Eastern Ghats. ShevroyHills and the Javadi Hills are located to thesoutheast of the Eastern Ghats. Locate thefamous hill stations of Udagamandalam,popularly known as Ooty and the Kodaikanal.

One of the distinct features of the peninsularplateau is the black soil area known as DeceanTrap. This is of volcanic origin hence the rocksare igneous. Actually these rocks havedenuded over time and are responsible for theformation of black soil. The Aravali Hills lie onthe western and northwestern margins of the

The soil in this region contains calcareousdeposites locally known as kankar. The newer,younger deposits of the flood plains are calledkhadar. They are renewed almost every yearand so are fertile, thus, ideal for intensiveagriculture.

The Peninsular Plateau

The Peninsular plateau is a tablelandcomposed of the old crystalline, igneous andmetamorphic rocks. It was formed due to thebreaking and drifting of the Gondwana landand thus, making it a part of the oldestlandmass. The plateau has broad and shallowvalleys and rounded hills. This plateauconsists of two broad divisions, namely, theCentral Highlands and the Deccan Plateau.The part of the Peninsular plateau lying tothe north of the Narmada river covering amajor area of the Malwa plateau is known asthe Central Highlands. The Vindhyan rangeis bounded by the Central Highlands on thesouth and the Aravalis on the northwest. Thefurther westward extension gradually mergeswith the sandy and rocky desert of Rajasthan.The flow of the rivers draining this region,namely the Chambal, the Sind, the Betwa andKen is from southwest to northeast, thusindicating the slope. The Central Highlandsare wider in the west but narrower in the east.The eastward extensions of this plateau arelocally known as the Bundelkhand andBaghelkhand. The Chotanagpur plateaumarks the further eastward extension,drained by the Damodar river.

Figure 2.8 : A waterfall in Chotanagpur Plateau

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CONTEMPORARY INDIA14

peninsular plateau. These are highly erodedhills and are found as broken hills. They extendfrom Gujarat to Delhi in a southwest-northeastdirection.

The Indian Desert

The Indian desest lies towards the westernmargins of the Aravali Hills. It is an undulatingsandy plain covered with sand dunes. Thisregion receives very low rainfall below 150 mmper year. It has arid climate with low vegetatincover. Streams appear during the rainyseason. Soon after they disappear into thesand as they do not have enough water toreach the sea. Luni is the only large river inthis region.

The plain along the Bay of Bengal are wideand level. In the northern part, it is referred toas the Northern Circar, while the southern partis known as the Coromandal Coast. Largerivers such as the Mahanadi, the Godavari, theKrishna and the Kaveri have farmed extensivedelta on this coast. Lake Chilika is animportant feature along the eastern coast.

The Chilika Lake is thelargest salt water lake in India. It lies in the stateof Orissa, to the south of the Mahanadi delta.

The Islands

You have already seen that India has a vast mainland. Besides this, the country has also two groupsof islands. Can you identify these island groups?

Figure 2.10 : The Coastal Plains

Figure 2.11 : An Island

Figure 2.9 : The Indian Desert

Barchans (crescent shaped dunes) coverlarger areas but longitudinal dunes becomemore promiment near the Indo-Pakistanboundary. If you visit Jaisalmer, you may goto see a group of barchans.

The Coastal Plains

The Peninsular plateau is flanked by stretchof narrow coastal strips, running along theArabian Sea on the west and the Bay of Bengalon the east. The western coast, sandwichedbetween the Western Ghats and the ArabianSea, is a narrow plain. It consists of threesections. The northern part of the coast is calledthe Konkan (Mumbai – Goa), the central stretchis called the Kannad Plain while the southernstretch is referred to as the Malabar coast.

Locate the Lakshadweep Islands grouplying close to the Malabar coast of Kerala. Thisgroup of islands is composed of small coralisalnds. Earlier they were known as Laccadive,Minicoy and Amindive. In 1973 these were

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PHYSICAL FEATURES OF INDIA 15

Corals

Coral polyps are short-lived microscopicorganisms, which live in colonies. They flourishin shallow, mud free and warm waters. Theysecrete hard rock like substance. The coralsecretion and their skeletons from coral depositsin the form of reefs:. they are mainly of threekinds: barrier reef. fringing reef and atolls. TheGreat Barrier Reef of Australia is a good exampleof the first kind of coral reefs. Atolls are circularor horse shoe shaped coral reefs.

named as Lakshadweep. It covers small areaof 32 sq km. Kavaratti island is theadministrative headquarters of Lakshadweep.This island group has great diversity of floraand fauna. The Pitli island, which isuninhabited, has a bird sanctuary.

starategic importance for the country. Thereis great diversity of flora and fauna in thisgroup of islands too. These islands lie close toequator and experience equatorial climate andhas thick forest cover.

1. Choose the right answer from the four alternatives given below.(i) A landmass bounded by sea on three sides is referred to as

(a) Coast (c) Peninsula(b) Island (d) none of the above

(ii) Mountain ranges in the eastern part of India forming its boundary withMyanmar are collectively called as(a) Himachal (c) Purvanchal(b) Uttaranchal (d) none of the above

(iii) The western coastal strip, south of Goa is referred to as(a) Coromandal (c) Kannad(b) Konkan (d) Northern Circar

(iv) The highest peak in the Eastern Ghats is(a) Anai Mudi (c) Mahendragiri(b) Kanchenjunga (d) Khasi

2 Answer the following questions briefly.(i) What are tectonic plates?

(ii) Which continents of today were part of the Gondwana land?

Now you see the elongated chain of islandslocated in the Bay of Bengal extending fromnorth to south. These are Andaman andNicobar islands. They are bigger in size andare more numerous and scattered. The entiregroup of islands is divided into two broadcategories – The Andaman in the north andthe Nicobar in the south. It is believed that theseislands are an elevated portion of submarinemountains. These island groups are of great

India’s only active volcano isfound on Barren island in Andaman and Nicobargroup of Islands.

A detailed account of the differentphysiographic units highlights the uniquefeatures of each region. It would, hoever,be clear that each region complements theother and makes the country richer in itsnatural resources. The northern mountainsare the major sources of water and forestwealth. The norhtern plains are thegranaries of the country. They provide thebase for early civilisations. The plateau is astorehouse of minerals, which has played acrucial role in the industrialisation of thecountry. The coastal region and islandgroups provide sites for fishing and portactivities. Thus, the diverse physicalfeatures of the land have immense futurepossibilities of development.

EXERCISE

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CONTEMPORARY INDIA16

(iii) What is the bhabar?(iv) Name the three major divisions of the Himalayas from north to south.(v) Which plateau lies between the Aravali and the Vindhyan ranges?

(vi) Name the island group of India having coral origin.3. Distinguish between

(i) Converging and diverging tectonic plates(ii) Bhangar and Khadar

(iii) Western Ghats and Eastern Ghats4. Describe how the Himalayas were formed.5. Which are the major physiographic divisions of India? Contrast the relief of the

Himalayan region with that of the Peninsular plateau.6. Give an account of the Northern Plains of India.7. Write short notes on the following.

(i) The Indian Desert(ii) The Central Highlands

(iii) The Island groups of India

MAP SKILLS

On an outline map of India show the following.(i) Mountain and hill ranges – the Karakoram, the Zaskar, the Patkai Bum, the

Jaintia, the Vindhya range, the Aravali, and the Cardamom hills.(ii) Peaks – K2, Kanchenjunga, Nanga Parbat and the Anai Mudi.

(iii) Plateaus, Chotanagpur and Malwa(iv) The Indian Desert, Western Ghats, Lakshadweep Islands

PROJECT/ACTIVITY

Locate the peaks, passes, ranges, plateaus, hills, and duns hidden in the puzzle.Try to find where these features are located. You may start your search horizontally,vertically or diagonally.

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Water Divide

Sream

ASrea

mB

Figure 3.1 : Water Divide

DRAINAGE

The term drainage describes the riversystem of an area. Look at the physicalmap. You will notice that small streams

flowing from different directions come togetherto form the main river, which ultimately drainsinto a large water body such as a lake or a seaor an ocean. The area drained by a single riversystem is called a drainage basin. A closerobservation on a map will indicate that anyelevated area, such as a mountain or an upland,separates two drainage basins. Such an uplandis known as a water divide (Figure 3.1).

The world’s largest drainagebasin is of the Nile river in Egypt

Figure 3.2 : A Gorge

subcontinent. Accordingly, the Indian riversare divided into two major groups:• the Himalayan rivers; and• the Peninsular rivers.

Apart from originating from the two majorphysiographic regions of India, the Himalayanand the Peninsular rivers are different fromeach other in many ways. Most of theHimalayan rivers are perennial. It meansthat they have water throughout the year.These rivers receive water from rain as wellas from melted snow from the loftymountains. The two major Himalayan rivers,the Indus and the Brahmaputra originatefrom the north of the mountain ranges. Theyhave cut through the mountains makinggorges. The Himalayan rivers have longcourses from their source to the sea. Theyperform intensive erosional activity in theirupper courses and carry huge loads of siltand sand. In the middle and the lower courses,these rivers form meanders, oxbow lakes, andmany other depositional features in their

3

• Which river has the largest basin in India?

DRAINAGE SYSTEMS IN INDIA

The drainage systems of India are mainlycontrolled by the broad relief features of the

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18 CONTEMPORARY INDIA

floodplains. They also have well-developeddeltas (Figure 3.3).

A large number of the Peninsular rivers areseasonal, as their flow is dependent on rainfall.During the dry season, even the large rivershave reduced flow of water in their channels.The Peninsular rivers have shorter and

shallower courses as compared to theirHimalayan counterparts. However, some ofthem originate in the central highlands and flowtowards the west. Can you identify two suchlarge rivers? Most of the rivers of peninsularIndia originate in the Western Ghats and flowtowards the Bay of Bengal.

The Himalayan Rivers

The major Himalayan rivers are the Indus, theGanga and the Brahmaputra. These rivers arelong, and are joined by many large andimportant tributaries. A river alongwith itstributaries may be called a river system.

The Indus River System

The river Indus rises in Tibet, near LakeMansarowar. Flowing west, it enters India in theLadakh district of Jammu and Kashmir. It formsa picturesque gorge in this part. Severaltributaries, the Zaskar, the Nubra, the Shyokand the Hunza, join it in the Kashmir region.The Indus flows through Baltistan and Gilgit andemerges from the mountains at Attock. TheSatluj, the Beas, the Ravi, the Chenab and theJhelum join together to enter the Indus nearMithankot in Pakistan. Beyond this, the Indusflows southwards eventually reaching theArabian Sea, east of Karachi. The Indus plainhas a very gentle slope. With a total length of2900 km, the Indus is one of the longest rivers

Source of River

Upper Course

Middle Course

Ox-Bow Lake

LowerCourse

Meander

Delta

Figure 3.3 : Some Features Made by Rivers

Drainage Patterns

The streams within a drainage basin formcertain patterns, depending on the slopeof land, underlying rock structure as wellas the climatic conditions of the area.These are dendritic, trellis, rectangular,and radial patterns. The dendritic patterndevelops where the river channel followsthe slope of the terrain. The stream withits tributaries resembles the branches ofa tree, thus the name dendritic. A riverjoined by its tributaries, at approximatelyright angles, develops a trellis pattern. Atrellis drainage pattern develops wherehard and soft rocks exist parallel to eachother. A rectangular drainage patterndevelops on a strongly jointed rockyterrain. The radial pattern develops when streams flow in differentdirections from a central peak or dome like structure.

A combination of several patterns may be found in the same drainage basin.

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DRAINAGE 19

Figure 3.4 : Major Rivers and Lakes

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20 CONTEMPORARY INDIA

of the world. A little over a third of the Indusbasin is located in India in the states of Jammuand Kashmir, Himachal Pradesh and the Punjaband the rest is in Pakistan.

• According to the regulationsof the Indus Water Treaty (1960), India can useonly 20 per cent of the total water carried by Indusriver system. This water is used for irrigation inthe Punjab, Haryana and the southern andwestern parts of Rajasthan.

The Ganga River System

The headwaters of the Ganga, called the‘Bhagirathi’ is fed by the Gangotri Glacier andjoined by the Alaknanda at Devaprayag inUttaranchal. At Haridwar the Ganga emergesfrom the mountains on to the plains.

The main tributaries, which come from thepeninsular uplands, are the Chambal, theBetwa and the Son. These rise from semi aridareas, have shorter courses and do not carrymuch water in them. Find out where and howthey ultimately join the Ganga.

Enlarged with the waters from its right andleft bank tributaries, the Ganga flowseastwards till Farakka in West Bengal. This isthe northernmost point of the Ganga delta. Theriver bifurcates here; the Bhagirathi-Hooghly(a distributary) flows southwards through thedeltaic plains to the Bay of Bengal. Themainstream, flows southwards intoBangladesh and is joined by the Brahmaputra.Further down stream, it is known as theMeghna. This mighty river, with waters fromthe Ganga, and the Brahmaputra, flows intothe Bay of Bengal. The delta formed by theserivers is known as the Sunderban delta.

• The Sundarban Delta derivedits name from the Sundari tree which grows well inmarshland.• It is the world’s largest and fastest growing delta.It is also the home of Royal Bengal tiger.

The length of the Ganga is over 2500 km.Look at figure 3.4; can you identify the type ofdrainage pattern formed by the Ganga riversystem? Ambala is located on the water dividebetween th Indus and the Ganga river systems.The plains from Ambala to the Sunderbanstretch over nearly 1800 km, but the fall in itsslope is hardly 300 metres. In other words,there is a fall of just one metre for every 6 km.Therefore, the river develops large meanders.

The Brahmaputra River System

The Brahmaputra rises in Tibet east ofMansarowar lake very close to the sources ofthe Indus and the Satluj. It is slightly longerthan the Indus, and most of its course liesoutside India. It flows eastwards parallel tothe Himalayas. On reaching the NamchaBarwa (7757 m), it takes a ‘U’ turn and entersIndia in Arunachal Pradesh through a gorge.Here, it is called the Dihang and it is joinedby the Dibang, the Lohit, the Kenula and

Figure 3.5 : Confluence of Bhagirathi and Alaknanda atDevaprayag

The Ganga is joined by many tributariesfrom the Himalayas, a few of them being majorrivers such as the Yamuna, the Ghaghara, theGandak and the Kosi. The river Yamuna risesfrom the Yamunotri Glacier in the Himalayas.It flows parallel to the Ganga and as a rightbank tributary, meets the Ganga at Allahabad.The Ghaghara, the Gandak and the Kosi risein the Nepal Himalaya. They are the rivers,which flood parts of the northern plains everyyear, causing widespread damage to life andproperty but enriching the soil for the extensiveagricultural lands.

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DRAINAGE 21

many other tributaries to form theBrahmaputra in Assam.

• Brahmaputra is known asthe Tsang Po in Tibet and Jamuna in Bangladesh.

In Tibet the river carries a smaller volume ofwater and less silt as it is a cold and a dry area.In India it passes through a region of high rainfall.Here the river carries a large volume of water andconsiderable amount of silt. The Brahmaputrahas a braided channel in its entire length inAssam and forms many riverine islands. Do youremember the name of the world’s largest riverineisland formed by the Brahmaputra?

Every year during the rainy season, theriver overflows its banks, causing widespreaddevastation due to floods in Assam andBangladesh. Unlike other north Indian riversthe Brahmaputra is marked by huge depositsof silt on its bed causing the river bed to rise.The river also shifts its channel frequently.

The Peninsular Rivers

The main water divide in Peninsular India isformed by the Western Ghats, which runs fromnorth to south close to the western coast. Mostof the major rivers of the Peninsula such asthe Mahanadi, the Godavari, the Krishna andthe Kaveri flow eastwards and drain into theBay of Bengal. These rivers make deltas attheir mouths. There are numerous smallstreams flowing west of the Western Ghats.The Narmada and the Tapi are the only longrivers, which flow west and make esturies. Thedrainage basins of the peninsular rivers arecomparitevely small in size.

The Narmada Basin

The Narmada rises in the Amarkantak hillsin Madhya Pradesh. It flows towards the westin a rift valley formed due to faulting. On itsway to the sea, the Narmada creates manypicturesque locations. The ‘Marble rocks’,near Jabalpur where the Narmada flowsthrough a deep gorge, and the ‘Dhuadharfalls’ where the river plunges over steep rocks,are some of the notable ones.

All the tributaries of the Narmada are veryshort and most of these join the main streamat right angles. The Narmada basin covers partsof Madhya Pradesh and Gujarat.

The Tapi Basin

The Tapi rises in the Satpura ranges, in theBetul district of Madhya Pradesh. It also flowsin a rift valley parallel to the Narmada but it ismuch shorter in length. Its basin covers partsof Madhya Pradesh, Gujarat and Maharashtra.

The coastal plains between western ghatsand the Arabian sea are very narrow. Hence,the coastal rivers are short. The main westflowing rivers are Sabarmati, Mahi,Bharathpuzha and Periyar. Find out the statesin which these rivers drain the water.

The Godavari Basin

The Godavari is the largest Peninsular river.It rises from the slopes of the Western Ghatsin the Nasik district of Maharashtra. Itslength is about 1500 km. It drains into theBay of Bengal. Its drainage basin is also thelargest among the peninsular rivers. Thebasin covers parts of Maharashtra (about 50per cent of the basin area lies in Maharashtra),Madhya Pradesh, Orissa and AndhraPradesh. The Godavari is joined by a numberof tributaries such as the Purna, the Wardha,the Pranhita, the Manjra, the Wainganga andthe Penganga. The last three tributaries arevery large. Because of its length and thearea it covers, it is also known as the‘Dakshin Ganga’.

The Mahanadi Basin

The Mahanadi rises in the highlands ofChhattisgarh. It flows through Orissa to reachthe Bay of Bengal. The length of the river isabout 860 km. Its drainage basin is shared byMaharashtra, Chhattisgarh, Jharkhand,and Orissa.

The Krishna Basin

Rising from a spring near Mahabaleshwar, theKrishna flows for about 1400 km and reachesthe Bay of Bengal. The Tungabhadra, theKoyana, the Ghatprabha, the Musi and theBhima are some of its tributaries. Its drainage

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22 CONTEMPORARY INDIA

basin is shared by Maharasthra, Karnatakaand Andhra Pradesh.

The Kaveri Basin

The Kaveri rises in the Brahmagri range of theWestern Ghats and it reaches the Bay of Bengalin south of Cuddalore, in Tamil Nadu. Totallength of the river is about 760 km. Its maintributaries are Amravati, Bhavani, Hemavatiand Kabini. Its basin drains parts ofKarnataka, Kerala and Tamil Nadu.

• The river Kaveri makes thesecond biggest waterfall in India. It is known asSivasamudram. The fall supplies hydroelectricpower to Mysore, Bangalore and the Kolar GoldField.

• The name of the biggest waterfallin India.

Beside these major rivers, there are somesmaller rivers flowing towards the east. TheDamoder, the Brahmani, the Baitarni and theSubarn rekha are some notable examples.Locate them in you atlas.

• 71 per cent of the world’ssurface is covered with water, but 97 per cent ofthat is salt water.• Of the 3 per cent that is available as freshwater,three quarters of it is trapped as ice.

LAKES

You may be familiar with the valley of Kashmirand the famous Dal Lake, the house boats andshikaras, which attract thousands of touristsevery year. Similarly, you may have visitedsome other tourist spot near a lake and enjoyedboating, swimming and other water games.Imagine that if Srinagar, Nainital and othertourists places did not have a lake would theyhave been as attractive as they are today? Haveyou ever tried to know the importance of lakesin making a place attractive to tourists? Apartfrom attraction for tourists lakes are also usefulto human beings in many ways.

• Lakes of large extent are called the seas,like the Caspian, the Dead and the Aral seas.

India has many lakes. These differ fromeach other in the size, and othercharacteristics. Most lakes are permanent;some contain water only during the rainyseason, like the lakes in the basins of inlanddrainage of semi-arid regions. There are someof the lakes which are the result of the actionof glaciers and ice sheets, while the othershave been formed by wind, river action, andhuman activities.

A meandering river across a flood plainforms cut-offs that later develop into ox-bowlakes. Spits and bars form lagoons in thecoastal areas, eg the Chilika lake, the Pulicatlake, the Kolleru lake. Lakes in the region ofinland drainage are sometimes seasonal; forexample, the Sambhar lake in Rajasthan, whichis a salt water lake. Its water is used forproducing salt.

Most of the fresh water lakes are in theHimalayan region. They are of glacial origin.In other words, they formed when glaciersdug out a basin, which was later filled withsnowmelt. The Wular lake in Jammu andKashmir, in contrast, is the result of thetectonic activity. It is the largest freshwaterlake in India. The Dal lake, Bhimtal, Nainital,Loktak and Barapani are some otherimportant fresh water lakes.

Apart from natural lakes, the damming ofthe rivers for the generation of hydel power hasalso led to the formation of Lakes such as GuruGobind Sagar (Bhakra Nangal Project).

Figure 3.6 : Loktak Lake

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DRAINAGE 23

Activity

Make a list of natural and artifciallakes with the help of the atlas.

Lakes are of great value to human beings.A lake helps to regulate the flow of a river.During heavy rainfall, it prevents flooding andduring the dry season, it helps to maintainan even flow of water. Lakes can also be usedfor developing hydel power. They moderate theclimate of the surroundings; maintain theaquatic ecosystem, enhance natural beauty,help develop tourism and provide recreation.

ROLE OF RIVERS IN THE ECONOMY

Rivers have been of fundamental importancethroughout the human history. Water from therivers is a basic natural resource, essential forvarious human activities. Therefore, the riverbanks have attracted settlers from ancienttimes. These settlements have now become bigcities. Make a list of cities in your state whichare located on the bank of a river.

Using rivers for irrigation, navigation,hydro-power generation is of specialsignificance – particularly to a country likeIndia, where agriculture is the major sourceof livelihood of the majority of its population.

RIVER POLLUTION

The growing domestic, municipal, industrialand agricultural demand for water from riversnaturally affects the quality of water. As aresult, more and more water is being drainedout of the rivers reducing their volume. Onthe other hand, a heavy load of untreated

sewage and industrial effluents are emptiedinto the rivers. This affects not only the qualityof water but also the self-cleansing capacityof the river. For example, given the adequatestreamflow, the Ganga water is able to diluteand assimilate pollution loads within 20 kmof large cities. But the increasingurbanisation and industrialisation do notallow it to happen and the pollution level ofmany rivers has been rising. Concern overrising pollution in our rivers led to thelaunching of various action plans to clean therivers. Have you heard about such actionplans? How does our health get affected bypolluted river water? Think about “ life ofhuman beings without fresh water” Arrangea debate on this topic in the class.

National River Conservation Plan (NRCP)

The activities of Ganga Action Plan (GAP)phase-I, initiated in 1985, were declaredclosed on 31st March 2000. The SteeringCommittee of the National RiverConservation Authority reviewed theprogress of the GAP and necessary correctionon the basis of lessons learnt andexperiences gained from GAP Phase-I. Thesehave been applied to the major pollutedrivers of the country under the NRCP.

The Ganga Action Plan (GAP) Phase-II,has been merged with the NRCP. Theexpanded NRCP now covers 152 towns locatedalong 27 interstate rivers in 16 states. Underthis action plan, pollution abatement worksare being taken up in 57 towns. A total of215 schemes of pollution abatement havebeen sanctioned. So far, 69 schemes havebeen completed under this action plan. Amillion litres of sewage is targeted to beintercepted, diverted and treated.

1. Choose the right answer from the four alternatives given below.(i) Which one of the following describes the drainage patterns resembling the

branches of a tree?(a) Radial (c) Centrifugal(b) Dendritic (d) Trellis

EXERCISE

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24 CONTEMPORARY INDIA

(ii) In which of the following states is the Wular lake located?(a) Rajasthan (c) Punjab(b) Uttar Pradesh (d) Jammu and Kashmir

(iii) The river Narmada has its source at(a) Satpura (c) Amarkantak(b) Brahmagiri (d) Slopes of the Western ghats

(iv) Which one of the following lakes is a salt water lake?(a) Sambhar (c) Wular(b) Dal (d) Gobind Sagar

(v) Which one of the following is the longest river of the Peninsular India?(a) Narmada (c) Godavari(b) Krishma (d) Mahanadi

(vi) Which one amongst the following rivers flows through a rift valley?(a) Damodar (c) Krishna(b) Tungabhadra (d) Tapi

2. Answer the following questions briefly.(i) What is meant by a water divide? Give an example.(ii) Which is the largest river basin in India?

(iii) Where do the rivers Indus and Ganga have their origin?(iv) Name the two headstreams of the Ganga. Where do they meet to form the Ganga?(v) Why does the Brahmaputra in its Tibetan part have less silt, despite a

longer course?(vi) Which two Peninsular rivers flow through trough?(vii) State some economic benefits of rivers and lakes.

3. Below are given names of a few lakes of India. Group them under two categories– natural and created by human beings.

(a) Wular (b) Dal(c) Nainital (d) Bhimtal(e) Gobind Sagar (f) Loktak(g) Barapani (h) Chilika(i) Sambhar (j) Rana Pratap Sagar(k) Nizam Sagar (l) Pulicat

(m) Nagarjuna Sagar (n) Hirakund

4. Discuss the significant difference between the Himalayan and the Peninsularrivers.

5. Compare the east flowing and the west flowing rivers of the Peninsular plateau.

6. Why are rivers important for the country’s economy?

Map Skills

(i) On an outline map of India mark and label the following rivers: Ganga,Satluj, Damodar, Krishna, Narmada, Tapi, Mahanadi, and Brahmaputra.

(ii) On an outline map of India mark and label the following lakes: Chilika,Sambhar, Wular, Pulicat, Kolleru.

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DRAINAGE 25

Project/Activity

Solve this crossword puzzle with the help of given clues.

Across

1. Nagarjuna Sagar is a river valley project. Name the river?2. The longest river of India.3. The river which originates from a place known as Beas Kund.4. The river which rises in the Betul district of MP and flows westwards.5. The river which is known as the “Sorrow” of Bihar.6. The river on which the reservior for India Gandhi canal has been built.7. The river whose source lies near Rohtang Pass.8. The longest river of Peninsular India?

Down

9. A tributary of Indus originating from Himachal Pradesh.10. The river flowing through fault, drains into the Arabian Sea.11. A river of south India, which receives rain water both in summer and winter.12. A river which flows through Ladakh, Gilgit and Pakistan.13. An important river of the Indian desert.14. The river which joins Chenab in Pakistan.15. A river which rises at Yamunotri glacier.

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In the last two chapters you have read aboutthe landforms and the drainage ofour country. These are the two of the three

basic elements that one learns about the naturalenvironment of any area. In this chapter youwill learn about the third, that is, theatmospheric conditions that prevail over ourcountry. Why do we wear woollens in Decemberor why it is hot and uncomfortable in the monthof May, and why it rains in June - July? Theanswers to all these questions can be found outby studying about the climate of India.

Climate refers to the sum total of weatherconditions and variations over a large area fora long period of time (more than thirty years).Weather refers to the state of the atmosphereover an area at any point of time. The elementsof weather and climate are the same, i.e.temperature, atmospheric pressure, wind,humidity and precipitation. You may haveobserved that the weather conditions fluctuatevery often even within a day. But there is somecommon pattern over a few weeks or months,i.e. days are cool or hot, windy or calm, cloudyor bright, and wet or dry. On the basis of thegeneralised monthly atmospheric conditions,the year is divided into seasons such as winter,summer or rainy seasons.

The world is divided into a number ofclimatic regions. Do you know what type ofclimate India has and why it is so? We willlearn about it in this chapter.

• The word monsoon isderived from the Arabic word ‘mausim’ whichliterally means season.• ‘Monsoon’ refers to the seasonal reversal in thewind direction during a year.

CLIMATE

The climate of India is described as the‘monsoon’ type. This type of climate is foundmainly in the south and the Southeast Asia.Despite an overall unity in the general pattern,there are perceptible regional variations inclimatic conditions within the country. Let ustake two important elements – temperature andprecipitation, and examine how they vary fromplace to place and season to season.

In summer, the mercury occasionallytouches 50°C in some parts of the Rajasthandesert, whereas it may be around 20°C inPahalgam in Jammu and Kashmir. On a winternight, temperature at Drass in Jammu andKashmir may be as low as minus 45°C.Tiruvananthapuram, on the other hand, mayhave a temperature of 20°C.

In certain places there is awide difference between day and nighttemperatures. In the Thar Desert the daytemperature may rise to 50°C, and drop downto near 15°C the same night. On the other hand,there is hardly any difference in day and nighttemperatures in the Andaman and Nicobarislands or in Kerala.

Let us now look at precipitation. There arevariations not only in the form and types ofprecipitation but also in its amount and theseasonal distribution. While precipitation ismostly in the form of snowfall in the upper partsof Himalayas, it rains over the rest of thecountry. The annual precipitation varies fromover 400 cm in Meghalaya to less than 10 cmin Ladakh and western Rajasthan. Most partsof the country receive rainfall from June toSeptember. But some parts like the Tamil Nadu

4

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CLIMATE 27

•Why most of the world’s deserts arelocated in the western margins of continents in thesubtropics?

Finally, relief too plays a major role indetermining the climate of a place. Highmountains act as barriers for cold or hot winds;they may also cause precipitation if they are highenough and lie in the path of rain-bearing winds.The leeward side of mountains remains dry.

FACTORS AFFECTING INDIA’S CLIMATE

Latitude

The Tropic of Cancer passes through the middleof the country from the Rann of Kuchchh in thewest to Mizoram in the east. Almost half of thecountry, lying south of the Tropic of Cancer,belongs to the tropical area. All the remainingarea, north of the Tropic, lies in the sub-tropics.Therefore, India’s climate has characteristics oftropical as well as subtropical climates.

Altitude

India has mountains to the north, which havean average height of about 6,000 metres. Indiaalso has a vast coastal area where themaximum elevation is about 30 metres. TheHimalayas prevent the cold winds from CentralAsia from entering the subcontinent. It isbecause of these mountains that thissubcontinent experiences comparativelymilder winters as compared to central Asia.

Pressure and Winds

The climate and associated weather conditionsin India are governed by the followingatmospheric conditions:

• Pressure and surface winds;• Upper air circulation; and• Western cyclonic disturbances and

tropical cyclones.

India lies in the region of north easterlywinds. These winds originate from thesubtropical high-pressure belt of the northern

coast get most of its rain during October andNovember.

In general, coastal areas experience lesscontrasts in temperature conditions. Seasonalcontrasts are more in the interior of thecountry. There is decrease in rainfall generallyfrom east to west in the Northern Plains. Thesevariations have given rise to variety in lives ofpeople – in terms of the food they eat, theclothes they wear and also the kind of housesthey live in.

• Why the houses in Rajasthan have thickwalls and flat roofs?

• Why is it that the houses in the Tarai region andin Goa and Mangalore have sloping roofs?

• Why houses in Assam are built on stilts?

CLIMATIC CONTROLS

There are six major controls of the climate ofany place. They are: latitude, altitude,pressure and wind system, distance fromthe sea (continentality), ocean currents andrelief features.

Due to the curvature of the earth, theamount of solar energy received variesaccording to latitude. As a result, airtemperature decreases from the equatortowards the poles. As one goes from thesurface of the earth to higher altitudes, theatmosphere becomes less dense andtemperature decreases. The hills are thereforecooler during summers. The pressure andwind system of any area depend on thelatitude and altitude of the place. Thus itinfluences the temperature and rainfallpattern. The sea exerts a moderating influenceon climate: As the distance from the seaincreases, its moderating influence decreasesand the people experience extreme weatherconditions. This condition is known ascontinentality (i.e. very hot during summersand very cold during winters). Ocean currentsalong with onshore winds affect the climate ofthe coastal areas, For example, any coastalarea with warm or cold currents flowing pastit, will be warmed or cooled if the winds areonshore.

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CONTEMPORARY INDIA28

hemisphere. They blow south, get deflected tothe right due to the Coriolis force, and moveon towards the equatorial low-pressure area.Generally, these winds carry very littlemoisture as they originate and blow over land.Therefore, they bring little or no rain. Hence,India should have been an arid land, but, it isnot so. Let us see why?

Coriolis force: An apparent force caused by the earth’srotation. The Coriolis force is responsible for deflectingwinds towards the right in the northern hemisphereand towards the left in the southern hemisphere. Thisis also known as ‘Ferrel’s Law’.

The pressure and wind conditions overIndia are unique. During winter, there is ahigh-pressure area north of the Himalayas.Cold dry winds blow from this region to thelow-pressure areas over the oceans to thesouth. In summer, a low-pressure areadevelops over interior Asia as well as overnorthwestern India. This causes a completereversal of the direction of winds duringsummer. Air moves from the high-pressurearea over the southern Indian Ocean, in asouth-easterly direction, crosses the equator,and turns right towards the low-pressure areasover the Indian subcontinent. These are knownas the Southwest Monsoon winds. These windsblow over the warm oceans, gather moistureand bring widespread rainfall over themainland of India.

The upper air circulation in this region isdominated by a westerly flow. An importantcomponent of this flow is the jet stream.

These jet streams are located approximatelyover 27°-30° north latitude, therefore, they areknown as subtropical westerly jet streams. OverIndia, these jet streams blow south of the

Himalayas, all through the year except insummer. The western cyclonic disturbancesexperienced in the north and north-western partsof the country are brought in by this westerlyflow. In summer, the subtropical westerly jetstream moves north of the Himalayas with theapparent movement of the sun. An easterly jetstream, called the tropical easterly jet streamblows over peninsular India, approximately over14°N during the summer months.

Western Cyclonic Disturbances

The western cyclonic disturbances are weatherphenomena of the winter months brought in by thewesterly flow from the Mediterranean region. Theyusually influence the weather of the north andnorth-western regions of India. Tropical cyclonesoccur during the monsoon as well as in October -November, and are part of the easterly flow. Thesedistrurbances affect the coastal regions of thecountry. Have you read or heard about thedisasters caused by them on Orissa and AndhraPradesh coast?

THE INDIAN MONSOON

The climate of India is strongly influenced bymonsoon winds. The sailors who came to Indiain historic times were one of the first to havenoticed the phenomenon of the monsoon. Theybenefited from the reversal of the wind systemas they came by sailing ships at the mercy ofwinds. The Arabs, who had also come to Indiaas traders named this seasonal reversal of thewind system ‘monsoon’.

Figure 4.1 : Arrival of Monsoon

Jet stream: These are a narrow belt of highaltitude (above 12,000 m) westerly winds in thetroposphere. Their speed varies from about 110km/h in summer to about 184 km/h in winter.A number of separate jet streams have beenidentified. The most constant are the mid-latitudeand the sub tropical jet stream.

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CLIMATE 29

Figure 4.3 : Atmospheric Conditions over the Indian Subcontinent in the Month of June

Figure 4.2 : Atmospheric Conditions over the Indian Subcontinent in the Month of January

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conditions is known as the SouthernOscillation or SO. The difference in pressureover Tahiti (Pacific Ocean, 18°S/149°W) andDarwin in northern Australia (Indian Ocean,12°30’S/131°E) is computed to predict theintensity of the monsoons. If the pressuredifferences were negative, it would mean belowaverage and late monsoons. A feature connectedwith the SO is the El Nino, a warm ocean currentthat flows past the Peruvian Coast, in place ofthe cold Peruvian current, every 2 to 5 years.The changes in pressure conditions areconnected to the El Nino. Hence, thephenomenon is referred to as ENSO (El NinoSouthern Oscillations).

El Nino: This is a name given to the periodicdevelopment of a warm ocean current along thecoast of Peru as a temporary replacement of thecold Peruvian current. ‘El Nino’ is a Spanish wordmeaning ‘the child’, and refers to the baby Christ,as this current starts flowing during Christmas.The presence of the El Nino leads to an increasein sea-surface temperatures and weakening ofthe trade winds in the region.

THE ONSET OF THE MONSOON AND WITHDRAWAL

The Monsoon, unlike the trades, are not steadywinds but are pulsating in nature, affected bydifferent atmospheric conditions encounteredby it, on its way over the warm tropical seas.The duration of the monsoon is between 100-120 days from early June to mid-September.Around the time of its arrival, the normalrainfall increases suddenly and continuesconstantly for several days. This is known asthe ‘burst’ of the monsoon, and can bedistinguished from the pre-monsoon showers.The monsoon arrives at the southern tip of theIndian peninsula generally by the first week ofJune. Subsequently, it divides into two – theArabian Sea branch and the Bay of Bengalbranch. The Arabian Sea branch reachesMumbai about ten days later onapproximately the 10th of June. This is a fairlyrapid advance. The Bay of Bengal branch alsoadvances rapidly and arrives in Assam in thefirst week of June. The lofty mountains causesthe monsoon winds to deflect towards the west

The monsoons are experienced in thetropical area roughly between 20° N and 20°S. To understand the mechanism of themonsoons, the following facts are important.

(a) The differential heating and cooling ofland and water creates low pressure on thelandmass of India while the seas aroundexperience comparatively high pressure.

(b) The shift of the position of Inter TropicalConvergence Zone (ITCZ) in summer, overthe Ganga plain (this is the equatorial troughnormally positioned about 5°N of theequator – also known as the monsoon-trough during the monsoon season).

(c) The presence of the high-pressure area,east of Madagascar, approximately at20°S over the Indian Ocean. The intensityand position of this high-pressure areaaffects the Indian Monsoon.

(d) The Tibetan plateau gets intenselyheated during summer, which results instrong vertical air currents and theformation of high pressure over the plateauat about 9 km above sea level.

(e) The movement of the westerly jet streamto the north of the Himalayas and thepresence of the tropical easterly jetstream over the Indian peninsula duringsummer.

Inter Tropical Convergence Zone

The Inter Tropical Convergence Zone (ITCZ,) is abroad trough of low pressure in equatoriallatitudes. This is where the northeast and thesoutheast trade winds converge. Thisconvergence zone lies more or less parallel tothe equator but moves north or south with theapparent movement of the sun.

Apart from this, it has also been noticed thatchanges in the pressure conditions over thesouthern oceans also affect the monsoons.Normally when the tropical eastern south PacificOcean experiences high pressure, the tropicaleastern Indian Ocean experiences low pressure.But in certain years, there is a reversal in thepressure conditions and the eastern Pacific haslower pressure in comparison to the easternIndian Ocean. This periodic change in pressure

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CLIMATE 31

over the Ganga plains. By mid-June theArabian Sea branch of the monsoon arrivesover Saurashtra-Kuchchh and the central partof the country. The Arabian Sea and the Bayof Bengal branches of the monsoon merge overthe northwestern part of the Ganga plains.Delhi generally receives the monsoon showersfrom the Bay of Bengal branch by the end ofJune (tentative date is 29th of June). By the firstweek of July, western Uttar Pradesh, Punjab,Haryana and eastern Rajasthan experience themonsoon. By mid-July, the monsoon reachesHimachal Pradesh and the rest of the country(Figure 4.3).

Withdrawal or the retreat of the monsoonis a more gradual process (Figure 4.4). Thewithdrawal of the monsoon begins innorthwestern states of India by earlySeptember. By mid-October, it withdrawscompletely from the northern half of thepeninsula. The withdrawal from the southernhalf of the peninsula is fairly rapid. By earlyDecember, the monsoon has withdrawn fromthe rest of the country.

The islands receive the very first monsoonshowers, progressively from south to north,from the first week of April to the first week ofMay. The withdrawal, takes place progressivelyfrom north to south from the first week ofDecember to the first week of January. By thistime the rest of the country is already underthe influence of the winter monsoon.

THE SEASONS

The monsoon type of climate is characterisedby a distinct seasonal pattern. The weatherconditions greatly change from one season tothe other. These changes are particularlynoticeable in the interior parts of the country.The coastal areas do not experience muchvariation in temperature though there isvariation in rainfall pattern. How many seasonsare experienced in your place? Four mainseasons can be identified in India – the coldweather season, the hot weather season, theadvancing monsoon and the retreatingmonsoon with some regional variations.

The Cold Weather Season (Winter)

The cold weather season begins from mid-November in northern India and stays tillFebruary. December and January are the coldestmonths in the northern part of India. Thetemperature decreases from south to the north.The average temperature of Chennai, on theeastern coast, is between 24° - 25° Celsius, whilein the northern plains, it ranges between 10° -15° Celsius. Days are warm and nights are cold.Frost is common in the north and the higherslopes of the Himalayas experience snowfall.

During this season, the northeast tradewinds prevail over the country. They blow fromland to sea and hence, for most part of thecountry, it is a dry season. Some amount ofrainfall occurs on the Tamil Nadu coast fromthese winds as, here they blow from sea to land.

In the northern part of the country, a feeblehigh-pressure region develops, with light windsmoving outwards from this area. Influenced bythe relief, these winds blow through the Gangavalley from the west and the northwest. Theweather is normally marked by clear sky, lowtemperatures and low humidity and feeble,variable winds.

A characteristic feature of the cold weatherseason over the northern plains is the inflow ofcyclonic disturbances from the west and thenorthwest. These low-pressure systems,originate over the Mediterranean Sea andwestern Asia and move into India, along withthe westerly flow. They cause the much-neededwinter rains over the plains and snowfall in themountains. Although the total amount ofwinter rainfall locally known as ‘mahawat’ issmall, they are of immense importance for thecultivation of ‘rabi’ crops.

The peninsular region does not have a well-defined cold season. There is hardly anynoticeable seasonal change in temperaturepattern during winters due to the moderatinginfluence of the sea.

The Hot Weather Season (Summer)

Due to the apparent northward movement of thesun, the global heat belt shifts northward. Assuch, from March to May, it is hot weather season

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Figure 4.4 : Advancing Monsoon

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CLIMATE 33

in India. The influence of the shifting of the heatbelt can be seen clearly from temperaturerecordings taken during March-May at differentlatitudes. In March, the highest temperature isabout 38° Celsius, recorded on the Deccanplateau. In April, temperatures in Gujarat andMadhya Pradesh are around 42° Celsius. In May,temperature of 45° Celsius is common in thenorthwestern parts of the country. In peninsularIndia, temperatures remain lower due to themoderating influence of the oceans.

The summer months experience risingtemperature and falling air pressure in thenorthern part of the country. Towards the endof May, an elongated low-pressure areadevelops in the region extending from the TharDesert in the northwest to Patna andChotanagpur plateau in the east andsoutheast. Circulation of air begins to set inaround this trough.

A striking feature of the hot weather seasonis the ‘loo’. These are strong, gusty, hot, drywinds blowing during the day over the north andnorthwestern India. Sometimes they evencontinue until late in the evening. Direct exposureto these winds may even prove to be fatal. Duststorms are very common during the month ofMay in northern India. These storms bringtemporary relief as they lower the temperatureand may bring light rain and cool breeze. This isalso the season for localised thunderstorms,associated with violent winds, torrentialdownpours, often accompanied by hail. In WestBengal, these storms are known as the ‘KaalBaisakhi’ calamity for the month of Baisakh.

Towards the close of the summer season,pre-monsoon showers are common especially,in Kerala and Karnataka. They help in the earlyripening of mangoes, and are often referred toas ‘mango showers’.

Advancing Monsoon (The Rainy Season)

By early June, the low-pressure condition overthe northern plains intensifies. It attracts, thetrade winds of the southern hemisphere. Thesesouth-east trade winds originate over thewarm subtropical areas of the southern oceans.They cross the equator and blow in a south-

westerly direction entering the Indian peninsulaas the south-west monsoon. As these windsblow over warm oceans, they bring abundantmoisture to the subcontinent. These winds arestrong and blow at an average velocity of 30km per hour. With the exception of the extremenorth-west, the monsoon winds cover thecountry in about a month.

The inflow of the south-west monsoon intoIndia brings about a total change in theweather. Early in the season, the windwardside of the Western Ghats receives very heavyrainfall, more than 250 cm. The DeccanPlateau and parts of Madhya Pradesh alsoreceive some amount of rain in spite of lyingin the rain shadow area. The maximum rainfallof this season is received in the north-easternpart of the country. Mawsynram in thesouthern ranges of the Khasi Hills receives thehighest average rainfall in the world. Rainfallin the Ganga valley decreases from the east tothe west. Rajasthan and parts of Gujarat getscanty rainfall.

Another phenomenon associated with themonsoon is its tendency to have ‘breaks’ inrainfall. Thus, it has wet and dry spells. Inother words, the monsoon rains take placeonly for a few days at a time. They areinterspersed with rainless intervals. Thesebreaks in monsoon are related to themovement of the monsoon trough. Forvarious reasons, the trough and its axis keepon moving northward or southward, whichdetermines the spatial distribution of rainfall.When the axis of the monsoon trough lies overthe plains, rainfall is good in these parts. Onthe other hand, whenever the axis shifts closerto the Himalayas, there are longer dry spellsin the plains, and widespread rain occur inthe mountainous catchment areas of theHimalayan rivers. These heavy rain bring intheir wake, devastating floods causingdamage to life and property in the plains. Thefrequency and intensity of tropicaldepressions too, determine the amount andduration of monsoon rains. Thesedepressions form at the head of the Bay ofBengal and cross over to the mainland. Thedepressions follow the axis of the “monsoon

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Figure 4.5 : Retreating Monsoon

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CLIMATE 35

Mawsynram, the wettestplace on the earth is also reputed for itsstalagmite and stalactite caves.

trough of low pressure”. The monsoon isknown for its uncertainties. The alternationof dry and wet spells vary in intensity,frequency and duration. While it causesheavy floods one part, it may be responsiblefor droughts in the other. It is often irregularin its arrival and its retreat. Hence, itsometimes disturbs the farming schedule ofmillions of farmers all over the country.

Retreating Monsoon(The Transition Season)

During October-November, with the apparentmovement of the sun towards the south, themonsoon trough or the low-pressure troughover the northern plains becomes weaker. Thisis gradually replaced by a high-pressuresystem. The south-west monsoon windsweaken and start withdrawing gradually. Bythe beginning of October, the monsoonwithdraws from the Northern Plains.

The months of October-November form aperiod of transition from hot rainy season todry winter conditions. The retreat of themonsoon is marked by clear skies and rise in

deltas of the Godavari, the Krishna and theKaveri are frequently struck by cyclones, whichcause great damage to life and property.Sometimes, these cyclones arrive at the coastsof Orissa, West Bengal and Bangladesh. Thebulk of the rainfall of the Coromandel Coast isderived from depressions and cyclones.

DISTRIBUTION OF RAINFALL

The western coast and northeastern Indiareceive over about 400 cm of rainfall annualy.However, it is less than 60 cm in westernRajasthan and adjoining parts of Gujarat,Haryana and Punjab. Rainfall is equally lowin the interior of the Deccan plateau, and eastof the Sahyadris. Why do these regions receivelow rainfall? A third area of low precipitationis around Leh in Jammu and Kashmir. The restof the country receives moderate rainfall.Snowfall is restricted to the Himalayan region.

Owing to the nature of monsoons, theannual rainfall is highly variable from year toyear. Variability is high in the regions of lowrainfall such as parts of Rajasthan, Gujarat andthe leeward side of the Western Ghats. As such,while areas of high rainfall are liable to beaffected by floods, areas of low rainfall aredrought-prone (Figure 4.6 and 4.7).

MONSOON AS A UNIFYING BOND

You have already known the way theHimalayas protect the subcontinent fromextremely cold winds from central Asia. Thisenables northern India to have uniformlyhigher temperatures when compared to otherareas on the same latitudes. Similarly, thepeninsular plateau, under the influence of thesea from three sides, has moderatetemperatures. Despite such moderatinginfluences, there are great variations in thetemperature conditions. Nevertheless, theunifying influence of the monsoon on theIndian subcontinent is quite perceptible. Theseasonal alteration of the wind systems andthe associated weather conditions provide arhythmic cycle of seasons. Even theuncertainties of rain and uneven distribution

temperature. While day temperatures arehigh, nights are cool and pleasant. The landis still moist. Owing to the conditions of hightemperature and humidity, the weatherbecomes rather oppressive during the day.This is commonly known as ‘October heat’. Inthe second half of October, the mercury beginsto fall rapidly in northern India.

The low-pressure conditions, over north-western India, get transferred to the Bay ofBengal by early November. This shift isassociated with the occurrence of cyclonicdepressions, which originate over theAndaman Sea. These cyclones generally crossthe eastern coasts of India cause heavy andwidespread rain. These tropical cyclones areoften very destructive. The thickly populated

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Figure 4.6 : Seasonal Rainfall (June-September)

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CLIMATE 37

Figure 4.7 : Annual Rainfall

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CONTEMPORARY INDIA38

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CLIMATE 39

are very much typical of the monsoons. TheIndian landscape, its animal and plant life,its entire agricultural calendar and the life ofthe people, including their festivities, revolvearound this phenomenon. Year after year,people of India from north to south and from

1. Choose the correct answer from the four alternatives given below.(i) Which one of the following places receives the highest rainfall in the world?

(a) Silchar (c) Cherrapunji(b) Mawsynram (d) Guwahati

(ii) The wind blowing in the northern plains in summers is known as:(a) Kaal Baisakhi (c) Trade Winds(b) Loo (d) None of the above

(iii) Which one of the following causes rainfall during winters in north-westernpart of India.(a) Cyclonic depression (c) Western disturbances(b) Retreating monsoon (d) Southwest monsoon

(iv) Monsoon arrives in India approximately in:(a) Early May (c) Early June(b) Early July (d) Early August

(v) Which one of the following characterises the cold weather season in India?(a) Warm days and warm nights(b) Warm days and cold nights(c) Cool days and cold nights(d) Cold days and warm nights

2. Answer the following questions briefly.(i) What are the controls affecting the climate of India?

(ii) Why does India have a monsoon type of climate?(iii) Which part of India does experience the highest diurnal range of temperature

and why?(iv) Which winds account for rainfall along the Malabar coast?(v) What are Jet streams and how do they affect the climate of India?(vi) Define monsoons. What do you understand by “break” in monsoon?

(vii) Why is the monsoon considered a unifying bond?3. Why does the rainfall decrease from the east to the west in Northern India.4. Give reasons as to why.

(i) Seasonal reversal of wind direction takes place over the Indiansubcontinent?

(ii) The bulk of rainfall in India is concentrated over a few months.(iii) The Tamil Nadu coast receives winter rainfall.(iv) The delta region of the eastern coast is frequently struck by cyclones.(v) Parts of Rajasthan, Gujarat and the leeward side of the Western Ghats are

drought-prone.

east to west, eagerly await the arrival of themonsoon. These monsoon winds bind thewhole country by providing water to set theagricultural activities in motion. The rivervalleys which carry this water also unite as asingle river valley unit.

EXERCISE

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CONTEMPORARY INDIA40

5. Describe the regional variations in the climatic conditions of India with the helpof suitable examples.

6. Discuss the mechanism of monsoons.7. Give an account of weather conditions and characteristics of the cold season.8. Give the characteristics and effects of the monsoon rainfall in India.

MAP SKILLS

On an outline map of India, show the following.(i) Areas receiving rainfall over 400 cm.(ii) Areas receiving less than 20 cm of rainfall.

(iii) The direction of the south-west monsoon over India.

PROJECT/ACTIVITY

(i) Find out which songs, dances, festivals and special food preparations areassociated with certain seasons in your region. Do they have somecommonality with other regions of India?

(ii) Collect photographs of typical rural houses, and clothing of people fromdifferent regions of India. Examine whether they reflect any relationshipwith the climatic condition andrelief of the area.

FOR DOING IT YOURSELF

1. In Table-I the average mean montlytemperatures and amounts of rainfall of tenrepresentative stations have been given. It isfor you to study on your own and convert theminto ‘temperature and rainfall’ graphs. Aglance at these visual representations will helpyou to grasp instantly the smilarities anddifferences between them. One such graph(Figure 1) is already prepared for you. See ifyou can arrive at some broad generalisationsabout our diverse climatic conditions. We hopeyou are in for a great joy of learning. Do thefollowing activities.

Figure 1 : Temperature and Rainfall of Delhi

2. Re-arrange the ten stations in two different sequences:(i) According to their distance from the equator.(ii) According to their altitude above mean sea-level.

3. (i) Name two rainest stations.(ii) Name two driest stations.(iii) Two stations with most euqable climate.(iv) Two stations with most extreme climate.(v) Two stations most influenced by the Arabian branch of southwest monsoons.(vi) Two stations most influenced by the Bay of Bengal branch of south-west monsoons.(vii) Two stations influenced by both branches of the south-west monsoons(viii) Two stations influenced by retreating and north-east monsoons.(ix) Two stations receiving winter showers from the western disturbances.(x) The two hottest stations in the months of

(a) February (b) April (c) May (d) June

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CLIMATE 41

4. Now find out(i) Why are Tiruvanantapuram and Shillong rainier in June than in July?(ii) Why is July rainier in Mumbai than in Tiruvanantapuram?(iii) Why are southwest monsoons less rainy in Chennai?(iv) Why is Shillong rainier than Kolkata?(v) Why is Kolkata rainier in July than in June unlike Shillong which is rainier in June than

in July?(vi) Why does Delhi receive more rain than Jodhpur?

5. Now think why— Tiruvanantapuram has equable climate?— Chennai has more rains only after the fury of monsoon is over in most parts of the country?— Jodhpur has a hot desert type of climate?— Leh has moderate precipitation almost throughut the year?— while in Delhi and Jodhpur most of the rain is confined to nearly three months, in

Tiruvanantapuram and Shillong it is almost nine months of the year?In spite of these facts see carefully if there are strong evidences to conclude that the monsoons

still provide a very strong framework lending overall climatic unity to the whole country.

Stations LatitudeAltitude Jan Feb. Mar. Apr. May. Jun. Jul. Aug. Sep. Otc. Nov. Dec. Annual(Metres) Rainfall

Temperature (°C) 20.5 22.7 25.2 27.1 26.7 24.2 23.0 23.0 23.1 22.9 18.9 20.2Bangalore 12°58'N 909

Rainfall (cm) 0.7 0.9 1.1 4.5 10.7 7.1 11.1 13.7 16.4 15.3 6.1 1.3 88.9

Temperature (°C) 24.4 24.4 26.7 28.3 30.0 28.9 27.2 27.2 27.2 27.8 27.2 25.0Mumbai 19° N 11

Rainfall (cm) 0.2 0.2 – – 1.8 50.6 61.0 36.9 26.9 4.8 1.0 – 183.4

Temperature (°C) 19.6 22.0 27.1 30.1 30.4 29.9 28.9 28.7 28.9 27.6 23.4 19.7Kolkata 22°34' N 6

Rainfall (cm) 1.2 2.8 3.4 5.1 13.4 29.0 33.1 33.4 25.3 12.7 2.7 0.4 162.5

Temperature (°C) 14.4 16.7 23.3 30.0 33.3 33.3 30.0 29.4 28.9 25.6 19.4 15.6Delhi 29° N 219

Rainfall (cm) 2.5 1.5 1.3 1.0 1.8 7.4 19.3 17.8 11.9 1.3 0.2 1.0 67.0

Temperature (°C) 16.8 19.2 26.6 29.8 33.3 33.9 31.3 29.0 20.1 27.0 20.1 14.9Jodhpur 26°18' N 224

Rainfall (cm) 0.5 0.6 0.3 0.3 1.0 3.1 10.8 13.1 5.7 0.8 0.2 0.2 36.6

Temperature (°C) 24.5 25.7 27.7 30.4 33.0 32.5 31.0 30.2 29.8 28.0 25.9 24.7Chennai 13°4' N 7

Rainfall (cm) 4.6 1.3 1.3 1.8 3.8 4.5 8.7 11.3 11.9 30.6 35.0 13.9 128.6

Temperature (°C) 21.5 23.9 28.3 32.7 35.5 32.0 27.7 27.3 27.9 26.7 23.1 20.7Nagpur 21°9' N 312

Rainfall (cm) 1.1 2.3 1.7 1.6 2.1 22.2 37.6 28.6 18.5 5.5 2.0 1.0 124.2

Temperature (°C) 9.8 11.3 15.9 18.5 19.2 20.5 21.1 20.9 20.0 17.2 13.3 10.4Shillong 24°34' N 1461

Rainfall (cm) 1.4 2.9 5.6 14.6 29.5 47.6 35.9 34.3 30.2 18.8 3.8 0.6 225.3

Temperature (°C) 26.7 27.3 28.3 28.7 28.6 26.6 26.2 2.6.2 26.5 26.7 26.6 26.5Tiruvanatapuram 8°29' N 61

Rainfall (cm) 2.3 2.1 3.7 10.6 20.8 35.6 22.3 14.6 13.8 27.3 20.6 7.5 181.2

Temperature (°C) – 8.5 – 7.2 – 0.6 6.1 10.0 14.4 17.2 16.1 12.2 6.1 0.0 – 5.6Leh 34° N 34°N 3506

Rainfall (cm) 1.0 0.8 0.8 0.5 0.5 0.5 1.3 1.3 0.8 0.5 – 0.5 8.5

Table I

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Have you observed the type of trees,bushes, grasses and birds in the fieldsand parks in and around your school?

Are they similar or there are variations? Indiabeing a vast country you can imagine thetypes of bio-forms available through out thecountry.

Our country India is one of the twelvemega bio-diversity countries of the world.With about 47,000 plant species Indiaoccupies tenth place in the world and fourthin Asia in plant diversity. There are about15,000 flowering plants in India whichaccount for 6 per cent in the world’s totalnumber of flowering plants. The country hasmany non-flowering plants such as ferns,algae and fungi. India also has 89,000 speciesof animals as well as a rich variety of fish inits fresh and marine waters.

Natural vegetation refers to a plantcommunity which has grown naturally withouthuman aid and has been left undisturbed byhumans for a long time. This is termed as avirgin vegetation. Thus, cultivated crops andfruits, orchards form part of vegetation but notnatural vegetation.

The virgin vegetation, whichare purely Indian are known as endemic orindigenous species but those which have comefrom outside India are termed as exotic plants.

The term flora is used to denote plants ofa particular region or period. Similarly, thespecies of animals are referred to as fauna. Thishuge diversity in flora and fauna kingdom isdue to the following factors.

NATURAL VEGETATION AND WILD LIFE

RELIEF

Land

Land affects the natural vegetation directlyand indirectly. Do you expect the same typeof vegetation in mountainous, plateau andplain areas or in dry and wet regions? Thenature of land influences the type ofvegetation. The fertile level is generally devotedto agriculture. The undulating and roughterrains are areas where grassland andwoodlands develop and give shelter to avariety of wild life.

Soil

The soils also vary over space. Different typesof soils provide basis for different types ofvegetation. The sandy soils of the desertsupport cactus and thorny bushes while wet,marshy, deltaic soils support mangroves anddeltaic vegetation. The hill slopes with somedepth of soil have conical trees.

CLIMATE

Temperature

The character and extent of vegetation aremainly determined by temperature along withhumidity in the air, precipitation and soil. Onthe slopes of the Himalayas and the hills of thePeninsula above the height of 915 metres, thefall in the temperature affects the types ofvegetation and its growth, and changes it fromtropical to subtropical temperate and alpinevegetation.

5

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NATURAL VEGETATION AND WILD LIFE 43

Photoperiod (Sunlight )

The variation in duration of sunlight at differentplaces is due to differences in latitude, altitude,season and duration of the day. Due to longerduration of sunlight, trees grow faster insummer.

Why are the southern slopes in Himalayanregion covered with thick vegetation cover as comparedto northern slopes of the same hills?

Precipitation

In India almost the entire rainfall is brought inby the advancing southwest monsoon (June toSeptember) and retreating northeast monsoons.Areas of heavy rainfall have more dense vegetationas compared to other areas of less rainfall.

Why have the western stopes of thewestern ghats covered with thick forests and notthe eastern slopes?

Have you ever thought as to why forestsare important for human beings? Forests arerenewable resources and play a major role inenhancing the quality of environment. Theymodify local climate, control soil erosion,regulate stream flow, support a variety ofindustries, provide livelihood for manycommunities and offer panoramic or scenicview for recreation. It controls wind force andtemperature and causes rainfall. It provideshumus to the soil and shelter to the wild life.India’s natural vegetation has undergonemany changes due to several factors such asthe growing demand for cultivated land,

development of industries and mining,urbanisation and over-grazing of pastures.

ActivityCelebrate Van Mahotsav in your school/localityand plant few spalings and notice their growth

The vegetation cover of India in large partsis no more natural in the real sense. Except insome inaccessible regions like the Himalayas,the hilly region of central India and themarusthali, the vegetation of most of the areashas been modified at some places, or replacedor degraded by human occupancy.

Activity

Study the bar graph (Figure 5.1) andanswer the following questions.

(i) Name the state having maximum area underforest cover.

(ii) Name the union territory having minimumarea under forest cover and why?

In 2001, the actual forestcover in India was only 20.55 per cent.

ECOSYSTEM

Plants occur in distinct groups of communitiesin areas having similar climatic conditions. Thenature of the plants in an area, to a large extent,determines the animal life in that area. Whenthe vegetation is altered, the animal life alsochanges. All the plants and animals in an areaare interdependent and interrelated to eachother in their physical environment, thus,

Source : Environment Atlas of India, June 2001, Central Pollution Control Board Delhi

Table 5.1 : Temperature Characteristics of the Vegetation Zones

Vegetation Zones Mean annual Mean Temp. Remarks

Average Temp. inJan. in

(in degree C) degrees C

Tropical Above 24°C Above 18° No Frost

Sub-tropical 17°C to 24°C 10°C to 18°C Frost is rare

Temperate 7°C to 17° C -1°C to (-10 ) °C Frost some snow

Alpine Below 7°C Below–1°C Snow

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CONTEMPORARY INDIA44

forming an ecosystem. Human beings arealso an integral part of the ecosystem. Howdo the human beings influence the ecologyof a region? They utilise the vegetation andwild life. The greed of human beings leads toover utilisation of these resources. They cutthe trees and kill the animals creatingecological imbalance. As a result some of theplants and animals have reached the vergeof extinction.

Do you know that a very large ecosystemon land having distinct types of vegetation andanimal life is called a biome. The biomes areidentified on the basis of plants.

TYPES OF VEGETATION

The following major types of vegetation maybe identified in our country (Figure 5.3).(i) Tropical Rain Forests(ii) Tropical Deciduous Forests(iii) Tropical Thorn Forests and Scrubs(iv) Montane Forests(v) Mangrove Forests

Tropical Rain Forests

These forests are restricted to heavy rainfall

Figure 5.1 Area Under Forest Cover

areas of the Western Ghats and the islandgroups of Lakshadweep, Andaman and Nicobar,upper parts of Assam and Tamil Nadu coast.

100

80

60

40

20

0

AN

DH

RA

PR

AD

ES

H

AR

UN

AC

HA

LP

RA

DE

SH

AS

SA

M

BIH

AR

&JH

AR

KH

AN

D

GO

AG

UJA

RAT

HA

RYA

NA

HIM

AC

HA

LP

RA

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SH

JA

MM

UA

ND

KA

SH

MIR

KA

RN

ATA

KA

KE

RA

LA

MA

DH

YA

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ES

H&

CH

HATIS

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TR

AM

AN

IPU

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LAYA

MIZ

OR

AM

NA

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OR

ISS

AP

UN

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BR

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AN

SIK

KIM

TA

MIL

NA

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UTTA

RP

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DE

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&U

TTA

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ISLA

ND

SC

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NA

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AV

ELI

DA

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N&

DIU

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LH

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EP

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ER

RY

Source : Environment Atlas of India, June 2001, Central Pollution Control Board Delhi

AR

EA

IN

PE

RC

EN

T

ACTUAL FOREST AREA

Figure 5.2 : Tropical Rain Forest

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NATURAL VEGETATION AND WILD LIFE 45

Study the given map for the forest cover and try to find the reasons as to why certain states have more area underforest as compared to others?

Figure 5.3 : Natural Vegetation

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CONTEMPORARY INDIA46

Figure 5.4 : Tropical Deciduous Forest

In these forests, the common animals foundare lion, tiger, pig, deer and elephant. A hugevariety of birds, lizards, snakes, and tortoisesare also found here.

The Thorn Forests and Scrubs

In regions with less than 70 cm of rainfall,the natural vegetation consists of thorny treesand bushes. This type of vegetation is foundin the north-western part of the countryincluding semi-arid areas of Gujarat,Rajasthan, Madhya Pradesh, Chhattisgarh,Uttar Pradesh and Haryana. Acacias, palms,euphorbias and cacti are the main plantspecies. Trees are scattered and have long rootspenetrating deep into the soil in order to getmoisture. The stems are succulent to conservewater. Leaves are mostly thick and small tominimize evaporation. These forests give wayto thorn forests and scrubs in arid areas.

Figure 5.5 : Thorn Forests and Scrubs

They are at their best in areas having more than200 cm of rainfall with a short dry season. Thetrees reach great heights up to 60 metres or evenabove. Since the region is warm and wetthroughout the year, it has a luxuriantvegetation of all kinds – trees, shrubs, andcreepers giving it a multilayered structure. Thereis no definite time for trees to shed their leaves.As such, these forests appear green all the yearround.

Some of the commercially important treesof this forest are ebony, mahogany, rosewood,rubber and cinchona.

The common animals found in these forestsare elephants, monkey, lemur and deer. Theone horned rhinoceros are found in the junglesof Assam and West Bengal. Besides theseanimals plenty of birds, bats, sloth, scorpionsand snails are also found in these jungles.

Tropical Deciduous Forests

These are the most widespread forests of India.They are also called the monsoon forests andspread over the region receiving rainfallbetween 200 cm and 70 cm. Trees of thisforest-type shed their leaves for about six toeight weeks in dry summer.

On the basis of the availability of water,these forests are further divided into moist anddry deciduous. The former is found in areasreceiving rainfall between 200 and 100 cm.These forests exist, therefore, mostly in theeastern part of the country – northeasternstates, along the foothills of the Himalayas,Jharkhand, West Orissa and Chhattisgarh, andon the eastern slopes of the Western Ghats.Teak is the most dominant species of this forest.Bamboos, sal, shisham, sandalwood, khair,kusum, arjun, mulberry are other commerciallyimportant species.

The dry deciduous forests are found in areashaving rainfall between 100 cm and 70 cm.These forests are found in the rainier parts ofthe peninsular plateau and the plains of Biharand Uttar Pradesh. There are open stretchesin which Teak, Sal, Peepal, Neem grow. A largepart of this region has been cleared forcultivation and some parts are used for grazing.

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NATURAL VEGETATION AND WILD LIFE 47

Figure 5.7 : Mangrove Forests

In these forests, the common animals arerats, mice, rabbits, fox, wolf, tiger, lion, wildass, horses and camels.

Montane Forests

In mountainous areas, the decrease intemperature with increasing altitude leads tothe corresponding change in naturalvegetation. As such, there is a succession ofnatural vegetation belts in the same order aswe see from the tropical to the tundra region.The wet temperate type of forests are foundbetween a height of 1000 and 2000 metres.Evergreen broad-leaf trees such as oaks andchestnuts predominate. Between 1500 and3000 metres, temperate forests containingconiferous trees like pine, deodar, silver fir,spruce and cedar, are found. These forestscover mostly the southern slopes of theHimalayas, places having high altitude insouthern and north-east India. At higherelevations, temperate grasslands are common.At high altitudes, generally more than 3,600metres above sea-level, temperate forests andgrasslands give way to the Alpine vegetation.Silver fir, junipers, pines and birches are thecommon trees of these forests. However, theyget progressively stunted as they approachthe snow-line. Ultimately through shrubs andscrubs, they merge into the Alpinegrasslands. These are used extensively for

grazing by nomadic tribes like the Gujjarsand the Bakarwals. At higher altitudes,mosses and lichens form part of tundravegetation.

The common animals found in these forestsare Kashmir stag, spotted dear, wild sheep, jackrabbit, Tibetan antelope, yak, snow leopard,squirrels, Shaggy horn wild ibex, bear and rarered panda, sheep and goats with thick hair.

Mangrove Forests

The mangrove tidal forests are found in theareas of coasts influenced by tides. Mud andsilt get accumutated on such coasts. Densemangroves are the common varieties with roots

of the plants submerged under water. Thedeltas of the Ganga, the Mahanadi, theKrishana, the Godavari and the Kaveri arecovered by such vegetation. In the Ganga-Brahamaputra delta, sundari trees arefound, which provide durable hard timber.Palm, coconut, keora, agar, also grow insome parts of the delta.

Royal Bengal Tiger is the famous animalin these forests. Turtles, crocodiles, gharialsand snakes are also found in these forests.

Let us discuss : What will happen if plants andanimals disappear from the earth’s surface? canthe human beings survive under such a situation?Why is bio-diversity necessary and why should itbe conserved?

Figure 5.6 : Montane Forests

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CONTEMPORARY INDIA48

MEDICINAL PLANTSIndia is known for its herbs and spices from ancient times. Some 2,000 plants have been described in Ayurvedaand atleast 500 are in regular use. The World Conservation Union’s Red list has named 352 medicinal plants ofwhich 52 are critically threatened and 49 endangered. The commonly used plants in India are:

Sarpagandha : Used to treat blood pressure; it is found only in India.Jamun : The juice from ripe fruit is used to prepare vinegar which is carminative and diuretic, and

has digestive properties. The powder of the seed is used for controlling diabetes.Arjun : The fresh juice of leaves is a cure for earache. It is also used to regulate blood pressure.Babool : Leaves are used as a cure for eye sores. Its gum is used as a tonic.Neem : Has high antibiotic and antibacterial properties.Tulsi Plant : Is used to cure cough and cold.Kachnar : Is used to cure asthma and ulcers. The buds and roots are good for digestive problems.

Identify more medicinal plants in your area. Which plants are used as medicines by localpeople to cure some diseases?

WILD LIFE

Like its flora, India is also rich in its fauna. Ithas more than 89,000 of animal species. Thecountry has more than 1200 species of birds.They constitute 13% of the world’s total. Thereare 2500 species of fish, which account fornearly 12% of the world’s stock. It also sharesbetween 5 and 8 per cent of the world’samphibians, reptiles and mammals.

The elephants are the most majesticanimals among the mammals. They are foundin the hot wet forests of Assam, Karnataka andKerala. One-horned rhinoceroses are the otheranimals, which live in swampy and marshylands of Assam and West Bengal. Arid areasof the Rann of Kachchh and the Thar Desertare the habitat for wild ass and camelsrespectively. Indian bison, nilgai (blue bull),chousingha (four horned antelope), gazel and

different species of deer are someother animals found in India. It alsohas several species of monkeys.

Wildlife ProtectionAct, was implemented in 1972 in India.

India is the only country in theworld that has both tigers and lions.The natural habitat of the Indian lionis the Gir forest in Gujarat. Tigers arefound in the forests of Madhya Pradesh,the Sundarbans of West Bengal and theHimalayan region. Leopards too aremembers of the cat family. They are

important among animals of prey.

The Himalayas harbour a hardy range ofanimals, which survive in extreme cold.Ladhak’s freezing high altitudes are a home toyak, the shaggy horned wild ox weighingaround one tonne, the Tibetan antelope, thebharal (blue sheep), wild sheep, and the kiang(Tibetan wild ass). Furhtermore, the ibex, bear,snow-leopard and very rare red panda arefound in certain pockets.

In the rivers, lakes and coastal areas,turtles, crocodiles and gharials are found. The

Source : Medicinal Plants by Dr. S.K. Jain, 5th edition 1994, National Book Trust of Inida

ActivityCan you identify the type of forest shown in thispicture? Identify some trees in it. What type ofsimilarity/dissimilarity you notice in this typeof vegetation from the one found in your region?

Do you know

The Gir Forest is thelast remaining habitat

of the Asiatic lion.

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NATURAL VEGETATION AND WILD LIFE 49

Figure 5.8 : Wildlife Reserves

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CONTEMPORARY INDIA50

latter is the only representative of a variety ofcrocodile, found in the world today.

Bird life in India is colourful. Peacocks,peasants, ducks, parakeets, cranes andpigeons are some of the birds inhabiting theforests and wetlands of the country.

We have selected our crops from a bio-diverse environment i.e. from the reserve ofedible plants. We also experimented andselected many medicinal plants. The animalswere selected from large stock provided bynature as milch animal. They also providedus draught power, transportation, meat,eggs. The fish provide nutritive food. Manyinsects help in pollination of crops and fruittrees and exert biological control on suchinsects, which are harmful. Every species hasa role to play in the ecosystem. Hence,conservation is essential. As has beenmentioned earlier due to excessiveexploitation of the plants and animalresources by human beings, the ecosystem

has been disturbed. About 1,300 plantspecies are endangered and 20 species areextinct. Quite a few animal species are alsoendangered and some have become extinct.

The main causes for this major threat tonature are hunting by greedy hunters forcommercial purposes. Pollution due tochemical and industrial waste, acid deposits,introduction of alien species and recklesscutting of the forests to bring land undercultivation and inhabitation, are alsoresponsible for the imbalance.

To protect the flora and fauna of thecounty, the government has taken many steps.

(i) Fourteen biosphere reserves have been setup in the country to protect flora and fauna.Four out of these, the Sunderbans in theWest Bengal, Nanda Devi in Uttaranchal,the Gulf of Mannar in Tamil Nadu and theNilgiris (Kerala, Karnataka and TamilNadu) have been included in the worldnetwork of Biosphese reserves.

Activity(i) Find out from the above newspaper cuttings, the main concern highlighted in the given news items.(ii) Collect more information about various endangered species from newspapers and magazines.(iii) Find out various steps taken by the Indian government to protect them.(iv) Discribe how you can contribute to the protection of endangered animals and birds?

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NATURAL VEGETATION AND WILD LIFE 51

1. Choose the right answer from the four alternatives given below:

(i) To which one of the following types of vegetation does rubber belong to?

(a) Tundra (c) Himalayan

(b) Tidal (d) Tropical Evergreen

(ii) Cinchona trees are found in the areas of rainfall more than

(a) 100 cm (c) 70 cm

(b) 50 cm (d) less than 50 cm

(iii) In which of the following state is the Simlipal bio-reserve located?

(a) Punjab (b) Delhi

(c) Orissa (d) West Bengal

(iv) Which one of the following bio-reserves of India is not included in the worldnetwork of bioreserve?

(a) Manas (c) Gulf of Mannar

(b) Dihang-Dibang (d) Nanda devi

Fourteen Bio-reserves

• Sunderbans • Simlipal• Gulf of Mannar • Dihang-Dibang• The Nilgiris • Dibru Saikhowa• Nanda Devi • Agasthyamalai• Nokrek • Kanchenjunga• Great Nicobar • Pachmari• Manas • Achanakmar-Amarkantak

(ii) Financial and technical assistance isprovided to many Botanical Gardens by thegovernment since 1992.

Migratory BirdsSome of the wetlands of India are popularwith migratory birds. During winter,birds, such as Siberian Crane come inlarge numbers. One such placefavourable with birds is the Rann ofKachchh. At a place where the desertmerges with the sea, flamingo with theirbrilliant, pink plumage, come inthousands to build nest mounds from thesalty mud and raise their young ones. Itis one among many extraordinary sightsin the country. Is it not a rich naturalheritage of ours?

(iii) Project Tiger, Project Rhino, Project GreatIndian Bustard and many other eco-developmental projects have beenintroduced.

(iv) 89 National Parks, 49 Wildlife sanctuariesand Zoological gardens are set up to takecare of Natural heritage.

All of us must realise the importance of thenatural ecosystem for our own survival. Itis possible if indiscriminate destruction ofnatural environment is put to animmediate end.

EXERCISE

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CONTEMPORARY INDIA52

2. Answer the following questions briefly.

(i) Define an ecosystem.

(ii) What factors are responsible for the distribution of plants and animals inIndia?

(iii) What is a bio-reserve? Give two examples.

(iv) Name two animals having habitat in tropical and montane type of vegetation.

3. Distinguish between

(i) Flora and Fauna

(ii) Tropical Evergreen and Deciduous forests

4. Name different types of Vegetation found in India and describe the vegetation ofhigh altitudes.

5. Quite a few species of plants and animals are endangered in India. Why?

6. Why has India a rich heritage of flora and fauna?

Map Skills

On an outline map of India, label the following.

(i) Areas of Evergreen Forests

(ii) Areas of Dry Deciduous Forests

(iii) Two national parks each in Northern, Southern, Eastern and Western partsof the Country

Project/Activity

(i) Find some trees in your neighbourhood having medicinal values.

(ii) Find ten occupations getting raw material from forests and wild life.

(iii) Write a poem or paragraph showing the importance of wild life.

(iv) Write the script of a street play giving the importance of tree plantation andtry to enact it in your locality.

(v) Plant a tree either on your birthday or one of your family member’s birthday.Note the growth of the tree and notice in which season it grows faster.

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POPULATION

Can you imagine a world without humanbeings? Who would have utilisedresources and created the social and

cultural environment? The people areimportant to develop the economy and society.The people make and use resources and arethemselves resources with varying quality.Coal is but a piece of rock, until people wereable to invent technology to obtain it and makeit a ‘resource’. Natural events like a river floodor Tsunami becomes a ‘disaster’ only whenthey affect a crowded village or a town.

Hence, population is the pivotal element insocial studies. It is the point of reference fromwhich all other elements are observed and fromwhich they derive significance and meaning.‘Resources’, ‘calamities’ and ‘disasters’ are allmeaningful only in relation to human beings.Their numbers, distribution, growth andcharacteristics or qualities provide the basicbackground for understanding andappreciating all aspects of the environment.

Human beings are producers andconsumers of earth’s resources. Therefore, itis important to know how many people arethere in a country, where do they live, how andwhy their numbers are increasing and whatare their characteristics. The census of Indiaprovides us with information regarding thepopulation of our country.

We are primarily concerned with threemajor questions about the population:

(i) Population size and distribution: Howmany people are there and where are theylocated?

(ii) Population growth and processes ofpopulation change: How has thepopulation grown and changed throughtime?

(iii) Characteristics or qualities of thepopulation: What are their age, sex-composition, literacy levels, occupationalstructure and health conditions?

POPULATION SIZE AND DISTRIBUTION

India’s Population Size and Distribution byNumbers

India’s population as on March 2001 stood at1,028 million, which account for 16.7 per centof the world’s population. These 1.02 billionpeople are unevenly distributed over ourcountry’s vast area of 3.28 million square km,which accounts for 2.4 per cent of the world’sarea (Figure 6.1)

The 2001 Census data reveals that UttarPradesh with a population size of 166 millionpeople is the most populous state of India. UttarPradesh accounts for about 16 per cent of the

CensusA census is an official enumeration of population done periodically. In India the first census was held in the year1872. The first complete census, however was taken in the year 1881. Since then censuses have been heldregularly every tenth year.

The Indian Census is the most comprehensive source of demographic, social and economic data. Have youever seen a census report? Check in your library if it has one.

6

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54 CONTEMPORARY INDIA

?Do You Know Only Bangladesh and Japan havehigher average population densities

than India. Find out the population densities ofBangladesh and Japan.

is calculated as the number of persons per unitarea. India is one of the most densely populatedcountries of the world.

The population density of India in the year2001 was 324 persons per sq km. Densitiesvary from 904 persons per sq km in WestBengal to only 13 persons per sq km inArunachal Pradesh. A study of the figure 6.3shows the pattern of uneven distribution ofpopulation densities at the state level.

Activity

Study the figure 6.3 and compare it withfigure 2.4 and figure 4.7. Do you find any

corelation between these maps?

Note the states with population densitiesbelow 250 persons per square km. Ruggedterrain and unfavourable climatic conditionsare primarily responsible for sparse populationin these areas. Which states have density below100 persons per square km?

Assam and most of the Peninsular stateshave moderate population densities. Hilly,dissected and rocky nature of the terrain,moderate to low rainfall, shallow and lessfertile soils have influenced populationdensities in these areas.

The Northern Plains and Kerala in thesouth have high to very high populationdensities because of the flat plains with fertilesoils and abundant rainfall. Identify the threestates of the Northern Plains with highpopulation densities.

POPULATION GROWTH AND PROCESSES OF

POPULATION CHANGE

Population is a dynamic phenomenon. Thenumbers, distribution and composition of thepopulation are constantly changing. This is theinfluence of the interaction of the three processes,namely-births, deaths and migrations.

India, 16.7%

Rest of the world, 83.3%

Rest of the world, 97.6%

India, 2.4%

AREA

POPULATION

Fig 6.1 : India’s share of world’s area and population

Others 51.2%

UttarPradesh 16.16%

Maharashtra9.42%

Bihar8.02%

W. Bengal7.79%

AndhraPradesh 7.41%

country’s population. On the other hand, theHimalayan state Sikkim has a population ofjust about 0.5 million and Lakshadweep hasonly 60 thousand people.

Almost half of India’s population lives injust five states. These are Uttar Pradesh,Maharashtra, Bihar, West Bengal, and AndhraPradesh. Rajasthan, the biggest state in termsof area, has only 5.5 per cent of the totalpopulation of India (Figure 6.2)

• What could be the reason of unevendistribution of population in India?

India’s Population Distribution by Density

Population density provides a better pictureof the uneven distribution. Population density

Figure 6.2 : Distribution of Population

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POPULATION 55

Figure 6.3 : Density of Population in India

HARYANA

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56 CONTEMPORARY INDIA

12

10

8

6

4

2

0

1951 1961 1971 1981 1991 2001

2.5

2

1.5

1

0.5

0

Year

Po

pu

lati

on

inM

illio

ns

Total Pupulation

Annual Growth

An

nu

alG

row

thR

ate

%

Table 6.1 and figure 6.4 reveal that from1951 to 1981, the annual rate of populationgrowth was steadily increasing; whichexplains the rapid increase in populationfrom 361 million in 1951 to 683 million in1981.

• Table 6.1 reveals that despite thedecline in growth rates, the number of people beingadded every decade is steadily increasing. Why?

Since 1981, however, the rate of growthstarted declining gradually. During thisperiod, birth rates declined rapidly. Still 182million people were added to the totalpopulation in the 1990s alone (an annualaddition larger than ever before).

It is essential to realise that India has a verylarge population. When a low annual rate isapplied to a very large population, it yields alarge absolute increase. When more than abillion people increase even at a lower rate, thetotal numbers being added becomes very large.India’s current annual increase in populationof 15.5 million is large enough to neutraliseefforts to conserve the resource endowmentand environment.

The declining trend of the growth rate isindeed a positive indicator of the efforts of birthcontrol. Despite that, the total additions to thepopulation base continue to grow, and Indiamay overtake China in 2045 to become themost populous country in the world.

Population Growth

Growth of population refers to the change inthe number of inhabitants of a country/territoryduring a specific period of time, say during thelast ten years. Such a change can be expressedin two ways: in terms of absolute numbers andin terms of percentage change per year.

The absolute numbers added each year ordecade is the magnitude of increase. It isobtained by simply subtracting the earlierpopulation (e.g. that of 1991) from the laterpopulation (e.g. that of 2001). It is referred toas the absolute increase.

The rate or the pace of population increaseis the other important aspect. It is studied inper cent per annum, e.g. a rate of increase of 2per cent per annum means that in a given year,there was an increase of two persons for every100 persons in the base population. This isreferred to as the annual growth rate.

India’s population has been steadilyincreasing from 361 million in 1951 to 1028million in 2001.

Table 6.1 : The Magnitude and Rate of India’sPopulation Growth

Year Total Absolute AnnualPopulation Increase in Growth(in millions) the decade Rate

(in million) ( % )

1951 361.0 42.43 1.251961 439.2 78.15 1.961971 548.2 108.92 2.201981 683.3 135.17 2.221991 846.4 163.09 2.142001 1028.7 182.32 1.93

Figure 6.4 : India’s Population and Population Growth Rates during 1951-2001

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POPULATION 57

Processes of Population Change/Growth

There are three main processes of change ofpopulation : birth rates, death rates andmigration.

The natural increase of population is thedifference between birth rates and death rates.

Birth rate is the number of live births perthousand persons in a year. It is a majorcomponent of growth because in India, birthrates have always been higher than deathrates.

Death rate is the number of deaths perthousand persons in a year. The main causeof the rate of growth of the Indian populationhas been the rapid decline in death rates.

Till 1980, high birth rates and decliningdeath rates led to a large difference betweenbirth rates and death rates resulting in higherrates of population growth. Since 1981, birthrates have also started declining gradually,resulting in a gradual decline in the rate ofpopulation growth. What are the reasons forthis trend?

The third component of population growthis migration. Migration is the movement ofpeople across regions and territories. Migrationcan be internal (within the country) orinternational (between the countries).

Internal migration does not change the sizeof the population, but influences the distributionof population within the nation. Migration playsa very significant role in changing the compositionand distribution of population.

ActivityOn a map, trace the migration of each

of your grandparents and parentssince their birth. Try and analyse the

reasons for each move.

In India, most migrations have been fromrural to urban areas because of the “push”factor in rural areas. These are adverseconditions of poverty and unemployment in therural areas and the “pull” of the city in termsof increased employment opportunities andbetter living conditions.

Migration is an important determinant ofpopulation change. It changes not only the

population size but also the populationcomposition of urban and rural populationsin terms of age and sex composition. In India,the rural-urban migration has resulted in asteady increase in the percentage of populationin cities and towns. The urban population hasincreased from 17.29 per cent of the totalpopulation in 1951 to 27.78 per cent in 2001.There has been a significant increase in thenumber of ‘million plus cities’ from 23 to 35 injust one decade i.e. 1991 to 2001.

Age Composition

The age composition of a population refers tothe number of people in different age groupsin a country. It is one of the most basiccharacteristics of a population. To an importantdegree, a person’s age influences what heneeds, buys, does and his capacity to perform.Consequently, the number and percentage ofa population found within the children,working age and aged groups are notabledeterminants of the population’s social andeconomic structure.

The population of a nation is generallygrouped into three broad categories:

Children (generally below 15 years)

They are economically unproductive and needto be provided with food, clothing, educationand medical care.

Figure 6.5: India: Age Composition

Adults, 58.7%

Aged, 6.9%

Children, 34.4%

India : Age Structure

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58 CONTEMPORARY INDIA

Working Age (15-59 years)

They are economically productive andbiologically reproductive. They comprise theworking population.

Aged (Above 59 years)

They can be economically productive thoughthey and may have retired. They may beworking voluntarily but they are not availablefor employment through recruitment.

The percentage of children and the agedaffect the dependency ratio because thesegroups are not producers. The proportion ofthe three groups in India’s population isalready presented in figure 6.5 .

Activity :(i) How many children do you know who are

engaged as household helpers, labourers inyour locality?

(ii) How many adults do you know in your localitywho are unemployed?

(iii) What do you feel are the reasons for this?

Sex Ratio

Sex ratio is defined as the number of femalesper 1000 males in the population. Thisinformation is an important social indicatorto measure the extent of equality betweenmales and females in a society at a given time.The sex ratio in the country has alwaysremained unfavourable to females. Find outwhy this is so? Table 6.2 shows the sex ratiofrom 1951-2001.

Table 6.2 : India : Sex Ratio 1951-2001

Census year Sex ratio(Females per 1000 males)

1951 9461961 9411971 9301981 9341991 9292001 933

• Kerala has a sex ratio of 1058females per 1000 males, Pondicherry has 1001females for every 1000males, while Delhi hasonly 821 females per 1000 and Haryana hasjust 861.

• What could be the reasons for suchvariations?

Literacy Rates

Literacy is a very important quality of apopulation. Obviously, only an informed andeducated citizen can make intelligent choicesand undertake research and developmentprojects. Low levels of literacy are a seriousobstacle for economic improvement.

According to the Census of 2001, a personaged 7 years. and above who can read andwrite with understanding in any language, istreated as literate.

There has been a steady improvement inthe literacy levels in India. The literacy rate inthe country as per the Census of 2001 is 64.84per cent; 75.26 per cent for males and 53.67per cent for females. Why do such differencesexist?

Occupational Structure

The percentage of population that iseconomically active is an important index ofdevelopment. The distribution of thepopulation according to different types ofoccupation is referred to as the occupationalstructure. An enormous variety of occupationsare found in any country. Occupations aregenerally classified as primary, secondary, andtertiary.

Primary activities include agriculture,animal husbandry, forestry, fishing, miningand quarrying etc. Secondary activities includemanufacturing industry, building andconstruction work etc. Tertiary activitiesinclude transport, communications,commerce, administration and other services.

The proportion of people working indifferent activities varies in developed anddeveloping countries. Developed nations havea high proportion of people in secondary, andtertiary activities. Developing countries tendto have a higher proportion of their workforceengaged in primary activities. In India, about64 per cent of the population is engaged onlyin agriculture. The proportion of populationdependent on secondary and tertiary sectors

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POPULATION 59

is about 13 and 20 per cent respectively. Therehas been an occupational shift in favour ofsecondary and tertiary sectors because ofgrowing industrialisation and urbanisation inrecent times.

Health

Health is an important component ofpopulation composition, which affects theprocess of development. Sustained efforts ofgovernment programmes have registeredsignificant improvements in the healthconditions of the Indian population. Deathrates have declined from 25 per 1000population in 1951 to 8.1 per 1000 in 2001and life expectancy at birth has increased from36.7 years in 1951 to 64.6 years in 2001.

The substantial improvement is the resultof many factors including improvement inpublic health, prevention of infectious diseasesand application of modern medical practicesin diagnosis and treatment of ailments.

Despite considerable achievements, thehealth situation is a matter of major concernfor India. The per capita calorie consumptionis much below the recommended levels andmalnutrition afflicts a large percentage of ourpopulation. Safe drinking water and basicsanitation amenities are available to only one-third of the rural population. These problemsneed to be tackled through an appropriatepopulation policy.

Adolescent Population

The most significant feature of the Indianpopulation is the size of its adolescentpopulation. It constitutes one-fifth of the totalpopulation of India. Adolescents are generallygrouped in the age-group of 10 to 19 years.They are the most important resource for thefuture. Nutrition requirements of adolescentsare higher than those of a normal child or adult.Poor nutrition can lead to deficiency andstunted growth. But in India, the diet availableto adolescents is inadequate in all nutrients. Alarge number of adolescent girls suffer from

anaemia. Their problems have so far notreceived adequate attention in the process ofdevelopment. The adolescent girls have to besensitised to the problems they confront. Theirawareness can be improved through the spreadof literacy and education among them.

National Population Policy

Recognising that the planning of families wouldimprove individual health and welfare, theGovernment of India initiated thecomprehensive Family Planning Programme in1952. The Family Welfare Programme hassought to promote responsible and plannedparenthood on a voluntary basis. The NationalPopulation Policy 2000 is a culmination ofyears of planned efforts.

The NPP 2000 provides a policy frameworkfor imparting free and compulsory schooleducation up to 14 years of age, reducinginfant mortality rate to below 30 per 1000 livebirths, achieving universal immunisation ofchildren against all vaccine preventablediseases, promoting delayed marriage for girls,and making family welfare a people-centeredprogramme.

NPP 2000 and Adolescents

NPP 2000 identified adolescents as one of themajor sections of the population that needgreater attention. Besides nutritionalrequirements, the policy put greater emphasison other important needs of adolescentsincluding protection from unwantedpregnancies and sexually transmitted diseases(STD). It called for programmes that aimtowards encouraging delayed marriage andchild-bearing, education of adolescents aboutthe risks of unprotected sex, makingcontraceptive services accessible andaffordable, providing food supplements,nutritional services, strengthening legalmeasures to prevent child marriage.

People are the nation’s most valuableresource. A well- educated healthy populationprovides potential power.

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60 CONTEMPORARY INDIA

1. Choose the right answer from the four alternatives given below.

(i) Migrations change the number, distribution and composition of thepopulation in

(a) the area of departure (c) both the area of departure and arrival

(b) the area of arrival (d) none of the above

(ii) A large proportion of children in a population is a result of

(a) high birth rates (c) high death rates

(b) high life expectancies (d) more married couples

(iii) The magnitude of population growth refers to

(a) the total population of an area

(b) the number of persons added each year

(c) the rate at which the population increases

(d) the number of females per thousand males

(iv) According to the Census 2001, a “literate” person is one who

(a) can read and write his/her name

(b) can read and write any language

(c) is 7 years old and can read and write any language with understanding

(d) knows the 3 ‘R’s (reading, writing, arithematic)

2. Answer the following questions briefly.

(i) Why is the rate of population growth in India declining since 1981?

(ii) Discuss the major components of population growth.

(iii) Define age structure, death rate and birth rate.

(iv) How is migration a determinant factor of population change?

3. Distinguish between population growth and population change.

4. What is the relation between occupational structure and development?

5. What are the advantages of having a healthy population?

6. What are the significant features of the National Population Policy 2000?

PROJECT/ACTIVITY

Conduct a class census by preparing a questionnaire. The questionnaire shouldcontain minimum five questions. Questions should relate to students, theirfamily members, their class performance, their health etc. Each student isrequired to fill up the questionnaire. Compile the information in numerical terms(in terms of percentage). Present the information through pie-chart, bar-diagramor in any other way.

EXERCISE

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POPULATION 61

GLOSSARY

Adolescence : Adolescence is a period in which a person is no longer a child andnot yet an adult. Such persons are grouped in the age group of10 to 19 years.

Alluvial plain : A level tract of land made up of alluvium or fine rock materialbrought down by a river.

Base population : The total population of an area at the beginning of a given timeperiod.

Biome : Plant communities occuring in distinct groups in areas havingsimilar climatic conditions.

Birth rate : The number of live births for every 1000 persons in a year.Climate : The average weathr conditions of a sizeable area of the Earth’s

surface over a period of time.Depression : In meteorology; it denotes an area of relatively low atmospheric

pressure, which is found mainly in temperate regions. In geology,it refers to a hollow sunken area of the earth’s surface.

Death rate : The number of deaths per 1000 persons in year.Density of population : The average number of persons per unit area, such as a square

kilometre.Dependency ratio : The ratio of people of dependent age (below 15 and above 60 years)

to people of economically active ages (15-59 years).Ecosystem : A system which comprises the physical environment and the

organisms living therein.Environment : Surroundings or the conditions under which a person or thing

exists and develops his or its character. It covers both physicaland cultural elements.

Fault : A linear break in rocks of the earth’s crust along which there hasbeen displacement in a horizontal, vertical or oblique direction.

Fauna : The animal life of a given area.Flora : The total vegetatin or plant cover of a region.Fold : A bend in the rock strata resulting from compression of an area of

the earth’s crust.Geosyncline : A narrow, shallow, elongated basin with a sinking bottom in which

a considerable thickness of sediments was deposited by the riverscoming from Angara and Gondwanaland.

Glacier : A mass of snow and ice that moves slowly under the influence ofgravity along a confined course away from its place of accumulation.

Growth rate of population : The growth rate of population indicates the rate at which thepopulation is grwing. In estimating the growth rate the increase inpopulation is compared with the base population. It can bemeasured annually or over a decade.

Indian Mainland : It refers to the contiguous stretch of landmass from Jammu andKashmir to Kanniyakumari and from Gujarat to ArunachalPradesh.

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62 CONTEMPORARY INDIA

Indian Standard Time : The local time along the Standard Meridian of India (82°30'E).Inland drainage : A drainage system in which the waters of the rivers do not reach

the oceans but fall into an inland sea or lake.Igneous rocks : Rocks formed as a result of solidification of magma either below

the earth’s surface or above it.Lagoon : A salt-water lake separated from the sea by the sandbars and spits.Lake : A body of water that lies in a hollow in the earht’s surface and is

entirely surrounded by land.Lithospheric Plates : Large segments of the earth’s crust composed of continental and

oceanic lithospheric parts, floating above the asthenosphere.Life expectancy : The average number of years one is expected to live.Local Time : The time of a place determined by the midday sun is called the

local time.Metamorphic rocks : Deformation and alteration of pre-existing igneous and

sedimentary rocks as a result of changes in physical and chemicalconditions due to intense heat or pressure.

Migration : Movement of people from one place to another. Internal migrationmeans movement of people within a country and external migrationmeans movement of people between countries. When people cometo a country from another country, it is called immigration andwhen they leave that contry, it is called emigration.

Million Plus cities : Cities with a population of more than one million or 10 lakh.Monsson : A complete reversal of winds over a large area leading to a change

of seasons.Mountain : An upward projected features of the earth’s surface that rises to

high altitude and usually possesses steep slopes.National park : A reserved area for preserving its natural vegetaion, wild life and

the natural environment.Plain : An extensive area of flat or gently undulating land.Plateau : An extensive elevated area of relatively flat land.Plate Tectonics : The scientific concept that explains the movements of the crustal

plates.Relief : The differences in elevation or the physical outline of the land surfac

or ocean floor.Subsidence : In meteorology, it is the downward movement of the air. In geology,

it refers to the sinking of a portion of the earth’s surface.Sedimentary rocks : Rocks composed of sediments and generally having a layered

structure.Sex-ratio : Sex-ratio is defined as the number of females per thousands males.Sub-Continent : A big landmass, which stands out as a distinct geographicl unit

from the rest of the continent.Tectonic : Forces originating within the earth and responsible for bringing

widespread changes in the landform features.Young mountains : The fold mountains formed during the most recent major phase

of folding in the earth’s curst.