Physical Features of India

INTRODUCTION #

The largest democracy in the world, the land also known as Bharat or Hindustan is unique with its incredible diversity, both culturally and physically. The second largest populous country, India is home to around 17.5 per cent of world’s population. The country, however, accounts for 2.42 per cent of the total world area.

Geographical Position of India #

India lies entirely on the Indian Plate in the northern portion of the Indo-Australian Plate. The country lies to the north of the equator between 8°4’ and 37°6’ North latitude and 68°7’ and 97°25’ East longitude. It is the seventh largest country in the world, with a total land area of 3,287,263 square kilometres (1,269,219 sq miles). India measures 3,214 km (1,997 miles) from North to South and 2,993 km (1,860 mi) from East to west. It has a land frontier of 15,200 km (9,445 miles) and a coastline of 7,517 km (4,671 miles).

India is bounded in the southwest by the Arabian Sea, in the southeast by the Bay of Bengal and by the Indian Ocean in the south. Cape Comorin consti- tutes the southern tip of the Indian peninsula, which narrows before ending in the Indian Ocean. The southernmost part of India is Indira Point in the Andaman and Nicobar Islands. The Maldives, Sri Lanka and Indonesia are island nations to the south of India with Sri Lanka separated from India by a narrow channel of sea formed by Palk Strait and the Gulf of Mannar. The territorial waters of India extend into the sea to a distance of 12 nautical miles (13.8 miles; 22.2 km) measured from the appropriate baseline.

The northern frontiers of India are defined largely by the Himalayan mountain range where its political boundaries with China, Bhutan, and Nepal lies. Its western borders with Pakistan lies in the Punjab Plain and the Thar Desert. In the far northeast, the Chin Hills and Kachin Hills, deeply forested mountainous regions, separate India from Burma while its political border with Bangladesh is defined by the watershed region of the Indo-Gangetic Plain, the Khasi hills and Mizo Hills.

The Ganges is the longest river originating in India and forms the Indo-Gangetic Plain. The Gan- ges-Brahmaputra system occupies most of northern, central and eastern India, while the Deccan Plateau occupies most of southern India. Along its western frontier is the Thar Desert, which is the seventh-larg- est desert in the world.

Officially, India’s highest point is K-2 at 8,611 m (28,251 ft), though it lies in Gilgit-Baltistan, part of the disputed Kashmir region. Kanchanjunga in Sikkim at 8,598 m (28,209 ft) is the highest point within India’s current geographic boundaries. Climate across India ranges from equatorial in the far south, to Alpine in the upper reaches of the Himalayas.

The country’s land is flanked by the Bay of Bengal and the Arabian Sea, along the southeast and along the southwest respectively. On the western border Pakistan is situated and in the east, Bang- ladesh and Burma. Along her northern boundary are Bhutan, Nepal, and Tibet and Sinkiang region of China. The Gulf of Mannar and the Palk Strait separate India from Sri Lanka. The Andaman and Nicobar Islands in the Bay of Bengal and Lakshad- weep in the Arabian Sea are parts of the Indian Territory.

International Boundaries #

The Indian peninsula in the south is bounded on the west by the Arabian Sea, on the east by the Bay of Bengal and on the south by the Indian Ocean. Sri Lanka lies off the southeast coast, and the Maldives off the southwest coast. In the North, North East and North West of the subcontinent lies the Himalayan ranges. India shares borders to the northwest with Afghanistan (106 km) and Pakistan, to the north with China, Nepal and Bhutan, and to the east with Bangladesh and Myanmar.

India’s borders run a total length of 15,106.70 km (9,387 miles). Its borders with Pakistan and Bangla- desh were delineated according to the Radcliff Line, which was created in 1947 during Partition of India. Its western border with Pakistan extends upto 3,323 km (2,065 miles), dividing the Punjab region and running along the boundaries of the Thar Desert and the Rann of Kutch. Both nations delineated a Line of Control (LoC) to serve as the informal boundary between the Indian and Pakistan-administered areas of Kashmir. According to India’s claim, it shares a 106 km border with Afghanistan in northwestern Kashmir, which is under Pakistani control.

India’s border with Bangladesh runs 4,096.70 km (2,546 miles). There are 92 enclaves of Bang- ladesh on Indian soil and 106 enclaves of India are on Bangladeshi soil. The Teen Bigha Corridor is a strip of land formerly belonging to India on the West Bengal-Bangladesh border which has been leased indefinitely to Bangladesh so that it can access its Dehgram-Angalpota enclaves.

The Line of Actual Control (LAC) is the effective border between India and the People’s Republic of China. It traverses 4,057 km along the Indian states of Jammu and Kashmir, Uttarakhand, Himachal Pradesh, Sikkim and Arunachal Pradesh. Both nations lay claim to the Aksai Chin region of northeastern Kashmir, which fell into Chinese control during the Sino-Indian War of 1962.The border with Burma (Myanmar) extends up to 1,643 km (1,021 miles) along the southern borders of India’s northeastern states. Located amidst the Himalayan range, India’s border with Bhutan runs 699 km (434 miles). The border with Nepal runs 1,751 km (1,088 miles) along the foothills of the Himalayas in northern India. The Siliguri Corridor,

narrowed sharply by the borders of Bhutan, Nepal and Bangladesh, connects peninsular India with the northeastern states.

Geology of India #

The Indian craton was once part of the Super- continent of Pangaea. At that time, it was attached to Madagascar and southern Africa on the south west coast, and Australia along the east coast. During the Jurassic Period, rifting caused Pangaea to break apart into two supercontinents namely, Gondwana (to the south) and Laurasia (to the north). The Indian craton remained attached to Gondwana, until the Supercontinent began to rift apart about in the early Cretaceous, around 125 Ma. The Indian Plate then drifted northward toward the Eurasian Plate. It is generally believed that the Indian plate separated from Madagascar about 90 Ma. This orogeny, which is continuing today, is related to closure of the Tethys Ocean. The closure of this ocean, which created the Alps in Europe, and the Caucasus range in western Asia, created Himalaya Mountains and the Tibetan Plateau in South Asia. The current orogenic event is causing parts of the Asian continent to deform west- ward and eastward on either side of the orogeny. Concurrently with this collision, the Indian Plate sutured on to the adjacent Australian Plate, forming a new larger plate, the Indo-Australian Plate.

Greater/Inner Himalayas	Lesser/Middle Himalayas	Outer/Lower Himalayas
The highest mountain range of the Himalayas.	Situated to the south of the Himadri.	This is the outer most range to the south of the Lesser Himalayas.
These ranges have an average height of about 6000 m.	Average height is above 3000 m.	These discon- tinuous ranges join the lesser Himalayas in the extreme east.
Highest Mountain peaks are situated in this range. (e.g.Kanchan- junga-8595m, Nangapar- bat-8126m).	Many health resorts are situated on the southern slope of the mountain range, e.g.: Shimla, Darjeeling	Its average height is about 1200m.

The source of	—	There are sev-
Ganges and		eral elongated
Yamuna.		and flat valleys
		running parallel
		to the mountain
		ranges. They
		are called
		“duns”. (e.g.:
		Dehradun)

Evolution of India #

The cooling and solidification of the upper crust of the earth surface marked the earliest phase of tectonic evolution in the Archaean era (prior to 2.5 billion years) which is represented by the exposure of gneisses and granites especially on the Peninsula. These formed the core of the Indian craton. The Aravalli Range is the remnant of an early Prote- rozoic orogeny called the Aravalli-Delhi orogeny that joined the two older segments that make up the Indian craton. It extends approximately 500 kilometers from its northern end to isolated hills and rocky ridges into Haryana, ending near Delhi. Minor igneous intrusions, deformation (folding and fault- ing) and subsequent metamorphism of the Aravalli Mountains represent the main phase of orogenesis. The erosion of the mountains and further deformation of the sediments of the Dharwarian group marks the second phase. The volcanic activities and intrusions, associated with this second phase are recorded in composition of these sediments.

Early to Late Proterozoic calcareous and are- naceous deposits, which correspond to humid and semi-arid climatic regimes, deposited the Cuddapah and Vindhyan basins. These basins, which border or lie within the existing crystalline basement, were uplifted during the Cambrian (500 Ma). The Vin- dhyans are believed to have been deposited between around 1700 and 650 Ma.

Early Palaeozoic rocks are found in the Him- alayas and consist of southerly-derived sediments eroded from the crystalline craton and deposited on the Indian platform.

In the Late Paleozoic, Permo-Carboniferous glaciations left extensive glacio-fluvial deposits across central India, in new basins created by sag/ normal faulting. These tillites and glacially derived sediments are designated the Gondwana series. The

sediments are overlain by rocks resulting from a Permian marine transgression (270 Ma)

The late Paleozoic coincided with the deforma- tion and drift of the Gondwana super-continent. To this drift, the uplift of the Vindhyan sediments and the deposition of northern peripheral sediments in the Himalayan Sea can be attributed.

During the Jurassic, as Pangaea began to rift apart, large grabens formed in central India filling with Upper Jurassic and Lower Cretaceous sand- stones and conglomerates.

By the Late Cretaceous, India had separated from Australia and Africa and was moving north- ward towards Asia. At this time, prior to the Dec- can eruptions, uplift in southern India resulted in sedimentation in the adjacent nascent Indian Ocean. Exposures of these rocks occur along the south Indian coast at Pondicherry and in Tamil Nadu.

At the close of the Mesozoic era, one of the greatest volcanic eruptions in earth’s history occurred, the Deccan lava flows. Covering more than 500,000 square kilometers area, these mark the final break from Gondwana. In the early Tertiary, the first phase of the Himalayan orogeny, the Karakoram phase occurred. The Himalayan orogeny has continued to the present day.

Physiographic Division of india #

The four major geographical regions of India

are:

1. The Great Himalayan range,
2. The Indo Gangetic Plain,
3. The Deccan Plateau and Peninsula,
4. The Coastal plains
5. The Islands

Himalayan Mountain System #

This is the great wall like physiographic unit, which stretches from Kashmir in the North West to the Indian border in the east. This region is formed by the Karakoram, Ladakh, Zaskar and the Himala- yan range of mountains and the eastern highlands. These mountain ranges are subdivided into three divisions namely, Trans Himalayas, Himalayas and the Eastern himalayas.

The Trans Himalayas comprises the Karakoram, Ladakh and Zaskar ranges that originates from the Pamir Knot. The highest peak in India, ‘Mount K2’ (Mt. Godwin Austin, 8611m) is in the Karakoram Range. The Himalayas can be divided into – (i) The Himalayan ranges (ii) The Trans-Himalayas (iii) The Eastern Hills.

The height of the mountain ranges gradually decreases as they approach the eastern parts of the Northern mountainous regions. This region with an average height of 500m to 3000m above MSL is known as the Eastern highlands (Purvanchal).

1. Duns: The longitudinal valley lying between Lesser Himalaya and Shiwaliks are known as duns
2. The Himalayan Mountains are also known as the Himadri, Himaven or Himachal.
3. It consists of the youngest and the loftiest, rugged tertiary mountain chains of the World.
4. It is characterized by youthfulness, great deal of folding and deformation tectonic origin and great erosive power of rivers.
5. It stretches for a distance of over 2400 km (over 22° longitude) from Indus gorge in the west to the Brahmaputra gorge (Dihang gorge) in the east.
6. The width of the Himalayas varies from 500 km in Kashmir to 200 km in Arunachal Pradesh, i.e., it becomes narrower from west to east.
7. It extends from west to east in arcate shape which is convex to the south.

Origin of Himalayan Mountain #

Plate tectonics is the most recent and widely acclaimed theory for the origin of Himalayas. Plate is a broad segment of lithosphere that floats on the underlying asthenosphere and moves independently of other plates. When two plates move towards each other, converge and in the process one plate overrides the other. The overridden plate is sub ducted and goes under the asthenosphere and is lost or consumed. It is the converging boundary of plates where folded mountains like the Himalayas build up. When two convergent plates composed of continental crusts collide against each other, the

denser plate is sub ducted under the lighter plate. The resultant lateral compression squeezes and folds the sediments deposited on either side of the continental plate margins. Himalayas are the product of such a process on the conveyance zone of the Asiatic plate in north and the Indian plate in the south.

Around 70 million years ago, the Indian plate started moving towards the Asian plate and the Tethys Sea began to contract. The sediment got folded in three successive phases giving rise to three ranges of Himalayas explained below.

Division of Himalayas #

1. The Great Himalaya: This is also known as inner Himalaya, Central Himalaya or Hi- madri. It is mainly formed of central crys- tallines (granites and gneisses) overlain by metamorphosed sedimentary races. It is the most continuous range consisting of loftiest peaks with an average height of 6000 meters. The core of these mountains is composed of Archaean rocks like granite, gneisses and the schists. The folds in this range are asymmet- rical with steep south slope and gentle North Slope. It extends in arcate shape, from Nanga Parbat in north-west and Namcha Barwa in the north-east, which is convex to the south. Average elevation is 6100m in and average width is about 25km.
2. The Middle or the Lesser Himalaya: It is also called the Himachal or Lower Himalaya. It is mainly composed of metamorphic rocks and unfossiliferous sedimentary rocks. The southern slopes are bare and rugged while the northern slopes are thickly forested. The Pir Panjal, the Dhauladhar, the Musoorie range, Nag Tibba and the Mahabharata are the im- portant ranges. The Pir Panjal in Kashmir is the longest and the most important range. Banihal pass situated in the Pir Panjal range is used by the Jammu-Srinagar national high- way. The valley of Kashmir lies between the Pir Panjal and the Zaskar range. Most of the hill stations (Shimla, Musoorie, Ranikhet, Nainital, Almora and Darjeeling etc.) lie in this section. Average elevation in 3500 m to 5000 m and average width is 60-80 km.

Mountain Peaks in the Himalaya
Mt Everest	8848 M
Mt K2	8611 M
Kanchanjunga	8598 M
Makalu	8481 M
Dhaulagiri	8172 M
Annapurna	8078 M

• The Shiwaliks or the Outer Himalaya: Consists of foothills which almost from Pot- war plateau to Brahmaputra valley. These ranges are mainly made up of fluvial depos- its like sand, clay, Rounded stones, gravels, slates etc. This section is characterized by poor drainage, which is move pronounced in Terai region. Its eastern part upto Nepal is thickly forested but the forest cover becomes thin in the west. Average elevation is 1000m

– 1500m while average width is 15-50 km. The gorges of Tista and Raidak have jointly formed a gap 80-90 km wide in the Shiwalik range. Shiwalik are known by different names in different areas. They are called Dafla, Miri, Abor and Mishmi hills in Arunachal Pradesh, and Jammu hills in Jammu.

Regional Division of Himalayas #

On the basis of river valleys, Himalayas can be longitudinally divided into the following sections:

(I)   Kashmir Himalaya #

1. Average elevation is about 3000m.
   1. This section has the largest share of snow and glaciers.
   1. Two important passes: Pir Panjal and Banihal

– lie in Pir Panjal range.

• The Valley of Kashmir lies in this section.

(II)   Punjab Himalaya #

1. Stretches eastward upto Satluj for about 570km.
   1. High Peaks are rare.
   1. Main ranges: Karakoram, Ladakh, Pir Panjal, Zaskar and Dhauladhar
   1. Important Passes: Zojila, Rohtang and Bara Lacha la.

• Important Valleys: Kangra, Lahul and Spiti.
  • This section is important for fruit cultivation (horticulture) and scenic beauty.

(III)   Kumaon Himalaya #

1. Stretches from Satluj to Kali River for about 320 km and the general elevation is higher than Punjab Himalayas.
   1. Its western part is called Garhwal Himalaya while eastern part is known as Kumaon Hi- malaya proper.
   1. Important peaks: Nanda Devi, Kamet, Tri- shul, Badrinath, and Kedarnath.
   1. Nanda Devi is the highest peak in this sec- tion.
   1. Important lakes: Nainital and Bhimtal
   1. Several duns lie between Middle Himalayas and Shiwaliks.

(IV)   Central Himalaya #

1. Extends from river Kali to Tista for about 800km.
   1. Most of it parts lies in Nepal and hence it is also called as Nepal Himalaya.
   1. This section has some of the world’s highest peaks, such as Mt. Everest, Makalu, Kan- chanjunga, Dhaulagiri, Annapurna, and Go- sainthan.
   1. This section is known as Sikkim Himalaya in Sikkim, Darjeeling Himalaya in West Bengal and Bhutan Himalaya in Bhutan.
   1. Bilafond la also known as “pass of the butter-

flies”.

• Saltoro pass is a mountain pass situated in Saltoro ridge on the west of siachen glacier.
  • Chang la is the main gateway for the chang tang plateau, situated in the Himalayas.
  • The Debsa pass provides an easier and short- er alternative to the traditional Pin-Parbati pass route between Kullu and Spiti.

(V)   Assam Himalaya #

1. Stretches from river Tista to Brahmaputra for about 720 km.
   1. Pauhunri and Kulakangri are important peaks.

• The Naga hills and Patkai Bum hills of this section forms the watershed between India and Myanmar.

(VI)   Trans Himalayas #

1. It immediately lies north of the Great Hima- layan range.
   1. It is also called the Tibetan Himalaya because most of it lies in Tibet.
   1. The Zaskar, the Ladakh, the Kailash and the Karakoram are the main ranges of this system.
   1. Mt. K-2 (Godwin Austin), Nanga Parbat, Rakaposhi, Haramosh, Gasherbrum-I (Hidden Peak), Gasherbrum-II etc. are important peaks.
   1. This section has some of the world’s largest glaciers – Siachen, Hispar, Biafo, Batura and Baltoro.
   1. Ladakh Plateau (5000m), the highest plateau of the Indian Union, lies to the north-east of the Karakoram range. It has been dissect- ed into a number of plains and mountains. The most outstanding among them are Ak- sai Chin, Soda Plains, Lingzi Tang, Depsang Plains, and Chang Chenmo.

(VII)  Eastern Hills or the Purvanchal Hills #

After crossing the Dihang gorge (Brahmaputra gorge), the Himalayas suddenly turn southward and forms a series of comparatively low hills running in the shape of a crescent with its convex side pointing towards the west. These hills are collectively called the Purvanchal because they are located in the east- ern part of the country. It extends from Arunachal Pradesh in the north to Mizoram in the south and form boundary between India and Myanmar. The Indo-Burma hill range is a part of the Arakan Yoma Suture zone that stretches south through Andaman – Nicobar island chain to Sunda. The elevation of the Eastern Hills (Purvanchal) decreases from north to south and it is characterized by rough terrain, dense forests and swift streams. All these Ranges are generally 2,000m or less in height but are rather forbidding because of dense forests, very rough terrace and inhospitable tribe.

It comprises of the following hills – #

• Mishmi hills: Contains the loftiest range of the Purvanchal. Dapha Bum is its highest peak.

• Patkai Bum Range: It is the northernmost range forming the easternmost limit of the Great Himalaya Mountains, has synclinal structure and is made up of Tipam sandstone.
• Naga Hills: It lies south to the Patkai Bum and Saramati (3826m) is its highest peak. Pat- kai Bum and Naga hills form the watershed between India and Myanmar.
• Manipur Hills: It is south to Naga hills and form boundary between Manipur and Myan- mar. Its central part is a large basin which appears to be bed of an old lake, a remnant of which occupies the south-east corner of the basin and is known as Loktak Lake. The Barail Range separates Naga Hills from Ma- nipur hills.
• Mizo Hills (Lushai Hills): It lies south to the Manipur hills and its highest point is the Blue Mountain (2157m) in the south.

Importance of the Himalayas #

The Himalayas comprises the most dominating geographical feature of India. No other mountain range anywhere in world has affected the life of people and shaped the destiny of a nation as the Himalayas have in respect of India. The Himalayas are the body and soul of India. In a very special measure, the Himalayas constitute India’s national mountain system.

The following few points will bring out the significance of the Himalayan Mountains to India.

1. Climatic Influence: The Himalayas plays a very significant role in influencing the climate of India by virtue of their high altitude, length and direction; they effectively intercept the summer monsoons coming from the Bay of Bengal and Arabian Sea and cause precipita- tion in the form of rain or snow. Besides, they prevent the cold continental air masses of central Asia from entering into India. If there had been no Himalayas, the whole of Indian would have been a desert in the absence of precipitation and its winters would have been very severe under the influence of cold air- masses coming from Central Asia. According to the latest meteorological studies, the Hi- malayas are responsible for splitting the jet

stream into two branches and these in turn play an extremely important role in bring monsoons in India.

• Source of RiversL Almost all the great rivers of India have their sources in the Himalayas ranges. Abundant rainfall and vast snow- fields as well as large glaciers are the feeding grounds of the mighty rivers of India. Snow melt in summer provides water to these rivers even during dry season and these are peren- nial rivers. The Himalayan Rivers, along with hundreds of their tributaries, forms the very basis of life in the whole of north India.
• Defence: The Himalayas have been protect- ing Indian from outside invaders since the early times thus serving as a defence barri- er. But the Chinese aggression on India in October, 1962 has reduced the defence sig- nificance of the Himalayas to a considerable extent. In spite of advancement in modern warfare technology, the defence significance of the Himalayas cannot be ignored altogeth- er.
• Hydroelectricity: The Himalayan region offers several sites which can be used for producing hydroelectricity. There are natural waterfalls at certain places while dams can be constructed across rivers at some other plac- es. The vast power potential of the Himalayan Rivers still awaits proper utilization.
• Forest Wealth: The Himalayan ranges are very rich in forest resources. In their altitude, the Himalayan ranges show a succession of vegetal cover from the tropical to the Alpine. The Himalayan forests provide fuel wood and a large variety of raw materials for for- est based industries. Besides many medicinal plants grow in the Himalayan region. Several patches are covered with grass offering rich pastures for grazing animals.
• Agriculture: The Himalayas does not offer extensive flat lands for agriculture but some of the slopes are terraced for cultivation. Rice is the main crop on the terraced slopes. The other crops are wheat, maize, potatoes, to- bacco and ginger. Tea is a unique crop which can be grown on the hill slopes only. A wide

variety of fruits such as apples, pears, grapes, mulberry, walnut, cherries, peaches, apricot, etc. are also grown in the Himalayan region.

• Tourism: By virtue of their scenic beauty and healthy environment, the Himalayan rang- es have developed a large number of tourist spots. The hilly areas in the Himalayas offers cool and comfortable climate when the neigh- bouring plains are reeling under the scorching heat of the summer season. Millions of tour- ists from different parts of the country as well as from abroad throng the Himalayas tourist centres to enjoy their natural beauty and to escape from the summer heat of the plains. The increasing popularity of winter sports and the craze to enjoy snowfall has increased the rust of tourists in winters also. Srinagar, Dalhousie, Dharmashala, Chamba, Shimla, Kulu, Manali, Mussoorie, Nainital, Ranikhet, Almora, Darjeeling, Mirik, Gangtok etc. are important tourist centres in the Himalayas.
• Pilgrimage: Apart from places of tourists in- terest, the Himalayas are proud of being stud- ded with sanctified shrines which are consid- ered to be abodes of the Gods. Large number of pilgrims trek through difficult terrain to pay their reverence to these sacred shrines. Kailas, Amarnath, Badrinath, Kedarnath, Vaishnu Devi, Jwalaji, Uttrkasi, Gangotri, Yamunotri, etc. are important places of pil- grimage.
• Minerals: The Himalayan region contains many valuable minerals. There are vast po- tentialities of mineral oil in the tertiary ricks. Coal is found in Kashmir. Copper, lead, zinc, nickel, cobalt, antimony, tungsten, gold, sil- ver, limestone, semi-precious and precious stones, gypsum and magnetite are known to occur at more than 100 localities in the Hi- malayas. Unfortunately most of the mineral resources cannot be exploited at the present level of technological advancement due to adverse geographical conditions. Further ad- vancements in modern technology may help in to use these resources, so the future possi- bilities of mineral exploitation in the Himala- yas are great.

The Northern Plains of India #

Lying between the Himalayas in the north and the stable peninsula in the south, it stretches from the arid and semi-arid plains of Rajasthan in the west to the Ganga delta in the east. It is drained by three major river systems; the Ganga system, the Indus system, the Brahmaputra system. The plain is believed to be formed from infilling of a marine depression or fore deep, that formed dome to Himalayan uplift and subsidence of the northern blank of the plateau, by alluvial deposits brought by both rivers Himalayan Rivers and Peninsular Rivers.

Origin of the Plain #

It is almost universally accepted that this vast plain has been formed as a result of filling of a deep depression lying between the Peninsular and the Himalayan region by the depositional work of the rivers coming from these two landmasses. How- ever, divergent views has been expressed regarding originally a deep depression or furrow lying between the Peninsula and the mountain region. The great Austrian geologist Edward Suess has suggested that “foredeep” was formed in front of high crust waves of the Himalayas as they were checked in their southward advance by inflexible solid landmass of the Peninsula. This foredeep was like a large syncline in which alluvium brought by the Hima- layan and the Peninsular Rivers was deposited. In due course of time, this was filled with alluvium and the Great Plain of North India was formed. It rests on the hard and crystalline rocks through which the region is connected to the Himalayan and the Peninsular blocks. Sir Sydney Burrard, on the other hand, thinks that the Indo-Gangetic alluvium conceals a great deep rift, or fracture, in the earth’s sub-crust, several thousand metres deep, the hollow being subsequently filled up by detrital. He ascribes to such sub-crustal cracks or rifts a fundamental importance in geotectonic and attributes the eleva- tion of the Himalayan chain to an incidental bending or curbing movement of the northern wall to the fissure. Such sunken tracts between parallel, vertical dislocations are called ‘Rift Valleys’. The rift valley between the Himalayan ranges and the Peninsula which gave birth to this plain was about 2,400 km long and hundreds of metres deep. His findings were based on some anomalies in the observations of the

deflections of the plumb line and other geodetic considerations. He described some other rift valleys of the Himalayan region as well as the rift valleys of Narmada and Tapi in the Peninsular India. Schol- ars like Hayden and R.D. Oldham as well as other geologists of the Geological Survey of India have not accepted Burrard’s view of the Indo-Gangetic depression. The main objection to Burrard’s views is that there is no trace of rift valley at the northern edge of the peninsula and that such vast rift valley is not possible.

According to the recent views expressed by many geologists and geographers, sediment depos- ited at the bed of the Tethys Sea was folded and warped due to northward drift of the Peninsula. Consequently the Himalayas and a trough to the south were formed. The origin of this depression or trough, lying at the foot of the mountain, is doubt- less intimately connected with the later. The Great plain represents the infilling of the foredeep warped down between the advancing Peninsular Block and the Himalayas. The infilling has been done by the deposition of the detritus of the mountains brought by the numerous rivers emerging from them during the period of great gradational activity. Geologically most parts of this plain are of the Pleistocene and Recent formations.

CHARACTERISTIC & GEO-MOR- PHOLOGICAL FEATURES #

From North to South #

1. Bhabar: It is a narrow belt of about 8-16km width running in east-west direction along the foot of the Shiwaliks with a remarkable continuity from the Indus to the Tista, where rivers descending from the Himalayas depos- it their load along the foothills in the form of alluvial fans. These are porous, gravel-ridden plain and due to high porosity the streams in this zone get lost in the ground except during the rainy season. It is comparatively narrow in the east and extensive in the western and northwestern hill of region. This area is not suitable for agriculture and only big trees with large Roots thrive in this belt.
2. Terai: The streams that disappear in Bhabar belt reappear in Terai region. It is 10-20 km

wide, ill drained, marshy, thickly forested area having a variety of wildlife. Most of the Terai land, especially in Punjab, Uttar Pradesh and Uttaranchal, has been reclaimed and turned into agricultural land which gives good crops of sugarcane, rice and wheat. Dudhwa nation- al park is situated in this region.

• Bhangar (Bengha): It is composed of old al- luvium in the form of terrace above the level of flood plains. These terraces are often im- pregnated with calcareous concretions known as Kankar.
• Khadar: It is composed of newer alluvium and forms the flood plains along the river banks, which is liable to inundations during flooding and rainy season.
• Reh or Kallar: It comprises barren saline ef- florescence’s of drier areas in Uttar Pradesh and Haryana.
• Bhur: It represents aeolian deposits during Pleistocene in the middle Ganga – Yamuna Doab.

Region-wise Division #

• Western Plains: These plains extend over Rajasthan desert, Rann of Kuchchh and dri- er parts of Punjab and Haryana, where wind action predominates over water action. This area was under sea from Permo-Carbon- iferous to Pleistocene. It is dotted with salt Lakes, such as Sambhar, Didwana, Degana, Pachpadra, Kuchaman,etc. Dhrian (shifting sandiness), Raun (Playa Lakes), Rohi (fertile plains west of Aravallis) are important geo- morphological features of this plain.
• Punjab – Haryana Plain: This plain is drained by five important rivers namely- Jhe- lum, Chenab, Ravi, Beas and Satluj, and the Panjdoabs (Doabs – the land between two rivers) are the most important feature of this section, which are as follows:
  • Bist: (Jalandhar Doab) between Beas and Satluj.
  • Bari: between Beas and Ravi.
  • Rachna: between Ravi and Chenab.
  • Chaj: between Chenab and Jhelum.
  • Sind Sagar: between Jhelum and Indus

The only river between the Yamuna and Satluj is the Ghaggar, which is considered to be the present day successor of the legendary Saras- wati river. The Khadar belt liable to flood- ing but agriculturally important is known as ‘Bets’. These Khadar belts are flanked by heavily gullied bluffs locally known as ‘Dha- yas’. The northern part of this plain adjoining the Shiwaliks has been intensively eroded by numerous streams called Chos.

• Ganga Plain: This is the largest unit of the Great plain of India stretching from Delhi to Kolkata in the static of U.P., Bihar and West-Bengal. The general slope of the entire plain is east and south – east. These plains can be divided into following: distinct cultur- al-geographical divisions.
• Ganga: Yamuna Doab: It is the largest doab between Ganga and Yamuna. The Bhangar uplands along the Yamuna and Chambal courses have been broken into intricate maze of ravines and gullies giv- ing rise to the badland topography. Bhabar plains, Terai, Bhangar, Khadar are strik- ing features of this section. Khots are intervening slopes between Bhangar and Khadar. Another unusual topographic fea- ture of the upper doab is Bhur which is formed of aeolian deposits during Pleisto- cene period.
• Rohilkhand Plains: To the east of Ganga- Yamuna doab it stretches from the foot- hills of Himalayas to the Ganga. Lying entirely in U.P. it is drained by Ramgan- ga, Gomati and Sarda rivers. The Bhabar and Terai plains are well developed in the north. The general slope is towards south- east.
• Awadh Plains: The major portion of low- land north of the Ganga, gently sloping eastwards, comes within this physiograph- ic region. Strips of Khadar and Bhangar are very conspicuous in this section; the Ghaghra is the master – stream traversing the whole length of the Awadh plains.
• Bihar Plains: After the end of Awadh plains in U.P., the next stretch of the Great Plains in the Bihar Plains, which is nar-

rowed eastwards by the prolongation of the Rajmahal hills. On the basis of differ- ing Relief and river conditions it can fur- ther be subdivided into two parts:

• North Bihar Plain – Lying north of Ganga and drained by it’s tributaries Ghaghra, Gandak, Kosi it slopes to- wards the south – east in the western part and south in the eastern part. A long live of marshes extends paral- lel to the Ganga; locally known as CHAURS. Some of them are deep enough to contain water throughout the years e.g. the Kabar Tal.
  • South Bihar Plain – lies west of Rajmahal hills and eastward side of southern bank of Ganga occur vast depression known as Jala near Patna and Tal hear Mokama.
• North Bengal Plains: Extending from the foot of the Eastern Himalaya to the north- ern limit of the Bengal basin, it’s eastern part is drained by the rivers joining the Brahmaputra and western part by the trib- utaries of the Ganga. Powerful streams like Tista, Jaldhaka and Torsa drain it. Its northern fringe, known as the western Dhar, is well drained and is the ideal home of tea plantations. Farther south of Dhars lies the Bhangar land of Barind plain, which is the older delta of Ganga, formed during the Pleistocene period and subse- quently up-warped and eroded into terraces.
• Bengal Basin: It comprises of most of the alluvial plains of West Bengal and Ban- gladesh. The Ganga delta occupies the major portion of the Bengal Basin. The thickly forested Sunderbans in the south and the east Bhagirathi plains is the north, with its dead and dying rivers, offers con- tracting features.
• Rarh Plain: Though it is not a proper part of the delta, it is equally flat lowland to the west of the Bhagirathi. The natural of the Damodar and other rivers of this area are characteristic feature. The prolonged weath- ering has given rise to Lateritic silks. Da- modar River is accused to be the sorrow of Bengal due to its devastating nature.

Peninsular Plateau Region #

It is roughly triangular in shape whose base lies in the north coinciding with the southern edge of the great plain and apex in south is formed by Kanyakumari. It is surrounded by the hill ranges on all the three sides- to its north is the Aravali range, The major hill ranges Vindhyas, the Satpura the Bharmer and the Rajmahal hills while Western Ghats (Sahyadris) and Eastern Ghats forms its west- ern and eastern boundaries respectively.

It covers a total area of about 16 lakh sq km which is about half of the total land area of the country, and thus it is the largest physiographic unit of India. The general slope of the plateau is from west to east with the exception of Narmada-Tapi rift which slopes westwards. Following are important plateau and hill ranges of the peninsular plateau-

1. Aravali range – extends in north – east to south – west direction for about 800 km from Delhi to Ahmedabad. It is one of the world’s oldest mountains formed as a result of folding during Archaean era. The general elevation is 400- 800 m; Mt. Abu (1158 m) lies in this range. Guru Shikhar (1722 m), the highest peak, is situated in Mt Abu.
2. Marwar Upland – To the east of the Aravali Range also called upland of eastern Rajas- than. It is made up of sandstone, shales and limestones of the Vindhyan Period. Banas river drains this region.
3. The Central Highland – lying to the east of Marwar upland, also called Madhya Bharat Pathar. Most of it’s part is thickly forested and in its northern part are the ravines or bad- lands of the Chambal river.
4. Bundelkhand Upland – It lies between Ya- muna and Vindhyan scarpland. It is carved only of granite, known in Indian geology as ‘Bundelkhand Gneiss’.
5. Malwa Plateau – It lies north of Vindhyan range in M.P. It is composed of extensive lava flow and is covered with black soils. It is drained by Chambal, Parbati, Sindh, Kali, Betwa and Mahi.
6. Baghelkhand – Lying east of Maikal range, it is made of limestone and sandstone on the

west and granite in the east. The central part of the plateau act as water divide between the son drainage system in the north and Maha- nadi river system in the south. The scarps of Vindhyan sandstone between the Ganga plain and the Narmada – Son trough is the main physiographic element.

• Chotanagpur Plateau – The north – eastern projection of the Indian Peninsula, east of Ba- ghelkhand, lies mostly in Jharkhand, northern part of Chhattisgarh and Purulia district of West Bengal. It is composed mainly of Gond- wana Rocks with patches of Archaean gran- ite and gneisses and Deccan Lavas. Pat lands (high level laterite plateau) are the highest points of this region. The Damodar River flows through the middle of this region in a rift valley from west to east where Gondwana Coal fields are found.
  • Hazaribagh Plateau – A Peneplain to the north of Damodar River having aver- age elevation of 600m. Parasnath (1366 m) denotes the highest hill. It is made of granites and gneisses.
  • Ranchi Plateau – Lying south of Damo- dar. Its average elevation is about 600 m. Pats, Netarhat Pat (1119 m), Goru rise (1142 m) are the highest points.
  • Rajmahal Hills – forming the north – eastward edge of Chhotanagpur plateau are mostly made of basalt and are cov- ered by lava flows.
• Meghalaya Plateau (Shillong Plateau) – It is north-eastward extension of peninsular pla- teau which is separated from the main block by Garo Rajmahal Gap. It is largely formed of Archaean quartzites, shales and schists with granite intersections. Garo (900 m), Khasi – Jaintia (1500 m) and Mikir (700 m) are important hills lying in western, central and eastern parts of the plateau respectively. Shillong (1961 m) is the highest point.
• Deccan Plateau – The largest unit of penin- sular plateau (5 lakh sq. km), it is a triangular plateau bounded in north by Vindhyas , Sat- pura, Mahadev and Maikal ranges, Western Ghats in the west and Eastern Ghats in the

east. Average elevation is about 600 m (more in south then north) and general slope in from west to east. It is subdivided points.

• Maharashtra Plateau: Looking like a roll- ing plain, done to weathering, most of the region in underlain by basaltic rocks of lava origin. The horizontal lava sheets have led to the formation of typical Dec- can Trap. The entire area is covered by black cotton soil known as Regur soil.
  • Karnataka Plateau (Mysore Plateau) – Made up primarily of Archaean rocks. The highest peak is at Mulangiri (1918 m) in Baba budan Hills. Divided into two parts –
    • Malnad – hilly region with dense for- est.
    • Maidan – rolling plain with low gran- ite hills.
  • Telangana Plateau – In Andhra Pradesh consists of Archaean Gneisses, drained by Godavari, Krishna and Penneru.
• Chhattisgarh Plain – A saucer shaped de- pression drained by the upper basin of Maha- nadi, lying between Maikal range and Orissa hills. The basin is laid with nearly horizontal beds of limestone and shales deposited during the Cuddapah age.
• Vindhyan Range – Acting as watershed be- tween the Ganga system and the river systems of south India, it is an escarpment flanking the northern edge of Narmada – Son Trough. Most parts are composed of sedimentary rocks. Western part is covered with lava.
• Satpura Range – A series of seven mountains running in the east – west direction between Narmada and Tapi, have three distinct parts –
  • Western part – locally known as Rajpip- la hills and formed of basalt.
  • Central part – bordered on north by Ma- hadev hills and on the south by Gawligarh hills. Dhaupgarh is the highest peak near Pachmarhi hill station.
  • Eastern part – is Maikal Plateau.

Eastern Ghats #

The elevation of the Eastern Ghats is lower than that of the Western Ghats. They have an average height of 450 metres and rarely exceed 1200 metres. To the southernmost part of the Eastern Ghats are the low Sirumalai and Karanthamalai hills of southern Tamil Nadu. To the north of the Kaveri River are comparatively higher hills like Kollimalai, Pachaimalai, Shevroy (Servaroyan), Kalrayan Hills, Chitteri, Palamalai, and Mettur hills. Generally, the higher hill ranges experience a cooler and wetter type of climate than the surrounding plains. These hills harbour many coffee plantations and dry for- ests. The hill station of Yercaud is located in the Shevroy Hills.

In the Nilgiri Hills, which run east from the Western Ghats to the Kaveri River, there is a wooded ecological strip that connects the Eastern and Western Ghats. This region has the second-larg- est wild elephant population in India. The Ponnaiyar and Palar rivers flowing through gaps in the Ghats drain into the Bay of Bengal. These two rivers are separated by the Javadi Hills. Some isolated areas have waterfalls. The Kiliyur Falls is one of them .To the north of the Palar River in Andhra Pradesh, the central portion of the Eastern Ghats consist of two parallel ranges running approximately north-south; the lower Velikonda range lies to the east, and the higher Palikonda-Lankamalla- Nallamalla ranges lie to the west. The Velikonda range ultimately descends to the coastal plains in the northern Nellore district, while the Nallamalla Range continues to the Krishna River.

The Krishna and the Godavari are separated by a range of low hills. To the north of the Godavari river the Eastern Ghats record an abrupt increase in height, acting as the boundary between Andhra Pradesh and Orissa. The region possesses fertile soil. The Eastern Ghats are elder than the Western Ghats. The history of its origin is much complicated and takes off from the congregation and fragmentation of the ancient supercontinent of Rodinia and the assembly of the Gondwana supercontinent.

A chain of highly broken and detached hills starting from Mahanadi in Orissa to the Vagai River in Tamilnadu is known as Eastern Ghats. The Eastern Ghats are a series of discontinuous low ranges along

the Bay of Bengal coast running from the Mahanadi river valley for about 500 metres up to the Nilgiris in the south and forms the eastern edge of the dissected Deccan plateau .The Eastern Ghats start from the state of West Bengal in the north and culminates in the state of Tamil Nadu in the south. On the way they cover the states of Orissa and Andhra Pradesh. They are swept by the four chief rivers of southern India, the Godavari, Mahanadi, Krishna, and Kaveri. The Eastern Ghats are cut into various discontinuous hills by these rivers. They are separated from the Bay of Bengal by the coastal plains.

Characteristics of Eastern Ghats #

Eastern Ghats are older than Western Ghats. The elevation of Eastern Ghats is lower than the Western Ghats. It covers a total area of around 75,000 sq. km. Sirumalai and Karanthamalai hills of Tamil Nadu lies in the southern most part of the Eastern Ghats. North of Kaveri River is higher Kollimalai, Pachaimalai, Shevroy, Kalrayan Hills, Palamalai and Mettur hills in north Tamil Nadu.

One of the biggest characteristics of Eastern Ghats lies in its being extremely fertile. In fact, the Ghat is said to be the watershed of many rivers as the Ghat gets higher average waterfall. Due to higher rainfall, the fertile land results into better crops. Often referred as “Estuaries of India”, Eastern Ghats gift its inhabitant the popular profession of fisheries as its coastal area is full of fishing opportunity. Like Western Ghats, thus, Eastern Ghats also carry a heap of ecological importance.

(a)   Northern section – #

1. Between Mahanadi and Godavari, only in this part it exhibits the true mountaineer character.
   1. Composed of Khondalites & Charnokites, it is locally known as Maliyas.

(b)   Southern Section – #

1. Dissected due to large numbers of rivers.
   1. Biligiri Rangan Hills are famous for Sandal- wood and Teak forests.
   1. Malagiri range is famous for Sandalwood and other valuable timbers.
   1. Shevroy hills and Javadi hills are composed of Charnokite rocks.

• Nallamalla range in the most prominent range of this section whose southern part, the Pal- konda range is higher.
  • The Nilgiri (Blue mountain) – It is the nod- al point of three mountain systems– The Western Ghats, The Eastern Ghats and the southern hills. They are composed of strong Charnokites. Doda Beta (2637m), Makurti (2554m) and Wambadi Shola (2470 m) are three highest peaks. This belt is famous for rubber, tea and coffee plantation. Ooty, the most popular hill-station in South India is lo- cated in a broad undulating valley at the foot of Doda Beta.

Flora and Fauna of Eastern Ghats: The diver- sified ecological niches and environmental situation provide habitat for rich fauna. Eastern Ghats is home to largest number of Asiatic elephants in the world. Other large animals such as Nilgiri Tahr, Leopards, Gaurs, Sambar, and tigers abound the landscape. Apart from this, these Ghats are known for the wide variety of bird species. Eastern Ghats also holds the rich floral system. It is region where you may find large number of medicinal plants.

Tribal Population of Eastern Ghats: The land is also occupied by quite a few tribes which include Savara, Jatapu, Konda Dora, Gadaba, Khond, etc. These indigenous people have their own unique cultural heritage. These people follow the age old customs and traditions. They are still dependent on the forest produce and hunting for their livelihood. These tribes have good knowledge about the region and its produce and thereby make a good use of its medicinal plants.

Western Ghats The Western Ghats along the western coast of India separates the Deccan Plateau from a narrow coastal strip along the Arabian Sea. The range starts from the southern part of the Tapi River near the border area of Gujarat and Maharash- tra. It covers a length of around 1600 km running through the states of Maharashtra, Goa, Karnataka, Tamil Nadu and Kerala finally culminating at Kan- yakumari, in the southernmost tip of the peninsula.

Mountains, Gaps and Passes The Western Ghats have an average elevation of 1200 metres. However, in certain places they rise abruptly to a height of over 2440 metres. The Western Ghats of Maharash-

tra, extending from the Satpura Range to the north, travels south past Goa to Karnataka. The chief hill range of the segment is the Sahyadri range. Here we have two high peaks, Kalsubai, having a height of 1646 metres and Salher having a height of 1567 metres.

The Western Ghats are home to a number of gaps and passes, notable among them being the Thal Ghat and the Bhor Ghat. They link the interior of the Deccan with Mumbai. The southern part of the Western Ghats harbour the Nilgiri which serve as the meeting point o the Western and Eastern Ghats. The Nilgiris shows a steep rise from the plains and enclose between them the Karnataka Plateau. The Nilgiri Hills are home to two of the highest peaks of the Western Ghats: Dodabeta (2637 m) and Makurti (2554 m). To the south of the Nilgiri Hills is located the Palghat gap, extending from the east to the west of the Ghats. With a width of 24 km, the Palghat gap is an easy passageway across the Western Ghats. To the south of the Nilgiris are the Annamalai, Cardamom and Palni hills. The Anaimudi is the highest peak in Peninsular India. It is situated in the Annamalai hills and has a height of 2695 metres.

The narrow coastal plain between the Western Ghats and the Arabian Sea is known as the Konkan Coast in the north and the Malabar Coast in the south. The largest city amidst these mountains is Pune.

Climate and Rainfall #

The lower parts of the Western Ghats record humid and tropical type of climate. The elevated regions (1,500 m and above in the north and 2,000 m and above in the south) have a more temperate climate. Mean temperature varies from 24°C in the north to 20°C in the south. In the Western Ghats the climate is largely modified by the winds as they play a major role in the seasonal cycle. In summer they are responsible for ushering the monsoons while in the winter these winds provide a soothing effect. During the monsoon season between June and September, the path of the heavy, eastward-moving rain-bearing clouds is intercepted by the Western Ghats. This results in more rain on the windward side, an average of about 3,000 to 4,000 mm with occasional extremes of 9,000 mm. On the other hand the eastern region of the Western Ghats, which is

the rain-shadow region, records a meagre average of 1000 mm. The Coromandel Coast falls in the rain shadow of the Western Ghats, and receives a good deal less rainfall during the summer southwest monsoon, which contributes heavily to rainfall in the rest of India.

Significance of peninsular plateau: Peninsular area is the oldest and the most stable landmass of the Indian sub continent. It contains rich variety of minerals which occur in large quantities as copper, mica, iron, coal etc. a large part of North West pla- teau is covered with fertile black soil that is useful for growing cotton. Some other areas are suitable for cultivation of tea, coffee, rubber, millets, spices etc. The rivers originating in Western Ghats offers great opportunity for developing hydroelectricity and provide irrigation facilities to the agricultural crops.

Coastal Plains of India #

The plateau is flanked by coastal plains of var- ied width extending from Kutch to Orissa. There are striking difference between the eastern and the western coastal plains; with notable exception of Gujarat the west coast has narrow alluvial margin interspersed by hilly terrain .It has indentation except in the south where the beautiful Lagoons introduce an element of diversity. The eastern coast on the other hand has a wide plain with well developed deltas of the major rivers. The climatic transition between the south west monsoon regime of the north and the north -east monsoon regime of the south has given rise to interesting differences in the alluvial features in the two different stretches of the east coastal plain.

Eastern Coastal Plains #

The eastern coastal plains are located on a wide stretch of land between the Eastern Ghats of India and the Bay of Bengal. This stretch of land stretches to 120 km in width at parts. The eastern coastal plains extend from Tamil Nadu in the south to West Bengal in the north. The eastern coastal plains have rivers draining into them and river deltas also occupy the valleys.

The region of the eastern coastal plains is an expansive area and is divided into six regions. The six regions of the eastern coastal plains of India are the Mahanadi Delta, the Southern Andhra Pradesh

Plain, the Krishna Godavari deltas, the Kanyakumari Coast, the Coromandel and the Sandy Coastal regions.

Deltas of many of India’s rivers form a major portion of these plains. The Mahanadi, Godavari, Kaveri and Krishna rivers drain these plains. The region receives both the Northeast and Southwest monsoon rains with its annual rainfall averaging between 1,000 mm and 3,000 mm. The width of the plains varies from 100 to 130 km. It is locally known as Northern Circars between Mahanadi and Krishna rivers and Carnatic between Krishna and Kaveri rivers.

The eastern coastal plains are characterized by a temperature that exceeds 30 degrees Celsius and also experiences high levels of humidity. The rainfall of the region is also abundant in the region with rainfall amounts in excess of 1000 mm annually with the amount usually approaching 3000 mm. It is also of note that this region of the eastern coastal plain is subject to both northeast and southwest monsoon rains when these storms are in season.

It has three broad divisions: #

• Utkal Plains: It is the coastal track of Orissa including Mahanadi delta. Most prominent feature is Chilka Lake which is the largest lake in India.
  • Andhra Plains: It extends from Utkal Plains in the North of the Pulicat Lake in south (Sri- harikota Island is in this lake). Its most im- portant feature is the delta formation of River Godavari and River Kaveri. It also has Laka- na Lake.
  • Tamil Nadu Plains: It extends from Pulicat Lake to Kanyakumari. Most important fea- ture is Kaveri delta whose fertile soil and ir- rigation facilities make it a granary of South India where rice is the major crop.

Its characteristics are- #

1. Wider and drier (receives less rainfall) than the west coast plain.
   1. Contains shifting sand-dunes and stretches of saline soil.
   1. Deficient in rainfall.
   1. In Madras and Andhra Pradesh, it is called PYAN GHAT.

• Pulicat Lake near Madras, is a typical lagoon which is now separated from the sea by the Sriharikota island (an old beach ridge).
  • Chilka Lake, lying south of Mahanadi delta, originated due to the formation of a baymouth bar. Two river, Bhargavi and Daya, drain into the Lake, making the water sweet in the rainy season.

Western Coastal Plains #

The Western Coastal Plains is a thin strip of coastal plain 50 kilometres (31 miles) in width between the west coast of India and the Western Ghats hills. The plains begin at Gujarat in the north and end at Kerala in the south. It also includes the states of Maharashtra, Goa and Karnataka. The western coastal plain of India in contrast to the eastern coastal plain is located on a narrow strip of land. They extend from Gujarat in the north down 50 km to the south in Kerala and are characterized by numerous backwaters and rivers that flow into the region. These rivers that flow into the region lead to the forming of estuaries that are found in the western coastal plains of India. The western coastal plains are smaller than their eastern counterpart and the region is divided into three parts. The western coastal plains are divided into the regions of Kon- kan, Kanara, and the Malabar Coast.

Some Important Facts #

North Circars: Between the Mahanadi and the Krishna River.

Carnatic: Between the Krishna and the Cauvery river.

Coromandel: Between the Cauvery river and Kanyakumari.

Sub-divisions of the Coastal Plains: #

• Kutch Peninsula
  • It was an island surrounded by seas and La- goons. Later it became a part of mainland and developed as a broad plain by the sediments deposited by Indus river system.
  • It is made of tertiary rock system.
  • Due to the scarcity of rain and flowing sur- face water it has been developed as arid and semi-arid Landscape and, thus, the work of wind is predominant.

(ii)   Kathiawar Peninsula #

1. It is made of Deccan Lava.
   1. In central part, Mandav hills lies from which small streams radiates in all direction.
   1. Mt. Girnar, (of volcanic origin) is the highest point.
   1. The Gir range having dense forest and fa- mous as the home of Gir lion, is located in the southern part.
   1. Most of hills like Osem hills, Barda hills, etc. are of volcanic origin.

(iii)   Gujarat Plain #

1. Lying east of Kathiawar; slopes westwards.
   1. The eastern part is made of alluvium and in fertile enough to support agriculture while western part is mostly covered by wind blown loess which after weathering has given rise to semi-arid Landscape.

(iv)   Konkan Plain #

1. Lies south of Gujarat plain; stretches from Daman to Goa.
   1. It is characterised by cliffs of basaltic rocks.
   1. The submerged forests near the Bombay city suggest that the sea level rose on the Konkan coast in the past.

(v)   Karnataka Coastal Plains #

1. Stretches from Goa to Mangalore.
   1. Maximum width is found near Mangalore.
   1. Sharavati is the chief river, which makes Ger- soppa (Jog) falls before entering the plain.

(vi)   Kerala Plain (Malabar Plain) #

1. Stretches from Mangalore to Kanyakumari.
   1. Much wider & less hilly than Karnataka plain and other plain.
   1. Presence of Lakes, Lagoons, Backwaters, spits etc. is a significant characteristic of Ker- ala coast.
   1. Rivers are short and many of them dry up in summer.

Significance of coastal plains #

Large parts of the coastal plains of India are covered by fertile soils on which different crops

are grown. Rice is the main crop of these areas. Coconut trees grow along the coast. About 98% of the trade is carried out by the ports. Low lying areas of Gujarat are famous for producing salt whereas fishing is the main occupation of the people living in coastal areas.

The Indian Islands #

Apart from the large number of islands in the near proximity of the Indian coast, there are two main groups of islands in the Indian Ocean far away from the coast. One of them is the Andaman and Nicobar, Archipelago in the Bay of Bengal and the other is a group of tiny islands known as the Lakshadweep Islands in Arabian Sea. These islands have gained much importance and their study has become almost indispensable in view of the increas- ing interest of super powers in the geopolitics of the Indian Ocean.

The Andaman and Nicobar group of islands form an arcuate chain, convex to the west, extending from 6° 452 – 13° 452 N and 92° 10°–94° 152 E for

a distance of about 590 km with a maximum width of about 58 km. This archipelago is composed of 265 big and small islands covering a cumulative area of about 8249 sq km. The entire chain consists of two distinct groups of islands. The Great Andaman group of islands in the north is separated by the Ten Degree Channel from the Nicobar group in the south. The Andaman is a closely knit group of about 203 islands. It is 260 km long and 30 km wide with a total area of 6596 sq km. This group of islands is divided into three major groups viz. North Anda- man, Middle Andaman and South Andaman. Little Andaman is separated from the Great Anadmans by 50 km wide Duncan Passage.

The Nicobar group of islands consists of 7 big and 12 small islands together with several tiny islands. They are scattered over a length of 262 km with maximum width of 58 km covering an area of 1,653 sq km. The Great Nicobar, as its name suggests, is the largest island measuring 50 × 25 km. It is the southernmost island and is only 147 km away from Sumatra island of Indonesia.

Most of these islands are made of tertiary sandstone, limestone and shale resting on basic and ultrabasic volcanoes. The Barren and Narcondam islands, north of Port Blair, are volcanic islands.

Some of the islands are fringed with coral reefs. Many of them are covered with thick forests and some are highly dissected. Most of the islands are mountainous and reach considerable heights. Saddle peak (737 m) in North Andaman is the highest peak.

The Lakshadweep Islands in the Arabian Sea, though literally mean one lakh islands is only a group of 25 small islands. They are widely scattered over and area of 108.78 sq kms extending from 8° – 12° 202  N – 71° 452  74° E about 200-500 km

south-west of the Kerala coast. The islands north of 110 N are known as Amendivi Islands while those south of this latitude are called Cannanore Islands. In the extreme south is the Minicoy island. All are tiny islands of coral origin and are surrounded by fringing reefs. The largest and the most advanced is the Minicoy island with and are of 4.53 sq km. Betra has and area of only 0.12 sq km. Most of the islands have low elevation and does not rise more than five metre above sea level. Their topography is flat and relief features such as hills, streams, valleys, etc. are conspicuous by their absence. Shallow lagoons are seen their western side, while on the eastern seaboard the slopes are steeper.

The Western Coastal Plains #

• These plains are an example of submerged coastal plain.
• It is believed that the city of Dwaraka which was once a part of the Indian mainland situ- ated along the west coast is submerged under water.
• Because of this submergence it is a narrow belt and provides natural conditions for the development of ports and harbours. Kandla, Mazagaon, JLN port, Navha Sheva, Mar- magao, Mangalore, Cochin, etc. are some of the important natural ports located along the west coast.
• Western coast may be divided into following divisions –
  • the Kachchh and Kathiawar coast in Gu- jarat,
  • Konkan coast in Maharashtra,
  • Goan coast and Malabar coast in Karna- taka and Kerala respectively.

• The rivers flowing through this coastal plain do not form any delta.
• Malabar coast has got certain distinguishing features in the form of ‘Kayals’ (backwaters), which are used for fishing, inland navigation and also due to its special attraction for tourists. Every year the famous Nehru Trophy Vallamkali (boat race) is held in Punnamada Kayal in Kerala.

The Eastern Coastal Plain #

• This plain is broader and is an example of an emergent coast.
• There are well- developed deltas here, formed by the rivers flowing eastward in to the Bay of Bengal.
• These include the deltas of the Mahanadi, the Godavari, the Krishna and the Kaveri.
• Because of its emergent nature, it has less number of ports and harbours. (The continen- tal shelf extends up to 500 km into the sea, which makes it difficult for the development of good ports and harbours.

The Islands #

• There are two major island groups in India – one in the Bay of Bengal and the other in the Arabian Sea.

The Bay of Bengal islands groups consist of about 572 islands/islets.

• These are situated roughly between 6°N-14°N and 92°E -94°E.
• The two principal groups of islets include the Ritchie’s archipelago and the Labrynth island.

The entire group of island is divided into two broad categories – the Andaman in the north and the Nicobar in the south.

• They are separated by a water body which is called the Ten degree channel. These islands are an elevated portion of submarine mountains.
• However, some smaller islands are volcanic in origin. Barren island, the only active volcano in India is also situated in the Nicobar islands.
• The coastal line has some coral deposits, and beautiful beaches. These islands receive convectional rainfall and have an equatorial type of vegetation.

The Islands of the Arabian Sea #

• Include Lakshadweep and Minicoy.
• These are scattered between 8°N-12°N and 71°E -74°E longitude.
• These islands are located at a distance of280 km-480 km off the Kerala coast is built of coral deposits.
• There are approximately 36 islands of which 11 are inhabited.
• Minicoy is the largest island with an area of 453 sq. km.
• The entire group of islands is broadly divided by the Eleventh degree channel, north of which is the Amini Island and to the south of the Canannore Island.
• The Islands of this archipelago have storm beaches consisting of unconsolidated pebbles, shingles, cobbles and boulders on the eastern seaboar.