Physical Features of India
India has three distinct physical divisions. The northern boundaries of India are provided by the lofty ranges of the Himalayas, which run almost in a wall-like shape from north-west to north-east. India has the Great Plains of northern India formed by the basins of three mighty river systems - the Indus, the Ganga and the Brahmaputra.
Down below, India has the Deccan Plateau of the Peninsular India, which is geologically the oldest structure of the Indian subcontinent. It consists of huge rock blocks of very ancient times.
Physiographic Regions
The physical features of India can be grouped under the following physiographic divisions:
- The Northern Mountains
- The Northern (Indo Gangetic) Plains
- The Peninsular Plateau
- The Indian (Thar) Desert
- The Coastal Plains
- The Islands
The Himalayan Mountains
India's northern frontiers are distinctly marked out by the huge mountain wall stretching for about 3600 km comprising the snow-capped mountain ranges of the Karakoram and the Himalayas. The width of this mountain belt varies between 150 km and 400 km.
The Karakoram mountain ranges rise from the Pamir Knot in the north-west and stretch towards southeast up to the Indus gorge in Jammu and Kashmir. These ranges are 600 km long with the average width of 120 to 140 km. The world's second highest mountain peak K2 (Godwin Austen), which has a height of 8611 meters, belongs to this chain of mountains. Baltoro and Siachen Glacier also lie in the high valleys of Karakoram ranges.
To the south of the Karakoram Mountains is the Ladakh range and further below southwards is the Zaskar range of mountains, both of which lie in Jammu and Kashmir. The Ladakh range is Situated to the north of the Indus Tsangpo Suture Zone (ITSZ) and south of Karakoram, between River Indus and Shyok. The highest peak is Mt. Rakaposhi (steepest peak in the world).
The Himalayas which form almost a 2500 km long continuous mountain wall on India's North, extending from Indus in the west to Brahmaputra in the east, can be divided into Western, Central and Eastern Himalayas. The Western Himalayas encompass Jammu and Kashmir and Himachal Pradesh. The Central Himalayas are spread over Uttrakhand and Nepal. The Eastern Himalayas cover northern parts of the West Bengal and extend into Sikkim, Bhutan and Arunanchal Pradesh.
The Himalayas broadly consist of three parallel ranges of mountains - the Himadri, the Himachal and the Shivaliks. The Himadri range, also known as the Greater Himalayas, comprises the northernmost range and lies on the edge of the Tibetan Plateau. It is the highest mountain range with an average height of about 6000 metres above the sea level. The world's highest mountain peak, Mount Everest (8848 metres) in Nepal, belongs to the Greater Himalayas. Kanchenjunga (8598 metres), Nanga Parbat (8126 metres) and Nanda Devi (7817 metres) are the highest peaks of the Greater Himalayas in India.
Western Himalayas
- Lie to the west of 80 degree East longitude between the Indus and Kali river
- Rise gradually in a series of ranges
- Average annual rainfall is less than 100 cms
- Vegetation consists mainly of alpine and coniferous forests
Eastern Himalayas
- Lie to the east of 88 degree east longitude between the Tista and the Brahmaputra river
- Rise abruptly from the plains of Bihar and West Bengal
- Average annual rainfall is more than 200 cms
- Large tracks are covered with dense evergreen forests
South of the Himadri lies the Himachal range, which isalso known as the Middle or the Lesser Himalayas, which has a height varying between 3700 and 4500 metres above sea level. This range of alternating ridges and valleys and highly dissected uplands contains many of India's important hill stations. The beautiful Kashmir, Kulu and Kangra valleys of India and Kathmandu valley in Nepal, lie in this mountain range. The popular hill stations of Shimla (Himachal Pradesh), Mussoorie, Nainital (both in Uttrakhand) and Darjeeling (West Bengal) are also located on the Himachal ranges of the Himalayas.
The Shivalik range is the southernmost range of Himalayas which is the lowest among the Himalayan ranges with a height of between 900 metres to 1200 metres above the sea level. Made up of mud and soft rocks, it is a discontinuous range which lies on the northern border of the Ganga plain and extends towards east to merge with the main mountains.
Though the Himalayas, with their loftiest mountain ranges, form the impeccable barrier on India's northern frontiers, they do contain some gaps in their ranger which provide natural routes across these high mountains. These gaps, called passes, have not only been traditional trade routes over the past many centuries, but have also provided easy access to the foreign invaders and greatly influenced the course of India's history. The important passes in the Himalayas are the Jelep La, Shipki La, Nathu La, Bomdi La, etc.
On India's north-eastern side are located the Poorvanchal mountains, which consist of the Patkai Bum and the Naga Hills in the north; Mizo and Lushai Hills in the south, and the Garo, Khasi and Jaintia Hills in the centre. These mountain ranges are neither as tall nor as spectacular as the mighty Himalays.
The Great Plains of Northern India
India, which has the world's highest and the most spectacular mountas, is also fortunate in possessing one of the world's most extensive and fertile plains, approximately 2500 km from the Sutlej in the west to the Brahmaputra in the east made up of alluvial soil brought down in the form of fine silt by the mighty rivers. These Great Northern Plains consist of the Indus basin, the Ganga-Brahmaputra basin and the tributaries of these mighty river systems. The bulk of the Indus basin falls within Pakistan but a part of it is shared by Punjab and Haryana. The Ganga Brahmaputra basin is larger of the two and covers a large number of states in northern India.
The most salient characteristic feature of the Great Plains of northern India is the extreme horizontality or levelness. There is practically no difference in geomorphologic features of the two parts, the Indus basin and the Ganga-Brahmaputra basin, except the water divide which separates these two basins. This divide is made by a low narrow ridge of Aravalli range passing through Delhi and Ambala. The average height of the water divide is not more than 300 metres above the sea level, and this gives the plain a touch of continuity between these two drainage basins of the Indus and Ganga. According to the terrain characteristics, this plain can be divided into two parts:
- (i) The upland plain which lies above the flood level and is made up of old alluvium. This plain is called the Bangar Land
- (ii) The lowland plain, whichis liable to inundation during floods and thus acquires fresh doses of new alluvium. This is called the Khadar Land
The Drainage of the Great Plains
The Indus and the Ganga-Brahmaputra river systems together form the Great Plains of northern India.
River Indus is a trans-Himalayan river. It originates beyond Himalayas in Tibet and flows throughout in Pakistan. Among its tributaries, Jhelum and Chenab, which originate in India, also flow though Pakistan, while Ravi makes a small run through India before entering Pakistan. Only Sutlej, another trans-Himalayan river and a tributary of Indus flows for its major cause through India, while Beas, a tributary of Sutlej, remains in India throughout its journey in the plains. Thus, only a small portion of the Indus river basin, comprising Punjab and Haryana, lies in the northern plains of India.
The Ganga-Brahmaputra river system forms the largest part of the Great Plains of north India. It covers almost one-fourth of the total land area of the county. The Ganga rises from the Gangotri glacier in the Himalayas and is joined by the Yamuna and Sone rivers on its right bank. Rivers joining the Ganga on its left side are the Gomti, the Ghaghra, the Gandak and the Kosi.The Yamuna rises from the Yamunotri glacier in the Himalayas, but its important tributaries, the Chambal, the Betwa and the Ken rise from the Malwa Plateau.
Beyond Farakka, the main stream of the Ganga flows into Bangladesh and it known as the river Padma. Some 80 km above, before falling into the Bay of Bengal, Padma is joined by the mighty Brahmaputra, a trans-Himalayan river which rises from the Manasarovar Lake in Tibet. And together they from the world's largest and perhaps the most fertile delta in Indo - Bangladesh region. The other stream of Ganga, bifurcated at Farakka, runs southwards into West Bengal and is called river Hooghly. It splits up into a number of channels before falling into the Bay of Benagal beyond Kolkata.
The Great Plains of the north, being extremely fertile and most suited to agriculture, makes them the granary of India. Apart from the food scrops of rice, wheat and millets, this region also provides cash crops like sugarcane, oilseeds, jute, etc. This region has a dense population in its large number of towns and villages and also accounts for a number of industries.
The Great Plateau of Peninsular India
To the south of the Great Plains of northern India lies the old landmass of the Peninsular India which is made up of hard metamorphic rocks. This part of land adjoining northern plains, is known as the Great Plateau of Peninsular India. This Great Plateau has two distinct parts, the Malwa Plateau and the Deccan Plateau.
The Malwa Plateau, which comprises the northern region of the Great Plateau of Peninsular India, is bounded by the Aravalli hills in the north-west and the Vindhyas in the south, both these low old mountains forming the sharp edges of this plateau. The third side of this triangular Malwa Plateau, which extends from west to east, slopes gradually towards the plain of Ganga and merges into it. The valley of the river Narmada forms the southern boundary of the Malwa Plateau, while its extensions to the east form the Bundelkhand and Baghelkhand in southern Uttar Pradesh and Chotangpur in Jharkhand. Most of the rivers of this plateau flow northward into the river Yamuna. The Malwa Plateau, particularly its northeastern part called Chotanagpur plateau, is the richest mineral producing region of India.
The Deccan Plateau, which is roughly of a triangular shape, extends from the Satpura hills in the north to Kanyakumari, the southernmost tip of India ending in the Indian Ocean. On the western edge of the Plateau lie the Sahyadri, the Nilgiri, the Annamalai and the Cardamom Hills, the Annamalai and the Cadamom Hills, commonly known as the Western Ghats. Anaimudi peak in Kerala, with a height of 2695 metres above the sea level, is the highest peak of the Peninsular India. In the Nilgiris lies the Udagamandalam (Formerly Ooty), the best-known hill station of southern India.
From the Western Ghats, the Decan Plateau gradually slopes away towards east to the Bay of Bengal. The eastern edge of the Decan Plateau is less marked as the Eastern Ghats have discontinuous low hills called Mahendra Giri. All the major rivers of the Decan Plateau, Mahanadi, Godavari, Krishna and Cauvery, flow from west to east and piercing throught these low discontinuous ranges of the Eastern Ghat hill merge into the Bay of Bengal. Only Narmada and Tapti are the two major rivers which flow from east to west and fall in the Arabian Sea.
The north-western part of the Great Plateau is made up of lava flows or the igneous rocks called Basalt, also known as Decan Trap. These several hundred metres thick rocks are spread over the whole of Maharashtra and parts of Gujarat and Madhya Pradesh giving a thick dark sil in these regions. This soil, called Regur or Black soil, is especially suited to cotton cultivation and makes this region the most important cotton growing belt in India.
Many parts of the Great Plateau are rich in minerals and the famous gold fields of Kolar, the uranium deposits of Tamil Nadu and Jharkhand, the manganese, iron ore and copper deposits of the north-east lie in the regions comprising this Great Plateau.
The Great Desert of Rajasthan
To the north-west of the Malwa Plateau lies the Thar Desert or the Great Desert of Rajashtan. The desert, which it made up sand, interrupted by rocky hills and waterless valley, begins from the west of the Aravalli ranges and extends deep into Pakistan. The desert is the region of inland drainage system, as the few rivers that flow in this area either drain into the salt lakes or disappear into the sands. Only the river Luni drains off into the Rann of Kutch. The desert climate, being arid and unfavourable for human settlement, makes the area sparsely populated.
The Coastal Strips
The Deccan Plateau is flanked, on its west and east, by narrow coastal plains along the Arabian Sea and the Bay of Bengal. The western Coastal Plain lies between the Western Ghats and the Arabian Sea. The southern part of the Western coastal Plain, called the Malabar Coast, is narrow, uneven and gradually dissected by a number of fast flowing streams and rivers. It has a number of lagoons, backwaters and raised beaches. The northern part ofthe Western Coastal Plains, called the Konkan Coast, gets wider as it movers further northwards and encompasses plains of Gujarat.
The eastern coastal plain, lying between the Eastern Ghats and the Bay of Bengal, is wider and more leveled. It contains some of the most fertile and well-watered deltas formed by Krishna, Cauvery, Godavari and Mahanadi rivers. The southern part of the eastern Coastal Plains is known as Coromandel Coast and its northern part as the Northern Sircars. The soils of eastern coast are deep and fertile.
Features of Himalayan Rivers
- Perennial in nature
- Uncertain nature and caprician in behavior
- Some are meandering in their flow and subject to drastic change of course
- Rivers are in youthful stage
- Rivers are eroding, transporting and depositing agents.
Features of Peninsular Rivers
- Non - perennial in nature
- More stable, flow predictable
- No drastic change in course
- Rivers are in old stage
- Rivers are only depositing agents
West Coastal Plain
- Located between the Western Ghats and the Arbian Sea coast
- Narrow plain (average width 64 km)
- Drained by several short and swift streams which are unable to form deltas
- There are several lagoons especially in the southern part of this plain
- The western plain has indentated coast which supports many ports
- It is a submerged coast and hence tilting has left no scope for depositional action of the rivers
East Coastal Plain
- Located between the Eastern Ghats and the Bay of Bengal coast
- Comparatively broad (average width 80-100 km)
- Big rivers like the Mahanadi, the Godavari, the Krishna and the Cauvery have formed large deltas
- Lagoons are comparatively little in this plain
- The eastern plain has more or less a straight coast where good ports are lacking
- Mostly of emergent type, characterized by offshore bars, fine sea beaches, sand ridges and lagoons
Indian Islands
Besides the manland, India has two groups of islands, the Andaman and Nicobar islands in the Bay of Bengal and the Lakshadweep islands inthe Arabian Sea. The Andaman and Nicobar islands are a group of islands many of which are too small and uninhabited. The northern cluster of islands is called the Andamans, a group of 204 small islands, while the southern cluster is known as the Nicobar islands, a group of 19 islands. Together they form the Union Territory of the Andaman and Nicobar Islands, with Port Blair as the capital.
The Lakshadweep comprises a group of 27 coral islands scattered in the Arabian Sea, about 300 kilometres to the west of Kerala coast. None of these horse-shoe or ring shaped islands is more than a couple of kilometers in length and breadth and about 17 of these islands are uninhabited. The Kavaratti island is the capital of the union Territory of Lakshadweep.