Terrain is an area of land which usually has a particular type of physical feature. Like, Mumbai beach is sandy and Shillong is a hilly. India is a vast country with varied land forms and topography. Topography means the features of a place determined by nature. It is the description of various features and landscape on the surface of the earth.
India has the topographical diversity.This includes the Great Himalayas, the Northern Plain, the Thar desert, the coastal plains and the Peninsular Plateau. The reasons for variation in the topography could be:
- Differences in the rock formations. These landmasses have been formed in different geological periods.
- Number of processes such as weathering, erosion and deposition has modified these features to their present forms.
India is a country of physical diversity. There are high mountain peaks in some areas while in others, lie the flat plains formed by rivers. On the basis of physical features, India can be divided into following six divisions:
- The Northern mountains
- The Northern Plains
- The Peninsular Plateau
- The Indian Desert
- The Coastal Plains
- The Islands
1. The Northern Mountain
It is divided into three groups. They are:
- The Himalayas
- The Trans Himalayas
- The Puranchal hills
1. The Himalayan Mountains
Himalayas are the young fold mountains. This is the highest mountain range of the world. Himalayas act as natural barrier. The extreme cold, snow and rugged topography discourage the neighbors to enter India through Himalayas.
They run from west-east direction from Indus to Brahmaputra along the northern boundary of India covering a distance of 2500 km. Their width varies from 400 km in the west and 150 km in the East. The Himalayas may be divided into three parallel ranges:
- Greater Himalayas or Himadari
- Lesser Himalayas or Himachal
- Outer Himalayas or Siwaliks
(a) The Greater Himalayas or Himadari
The Greater Himalayas comprises of the northern most ranges and peaks. It has an average height of 6000 metres and width lies between 120 to 190 km. It is the most continuous range. It is snow bound and many glaciers descend from this range. It has high peaks like Mt. Everest, Kanchenjunga, Makalu, Dhaulagiri, Nanga Parbat, etc. having a height of more than 8000 metres.
Mt. Everest (8848 m) is the highest peak of the world and Kanchenjunga is the highest peak of Himalaya in India. High Mountain passes also exist in this range, namely, Bara Lacha-La, Shipki-La, Nathu-La, Zoji-La, Bomidi-La, etc. The Ganga and Yamuna rivers originates from this Himalayas.
(b) The Lesser Himalayas or Himachal
The altitude of this range lies between 1000 and 4500 metres and the average width is 50 km. The Prominent ranges in this are Pir Panjal, Dhaula Dhar and Mahabharata ranges. It compresses of many famous hill stations like Shimla, Dalhousie Darjeeling, Chakrata, Mussoorie, Nanital, etc. It also comprises of famous valleys like Kashmir, Kullu, Kangra, etc.
(c) The Outer Himalayas or the Siwaliks
It is the outer most range of the Himalayas. The altitude varies between 900-1100 meters and the width lies between 10-50 km. They have low hills like Jammu Hills, etc. The valleys lying between Siwalik and Lesser Himalayas (Himachal) are called ‘Duns’ like Dehra Dun, Kotli Dun and Patli Dun.
2. The Trans-Himalayan Ranges
It extends north of greater Himalaya and parallel to it is called zaskar range. North of Zaskar range lies Ladakh range. The Indus river flows between Zaskar and Ladakh range. The Karakoram range lie extreme north of the country. K2 is the second highest peak of the world.
3. The Purvanchal Hills
It comprises Mishami, Patkoi, Naga, Mizo hills which are located in eastern side. The Meghalaya plateau is also part of these hills which includes the hills of Garo, Khasi and Jaintia.
2. The Northern Plains
The Northern Plains are located between south of the Himalayas and north of the Peninsular plateau. It is formed by the deposition of the sediments brought by three main river systems: the Indus, the Ganga and the Brahmaputra.
From Punjab in the west to Assam in the east, this plain is about 2400 km long. Its width varies from about 300 km in the west to about 150 km in the east. It mainly includes the states of Punjab, Haryana, Uttar Pradesh, Bihar, West Bengal and Assam.
This plain is very fertile due to alluvial sediments brought by the rivers from the Himalayas. This plain is one of the largest and most fertile plains of the world. Major crops such as wheat, rice, sugarcane, pulses, oil seeds and jute are grown here. Due to proper irrigation, the plain makes significant contribution in the production of food grains.
The Northern plain is broadly divided into two parts:
- The Western plain
- The Ganga-Brahmaputra plain
(a) The Western Plain
This plain is formed by the river system of the Indus. It lies to the west of Aravallis. This plain is formed due to deposits brought by the rivers like the Satluj, the Beas and the Ravi. This part of the plain has doabs.
(b) The Ganga-Brahmaputra Plain
It is also formed by the deposition of the sediments brought by two main river systems, the Ganga and the Brahmaputra. The early civilisations like Mohenjo-Daro and Harappa also called river valley civilizations, were spread over plain areas. This is because of the availability of fertile land and water through the river networks.
3. The Peninsular Plateau
The Peninsular plateau is a triangular shaped table land. It is part of ancient land mass called Gondwana level. It covers an area of nearly 5 lakh sq.km. It is spread over the states of Gujarat, Maharashtra, Bihar, Karnataka and Andhra Pradesh.
River Narmada divides the peninsular plateau into two parts:
- The Central Highlands
- Deccan Plateau
(i) The Central Highlands
It extends from Narmada river and the northern plains. Aravallis is the important mountain which extends from Gujrat through Rajasthan to Delhi. The highest peak of the Aravallis hills is Gurushikhar (1722 m) near Mt. Abu.
The Malwa Plateau and Chhota Nagpur plateau are parts of the central highlands. River Betwa, chambal and Ken are the important river of Malwa plateau while Mahadeo, Kaimur and Maikal are the important hills of Chhota Nagpur plateau. The valley of Narmada is lies between the Vindhyas and the satpura which flows east to west and joins the Arabian sea.
(ii) The Deccan Plateau
The Deccan plateau is separated by a fault (a fracture in the rock along which rocks have been relatively replaced), from Chota Nagpur plateau. The black soil area in the Deccan plateau is known as Deccan trap. It is formed due to volcanic eruptions. This soil is good for cotton and sugarcane cultivation. The Deccan plateau is broadly divided into:
- The Western Ghats
- The Eastern Ghats
(a) The Western Ghats
Western Ghats or Sahyadris lie on the Western edge of the Deccan plateau. It runs parallel to the western coast for about 1600 km. The average elevation of the Western Ghats is 1000 metres. The famous peaks in this area are Doda Betta, Anaimudi amd Makurti. The highest peak in this region is Anaimudi (2695 m.).
Western ghats are continuous and can be crossed through passes like Pal Ghat, Thal Ghot and Bhor Ghat. The rivers like Godavari, Bhima and Krishna flow eastward while the river Tapti flows westward. The streams form rapids & water falls before entering the Arabian Sea. The famous water falls are Jogfalls on Sharavati, Shiva Samudram falls on Kaveri, etc.
(b) The Eastern Ghats
The Eastern Ghats are discontinuous low belt. Their average elevation is 600 m. They run parallel to the east coast from south of Mahanadi valley to the Nilgiri hills. The highest peak in this region is Mahendragiri (1501 m).
The famous hills are Mahendragiri hills, Nimaigiri hills in Orissa, Nallamallai hills in Southern Andhra Pradesh, Kollimalai and Pachaimalai in Tamilnadu. The area is drained by the Mahanadi, Godawari, Krishna and Kaveri river systems. The Nilgiri hills join Western & Eastern Ghats in the south.
4. The Indian Desert
The Indian Desert lies towards the western margin of Aravali Hills. It is also called Thar Desert. It is the ninth largest desert in the world. It spreads over the states of Gujarat and Rajasthan.
This region has semi-arid and arid weather conditions. It receives less than 150 mm of rainfall per year. The vegetation cover is low with thorny bushes. Luni is the main river in this area. All other streams appear only at the time of rainfall otherwise they disappear into the sand.
5. The Coastal Plains
The coastal plains in India run parallel to the Arabian Sea & Bay of Bengal along the Peninsular Plateau. The western coastal plain is a narrow belt along the Arabian sea of about 10-20 km wide. It stretches from Rann of Kachchh to Kanya Kumari. Western coastal plains comprises of three sectors:
- Konkan Coast (Mumbai to Goa)
- Karnataka coast from Goa to Mangalore
- Malabar Coast (Mangalore to Kanya Kumari)
The eastern coast runs along Bay of Bengal. It is wider than the western coastal plain. Its average width is about 120 km. The northern part of the coast is called Northern Circar and the southern part is called Coromandal Coast.
Eastern coastal plain is marked by Deltas made by the rivers Mahanadi, Godavari, Krishna and Kaveri. The Chilka largest salt water lake in India in Odisha is located to the south of Mahanadi Delta. The coastal plains are belts for growing spices, rice, coconut, pepper, etc. They are centres of trade and commerce.
The coastal areas are known for fishing activities, therefore large number of fishing villages have developed along the coasts. Vembanad is famous lagoon which is located at Malabar coast.
6. The Islands
India has two main groups of Islands. There are 204 islands in Bay of Bengal called as Andaman and Nicobar islands and 43 islands in Arabian Sea called as Lakshadweep islands.
The Andaman & Nicobar island extend from north to south in Bay of Bengal. They are bigger in size. An active volcano is located on the Barren Island in Andaman & Nicobar group of islands.
Lakshadweep islands are located near Malabar coast of Kerala in the Arabian sea. They cover an area of 32 sq km. Kavarati is the capital of Lakshdweep. These islands are formed by corals and endowed with variety of flora and fauna. These islands are important tourist attraction and under water activities like snokling, such diving, deep sea diving and other sports make these island more popular.