Physical Features of India (Part 1)

• India has all major physical features of the Earth, i.e. mountains, plains, deserts, plateaus and islands.
• In India the soil colour varies from place to place as it is formed from different types of rocks.
• India is a large landmass formed during different geological periods.
• India’s relief features are outcome of other processes like weathering, erosion and deposition.
• India has varied physical features whose formation can be explained on the basis of the ‘Theory of Plate Tectonics’.
• According to the theory of Plate Tectonics the seven major and minor plates that form the Earth’s crust keep moving, causing stress and thus leading to folding, faulting and volcanic activity.
• Plates can have convergent, divergent and transform boundaries.
• India’s peninsular part is made from one of the oldest landmass of the world ‘Gondwana land’. It was a single landmass comprising of India, Australia, South Africa, South America and Antarctica.

Major Physiographic Divisions

The physical features of India are grouped under the following physiographic divisions:

• The Himalayan Mountains
• The Northern Plains
• The Peninsular Plateau
• The Indian Desert
• The Coastal Plains
• The Islands

1. The Himalayan Mountains

• The Himalayas are one of the loftiest and the most rugged mountain barriers. Being geologically young and structurally folded mountains, they run in the west-east direction from Indus to the Brahmaputra.
• The Himalayas length is 2,400 km, and the width varies from 400 km in Kashmir to 150 km in Arunachal Pradesh.
• Longitudinally, Himalayas consist of three parallel ranges-

The Himadri

• Also known as the Great or Inner Himalayas, these are the northernmost ranges of the Himalayas and the loftiest.
• The average height of the peaks is 6000 metres.
• Composed of granite
• Covered with snow most of the year
• Many glaciers have their origin in these ranges.

Himachal

• Also known as the Lesser Himalayas, they lie to the south of the Great Himalayas.
• Himachal is the most rugged mountain system and is composed of compressed and altered rocks.
• The average height varies from 3700 km to 4500 km, and the average width is 50 km.
• The most important range of the Himachal is Pir Panjal, along with the Dhaula Dhar and the Mahabharat
• Consist of famous valleys of Kashmir, Kangra and Kullu Valley of Himachal Pradesh.

The Shiwaliks

• These are the outermost ranges of the Himalayas.
• The height varies between 900 and 1100 metres, while the width is between 10 to 50 km.
• It consists of thick gravel and aluminium- deposits brought down by rivers.
• The valleys lying between Himachal and Shiwaliks are known as Duns. Dehradun, Kotli Dun and Patli Dun are some examples.

The Himalayas can also be divided from west to east based on regions and river valleys.

• Lying between Indus and Satluj – traditionally named Punjab Himalayas, but also called Kashmir and Himachal Himalaya in west and east, respectively
• Lying between Satluj and Kali – Kumaon Himalayas
• Lying between Kali and Teesta – Nepal Himalayas
• Lying between Teesta and Dihang – Assam Himalayas

The Himalayas running in the northeast region of India are called Purvanchal or Eastern hills. They are composed of strong sandstones. The Purvanchal consists of various hills such as the Patkai hills, the Naga hills, the Manipur hills and the Mizo hills.

The Brahmaputra is the easternmost boundary of the Himalayas.

2. The Northern Plain

The Northern Plains are extremely fertile, and that is the reason why they are called the “Food Bowl Of India”. Not only geographically, but also historically, these plains hold an important place in our culture. The earliest civilizations, the Indus Valley and the Vedic Civilizations boomed and flourished on these plains.

• The Northern Plains have been formed by three major river systems – the Indus, the Ganga, Brahmaputra, and their tributaries. The northern plain is about 2400 km long and 240 to 320 km wide. It is spread over an area of 7 lakh square km.
• Northern Plains is formed of alluvial soil, formed by the deposition from rivers. Along with dense soil cover, the region is accompanied by a favourable climate and adequate water supply, making the region suitable for agriculture.
• The Northern Plain is divided into three major sections:

1.  Punjab Plains – western part of the Northern Plain. It is formed by Indus and its tributaries (the Jhelum, the Chenab, the Ravi, the Beas and the Satluj). This section of the plain has doabs.
2.  Ganga Plain – lies between Ghaggar and Teesta rivers.
3. Brahmaputra Plain – lies in Assam.

Depending upon biological variations, Northern Plains can be divided into four sections.

1. Bhabar – it is a narrow belt of pebble deposits located parallel to the slopes of Shiwaliks. It is 8 to 16 km in width.
2.  Terai – It is a wet, marshy and swampy region located south of the bhabar belt. The region was densely covered with forests but was cleared off to accommodate migrants from Pakistan.
3. Bhangar – formed of older alluvium soil, it lies above the floodplains. It is a terrace-like structure that contains calcareous deposits, locally known as kankar.
4. Khadar – these are newer, the younger deposit of the floodplain formed. They are formed every year and so are fertile for intensive agriculture.

• Tributaries – streams or rivers which join a larger river
• Distributaries – streams or rivers which get branched out of the main river
• Majuli – in Assam – is the largest inhabited riverine island in the world