India - Physical features
According to one estimate, 29.3 per cent of area of India is occupied by mountains and hills, 27.7 per cent by plateaus and 43 per cent by plains. From a physiographical point of view, India can be divided into following regions:
(1) The Himalayan Mountains
(2) The Northern Plains
(3) The Peninsular Plateau
(4) The Indian Desert
(5) The Coastal Plains
(6) The Islands
1. The Himalayan Mountains
They include the mountains and plateaus of northern Kashmir, the Himalayas proper and the hills of Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura and Meghalaya. The Pamir Knot, popularly known as the “Roof of the World” is the connecting link between the Himalayas and the high ranges of Central Asia. The term “Himalaya” is derived from Sanskrit. It means “The Abode of Snow”. They are divided into three groups. They are
- The Himalayas
- The Trans-Himalayas
- Purvachal or the hills of the North-East.
1. The Himalayas
This is the highest mountain range of the world. It extends in the shape of an arc for a distance of about 2500 km from west to east along the northern boundary of India between the Indus gorge in Jammu and Kashmir in the west and Brahmaputra gorge in Arunachal Pradesh in the east. The breadth of the Himalayas ranges between 400 km in the west to 150 km in the east. It has three major ranges. These ranges are separated by deep valleys and plateaus. The high peaks of this part such as Nanga Parbat, Nanda Devi and Badrinath are very far from the plains. Three parallel ranges can be identified in the Himalayas. These are
(a) The Himadri,
(b) The Himachal and
a) The Himadri (The Greater Himalayas)
This is the northern most and the highest range of the Himalayas. This is the only range of the Himalaya which maintains its continuity from west to east. The Himadri range is the most continuous of all ranges. The core of this range is made up of granite rocks and flanked by metamorphic and sedimentary rocks. The extent of this range is between the Nanga Parbat peak (8126 m.) in the west and Namcha Barva peak (7756 m.) in the east. The average height of this range from sea level is about 6100 meters. The Greater Himalayas receive lesser rainfall as compared to the Lesser Himalayas and the Siwaliks. Physical weathering is less effective over the Greater Himalayas as compared to the other ranges. The highest peak of the world, Mount Everest, (8848 m) is situated in this range. Kanchenjunga, Makalu, Dhaulagiri, Annapurna are some of the notable peaks.
Kanchenjunga is the highest peak of Himalayas in India.
It is region of permanent snow cover. So, it has many glaciers. Gangothri, Yamunothri and Siachen are some of the glaciers. After melting of snow and ice, their water falls in the rivers of northern India making them perennial throughout the year.
b) The Lesser Himalayas or The Himachal
It is the middle range of Himalayas. Height of this range varies from 3, 700 to 4,500 m. Its width varies up to 80 km. The major rocks of this range are slate, limestone and quartzite. This region is subjected to extensive erosion due to heavy rainfall, deforestation and urbanization. Pir Panjal, Dhauladhar and Mahabharat are the mountain ranges found in this part. Major hill stations of the Himalayas are located in this range. Shimla, Mussourie, Nainital, Almora, Ranikhet and Darjeeling are the familiar ones.
c) The Shiwaliks or Outer Himalayas
The Shiwaliks extend from Jammu and Kashmir to Assam. It is partly made by the debris brought by the Himalayan rivers. The altitude varying between 900-1100 meters elevation of this range is 1300 m. The width of Shiwaliks varies from 10 km in the east to 50 km in the west. It is the most discontinuous range. The longitudinal valleys found between the Shiwaliks and the Lesser Himalayas are called Duns in the west and Duars in the east. These are the ideal sites for the development of settlements in this region.
Regional Divisions of Himalayas
From west to East, Himalayas have been divided into six regions viz. Kashmir Himalayas, Himachal Himalayas, Kumaun Himalayas, Central & Sikkim Himalayas, Arunachal Himalayas and Purvachal Himalayas.
The Kashmir Himalayas (Located between the rivers of Indus and Sutlej)
The Kashmir Himalayas have the largest number of Glaciers in India. The Ladakh region of the Kashmir Himalayas is India’s Cold Desert Biosphere reserve. A special feature of the valleys of Kashmir Himalayas is the Karewa deposits which are made up of silt, clay and sand. The Karewas are known for saffron cultivation and have orchards of fruits and dry fruits such as apple, peach, almond, and walnut. The major characters of Kashmir Himalayas are Glaciers, snow peaks, deep valleys and High Mountain passes. The important passes are Pir-Panjal, Banihal, Zoji-La, Saser-La, Chang-La, Jara-La etc.
The Himachal Himalayas (Located between the rivers of Sutlej and Kali)
Himachal Himalayas are spread in Himachal Pradesh. The Rohtang, Bara-Lacha, Shipki-La are important passes joining India and China. The valleys of Kullu, Kangra, Manali, Lahaul, Spiti are known for orchards and tourist spots.
The Kumaun Himalayas / Central Himalayas / Garhwal Himalayas
Kumaun Himalayas are located between the Sutlej and Kali rivers. They are home to India’s highest peak Nanda Devi. Other peaks located in Kumaun Himalayas are Kamet, Trishul, Badrinath, Kedarnath, Dunagiri, Gangotri etc. Gangotri and Pindar are important glaciers.
The Sikkim (Central) Himalayas (Located between the rivers of Kali and Tista)
Sikkim Himalayas are located beyond the Kali River up to the Teesta River. Most of them are located in Nepal and known as Central Himalayas. These Himalayas are home to highest peaks of Himalayas such as Everest, Kanchenjunga, Makalu, Dhaulagiri, and Annapurna. It is characterized by very few passes. Two passes viz. Nathu La and Jelep-La are important as they connect India’s Sikkim to Tibet of China.
2. The Trans-Himalayas
It is also known as western Himalaya’s. It lies to the north of the great Himalayan range. It lies in Jammu and Kashmir and Tibetan plateau. As its areal extent is more in Tibet, it is also known as Tibetan Himalayas. The Trans-Himalayas are about 40 km wide in its eastern and western extremities and about 225 km wide in its central part. They contain the Tethys sediments. The rocks of this region contain fossils bearing marine sediments which are underlain by ‘Tertiary granite’. It has partly metamorphosed sediments and constitutes the core of the Himalayan axis.
The prominent ranges of Trans Himalayas are Zaskar, Ladakh, Kailash, and Karakoram.
iii. Eastern Himalayas & Purvanchal Hills (Located between rivers of Tista and Dihang.)
The Eastern Himalayas occupy the Arunachal Pradesh and Bhutan. The important hills in this region are Aka Hills, Daphla Hills, Miri Hills, Mishmi Hills and Namcha Barwa. The Dihang and Debang passes of Arunachal Pradesh are its parts. Passing from Arunachal Pradesh, there is an eastward extension of the Himalayas in the north-eastern region of India. This is known as Purvanchal Hills. Purvanchal Hills comprises the Patkai hills, the Manipur hills, Bairal range, the Mizo hills and the Naga Hills
These are low hills, inhabited by numerous tribal groups practising Jhum cultivation. It is a densely forested area, mainly composed of strong sandstones. Most of these ranges are separated from each other by numerous small rivers. The Barak is an important river in Manipur and Mizoram. The physiography of Manipur is unique by the presence of a large lake known as ‘Loktak’ lake at the centre, surrounded by mountains from all sides. Mizoram which is also known as the ‘Molassis basin’ which is made up of soft unconsolidated deposits. Most of the rivers in Nagaland form the tributary of the Brahmaputra. While two rivers of Mizoram and Manipur are the tributaries of the Barak river, which in turn is the tributary of Meghna; the rivers in the eastern part of Manipur are the tributaries of Chindwin, which in turn is a tributary of the Irrawaddy of Myanmar.
Importance of Himalayas
- Himalayas blocks southwest monsoon winds and causes heavy rainfall to north India.
- It forms a natural barrier to the sub-continent.
- It is the source for many perennial rivers like Indus, Ganges, and Brahmaputra etc.
- The Northern Mountains are described as the paradise of tourists due to its natural beauty.
- Many hill stations and pilgrim centres like Amarnath, Kedarnath, Badrinath and Vaishnavidevi temples are situated here.
- It provides raw material for many forest based industries.
- It prevents the cold winds blowing from the central Asia and protects India from severe cold.
- Himalayas are renowned for the rich biodiversity.