What are the major physiographic divisions of india and explain?
Answers
Answer:
1) The Northern Mountains:
It stretches across northern India from Jammu and Kashmir to Arunachal Pradesh (about 2500 km) with a varying width of 240 to 320 km forming Himalaya in the East-West direction and its offshoots run in North-South direction along the India-Myanmar boundary traversing through Nagaland, Manipur and Mizoram known as eastern hills. They represent the youngest and highest folded mountains of the earth formed by the tectonic collision of the Indian plateau with the Eurasian plateau.
Longitudinally the Himalaya consist of four parallel range from South to North
i. The outer Himalayas (Shiwalik) It is almost continuous range of low hills, composed of unconsolidated tertiary sediments emerged as most recent phase in Himalaya orogeny.
ii. The lesser Himalayas (The Himachal) It generally consists of unfossiferous sediments or metamorphosed crystalline. Important range include the Dhauladhar, Pirpanjal, Nag Tiba, Mahabharat and Mussoorie range.
iii. The Greater Himalaya (The Himadri) This is the most continuous loftiest and northern most range of Himalayas. It has a core of Archaean granites, gneisses and schist’s rocks. This range contains one of the highest mountain peaks of the world.
iv. The Trans Himalaya It is also called the Tibetan Himalaya. This range consisting of mainly Karakoram, Ladakh and Kailash range.
2) Purvanchal:
This is the North-Eastern Himalayas that run north to South through Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura and eastern Assam.
3) The Great Plains:
The Great Plains of India consists largely of alluvial deposits brought down by the rivers originating in the Himalayan and the peninsular region. They are mainly formed by the alluvial deposits of the Indus, Ganga, Brahmaputra and their tributaries.
Northern plains is divided into four main divisions
i. The Bhabar:
The Bhabar belt is adjacent to the foothills of the Himalayas and consists of boulders and pebbles which have been carried down by streams. As the porosity of this belt is very high, the streams flow underground.
ii. The Tarai:
The Tarai belt lies south of the adjacent Bhabar region and is composed of newer alluvium. The underground streams reappear in this region.
iii. The Bhangar:
The Bhangar belt consists of older alluvium and forms the alluvial terrace of the flood plains.
iv. The Khadar:
It is made up of fresh newer alluvium which is deposited by the rivers flowing down the plain.
4) The Peninsular Plateau:
It covering an area of about 16 lakh sq km forms the largest and oldest physiographic division of India. It is bounded by the Aravallis in the North-West, Maikal range in the North, Hazaribagh and Rajmahal Hills in the North-East, the Western Ghats in the West and the Eastern Ghats in the East.
The peninsular plateau is divided into
i. Central High lands which include Aravalli Range, Malwa Plateau, Vidhya Range, Bundelkhand Plateau, Baghelkhand Plateau.
ii. Eastern Plateau-Chhota Nagpur plateau and Meghalaya Plateau
iii. The Deccan Plateau which include Mahadev Hills, Kaimur Hills, Maikal Range, Western Ghats, Nilgiri, Anaimalai Hills, Palani Hills and Cardamom Hills, Eastern Ghats (Shevaroy Hills, Javadi Hills, Palkonda Range Nallamala Hills) Mahendragiri. Maharashtra Plateau, Mahanadi Basin, Garhjat Hills, Karnataka Plateau, Telangana Plateau and Tamil Nadu Upland.
5) The Coastal Plains the West Coast Plain:
This is a narrow coastal strip in the West facing Arabian Sea. The plain area between the Western Ghats and the Arabian Sea from the gulf of Kuchchh and Gulf of Khambat located on either side of Kathiawar Peninsula is called Gujarat Plains.
To the South the coastline is more rugged. It is called the Konkan Coast up to Goa and from there onwards in Karnataka, it is the Kanara Coast, further South the part that lies in Kerala is called Malabar Coast till Kanyakumari, the southern tip of the Indian mainland
The East coastal plain is broader and more continuous than the West coastal plain and lies between the Eastern Ghats and the Bay of Bengal. A major part of the eastern Coastal Plains is covered by the deltaic deposits of rivers Mahanadi, Godavari, Krishna and Cauvery. It is called northern Circars between Mahanadi and Krishna rivers and Coromandel Coast South of the Cauveri up to the southernmost tip of the Indian mainland.
6) The Islands:
There are a number of small and large islands some of which are of volcanic origin while some are of coral origin.
i. Lakshadweep islands in the Arabian Sea are a group of 36 coral islands. They are located off the coast of Kerala. These islands are mostly flat and hardly a few metres above sea level.
ii. Andaman and Nicobar Islands lie in the Bay of Bengal. They are a group of 324 islands which are volcanic in nature. Andaman Islands are separated from the Nicobar Islands by the ten degree channel. They are mostly rugged mountainous hills and considered submerged part of Arakanyoma fold belt