10th Social Notes (Indian Physiography)

 10^th  Indian Physiography

I. Fill in the blanks with suitable answers.

1. The Greater Himalayas are also known as Himadri.

2. The lesser Himalaya are also known as Himachal.
3. In south India Anamudi is the heighest peak.
4. The Eastern Ghats meet the Western Ghats in the Niligiri hills.
5. The Northern Great plain is made up of alluvial soil.
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II. Discuss in groups and answer the following questions.

1. Which are the main physiographic divisions of India?
Ans: On the basis of physiography India can be divided into four divisions. They are:

a) Northern mountains.

b) The Northern Great plains.

c) The Peninsular Plateau.

d) The coastal plains and Islands.

 

2. State how the Northern Great Plains were formed?

Ans: The Northern Great Plains are in between the Himalayas and the Peninsular Plateau of India. It is formed by the depositional work of three river systems namely the Sutluj, the Ganga and the Brahmaputra. It is the largest alluvial soil tract in the world, extending east to west – a length of 2500 kms. Its average width varies from 240 to 340 kms. It covers an area of about 7 lakh km2. The plain is very flat and the rocks are not exposed on the surface.

 

3. Write briefly about the Siwalik hills.

Ans: The Siwalik Hills are the outermost ranges or foothills located to the south of the main Himalayas. They are the lowest range of the Himalayas, with a height of 600 to 1500mts and width varying from 15-150 km. They extend from Jammu and Kashmir in the west to Arunachal Pradesh in the east. They have flat-bottom, structured valleys, which are known as ‘Doons’. eg: Dehradoon.

The Himalayas act as natural frontiers and prevent foreign invasion, they prevent the cold winds from central Asia. They obstruct the rain-bearing winds and this causes heavy rainfall. They are a storehouse of minerals and the birthplace of many rivers and waterfalls.

 

4. Distinguish between the Eastern Ghats and the Western Ghats.
Ans:

Eastern  Ghats	Western Ghats
i) The Eastern Ghats run almost parallel to the east coast of India. They extend from the Mahanadi Valley in the north, towards the Niligiri hills in the south where they join the Western Ghats.	These are a continuous range running parallel to the west coast of India from the Tapi valley to Kanyakumari.
ii) They are lower than the Western Ghats	They are very steep on the western side and gentle on the eastern side.

 

5. State the importance of the Northern mountains.
Ans: a) The Himalayas act as natural frontiers and prevent foreign invasion, they prevent the cold winds from central Asia.

b) They obstruct the rain-bearing winds and this causes heavy rainfall.

c) Their slopes have thick forests and are ideal for plantation crops.