Northern Mountainous Region

The rivers originating from the Himalayas are perennial because their source is located in the Himalayan glaciers. The Himalaya receives much of it's rain from the south-western monsoon. Assertion and Reason both are true. However Reason (R) does not explain the Assertion (A) correctly

The rivers originating from the Himalayas are perennial because their source is located in the Himalayan glaciers. The Himalaya receives much of it's rain from the south-western monsoon. Assertion and Reason both are true. However Reason (R) does not explain the Assertion (A) correctly

On the basis of folds and age of formation, the Himalayas is divided into four parallel structural areas-

1. Trans Himalaya

2. Great Himalaya

3. the Middle Himalayas

4. Shiwalik

According to the above options Great Himalaya is the oldest range of Himalayas (Oligocene Epoch-24-37 million years ago). After this, the Middle Himalayas (mid-Miocene- 5-24 million years ago) and Shiwalik (Pliocene Epoch-2-5 million years ago) the newest range among them was formed.

If the Himalayan mountain range did,nt exist, most of India would have experienced cold waves coming from Siberia, the Indo-Gangetic Plain would have been deprived of such elaborative alluvial soil and the monsoon pattern would have been different from the present pattern. Significantly, the Himalays influence the monsoon pattern as they effectively intercept the summer monsoons coming from the Bay of Bengal and Arabian sea. It leads to precipitation in the snow of rain. Also, the Indus, Ganga's and their tributaries flowing from the Himalayan region create alluvial plains through erosion and deposition.

The flat plains along the sub-Himalayan region in North India, are called Bhabar. It is a narrow belt only 8 to 16 kms in width and lying parallel to the Shiwalik foothills at the break-up of the slope. This zone is studded with pebbles and it consists of porous beds which have been laid down by the numerous streams as they descend down the hills. The porosity is so high that all streams lose themselves in the Bhabar. South of the Bhabar is the Tarai belt, with an approximate width of 15-30 km where most of the streams and rivers re-emerge without having any properly demarcated channel, thereby, creating marshy and swampy conditions known as the Tarai. This has a luxurious growth of natural vegetation and houses a varied wildlife.

The foothills region of the Himalaya is called Shiwalik. These are the outer most range of the Himalayas. They extend over a width of 10-50 km and have an altitude varying between 900 to 1100 meters. These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges located farther north.

The foothills region of the Himalaya is called Shiwalik. These are the outer most range of the Himalayas. They extend over a width of 10-50 km and have an altitude varying between 900 to 1100 meters. These ranges are composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges located farther north.

Shiwalik or outer Himalaya has formed approximately 2-5 million years ago in Pliocene Epoch means in Cainozic Era .

Shiwalik or outer Himalaya has formed approximately 2-5 million years ago in Pliocene Epoch means in Cainozic Era .

Shiwalik or outer Himalaya has formed approximately 2-5 million years ago in Pliocene Epoch means in Cainozic Era .