Question

The Himalayan river are perenial while those flowing in southern part of the country r not

Answer 1

Because the water which flows in Himalayas river comes from Himalayas that is glaciers whereas in southern rivers are perinial as the get water only after rain.

Answer 2

because in Himalayan rivers water source is glacier Himalaya mountain so they are perenial as have water throughout year whereas in South rivers sources are rainwater so they are not perenial