Any upland or a mountain separating two adjoining drainage basins is known as water divide. An example of water divide is the Western Ghats.

 The Ganga river basin is the largest river basin in India.

The Indus river has its origin in Tibet near the Mansarovar Lake while the Ganga River has its origin in Gangotri Glacier in Uttaranchal.

Alaknanda and Bhagirathi are the two headstreams of the Ganga. They both meet to form the Ganga at Devprayag.

The Brahmaputra river, which is known as Tsangpo in Tibet, carries a smaller volume of water and less silt as it is a cold and a dry area. But once it enters India, Brahmaputra is fed by heavy rains, and it carries lot of water and silt.

The two rivers that flow through troughs are Narmada and Tapi. They form estuaries while entering the sea.

River is very beneficial for agricultural purpose and generating hydro-electricity. It provides fisheries, inland channels for transport. Lakes like the Sambhar Lake provide edible salt. They also help develop tourism and provide recreation.

Below are given names of a few lakes of India. Group those under two categories - natural and created by human beings.
(a) Wular (b) Dal (c) Nainital (d) Bhimtal (e) Gobind Sagar (f) Loktak (g) Barapani (h) Chilika (i) Sambhar (j) Rana Pratap Sagar (k) Nizam Sagar (l) Pulicat (m) Nagarjuna Sagar (n) Hirakud

Answer

Natural Lakes: Wular, Dal, Nainital, Bhimtal, Chilika, Pulicat, Sambhar, Barapani, Loktak
Created by human beings: Gobind Sagar, Hirakud, Rana Pratap Sagar, Nagarjuna Sagar, Nizam Sagar