(i) Any upland or a mountain separating two adjoining drainage basins is known as water divide. Though the Indus, the Sutlej and the Brahmaputra rivers rise very close to each other near the Mansarovar Lake but because of the water divides they flow in different directions.
(ii) The Ganga basin is the largest river basin in India.
(iii) The Indus river has its origin in Tibet near the Mansarovar Lake while the Ganga River has its origin in Gangotri Glacier in Uttaranchal.
(iv) Alaknanda and Bhagirathi are the two headstreams of the Ganga. They meet at Devaprayag.
(v) The Brahmaputra river, which is known as Tsangpo in Tibet, receives very little volume of water in Tibet so; it has very little silt there. On the other hand, this river when enters India it passes through such a region which receives heavy rainfall. As such in India, in India it carries a large volume of water and larger amount of silt.
(vi) Narmada and Tapi are two peninsular rivers which flow through trough.
(vii) Lake can be used for generating hydroelectricity. A lake can be a good tourist attraction. Rivers have been the centre of human civilization since ancient times. Even today, many big cities are situated on the bank of a river. River water is used for irrigation, navigation, hydroelectricity, fisheries, etc.