Rivers: The rivers constitute an important natural resource. They form the lifelines of the Indian masses. On the basis of origin they are broadly categorised as :
I. The Himalayan Rivers : It consists of the following three systems :
(i) The Indus System : The Indus rises in Tibet at an altitude of 5,180 metres near the Mansarovar Lake. It enters the Indian territory in Jammu & Kashmir where it receives Himalayan tributaries such as the Gartang, Zaskar, Dras, Shyok, Shigar, Nubra, Gilgit and Huza. Its well-known Punjab tributaries which make the Panjnad are Sutlej, Beas, Ravi, Chenab and Jhelum.
(ii) The Ganga System : The Ganga rises in Garhwal Himalayas in Uttaranchal at an altitude of 6,600 metres. This river system includes the Yamuna, the Gomti, the Ghaghara, the Gandak, the Ramganga, the Mahaganga, the Son and the Kosi.
(iii) The Brahmaputra System : It rises from a glacier located at 100 km south-east of Mansarovar Lake. In Bangladesh it joins Ganga and forms the world’s largest delta. Important tributaries of Brahmaputra river are Sabansiri, Bhareli, Manas, Dibang, Lohit and Dhansiri.
2. The Peninsular Rivers : The main rivers of the Peninsular Plateau originate from the Western Ghats and flow in a west-east direction to join the Bay of Bengal. The important rivers are the Mahanadi, the Godavari, the Krishna, the Cauvery, the Narmada and the Tapi.