Physical Features
India, with an area if 3.3 million Sq. Km, is a subcontinent. The peninsula is separated from mainland Asian by the Himalayas. The country lies between 80 4' and 3706' north of the equator and surrounded by the Bay of Bengal in the east, the Arabian Sea in the west and the Indian Ocean to the south.

The Himalayas from the highest mountain ranges in the world, extending 2,500km over northern India. Bounded by the Indus river in the west and the Brahamputra in the east, the three parallel ranges, the Himadri, Himachal and Shivaliks have deep canyons gorged by the following the rivers into the Gangetic plain.

River Systems
The rivers may be classified as following:

a) the Himalayan,
b) The Deccan,
c) the coastal and
d) the rivers of inland drainage basin.

The Himalayan rivers are generally a now fed and flow throughout the year. During the monsoon months (June to September), the Himalayas receive very heavy rainfall and the rivers carry the maximum amount of water, causing frequent floods The Decan rivers are generally rain-fed and, therefore, fluctuate greatly in volume.

A very large no of them are non-perennial. The coastal rivers, especially on the west coast, are short and have limited catchment areas, Most of these are non-perennial as well. The rivers on the inland drainage basin are few and ephemeral. They like the Saimber or are lost in the sands, having no outlet to the sea.