per cent comprising the Indus, the Narmada, the Tapi, the Mahi and the Periyar systems discharge their waters in the Arabian Sea. On the basis of the size of the watershed, the drainage basins of India are grouped into three categories: (i) Major river basins with more than , sq. km of catchment area. It includes drainage basins such as the Ganga, the Brahmaputra, the Krishna, the Tapi, the Narmada, the Mahi, the Pennar, the Sabarmati, the Barak, etc.
(Appendix III). (ii) Medium river basins with catchment area between , - , sq. km incorporating river basins such as the Kalindi, the Periyar, the Meghna, etc. (iii) Minor river basins with catchment area of less than , sq.
km include fairly good number of rivers flowing in the area of low rainfall. If you look at the Figure . you can see that many rivers have their sources in the Himalayas and discharge their waters either in the Bay of Bengal or in the Arabian Sea. Identify these rivers of North India.
Large rivers flowing on the Peninsular plateau have their origin in the Western Ghats and discharge their waters in the Bay of Bengal. Identify these rivers of the South India. The Narmada and Tapi are two large rivers which are exceptions. They along with many small rivers discharge their waters in the Arabian Sea.
Name these rivers of the western coastal region from the Konkan to the Malabar coast. On the basis of the mode of origin, nature and characteristics, the Indian drainage may also be classified into the Himalayan drainage and the Peninsular drainage. Although it has the problem of including the Chambal, the Betwa, the Son, etc. which are much older in age and origin than other rivers that have their origin in the Himalayas, it is the most accepted basis of classification.
Hence, this scheme has been followed in this book. D RAINAGE S YSTEMS OF I NDIA Indian drainage system consists of a large number of small and big rivers. It is the outcome of the evolutionary process of the three major physiographic