Freshwater discharge from the large and coastal peninsular rivers of India: Areassessment for sustainable water management.

Abstract

This study offers an updated mean annual water discharge of 10 large and 11 coastal basins of the Indian Peninsula and looks into environmental parameters influencing the water flux and discharge trends. The mean annual discharge of large and coastal rivers is estimated to be 221 and 294 km3. Thus, despite draining 25% of the Indian Peninsula, coastal rivers deliver more than half of the annual flux, and west-flowing coastal rivers contribute 85% of it. This study demonstrates temporal changes in the water discharge of various river basins. The presence of dams regulates discharge regimes of large rivers. The construction of large dams resulted in a significant decline in the water discharge of the Krishna, Cauvery, and Narmada. Through this study, we demonstrate the role of rainfall, catchment size, water loss through evapotranspiration and infiltration, and societal use of water in determining the runoff of each basin. We recommend tapping the water resources of the west-flowing rivers for proper planning, development, and management to reduce the water stress in the peninsular region and promoting sustainable management.