Use of high-resolution satellite data for the structural and agricultural inventory of tank irrigation systems.

Tanks are small storage reservoirs impounding the runoff from monsoon rains to regulate the supply of water mainly for irrigated command areas that are typically less than 200 ha. They account for one‐third of the irrigated areas in Tamil Nadu, Karnataka and Andhra Pradesh. Years of neglect and indifference in tank maintenance and management have eroded their functional efficiency and jeopardized their multifarious benefits. In Tamil Nadu, this has resulted in a decline in their contribution to irrigation from 40% in 1995 to 25% in 2000. The modernization of these tanks requires prioritization and investment. Remote sensing technology, with its unique advantages and the latest high‐resolution sensors, can provide the information on the agricultural, hydrological and structural conditions of the tank irrigation systems necessary for prioritization. The National Remote Sensing Centre (NRSC) has carried out a study of the Nanjur tank cascade in Tamil Nadu using high‐resolution data from the IKONOS satellite ...