HYDROLOGICAL INVESTIGATION OF • SUBARNAREKHA CATCHMENT USING SATELLITE IMAGERY

Abstract

The extreme scarcity of water in many parts of the world and their uneven distribution in time, coupled with ever increasing demands for water, have given rise to an urgent need for the accurate assessment and efficient manage-ment of these resources. Remote sensing techniques have already proved their worth in a number of fields and much work has been undertaken to develop their use in studies of hydrology and water resources. Keeping in view of above, a detailed study of the & foarnarekha catchment has been carried out using satellite imagery to find a suitable methodology so that reasonably accurate and dependable forecast can be made for water.. resources planning. In carrying out this study, LANDSAT imagery in band 5 on 1:1 million scale in conjunction with aerial photographs and topographical maps were analysed to get landuse and vegetal cover classification in categories (1) thick forest, (ii) thin forest, (iii) grassy land, (iv) cultivated land and (v) barren land. Using this data, along with rainfall and streamflow data at Mango Bridge and Adityapur gauging sites, the streamfiows were estimated by using three different iapproaches. These are: (i) Rational model with constant monthly runoff coeffi-cient. (ii) Rational model with variable monthly runoff coefficient.