Application of remote sensing techniques for hydrologic investigations of upper yamuna catchment

The demands of water in various spheres of life, and its insufficient supply to fulfill these demands, specially in the developing countries, has become day by day a great challange to the hydrologist. In such a situation it becomes imperative to search a suitable methodology which can be used efficiently to predict the stream flows using minimum ground data, time and funds. Recently Remote Sensing Techniques have become a more popular and suitable tool for such studies. Keeping in view this aspect of problem, an analysis of Upper Yamuna Catchment, using Landsat imagery, was carried out to obtain the catchment characteristics which affect stream flows. Landsat imagery in Bands 5 and 7 on 1:1 million scale were analysed to get landuse and vegetal cover classification in categories (1) thick forest (ii) thin forest (iii) bare land and cultivation and (iv) snow cover. Using this data, alongwith rainfall data from 20 raingauge stations and stream flow data at Dakpather and Lakhwar, the stream flows were estimated by using Lumped system and Distributed system Models based on Rational Method. The computed 10 day period stream flows of Tons Sub-Basin were compared with observed surface flows with the help of hydrographs, flow comparison graphs and average monsoon period and monthly flow values. Using the coefficients evaluated from Tons sub-basin, the stream flow of Yamuna sub-basin were computed and compared with the observed surface flows.