SIMULATION MODEL OF SEDIMENT YIELD FOR SMALL EXPERIMENTAL WATERSHED

Abstract

Study of runoff and sediment to evaluate yield from water-shed is essentially required for planning, management and 'evalua-tion of water resources. Considerable studies have been made so far to understand the runoff, and sediment processes by adopting simulation technique. The models developed in the recent past are quite sophisticated and having large data requirements. In the present study, an attempt has been made to develope a simpler, less comprehensive deterministic physical process hydrological model to predict daily runoff and sediment from an experimental watershed in snowfree mountaineous region from the available climatological data. The main data input to the model are physiographic data of watershed as area, slope, median elevation and cover density, climatological data as daily maximum and maximum temperature, solar radiation and precipitation. Interception is modelled by input of fractions of rainfall intercept for different rainfall intensities based on the actual observation. The model was applied to experimental watershed No.l at Rajpur situated in the Siwalik hill range at distance of 5 kms from Dehradun. The area of the watershed is 6.47 hectares having average slope of 26 percent and 88 percent covered with the coppice sal forests.