A GEOMORPHIC DATA MODEL FOR ESTIMATING SEDIMENT YIELD FROM SOUTHERN SIWALIKS

Abstract

Estimation of sediment yield of a watershed is difficult task due to various processes taking place both inside and outside the Earth. Collection of sediment data, during flow is very difficult job. Lack of data hinders the understanding of sedimentation process, which is essential for sustained development. Many sediment yield models such as 'USLE (Universal Soil Loss Equation), MUSLE (Modified Universal Soil Loss Equation), CREAMS (Chemicals, Runoff and Erosion From Agricultural Management Systems), SPUR (Simulation of Production and Utilization of Range Lands), SWRRB (Simulation for Water Resources in Rural Basins) and ANSWERS (Areal Non Point-Source Watershed Environment Response Simulations) apart from regression equations, are available, but these are site and object specific and are not accomodating Geomorphic processes. Geomorphic parameters are indicators of both endogenic and exogenic processes of the Earth, containing Wealth of information about sediment yield. Present study area, the Southern face of the Siwaliks where Geological conditions are favouring for higher sediment yield. Remote sensing techniques can be conveniently used to prepare the necessary data base required for sediment yield studies. In the present study several Geomorphic parameters have been evaluated and studied. It was found that basin area, drainage density, land slope, land cover and rainfall are most influential parameters. Based on these resourceful variables a sediment yield predictive model has been.proposed. The proposed model is simple and can be applied to any ungauged southern Siwalik catchment. Model input may be easily obtained from the analysis of remotely sensed data. The average annual maximum and minimum sediment yield have been found to be 30.94x103 0 r113 /year/sq.km and 1.80x103 m .m3 /year/ sq.km respectively. The model may be made efficient by incorporating, rock soil erodibility, and sediment transport.