Prediction of Sediment Erosion Pattern in Upper Tapi Basin, India

Physics-based distributed models are useful in identification of critical erosion-prone areas and planning soil conservation measures in the catchment. In this study, soil and water assessment tool (SWAT), a semidistributed hydrological model, is utilized for modelling sediment yield in Upper Tapi Basin, India. Twelve years of observed runoff and sediment yield data are used for calibration and validation of the aforesaid model. The performance indicators, viz. Nash- Sutcliffe efficiency and ratio of ischolar_main-mean-squared error to standard deviation showed good performance of calibrated model in prediction of sediment yield for independent datasets. The two adjoining subcatchments in the basin have shown contrasting behaviour with reference to sediment yield due to differences in their topography, land use-land cover, soil and climatic conditions. Also, simulated erosions at hydrological response units levels, enabled the investigators to demarcate the critical erosion-prone areas in the catchment. The SWAT model has further been used to assess the performance of various soil conservation measures, such as providing filter strips and stone bunds, in the critical erosion prone areas in reducing the sediment yield. Both soil conservations measures, being applied on equal areas, yielded comparative performance in controlling erosion from the catchment.