Spatial Soil Erosion and Sediment Yield Modeling of a Watershed Using GIS（Extracts）

The purpose of this study was to investigate the spatial distribution of annual soil loss using the USLE model with Geographic Information System（GIS）and Remote Sensing（RS）for the Wadsa-Chincholi watershed.The Arc GIS 9.3 software and RS（ERDAS IMAGINE 9.3 image processing software）provided spatial input data，and the USLE were used to predict the spatial distribution of the average annual sediment yield on grid basis.Cell based USLE parameters were multiplied in the specified into 50 m×50 m，100 m×100 m，200 m×200 m Grid Cell Size（GCS），and the average annual sediment yields were estimated at the outlet of watershed，for each year separately.Further，the sediment yields estimated by the Universal Soil Loss Equation（USLE）model were compared with observed data.The estimated average annual sediment yield from USLE model with 50 m×50 m，100 m×100 m and 200 m×200 m GCS was found to be 63.80，18.83 and 3.67 thm2·yr，respectively.The estimated sediment yields in 200 m×200 m GCS from the observed value are satisfactory matching.Hence，the results of USLE model at 200 m×200 m GCS can be applied for spatial sediment yield estimation from the Wadsa-Chincholi watershed.Therefore，area covered by very severe erosion class，severe erosion class，very high erosion class，high erosion and moderate erosion class need immediate attention from soil conservation point of view.