Soil Erosion Modeling Using Remote Sensing and GIS

Abstract

Besides a naturally occurring process, soil erosion results in a continuous loss of topsoil, ecological degradation, etc. Evaluating soil loss from watersheds is required while assessing the severity of soil erosion. The average annual soil loss from the Nathpa-Jhakri catchment has been estimated by employing the Revised Universal Soil Loss Equation (RUSLE) and Morgan-Morgan-Finney (MMF) models in the present study. The RUSLE factors and MMF parameters were calculated using meteorological data, FAO soil map, ASTER DEM map, European Space Agency (ESA) land use/cover map, and other reference studies. The model factors and parameters were integrated into the geographic information system (GIS) environment to estimate the soil loss. GIS was used in this study to generate, manipulate, and spatially organize disparate data for soil erosion modeling. The estimated average annual soil loss using the RUSLE and MMF models was 20.42 and 26.29 tons/ha/year, respectively. The coefficient of determination for sediment yield using the RUSLE and MMF models was 0.80 and 0.75, with a variation of 13.41% and 21.62%, respectively. Further, the total catchment area was categorized into the different erosion classes, viz., slight, moderate, high, very high, severe, and very severe. The RUSLE model showed that about 35.8% of the area of the Nathpa-Jhakri catchment lies in the slight to moderate, and 64.2% of the area lies in the high to very severe soil erosion classes. The soil loss estimated by MMF model showed that 13.88% of the Nathpa-Jhakri catchment area lies in the slight to moderate, and 86.12% of the area lies in the high to very severe soil erosion classes. The RUSLE model showed more precise results than the MMF model for the Nathpa-Jhakri catchment. Based on RUSLE model results, about 64.2% catchment area of the Nathpa-Jhakri needs immediate attention for proper land use management practices.