Quantification of soil erosion in small watersheds on the Loess Plateau based on a modified soil loss model

Abstract

The technology of slope vegetation system stability enhancement is an important part of the comprehensive ecological security improvement in small watersheds area of the Loess Plateau. The results of the comprehensive soil erosion improvement in the sub-basin are used to give an evaluation of the effectiveness of the gully slope vegetation restoration project. Soil erosion quantification distribution in the Sheep Sap Gully sub-basin of the Loess Plateau hilly gully area was simulated and explored by combining the modified universal soil loss equation RUSLE model with GIS and RS spatial information technology. The quantitative values of LS factor were extracted using DEM data, the R factor of rainfall erosion force was calculated using meteorological monitoring station data around this region, the K factor of erosion resistance was obtained based on the soil survey database, and the C factor and P factor of soil and water conservation measures were obtained by combining MODIS image data and previous research experience. The study concluded that (1) The erosion area ratio within the study area is 36.33%; (2) The quantitative grading standard of the pattern, the size of the erosion distribution area at all levels is ranked as light>moderate>very strong>strong>intense; (3) Under the conditions of land use and vegetation cover, strong erosion is mostly found in farming areas with sparse vegetation, while weak erosion is found in areas with lush vegetation such as forests and grasslands; (4) In terms of spatial distribution, erosion is greater in the south-western part of the basin than in the north-eastern part, and there is also strong erosion in the south-western part. The results of the study provide a reference for research into integration and synthesis of ecological security technologies for gully and slope management projects. The research content provides the basis and support for watershed governance and soil and water resource management and conservation.