Study On The Soil Erosion Control Benefit By Using The Method In Combination Of GIS And USLE

Wuqi County of Shanxi Province, located in the middle range of Yellow River, is one of the counties that suffer the most water and soil loss in the Loess plateau in China. It was the first county that practiced a voluntary program of comprehensive control and use of land. The program has achieved great success since its inauguration in 1998. However, the lack of a systemic and quantitative assessment of soil erosion has adversely affected the evaluation of the effectiveness of the program. We therefore developed prediction models of soil erosion by analyzing the field observation data from the Chaigou watershed. We have incorporated the GIS software (MapInfo and ArcView), USLE, and RS as a combinatorial method and established a spatial database. Using GIS's function of raster spatial analysis,we designed the watershed into uniformed grids of 30m×30m areas. The USLE was integrated with ArcView and Arc/Info to predict soil erosion in the Chaigou watershed after selecting valid USLE factor values including rainfall, soil, vegetation fraction, slope length, slope aspect, and soil and water conservation measures. And building spatial databases, the grid will be based on the effects of soil erosion and soil erosion factor calculated value of the conversion value for the land mass, according to the type of soil erosion and intensity distribution of a system of research, the last, in the soil erosion laws on the basis of the study made the corresponding soil erosion control measures.The soil erosion was estimated, and the critical areas of soil erosion in the watershed were identified. Average soil erosion amount was 12367.61t/km2·a befor conversing farmland to forest, which falls into the category of highest intention erosion. Highest intention erosion category occupied percent 27.91 of the total watershed areas. Average soil erosion amount was 8418.96t/km2·a after conversing farmland to forest, which falls into the category of highest intention erosion. Highest intention erosion category occupied percent 24.62 of the total watershed areas, mainly distributed in sports and Liang Yuan slope or steep slope which has a gradient 20 degree-25 degree. High erosion also distributed in the larger trenches, steep slopes or bed surface with a gradient of 30 degree or higher where there was no vegetation. By 1997 compared with 2005 data derived through the implementation of soil erosion returning works to reduce soil erosion 24637.22t in the same time.The use of GIS and RS and the combination of soil erosion USLE forecasts research methods, innovative, for similar studies with guiding significance; The results of this study can be directly...