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Soil erosion is the major environmental problems in the world, one of the soil erosion is mainly because reclaiming farmland, over-grazing, deforestation and unreasonable human activity development projects to cause, soil erosion caused by local hazards have soil erosion and desertification etc., also have deposition canal, caused flooding and different hazards caused flooding, etc.Previous domestic scholars in soil erosion quantitative evaluation research has made many achievements, but the study area and more focused on loess plateau and the southeast coastal area such as research work, to the south regions, especially with unique karst geological features of guangxi guilin district research is relatively rare. Li river, as the soul of guilin landscape, guilin tourism industry has been in plays an important role, but in recent years, li river flood water richful during prolonged facing maximum concentration increases, the cross-strait silting-up river shorten etc. Study the lijiang river upstream soil erosion conditions for the protection of li river coast have very scenery with realistic significance.Using RS and GIS technology quickly widespread regional soil erosion monitor and comprehensive quantitative analysis and evaluation of soil erosion, and is currently an important trend. This paper discusses the principle and method of remote sensing soil erosion, to lijiang upstream watershed as a research unit, with different years of TM/ETM+ image combination of the research region, frontipiece topographic map and other relevant documents as data sources, under general soil erosion equation (RUSLE), on the basis of remote sensing and GIS software software, obtain the slope, vegetation, rainfall erosivity, Soil erodibility impact such as soil erosion of each key factors, using ahp evaluation model to determine the weights of each factor, through the classification of dimensionless normalized, eliminate bring incomparability of river basin, in the end, soil erosion dynamic analysis and evaluation, the analysis results show little change in other factor, watershed vegetation health improved conditions, Compared to 1994 year,2005 year’s basin erosion degree has different rate reduced, erosion intensity has declined, lijiang river upstream vegetation protection work have certain effect; Using GIS spatial analysis function, estimated 2005 river region, analyzed the soil erosion and the soil erosion of the spatial distribution pattern and its environmental background factors (altitude, slope) spatial relations, this research results for regional soil and water conservation management and decision-making work provide scientific reference.
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