基于GIS和RUSLE的滇西北山区土壤侵蚀空间特征分析——以云南省丽江县为例

Analysis of Spatial Characteristics of Soil Erosion in Mountain Areas of Northwestern Yunnan Based on GIS and RUSLE

土壤侵蚀空间分布特征,是进行土壤侵蚀防治规划、实践的重要基础与依据。研究以云南省丽江县为例,应用RUSLE估算了县域土壤侵蚀量,并基于G IS的空间统计分析功能,分析了土壤侵蚀在海拔、坡度与土地利用类型等方面的空间分布特征。结果表明,全县平均土壤侵蚀模数为52.50 t/（hm^2.a）,属于强度侵蚀,县域东部的金沙江沿岸、3 500～6 000 m高程带、25°～90°坡度带,以及裸地与荒草地、旱地等不同类型区域是研究区土壤侵蚀治理的重点地区。

The spatial distribution characteristics are important basis for the planning and application of soil erosion prevention. In the study, taking Lijiang County of Yunnan Province as a case study, we estimated the soil loss in the whole county with the application of Revised Universal Soil Erosion （RUSLE） , A = R × K × LS× C × P, where A was annual mean soil erosion modulus, the rainfall erodibility factor （R） came from annual mean rainfall accumulated from May to October, the soil erodibility factor （K） depended on corresponding soil types, the topography factor （LS） was calculated according to elevation and slope, and the vegetation cover factor （C） and the soil and water conservation measure factor （P） was determined by land use types. Furthermore, the spatial distribution characteristics were also analyzed with the application of GIS in the view of elevation, slope and land use types. The results showed that the soil erosion modulus were 52.50 t/（ hm^2 · a） , which belonged to the grade of intensity erosion. The results also showed that soil erosion, especially soil erosion with high grade, mostly distributed in the following areas, that is riverside of Jinsha River in the east of the county, elevation area from 3 500 to 6 000 meters, slope area from 25 to 90 degree, and uncovered land, waste grassland, and dry land