基于GIS和RUSLE的土壤侵蚀量计算——以贵州省猫跳河流域为例

为了解西南喀斯特山区土壤侵蚀空间分布特征，该文以贵州省猫跳河流域为研究区，在GIS技术支撑下，应用修正的通用土壤流失方程（RUSLE）估算了研究区2002年现实土壤侵蚀量和潜在土壤侵蚀量，得到了研究区现实土壤侵蚀量和潜在土壤侵蚀量的空间分布特征，计算了各种土地利用类型的土壤保持能力，并对研究区土壤侵蚀防治措施进行了探讨.结果表明，研究区年均现实土壤侵蚀模数为28.70 t/（hm2·a），年均土壤流失量875.65×10.4 t/a，年均土壤保持量25 095.73×10.4 t/a.旱地的土壤保持能力最小，研究区进行水土流失防治除对25°以上的旱地实行退耕还林、裸岩荒地植树造林外，还应加强对6°～25°的旱地进行治理如坡改梯等. 

Estimation of soil erosion supported by GIS and RUSLE: A case study of Maotiaohe Watershed, Guizhou Province

Soil erosion in karst mountainous areas of southwest China is one of the determining factors for land degradation and productivity reduction. To explain the spatial characteristics of soil erosion in karst mountainous areas in southwest China, the authors used the Maotiaohe Watershed in Guizhou Province as study area Geographic Information System(GIS) technology and the Revised Universal Soil Loss Equation (RUSLE) were applied to estimate the potential and actual amount of soil erosion in Maotiaohe Watershed of Guizhou Province, present the spatial distribution characteristics of soil erosion in the watershed, calculate the soil conservation capacity by land use and then discuss the soil and water conservation countermeasures. Results showed that the soil erosion modulus and the actual amount of soil erosion were 28.70 t/(hm2·a) and 875.65×10.4 t/a, respectively, and the annual soil conservation amount was 25 095.73×10.4 t/a. Among land use types, the soil conservation capacity of dry land is the smallest. Apart from the option of returning all the farmland with a slope grade above 25°to woodland or grassland and afforestation in bare mountains, it is imperative to enforce proper management of farmlands with a slope grade of 6°-25°，such as terracing，in order to decrease soil loss.