基于GIS的岩溶槽谷区小流域土壤侵蚀量估算

在修正的通用土壤流失方程(RUSLE)中引入石漠化因子,以重庆市南川区木渡河小流域为研究对象,在GIS技术的支持下,对岩溶槽谷区小流域土壤侵蚀量的估算方法进行了探讨.研究结果表明,研究区现实土壤侵蚀量40011.51 t/a,土壤保持量835963.94 t/a.计算研究区及不同土地利用类型的现实土壤侵蚀模数时,石漠化程度越高,总面积现实土壤侵蚀模数和可流失面积现实土壤侵蚀模数的差异越大;在岩溶区,使用可流失面积现实土壤侵蚀模数更能真实的反映岩溶区土壤侵蚀的状况.研究区水田和林地土壤保持能力最大,旱地土壤保持能力最小,控制土壤侵蚀的有效措施是在裸岩山地和陡坡地植树造林,大于25°的陡坡地退耕还林还草,扩大林地面积,减小陡坡耕地面积.

Estimating Soil Erosion in Small Watershed of Karst Valley Area Using GIS

Soil erosion is one important factor for land degradation and productivity reduction in karst areas of southwest China.Rocky desertification was introduced to Revised Universal Soil Loss Equation (RUSLE) to estimate soil erosion in Mu-du-he small watershed in Chongqing.The results showed that the actual soil erosion amount and soil conservation amount were 40011.51t/a and 835963.94t/a, respectively. The discrepancy in the actual soil erosion modulus of total area and the actual soil erosion modulus of erosion area increased with the karst rocky desertification. The actual soil erosion modulus of erosion area was more feasible for describing soil erosion in karst area. The paddy and wood land have the best capacity to conserve soil, whilst the dry land has the worst one. The effective measurements for soil erosion control include afforestation barren hills and steep slopes, conversion cropland to forest and grassland for slopes steeper than 25°.