基于GIS和RULSE的三峡库区土壤侵蚀量估算分析

Estimating Soil Erosion in Three Gorges Reservoir Area Based on GIS and RUSLE

以三峡库区为研究对象,在GIS技术支持下,利用野外实测及DEM、土地利用、土壤类型、植被覆盖等数据,对修正后的通用土壤流失方程(RUSLE)中各因子进行量化分析,从而对三峡库区土壤侵蚀量进行估算,并对土壤侵蚀强度进行分级;在此基础上计算不同坡度、土地利用类型、土壤类型下的土壤侵蚀综合指数。结果表明,三峡库区年均土壤侵蚀量为19 364.71×104 t/a,平均土壤侵蚀模数为2 741.48t/(km2.a),属于中度侵蚀;68.57%的区域为微度侵蚀或轻度侵蚀,强度以上侵蚀主要分布在库区的东部,面积占库区的14.43%,侵蚀量却占总侵蚀量的58.67%,是预防和加强水土流失治理的重点区域。

Three Gorges Reservoir Area was chosen as the study area.The factors in the Revised Universal Soil Loss Equation（RUSLE） were quantitatively analyzed by using the digital elevation model（DEM）,land use type,soil types,vegetation cover and experiment measure based on GIS technology,and achieved soil erosion estimates in Three Gorges Reservoir Area.Then the corresponding soil erosion synthesized indexes of different slope,land use type and soil types were calculated.The results indicated that： the annual average soil erosion amount is 19 364.71×104 t,and the mean soil erosion modulus is 2 741.48 t/（km2·a）,and the erosion intensity is classified as moderate degree erosion.Micro-water areas and mild erosion area accounting for 68.57%,the serious eroded area which was mainly concentrated in the eastern only occupied 14.43% of the area,but contributed 58.67% of sediment and needed more protection.Through the size of soil erosion synthesized indexes can be seen the severity of soil erosion of different conditions.