基于DEM的帽儿山地区土壤侵蚀定量分析

DEM-based quantitative analysis of soil erosion——a case study of Maoershan region

以ArcGIS9.0为分析平台,采用修正的通用土壤流失方程为评价模型,通过数字高程模型(DEM)、土地利用类型和土壤类型等空间数据与属性数据,获取基于栅格数据的土壤侵蚀量和侵蚀强度。借助于分布指数,通过空间叠加分析,从高程、坡度与坡向3个方面对研究区域的土壤侵蚀进行了定量化分析,揭示了土壤侵蚀在海拔、坡度、坡向上的空间分布特征。研究结果表明:微度和轻度侵蚀在整个研究区域占绝对大的比例,说明该区域水土保持总体上良好;就土壤侵蚀在坡向上的分布特征而言,中强度、强度和极强度侵蚀主要分布于半阳坡和阳坡区域;轻度和中度侵蚀在各高程等级上的分布占据一定的比例,土壤侵蚀强度与海拔不成直接的线性联系。

Based on the platform of ArcGIS9.0, the evaluation model of soil erosion was made by using usual soil loss equation, the cell based on the soil loss and erosion intensity was calculated by using attribute data and spatial data that include DEM, land use types and soil types. The terrain factors（ elevation, slope and aspect） and distri- bution index was overlapped to quantitatively analyse the region soil erosion, which could study the soil erosion spa- tial distribution from terrains factors（ elevation, slope and aspect）. The results shown that weak and moderate erosion occupies dominant ratio on the whole ; on the soil erosion distribution of aspect, the distribution of mild, intensive and strongest grades erosion is main in the half - sunny and sunny aspect ; the moderate and mild erosion occupies a certain ratio in various elevation grades, which shows that there is no linear relation between soil erosion intensity and elevation.