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通过气象数据分析、实地调查、野外采样及室内分析、DEM计算、遥感解译等,建立了南水北调中线水源地丹江口水库区典型小流域地理数据库,确定了计算USLE因子指标的方法。在ArcGIS支持下,模拟了小流域土壤侵蚀强度的空间分布。将模拟结果分为微度、低度、中度、强度、剧烈侵蚀5级,建立土壤侵蚀与土地利用/土地覆盖类型及坡度之间的关系。结果表明:研究区年均土壤侵蚀量24.14t/hm2,远超该地区容许土壤流失量5t/(hm2·a)。96%的侵蚀区及95%的土壤侵蚀总量位于<25°区域。就土地利用/土地覆盖类型而言,陡坡耕作区是主要的土壤流失区。研究结果为水源区的土壤侵蚀治理提供参考意见,同时为USLE在无土壤类型图地区的应用提供一种方法借鉴。
Through the meteorological data analysis, field investigation, field sampling and indoor analysis, DEM calculation and remote sensing interpretation, a typical small watershed geographical database of Danjiangkou reservoir area in the mid-line of South-to-North Water Diversion Project was established and the method of calculating the USLE factor index was established. With the support of ArcGIS, the spatial distribution of soil erosion intensity in small watershed was simulated. The simulation results are divided into five stages of micro-degree, low degree, moderate degree, intensity and severe erosion, and the relationship between soil erosion and land use / land cover type and slope is established. The results showed that the annual average soil erosion in the study area was 24.14 t / hm2, far exceeding the permissible soil loss of 5 t / (hm2 · a) in the study area. 96% of the erosion area and 95% of the total soil erosion are located in the <25 ° area. In terms of land use / land cover types, steep slope farming areas are major areas of soil erosion. The results provide reference for soil erosion control in water source area and provide a reference for the application of USLE in soilless type map area.