基于RS和GIS技术对中国陕西省北部地区土壤水蚀风险评估

运用遥感(RS)和地理信息系统(GIS)技术来进行中国陕西省北部地区的土壤水蚀风险评估。综合运用RS和(31S技术以及修订的通用土壤流失方程式(简称RusLE)来定量化地评估土壤侵蚀。建立了一个关于土壤侵蚀、斜坡长度/坡度、降雨侵蚀和人类活动的评估系统。评估值输入修订的世界土壤亏损方程式中，用来计算土壤退化进程的风险，土壤退化又叫土壤侵蚀。利用榆林和靖边两地区的1987年和1999年的陆地卫星TM传感图像来制作研究区土地使用/覆盖情况的地图，然后用这些地图产生RusLE方程中的人类活动因子。使用ERmapper/Info两个软件来管理和处理主要数据，及处理卫星图像和表格数据源。根据统计分析，3985．9km^2(33．12％)的土地面积有轻微到中度的土壤侵蚀，2941．4km^2(24．44％)的土地面积有高的土壤侵蚀，总土地面积中3522．1km^2(29．27％)正面临着很高的土壤侵蚀风险，总体上来说，研究区处于高的土壤水蚀风险中。

Assessment of Soil Water Erosion Risk Using RS and GIS in Northern Part of Shaanxi Province, China

The remote sensing and GIS are applied to evaluate the soil water erosion risk in the northern part of Shaanxi Province, China. This research integrates the revised universal soil loss equation(RUSLE) with RS and GIS techniques to quantify erosion risk. A system is established for rating soil erodibility, slope length/gradient, rainfall erosivity and conservation practices. The rating values serve as inputs into a modified universal soil loss (equation)(USLE) to calculate the risk for soil degradation processes, namely soil water erosion. Two Landsat TM senses from 1987 and 1999 for each location in Yulin and Jinbian County were utilized to produce land use/cover maps of the study area based on the maximum likelihood classification method. These maps were then, used to generate the conservation practice factor in the RUSLE. ER mapper and Arc/Info software's were used to manage and manipulate thematic data, to process satellite images, and to tabulate data. Statistical analysis determined that 3 985.9 km~2 (33.12%) of land has slight to moderate soil degradation, 1 583.5 km~2(13.16%) has moderately high soil degradation, 2 941.4 km~2(24.44%) has high soil degradation and 3 522.1 km~2(29.27%) of the total land is at risk of a very high soil degradation. The study area, in general, is exposed to a high risk of soil water erosion.