基于SPOT5的密云水库上游土壤侵蚀风险空间格局分析

Assessment of Water Erosion Based on SPOT5 in the Upstream Area of Miyun Reservoir

基于SPOT5-10 m多光谱数据提取研究区的植被覆盖与土地利用/土地覆盖,利用1∶5万DEM数据提取研究区坡度信息,采用中华人民共和国水利部部颁标准评价研究区的水蚀风险等级,并与第二次全国土壤侵蚀遥感（Landsat TM）调查数据进行对比分析。结果表明：（1）从整体上看,区域的侵蚀状况有所好转,侵蚀面积减少了84.10km2,但极强度侵蚀面积增加了6.68 km2,剧烈侵蚀增加了0.03 km2。（2）从空间分布看,大于1 700 m的高程带侵蚀面积最小,500~800 m高程带的侵蚀面积最大;小于5°和大于35°的坡度带侵蚀面积最小,而15°~25°坡度带侵蚀面积最大。研究结果可以作为基础数据,为管理部门进行治理决策依据。

The paper extracted vegetation fraction and land use information from SPOT5-10 m multi-spectral images,and extracted slope information from DEM obtained from 1∶5 0 000 topographic map,and assessed the soil erosion risk according to the national professional standard of SL190-96 Standards for classification and Gradation of Soil Erosion.Subsequently we compared to the result of the second remote sensing investigation of soil erosion in China using Landsat TM in 2000.The results show that：（1） the overall erosion status is better than that of 2000,but more severe and extremely severe erosion appear in the study area.（2）From the elevation and slope zone,the elevation zone above 1 700 m has lowest erosion,and the zone between 500～800 m has the highest erosion;the slope zones less than 5° and greater than 35° have the highest erosion and the slope zone between 15° and 25° has the lowest erosion.These results will be used to assist the management department decision-making.