永定河治理区土壤侵蚀时空变化分析

Analysis of soil erosion temporal and spatial changes in the Yongding River controlling area

本文利用"北京一号"小卫星32 m多光谱数据提取研究区的植被覆盖信息与土地利用信息,利用1∶50 000DEM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"土壤侵蚀分类分级标准SL 190-96",评价研究区的水蚀风险等级;并结合全国第二次土壤侵蚀遥感(Landsat TM)调查数据,进行土壤侵蚀时空变化分析。结果显示,从整体上看,区域的侵蚀状况有所好转,从变化趋势看,侵蚀等级恶化的面积要大于侵蚀等级好转的面积,说明在整体侵蚀状况好转的表象下存在着侵蚀等级恶化的隐患。最后制作土壤侵蚀变化趋势图,为今后的土壤侵蚀治理工作提供参考。

The paper extracted vegetation fraction and land use information from Beijing-1 small satellite 32m muhi-spectral images, and extracted slope information from DEM obtained from 1 ： 50 000 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 it compared with the result of the Second Remote Sensing Investigation of Soil Erosion in China using Landsat TM in 2000, and analyzed the temporal and spatial changes of erosion risk. The results showed as follows： according to the overall status, the eroded area decreased by 2503.42 km2 , but the more severe and extremely severe area increased by 29.38 km2 and 18. 05 km2 respectively; according to the changing trends, the area sum of erosion level degradation is larger than the area sum of erosion level upgrade. The fact indicated that most regions still have degradation trend when the eroded area becomes smaller in the study area. Finally, it produced erosion changing trends map which would help control soil erosion.