香溪河流域土壤侵蚀风险评价

Risk assessment of soil erosion in Xiangxi River Basin of Yangtze River

香溪河流域内的土壤侵蚀量对长江中下游河段的含沙量有着重要影响。采用地质统计与GIS空间分析技术相结合的方法,对该流域内的土壤侵蚀状况进行了风险分析。结果表明,香溪河流域土壤侵蚀以中度和强度为主,侵蚀风险以轻险区为主,其中,土壤侵蚀发生的主要区域为植被覆盖度低于45%、坡度大于25°的区域和黄壤区域,15°以上的坡耕地基本为危险区域。研究结果为该地区土壤侵蚀防治提供了科学依据。

The amount of soil erosion in Xiangxi River Basin has an important impact on the sediment concentration in the middle and lower reaches of Yangtze River.The risk assessment of soil erosion in the basin is conducted with the combinative use of geostatistics and spatial analysis of GIS technology.The results show that the soil erosion of Xiangxi River Basin is mainly moderate and intensive,and the risk of erosion is mainly light.The main areas of soil erosion are the areas with coverage of vegetation less than 45% and the slope steeper than 25 °,as well as the area of yellow soil.Almost all sloping farmlands with gradient greater than 15° are dangerous.All of these results provide a scientific basis for the prevention of soil erosion in the region.