基于DEM的衡阳盆地水土流失估算

DEM-Based Assessment of Soil Erosion of the Hengyang Basin

水土流失是当今全球性的环境问题。衡阳盆地地处我国南方低山丘陵区,在湖南省的社会经济发展中有着重要的作用,开展对该地区的水土流失专门研究具有重要的实践意义。文章收集了衡阳盆地2000、2008年的Landsat影像数据、1959―2008年的降水数据、1﹕250 000 DEM数据和衡阳土壤分类图等研究资料,以RUSLE方程(通用土壤侵蚀方程)为基本方法,参考近年来国内关于该方程参数的计算方法,通过ArcGIS 9.2软件计算了衡阳盆地2000、2008年的土壤侵蚀量。在此基础上,将衡阳盆地的水土流失划分为微度、轻度、中度、强度和极强度侵蚀5个等级。结果表明:城镇与大型工程建设造成地表植被破坏是造成本地区水土流失的主要原因。近年来,衡阳盆地的土壤侵蚀状况总体好转,但仍然需要加强生态环境建设和水土流失治理。

Soil erosion is a common environmental problem in the world. Hengyang Basin, located in hilly region of South China, with a population of millions, plays an excellent role in social and economic development of Hunan Province. So, it is of practical significance to understand the soil erosion processes in the basin. This paper collects the following materials such as the landsat images of 2000 and 2008, precipitation data from 1959 to 2008, the 1/250 000 DEM data and Soil Taxomony map of Hengyang. With those materials, the paper uses the RUSLE equation to calculate the whole quantity of soil erosion of the Hengyang Basin in 2000 and 2008 with ArcGIS 9.2, and the parameters in the equation are calculated with the method used in domestic reports in recent years. According to our results, the soil erosion in the basin can be classified into five grades： light, mild, medium, severe, and most severe. The large-scale engineering construction is the main reason causing soil erosion in the Hengyang Basin. In recent years the soil erosion situation has been improved, but the ecological costruction and control of soil erosion still need to be strengthened.