The "four rivers" is the abbreviation for the Xiangjiang,Zhjiang,Yuanjing and Lishui rivers in Hunan The mid- and up-stream
districts of "four rivers" are main regions of
soil erosion in Hunan In this paper,the soil degradation mould and the reasons,area and harm of soil erosion of these districts are summarized and the measures for control of soil erosion presented From a great number of data,the influence of soil erosion on water and soil resources,water conservancy projects,rivers and the Dongting lake in these districts is elaborated The main reasons for soil erosion are discussed in the light of four natural factors such as geomorphy,rainfall,soil and vegetation and five artificial factors such as forest overfelling,farming methods,reclaim,hillside exploitation and project construction Some
countermeasures and proposals are presented on consolidating the existed achievement for treatment of soil erosion,executing the plan for water and soil reservation,improving the organization for water and soil reservation,strengthening the propagation and education concerning law of "water and soil reservation