长江三峡区的坡面土壤流失量和入江泥沙量研究

Research on Amount of Soil loss in Slope Surface and Sediment into the Yangtze River in Three-Gorge Region

通过野外调查,确定三峡区的水土流失程度分级,和不同土壤流失类别区。在流失程度区域内,据坡面土壤流失量调查,得出各区内的最大可能的流失量值和相应的泥沙输移比值。在对各土壤流失因子进行研究后提出了这一区域内的土壤流失方程。所得结果是:本区平均坡面土壤流失量3094t/km^2·a,全区年坡面流失总量约1.56×10~8t,入江泥沙量为895t/km^2·a,年总最约0.4×10~8;泥沙输移比值平均约0.28。土壤流失方程为: A=0.8351·R·K·Ls·C^(-2)

The gradation of water and soil loss and delimition of soil loss area have been made through the field surveys. The maximum possible value of soil loss and the corresponding ratio of sediment delivery to the Yangtze River have been obtained through the surveys of soil loss on the slope surface in differrnt soil loss regions. The soil loss equation suitable to this region is advanced after studying each erosion factor. The results indicate that an average amount of soil loss on the slope surface can reach 3 094 t/km^2·a, and total soil loss on the slope surface in the whole region is about 156 million t/km^2·a per year; and that the amount of incoming sediment into the Yangtze River reaches 895t/km^2·a; and total amount is 40 million tons per year. The average sediment delivery ratioes about 0.28. The soil loss equation is as follows: A=0.8351.R.k.LS.C^(-2·3)