三峡库区传统耕作措施水土保持机理研究

通过大量野外勘查、测量数据,说明了传统耕作措施的规律性及其坡长与坡度特征参数,同时将物理过程侵蚀模型(WEPP)模拟结果与实测数据进行对比分析,主要从坡长因子的角度阐明了传统耕作措施的水土保持作用机理。研究结果表明,实测的5°~10°、10°~15°、15°~20°、20°~25°、25°~30°坡面对应的坡长分别为7~10 m、5~7 m、4~6m、3~5 m、3~4 m,与同一坡度条件下WEPP模拟的坡面侵蚀发生的突增拐点值比较接近;传统耕作措施通过缩短坡长来分散坡面径流,阻止细股流的形成,从而有效防止了坡耕地中主要的侵蚀类型——细沟侵蚀。

Mechanism of Soil and Water Conservation of Conventional Farming Measures of the Three Gorges Reservoir Area

The paper explains the regularity of conventional farming measures and characteristic parameters of slope length and gradient through vast field survey and measured data.It conducts comparative analysis on the simulated results of Water Erosion Prediction Project(WEPP) with observed data and clarifies the function and mechanism of soil and water conservation of conventional farming measures mainly on the factor of slope length.The outcomes show that a) the corresponding observed slope length of 5°~10°,10°~15°,15°~20°,20°~25° and 25°~30° are 7~10 m,5~7 m,4~6 m,3~5 m and 3~4 m respectively,closing to the sudden increased inflexion values of slope erosion simulated by WEPP under the same condition of gradient and;b) through separating slope runoff and preventing formation of rills,the conventional farming measures could effectively prevent rill erosion which is the main erosion type of sloped lands.