坡度对坡面土壤侵蚀的影响分析

在运动波理论基础上，就影响土壤侵蚀的主要因素，包括降雨超渗净雨量，坡面流水深，流速和切应力，以及土壤抗冲蚀能力等随坡度的变化关系进行了理论分析，并进一步对坡面土壤侵蚀的坡度界限做了较细致分析，表明坡度界限是一个变量，随颗粒粒径，容重，坡面糙率，径流长度，降雨入渗差值（净面量），以及土壤摩擦系数等因素的不同而改变，给出了界限坡度的变化规律，并得出一般情况下土壤侵蚀的坡度界限值应在41．5－50度范围内的结论。

Influences of Slope Gradient on Soil Erosion

The main factors influencing soil erosion include the net rain excess, the water depth, the velocity, the shear stress of overland flows, and the erosion-resisting capacity of soil. The laws of these factors varying with the slope gradient were investigated by using the kinematic wave theory. Furthermore, the critical slope gradient of erosion was driven. The analysis shows that the critical slope gradient of soil erosion is dependent on grain size, soil bulk density, surface roughness, runoff length, net rain excess, and the friction coefficient of soil, etc. The critical slope gradient has been estimated theoretically with its range between 41.5°～50°.