黄土坡面片蚀水流含沙量变化过程试验研究

Experimental Study on Variation Process of Flow Sedimsent Concentration of Sheet Erosion of Loess Slope Surface

采用人工模拟降雨试验方法对黄土坡面片蚀水流含沙量变化过程进行研究,结果表明:不同雨强和坡度条件下,片蚀水流含沙量变化过程均表现为先增大后减小,最终趋于相对稳定的趋势;片蚀水流平均含沙量随雨强和坡度的增大而增大,分别可用幂函数方程和对数方程描述;雨强和坡度对片蚀水流含沙量的综合作用可用二元幂函数方程很好地描述,其中坡度对坡面片蚀水流含沙量的影响大于雨强;单位水流功率是与片蚀水流含沙量变化过程关系最密切的水动力学参数,是坡面片蚀水流含沙量变化过程发生发展的动力根源。

The paper studied the variation process of flow sediment concentration of sheet erosion of loess slope by using the method of artificial simulation rainfall.The outcomes show that a) under the conditions of different rainfall intensity and different slopes,the variation process of flow sediment concentration of sheet erosion shows increase first and then decrease and tends to relatively stable finally;b) The average flow sediment concentration of sheet erosion increases with the increases of rainfall intensity and slope and can be described by power function equation and logarithmic equation respectively;c) The comprehensive effect of rainfall intensity and slope to the flow sediment concentration of sheet erosion can be well described by binary power function equation,of which,the influence of slope to the flow sediment concentration of sheet erosion of slope surface is greater than that of rainfall intensity and;d) The unit stream power is the most important hydrodynamic parameter in the variation process of flow sediment concentration of sheet erosion and is the origin of the generation and development power of the variation process of flow sediment concentration of sheet erosion of slope surface.