泥沙输移与坡面降雨和径流能量的关系

Relationship between sediment transport with surface rainfall and runoff energies on sloping

从导致土壤侵蚀的降雨和径流能量出发,提出了基于物理学原理的降雨能和径流能的概念,并采用人工模拟降雨实验,分析了泥沙输移与降雨和径流能的关系,结果显示:坡面薄层径流泥沙剥蚀量随着地表坡度、降雨能和径流能的增加而增加,雨滴击溅作用下泥沙剥蚀量远远大于无雨滴击溅作用时泥沙剥蚀量;薄层水流泥沙浓度随着坡度和降雨能的增加而增加,当坡度和降雨能一定时,泥沙浓度随着径流能的增加而减小;降雨扰动系数与降雨和径流能的比值按照对数关系增长,在相同坡度下,当降雨能一定时,降雨扰动系数随着径流能的增加而减小,当径流能一定时,降雨扰动系数随着降雨能的增加而增加。降雨能是导致泥沙剥离的本质,径流能是泥沙搬运的动力。

From the view of rainfall and runoff energies resulting in soil erosion, this paper puts forward the conceptions of rainfall energy and runoff energy on the base of physics principle, and analyses the relationship between sediment transport with rainfall energy and runoff energy using the artificial rainfall. The results show that the rate of sediment detachment of sloping fallow overland flow increases with the rise of the slope gradient, rainfall energy and runoff energy, and the sediment detachment rates under raindrop impact are severe higher than under those without raindrop impact. The sediment concentration increases with the increase of the slope gradients and rainfall energies; when slope gradients and rainfall energy keep a constant, the sediment concentrations decrease with the increase of the rtmoff energies. Rainfall disturbed coefficients have a logarithm correlation with the rate of rainfall energy and runoff energy. On same slope gradient, when the rainfall energies keep a constant, the disturbed coefficient decreases as the runoff energies increases, when the runoff energies keep a constant, it increases as the rainfall energy increases. The rainfall energy is the essence to result in sediment detachment, and the runoff energy is the conveyer for erosion sediment.