本研究利用北京市延庆区的褐土和黑龙江省嫩江县的黑土进行了坡面流挟沙力试验，分析了坡面流水动力特性，对比分析了褐土、黑土水流挟沙力与中值粒径为0.28mm的沙粒水流挟沙力之间的差异。水槽长度为5m,宽度为0.4 m。试验共设计5个坡度（5.2%、10.4%、15.6%、20.7%和25.8%），6个流量（0.68、1.35、2.03、2.70、4.05和5.41×10-3m2/s）,共60组试验。主要结论如下： （1）在不同坡度条件下，褐土和黑土的坡面流挟沙力和流速、流量之间呈较好的幂函数关系。在不同流量条件下，褐土和黑土的坡面流挟沙力随坡度的变化呈幂函数形式变化。全面分析坡度和流量对土壤的坡面流挟沙力的影响，流量是土壤坡面流挟沙力的主要影响因素，可以用关于流量的线性函数来模拟土壤的坡面流挟沙力。坡度和流量对沙粒的坡面流挟沙力的影响作用基本相等，无法用关于流量的简单函数关系来模拟沙粒的坡面流挟沙力。 （2）褐土、黑土和沙的坡面流水流挟沙力均随着流速、水流剪切力和水流功率的增加而增加。对于褐土的水流挟沙力，水流挟沙力与流速、水流剪切力和水流功率的关系可以用幂函数表达，用流速模拟褐土的水流挟沙力效果最好。对于黑土的水流挟沙力，水流挟沙力与流速、水流剪切力和水流功率的关系可以用幂函数较好地表达，用流速模拟黑土的水流挟沙力效果最好。褐土和黑土的水流挟沙力和单位水流功率无法进行有效的拟合。对于沙的水流挟沙力，水流挟沙力随流速和水流功率的变化呈线性函数变化。水流挟沙力与水流剪切力和单位水流功率之间呈幂函数关系。用水流剪切力和水流功率模拟沙的挟沙力效果最好。 （3）用流速模拟水流挟沙力时，褐土和黑土的挟沙力与流速呈幂函数关系，沙的挟沙力与流速呈线性函数关系,流速对土壤坡面流挟沙力的影响作用大于对沙的影响。在相同流速、水流剪切力和水流功率条件下，褐土和黑土的水流挟沙力均大于沙的水流挟沙力。在相同流速条件下，黑土的水流挟沙力大于褐土的水流挟沙力。基于水流剪切力和水流功率的褐土和黑土坡面流挟沙力模拟公式基本相近，其微小差异可能和土壤机械组成、土壤团聚体特性、有机质含量以及下垫面粗糙度有关。 （4）已建立的基于中值粒径和水流剪切力的的挟沙力公式大致可以模拟黑土的坡面流挟沙力，但是对褐土的坡面流挟沙力并不适用。基于中值粒径和水流功率的挟沙力公式也不适用于褐土和黑土的挟沙力计算，但是可以对沙的坡面流挟沙力进行较好的模拟。

In this study,the cinnamon soil of Yanqing County in Beijing,the black soil of Nenjiang County in Heilongjiang Province and the sand with the median particle size of 0.28mm were used to be the experimental material. The test flume is 5m long and 0.4m wide.The experiment was designed with 5 slopes (5.2%, 10.4%, 15.6%, 20.7% and 25.8%), 6 flows (0.68, 1.35, 2.03, 2.70, 4.05 and 5.41×10-3m2/s).The main conclusions are as follows: (1) Under different slopes there is a good power function relation between the flow transport capacity of the soil and the flow velocity and flow discharge. Under different flow discharges the flow transport capacity of the soil changes with the change of the slope in power function. In this paper, the influence of slope and flow discharge on flow transport capacity of soil is analyzed comprehensively.And the flow discharge is the main influencing factor of the flow transport capacity.And the linear function of flow can be used to simulate the flow transport capacity of the soil. The effect of slope and flow discharge on the flow transport capacity of sand is basically equal. And it is impossible to simulate the flow transport capacity of sand by the simple function of flow discharge. (2) Flow transport capacity of the cinnamon soil, black soil and sand increased with the increase of the flow velocity, shear stress and stream power. The relationship between the flow transport capacity of the soil and the flow velocity, shear stress and stream power can be expressed as a power function. The flow velocity is the best hydraulic parameter which calculate the flow transport capacity of the soil. Flow transport capacity of the soil and the unit stream power cannot be effectively fitted. Flow transport capacity of the sand changes with a linear function as the flow velocity and the stream power change. Flow transport capacity of the sand has a power function relationship with the shear stress and the unit stream power.It is the best to simulate the flow transport capacity of the sand with the flow shear stress and the stream power. (3) When the flow velocity is used to simulate the flow transport capacity, the flow transport capacity of the soil has a power function relationship with the flow velocity.The flow transport capacity of the sand has a linear function with the flow velocity. The effect of the flow velocity on flow transport capacity of the soil is greater than that of the sand. Under the same flow velocity, shear stress and stream power, the flow transport capacity of the soil is greater than that of the sand. Under the same flow velocity, flow transport capacity of the black soil is greater than that of the cinnamon soil. The flow transport capacity formulas of cinnamon soil and the black soil based on the shear stress and the stream power are nearly similar.And the small differences may be related to the mechanical composition of soil , the characteristics of soil aggregate, the content of organic matter and the roughness of the surface. (4) The flow transport capacity formulas which obtained from sand is not suitable for the soil.