降雨作用下红土型坡面径流特性与土壤侵蚀的关系研究

发布时间：2018-11-09 09:54

【摘要】：针对云南红土型坡面和一定的雨强、坡度,运用人工模拟降雨水槽模型试验、土工试验及相关理论分析相结合的研究方法,揭示降雨作用下云南红土型坡面径流的水动力学特性及红土干密度、坡面侵蚀模数与坡面径流剪切力之间的关系。结果表明:(1)坡面径流平均流速随坡面径流历时呈先逐渐增大后趋于稳定的变化趋势,且坡面径流的平均流速随红土干密度的增大而显著增加。坡面径流平均流速与单宽流量呈幂函数关系(R~2=0.996)。(2)坡面径流平均水深随径流历时也呈先上升而后趋于稳定的变化过程,且干密度越大,平均径流水深也越大,平均径流水深与单宽流量也呈幂函数关系(R~2=0.996)。(3)在试验条件下,坡面径流流态属层流急流流态。(4)在试验条件和干密度一定的条件下,坡面侵蚀模数随径流剪切力的增大而增大,二者之间呈线性关系,当干密度为1.0,1.1,1.2,1.3,1.4 g/cm~3时,R~2最小为0.816,最大为0.945;坡面红土的临界剪切力分别为0.482,0.510,0.556,0.586,0.656 Pa。坡面径流特性受多种因素的联合作用,坡面侵蚀模数及红土临界剪切力与坡面径流特性和土壤自身特性密切相关。
[Abstract]:In order to study the hydrodynamic characteristics and the dry density of the lateritic slope surface runoff of Yunnan under the effect of rainfall, the study method of artificial simulated rainfall water tank model test, soil test and relevant theoretical analysis is applied to the red soil type slope surface and certain rain intensity and slope of Yunnan. The relationship between the erosion modulus of the slope and the shear force of the surface runoff. The results show that: (1) The average flow velocity of the slope surface runoff is gradually increased with the slope surface runoff, and the average flow velocity of the slope surface runoff increases with the increase of the red soil dry density. The mean flow velocity of the slope surface runoff is a power function relation with the single-width flow (R ~ 2 = 0. 996). (2) The average water depth of the runoff in the slope is also in the process of first rising and then stabilizing, and the higher the dry density, the greater the average runoff depth, and the average runoff depth and the single-width flow are also the power function relation (R ~ 2 = 0. 996). (3) Under the test condition, the flow state of the slope surface is in the laminar flow state. (4) Under the condition of the test condition and dry density, the erosion modulus of the slope surface is increased with the increase of the runoff shearing force, and the linear relation between them is linear. When the dry density is 1. 0, 1. 1, 1. 2, 1. 3, 1. 4 g/ cm ~ 3, the minimum R ~ 2 is 0.816, and the maximum is 0.945; The critical shear force of the red earth on the slope surface is 0. 482, 0. 510, 0. 556, 0. 586, 0. 656 Pa. The runoff characteristics of the slope surface are affected by the combination of various factors, the erosion modulus of the slope surface and the critical shear force of the red soil are closely related to the characteristics of the slope surface runoff and the characteristics of the soil.
【作者单位】：昆明理工大学电力工程学院;
【基金】：国家自然科学基金地区基金项目(51269006;51568031) Region Program of National Natural Science Foundation of China(51269006;51568031)
【分类号】：S157.1

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