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土壤侵蚀过程受控于侵蚀外营力和土壤抗侵蚀性能,深入理解坡面流水动力学特性及其侵蚀动力是研究土壤侵蚀动力学机制的基础。利用可变坡土槽,通过不同雨强(60、90和120 mm/h)和径流冲刷(10、15和20 L/min)组合模拟试验,研究了第四纪黏土红壤坡面水流的水动力学特征参数及其与土壤侵蚀量间的关系。结果显示:降雨和径流冲刷影响了坡面产流产沙过程和坡面流水力学特性,其中平均流速v、平均水深h、雷诺数Re和水流功率ω均随降雨强度和上方来水流量的增加而增大,相对水深曼宁糙率n/h则减小,其水力学他参数(弗如德数Fr、阻力系数f和水流剪切力τ)变化规律不明显。坡面水流平均速度取值范围为0.21~0.45 m/s,平均水深取值范围为5.6~9.4 mm,在试验条件下红壤坡面侵蚀水流流态大部分均处于“紊流-急流区”。不论从径流角度看或是从泥沙角度分析,由相对水深和曼宁糙率系数两种水动力因子共同组成的复合水动力特征参数-相对水深曼宁糙率,是表征不同上方来水流量和降雨强度条件下第四纪粘土红壤坡面侵蚀特征的水动力参数。
Soil erosion process is controlled by the erosion of the external force and soil erosion resistance, in-depth understanding of the slope hydrodynamic characteristics and erosion of the dynamics of soil erosion dynamics is the basis of the study. By using variable slope soil trough, the water flow in Quaternary clay red soil slope was studied through the combination of different rainfall intensities (60, 90 and 120 mm / h) and runoff erosion (10, 15 and 20 L / min) DYNAMIC CHARACTERISTICS PARAMETERS AND RELATIONSHIP BETWEEN SOIL EROSION AND SOIL EROSION. The results showed that rainfall and runoff scour affected the process of runoff and sediment production and hydraulic characteristics of slope, in which average flow velocity v, average depth h, Reynolds number Re and flow power ω both increased with rainfall intensity and flow rate above And the relative Manning roughness n / h of water depth decreases. The variation law of hydraulic parameters (Freudel number Fr, drag coefficient f and water flow shear force τ) is not obvious. The mean velocity of water flow on slope surface is in the range of 0.21-0.45 m / s and the average depth of water ranged from 5.6-9.4 mm. ". Whether from the perspective of runoff or sediment analysis, the composite hydrodynamic parameters, which are composed of relative water depth and Manning’s roughness coefficient, which is the relative hydrodynamic Manning roughness, represent the different upper water flow And the hydrodynamic parameters of the erosion characteristics on the slope of the Quaternary red clay under rainfall intensity conditions.