黄土坡面细沟侵蚀试验研究及土壤抗冲性评价

通过室内放水冲刷试验,分析了坡面侵蚀过程中跌坑产生与发育的机理,阐明了朔源侵蚀、边壁崩塌和细沟下切侵蚀之间的相互关系。研究了各放水流量下坡面产沙及细沟径流的变化规律,建立了坡面产沙量与细沟面积比例和流量关系。本通过对冲刷过程中各侵蚀营力的分析,得到了径流剪切作用产沙方程。研究表明,径流剪切产沙率和单位面积径流剪切力呈显的正相关关系,土壤颗粒被分离的临界剪切力为0．258N／m^2。

Experimental Research on Rill Erosion of Loessial Slope and Evaluation on Soil Anti-scourability

On the basis of scouring experiments indoors, the mechanism of the drop pit'genesis and development during the process of slope erosion is analyzed, and the relationship among headcut, bank landslip and downcut has been expounded. The variation regularity of the runoff and the sediment yield in each discharge was studied, and the relationship among the sediment, the runoff and the proportion of the rill area was obtained. Analyzing each erosion stress on the slope during the scouring, we get the runoff shearing sediment equation. The study shows that the sediment yield from runoff shearing take on a good positive correlation with the average runoff shear stress, and the critical shear stress of the runoff, by which the soil grain can just be dispersed, is 0.258 N/m².