黄土陡坡径流侵蚀产沙特性室内实验研究

通过室内土槽放水冲刷实验，研究了黄土区陡坡侵蚀产沙特性。结果表明径流输沙率随径流流量的增加而增加，径流输沙率随坡度呈抛物线形式变化，当坡度在21°～24°之间时输沙率最大；径流剪切力也具有类似变化。泥沙输移率与径流剪切力之间存在线性关系，径流临界剪切力为1.701 N/(m²·min)，发生细沟侵蚀的临界径流水深与坡度正弦值成反比。在实验条件下，坡面中上部土壤的侵蚀量占总侵蚀量的很大比重，表明土壤侵蚀主要发生在坡面中上部。坡面下部侵蚀微弱，以搬运上部来沙为主。

Indoor experiment of characteristics of runoff erosion in loess steep slope

The flume scouring experiment indoors was conducted to study the runoff erosion characteristics in loess slope. Results showed that the sediment transportation ratio increased with the discharge of flow increased and changed in parabola form with the slope gradient. The sediment transportation ratio reaches the maximum value when slope gradient is between 21°and 24°. The flow shear stress had the same trend. Linear relationship existed between sediment transportation ratio and shear stress, and critical shear stress of the flow was 1.701 N/(m²·min), consequently the critical flow depth for the occurrence of rill erosion had inverse ratio with the sine value of slope gradient. In this experiment, the sediment mostly came from the middle and the top parts of the slope, while had little erosion in the below part of slope, which was only transported the sediment from the up-slope.