黄土坡面汇流汇沙对浅沟侵蚀影响的试验研究

Experimental Study on Upslope Runoff Effects on Ephemeral Gully Erosion Processes at Loessial Hillslope

采用供沙土槽与试验土槽双土槽径流小区的人工模拟降雨试验,研究了不同含沙水流、不同降雨条件下坡面汇水汇沙对浅沟侵蚀过程的影响。结果表明,坡面浅沟侵蚀过程以侵蚀-搬运过程为主,当雨强为64mm/h和116mm/h时,坡面汇水使坡下方浅沟侵蚀产沙量分别增大26.2%～82.5%和23.5%～58.7%,坡面汇水引起坡下方的净侵蚀产沙量随坡面汇水含沙量的减小和降雨强度的增加而增大。

A dual-box system(one was the test box located at the downslope and the other was the feeder box located at the upslope)was used to quantify effect of up-slope runoff and sediment on down-slope ephemeral gully erosion process under different sediment concentrations from up-slope runoff and rainfall intensities. The results showed erosion-transport process with ephemeral gully slope was dominated. The sediment delivery caused by up-slope runoff increasd by 26.2%～82.5% and 23.5%～58.7% when rainfall increased from 64 mm/h to 116 mm/h. The sediment delivery caused by up-slope runoff increased with a decrease of sediment concentration and an increase of rainfall intensity.