黄土坡面坡长对侵蚀一搬运过程的影响研究

Effects of Slope Length on Detachment and Transport Processes on a Loessial Hillslope

通过不同降雨强度的模拟降雨试验,研究了15°时坡面坡长对黄土坡面侵蚀—搬运过程的影响。结果表明,坡面径流量随坡长的增加而增加,在50和75 mm/h降雨强度下,坡面径流量随坡长增加的幅度基本相同。在100 mm/h降雨强度下,当坡长小于5 m时,坡面径流量随坡长的增加幅度较小,而当坡长大于5 m时,坡面径流量随坡长增加的速率明显增大。在8 m坡长内,坡面侵蚀量随坡长变化呈波状起伏的交替变化;随坡长增加,坡面侵蚀现象呈现以侵蚀—搬运过程为主与以侵蚀—沉积过程为主的交替现象。

Effects of slope length on detachment and transport processes on a 15° loessial hillslope were quantitatively studied by using simulated rainfall of different intensities. Results showed that runoff discharge increased with an increase in slope gradient. At the 50 and 75 mm/h rainfall intensities, the increment of runoff discharge with an increase in slope length was approximately the same. At the 100.mm/h rainfall intensity, the increment of runoff discharge decreased for the 〈 5 m slope length, but for the 〉 5 m slope length, runoff discharge remarkably increased with an increase in slope length. Sediment yield was fluctuated obviously for the 8 m slope length. Sediment regime was characterized by an alternation of detachment-transport dominated and detachment- depo sitio n dominated.