论文部分内容阅读
采用间歇性室内人工模拟降雨试验,对15°黄土坡面细沟侵蚀动态发育时空分布规律及其水力学特性进行了研究。结果表明:细沟侵蚀过程为溅蚀-片蚀-跌坑-断续细沟-连续细沟-细沟崩塌,沟长发育迅速,沟宽和沟深发育相对缓慢。5场降雨结束,细沟平面密度、最长沟长、沟宽、沟深较发育初期分别增加了2.5倍、10.2倍、0.8倍和1.6倍;随着降雨历时的增加,坡面流速、水深、雷诺数都呈增加趋势,伴有较小波动;细沟内流速增长平稳,而细沟内水深与雷诺数呈波动性增长。弗劳德数波动较大,但随降雨场次的增加而增加。颗粒阻力与降雨阻力随降雨时间增加而减小,形态阻力随降雨场次增加而增大,叠加阻力前两场降雨波动较大,第三场降雨达到最小,后两场降雨又有所增加,最终稳定。前两场降雨,颗粒阻力占主导地位,后两场降雨,形态阻力成为主导阻力。
The intermittent indoor simulated rainfall experiment was used to study the spatiotemporal distribution and dynamics of rill erosion on 15 ° loess slope. The results show that the process of erosion is eroded - eclogite - eclogite - intermittent rill - continuous rill - rill collapse, with rapid development of groove length and relatively slow development of groove width and groove depth. At the end of the five rainfall events, the density of the rill, the longest gully, the width of the gully and the depth of the furrow increased 2.5 times, 10.2 times, 0.8 times and 1.6 times, respectively. With the increase of rainfall duration, , The Reynolds number showed an increasing trend with minor fluctuations; the flow velocity in the fine groove increased steadily while the water depth and Reynolds number in the fine groove showed a fluctuating increase. The Froude number fluctuated greatly, but increased with the increase of rainfall episode. The particle resistance and the rainfall resistance decreased with the increase of the rainfall time. The morphological resistance increased with the increase of the rainfall duration. The rainfall of the first two races had a great fluctuation, the third rained the smallest and the last two rains increased. Finally, stable. The first two rains, particle resistance dominant, the last two rains, form resistance as the dominant resistance.