不同草带空间分布对坡面细沟侵蚀调控机制

为了研究植被对坡面细沟侵蚀调控机制,采用模拟降雨试验,结合激光扫描方法,分析了不同草带分布沟坡面细沟侵蚀发生、发展过程。结果表明:草带位于梁峁坡下部60%,植被调控侵蚀效果最优,相比裸坡减少径流量7.4%,减少产沙量62.9%,相比蓄水减沙功效而言更具直接拦沙的功能。植被通过调控细沟侵蚀的发生、发展、发育过程实现了对土壤侵蚀的调控作用,尤其是对沟坡侵蚀产沙的调控作用;而且这种对侵蚀的调控作用不仅改变了细沟侵蚀发生的位置,而且改变了径流和侵蚀过程以及侵蚀方式;细沟侵蚀已经向面蚀(片蚀)转化,大幅度降低侵蚀程度。研究结果揭示了植被可以通过影响侵蚀方式来调控侵蚀输沙过程,有助于加深坡面植被对细沟侵蚀发育形态作用机理的理解。

Regulation Mechanisms of Different Spatial Distributions of Grass Belts on Slope Rill Erosion

In order to study the regulation mechanisms of vegetation on rill erosion in a slope, the occurrence and development process of rill erosion with different grass spatial distributions were studied by artificial rainfall simulator and three-dimensional scanning technology. The results showed that the grass strip positioned at about 60% of the hillslope length from the top could fully exhibit its regulation effect on erosion by reducing the runoff and sediment by 7.4% and 62.9% respectively compared with bare slope. The grass strip showed direct sediment interception more than its water storage function. The regulation of vegetation on soil erosion was realized by regulating the rill formation, development and density in a slope, especially at the gully-slope. Moreover, vegetation not only changed the occurrence position of rill erosion, but also changed the erosion process and erosion pattern, the degree of erosion was greatly reduced with rill erosion transforming into sheet erosion. The information indicated that vegetation can regulate the erosion sedimentation processes by affecting the erosion pattern, and the results can be useful for better understanding the effect of vegetation configuration on rill erosion development morphology in a slope.