中文摘要：

为深入研究植被的水土保持效益,本文通过5个覆盖度,6个坡度和7个流量的组合条件下室内放水试验,研究相对流速,相对水深,相对弗劳德数和相对阻力系数等相对水动力学参数,结果表明：随植被覆盖度和流量增加,相对流速和相对水深均增加,植被减流效果增强,覆盖度分界点为4.650%,且植被覆盖度对相对流速的影响与流量有关,而坡度对二者影响甚微;相对弗劳德数随植被覆盖度和流量增加而增大,植被削弱坡面流侵蚀能力越强,覆盖度分界点与流速一致;相对阻力系数随相对水深的增加呈线性增大。本文为植被措施的选择和植被减水减沙效益评估提供参考。

英文摘要：

To obtain an in-depth understanding of vegetation benefit in basin soil and water conservation, we have conducted laboratory tests on various relative hydrodynamics of overland flows - relative flow velocity, relative flow depth, relative Froude number, and relative resistance coefficient - using combinations of six slopes, seven flow discharges, and five types of vegetation coverage. The results show that as vegetation coverage or flow rate increases, both relative flow velocity and relative flow depth are increased and the vegetation effect in reducing flow velocity is enhanced. And the variation trends in both manifest a cut-off coverage of 4.7%. The vegetation effect on relative flow velocity depends much on flow rate but little on land slope, and flow rate are also independent of land slope. An increase in vegetation coverage or flow rate causes a higher relative Froude number and a greater capability of vegetation to weaken overland flow erosion. Relative resistance coefficient grows linearly with an increasing relative flow depth. This study would help the choice of vegetation measures and assessment of vegetation benefits in water conservation and sediment reduction.