牧草对坡面侵蚀动力参数的影响

通过室内模拟降雨试验，研究了不同盖度草地与裸地坡面的产流产沙过程与坡面流水动力学特性。试验结果表明，与裸地坡面相比，草地坡面的含沙量、平均输沙率、径流量以及坡面流速均有不同程度的降低。草地坡面的平均输沙率及坡面流速随草地盖度的增大而减小，而盖度对草地坡面径流量的影响则不明显。裸地坡面的输沙率随降雨历时呈高一低一高变化，而草地坡面的输沙率则随降雨历时呈幂函数递减。试验中坡面径流的弗劳德Fr数和雷诺Re数均属层流的缓流范畴。草地坡面的Darcv-weisbach和曼宁阻力系数随草地盖度的增大而增大，其值均大于裸地坡面相应的阻力系数。

Influence of forage grass on hydrodynamic characteristics of slope erosion

The generation process of runoff and sediment erosion and the hydrodynamic characteristics of flow on forage grass slope with different coverage are quantitatively studied in laboratory. The gradient of the slope being studied is 15°. The results show that the grass with different coverage will significantly reduce the sediment concentration, average sediment yield rate, runoff and flow velocity generated on the slope. The average sediment yield rate and flow velocity decrease with the increase of coverage, but the influence of coverage on runoff is not remarkable. The sediment yield rate of forage grass slope decreases with the duration of rainfall following a relationship of exponential law. The flow regime on the slope is tranquil and laminar. The flow resistance coefficient of forage grass slope increases with the increase of coverage, which is much higher than that of the slope without grass.