中文摘要：

利用人工模拟降雨试验,定量研究了不同降雨强度下20°陡坡面灌木的减流减沙效应,探讨了灌木保持水土作用的水力学机理。结果表明：在45、90和130 mm/h降雨强度下,灌木地坡面土壤的平均入渗率是裸地坡面入渗率的2.9～4.7倍;与裸地相比,灌木地径流流速减少59.4%～81.9%,径流量减少61.7%～80.6%,产沙量减少95.5%～99.3%;断面比能参数可表征为侵蚀产沙的主导因子,灌木地临界断面比能值为0.13cm,裸地临界断面比能值为0.074cm。研究结果对定量评价灌木减流减沙作用有一定的参考意义。

英文摘要：

Effect of shrubs on runoff and sediment reduction and its hydrodynamic mechanism were studied on a 20° slope using simulated rainfall experiment. The results show that the soil infiltration rate of the shrub slope is 2.9 -4.7 times higher than that of the bare slope under rainfall intensities of 45, 90 and 130 mm/h, respectively. Compared with those on the bare slope, the flow velocity, runoff and sediment yield on the shrub slope are decreased by 59.4% -81.9% , 61.7% -80.6% and 95.5% -99.3% , respectively. The hydrau- lic parameter of unit flow energy can be used as a dominant indicator for predicting the sediment yield. The critical unit flow energy of the bare slope and of the shrub slope is 0. 074 cm and 0. 13 cm, respectively. The experimental results are meaningful for quantifying effects of shrubs on reducing runoff and sediment yield.