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草被覆盖是影响坡面流流速变化过程及特征的重要因素之一。研究草被覆盖下坡面流流速时空分布特征,对揭示草被减蚀作用机理有重要作用。该文通过室内放水冲刷试验研究了黄土丘陵区坡沟系统坡面不同草被覆盖对坡面流流速变化过程及特征的影响。试验中共涉及坡沟系统坡面5种草被覆盖度、3种空间配置和2种放水冲刷流量。研究结果表明:放水流量为3.2 L/m in时,坡面草被覆盖对坡面流流速的延缓作用较大;流量为5.2 L/m in时作用相对减弱;坡面及沟坡平均流速随坡面草被覆盖度的增加呈指数下降趋势。坡面流流速在坡面的发展有一个坡长范围,试验中,在距坡顶3~4 m处,坡面流流速达到最大;坡面、沟坡各断面流速基本上都随着放水冲刷时间的延长而呈下降趋势。
Grass cover is one of the important factors that affect the process and characteristics of flow velocity variation in slope flow. Studying the spatiotemporal distribution characteristics of the flow velocity over the slope covered by grass plays an important role in revealing the mechanism by which the grass is eroded. In this paper, the effects of different grass coverings on slope flow velocity and process characteristics are studied through the indoor scouring test in loess hilly region. In the experiment, five types of grass cover, three kinds of space configuration and two kinds of drainage scouring flow were involved in slope system. The results show that: when the water discharge rate is 3.2 L / m in, the delaying action of grass cover on slope flow velocity is larger; the effect is weaker when the flow rate is 5.2 L / m in; The increase of grass coverage on the slope shows an exponential declining trend. In the experiment, the flow velocity reached the maximum at 3 ~ 4 m from the top of slope, and the flow velocity at each section of slope and gully slope was basically the same with the scouring The decline of the time showed a downward trend.