黄土坡面径流水动力过程试验研究

Experimental Study on Hydro-dynamic Process of Overland Flow on Loess Slope

通过室内坡面径流冲刷试验对坡面流水动力过程进行研究,分析坡面流水动力要素过程变化规律。结果表明:在不同坡度情况下,坡面平均流速随时间的变化过程可以划分为增加、减小、波动平衡状态3个不同的阶段;坡面坡度越大则坡面平均流速随时间的变化过程的阶段性越明显;在不同的坡度情况下,整个坡面、整个试验过程的平均水深和平均流速总体随着流量的增大而增大;在同一坡度下,坡面平均水深和平均流速并非随流量的增加而线性增加,其随时间过程线具有波动性,存在着相互交叉的现象;在不同的坡度情况下,坡面各断面平均流速总体有沿程增大的趋势;在同一坡度下,坡面平均流速并非沿程线性增加,坡面平均流速沿程分布线具有波动性,存在着相互交叉的现象。

Through the scouring experiment on loess slope,the hydro-dynamic process was studied and the changing process of the overland flow velocity and depth was analyzed.The results demonstrated that the change process of the mean of overland flow velocity could be divided to three different stages：Increase,reduce and balance.The stages became more obvious with increasing slope.The mean of overland flow velocity and depth increased with discharge raise under different slopes.Under the same slope the average value of overland flow velocity and depth increased nonlinearly with the increase of discharge.Its process curve existed the phenomenon of volatility and cross-cutting.Under different slopes the mean of cross section velocity had the increasing trend from top to bottom on loess slope.Under same slope cross sectional velocity did not increase linearly along the way,its distribution lines along the slope showed the phenomenon of cross-cutting and volatility.