降雨-径流-渗流耦合作用下边坡流场研究

Study on Slope Flow Field Under Coupling Interaction of Rainfall-runoff-seepage

降雨会影响边坡流场特性,由于流体的连续性,坡表径流和坡体渗流通常存在耦合联动现象。其中,坡表径流由N-S方程描述,坡内渗流采用Darcy定律描述。在速度滑移水-土界面边界条件下,通过分离变量法推导出流速分布、压强和流量的解析解及径流水面线的半解析解。此外,采用显式龙格-库塔方法求出不同位置的水深、流速和流量值。结果发现,边坡越陡,流体运动越快且水深越浅;降雨强度越大,整体水深越深;坡表处流速不等于0;且越靠近下游,径流量的占比越大。研究结果可为边坡流场特性研究提供参考。

Rainfall will affect the characteristics of slope flow field.Due to the continuous flow of fluid,the surface runoff and slope seepage usually exist a coupling linkage phenomenon.The surface runoff is described by the N-S equation,while the Darcy's law is used to describe the seepage in the slope.The analytical solutions of velocity distribution,pressure and discharge as well as the semi-analytical solution of runoff surface line are derived by the separation of variables method under the velocity slipping boundary condition at the interface between runoff and soil.In addition,the explicit Runge-Kutta method is adopted to solve the water depth,velocity and discharge values at different locations.The results show that the steeper the slope is,the faster the fluid movement and the shallower the water depth is.The greater the rainfall intensity is,the deeper the overall water depth is.The flow velocity at the slope surface is not equal to 0.The closer to the downstream,the larger the proportion of runoff flow discharge is.The study can provide reference for the research of the slope flow field characteristics.