扩散波模型在城市坡面汇流中的应用

为分析一维扩散波水动力方程在模拟城市地表降雨径流过程中的可行性,针对典型概化城市流域,采用一维扩散波水动力方程的数值解法模拟了一短历时强降雨事件,并对比SWMM模型模拟结果与扩散波模型模拟结果。结果表明,扩散波模型可以较好地体现降雨作用下地表径流过程的动力特点,但无法适用于过缓的地表坡度,解释了两者连续性方程的差异对模拟结果的影响,最后分析了扩散波模型下边界条件的确定方法。研究成果可为城市坡面汇流模拟提供参考。

Application of Diffusion Wave Model in Urban Surface Runoff

In order to analyze the feasibility of one-dimensional diffusive wave hydrodynamic equation in simulating urban surface rainfall runoff process, the numerical solution method of one-dimensional diffusive wave hydrodynamic equation was used to simulate a short duration and heavy rainfall event for the typical generalization of urban watershed. And then the simulation results of the diffusion wave model (DWM) was compared by using SWMM model. The results show that the DWM can reflect the dynamic characteristics of surface runoff process under rainfall, but it could not be applied to the surface slope with excessive slowness. The impact of the difference between the two continuity equations on the simulation results was explained. Finally, the determination method of downstream boundary condition of DWM was analyzed. The research results can provide reference for the simulation of urban surface runoff.