二维坡面雨洪水动力模型研究

由降雨产生的坡面洪水运动过程复杂,其可靠模拟仍有待深入。该文建立了基于浅水方程的二维坡面雨洪动力过程模拟的动力波模型,选用单坡、三阶坡面和复杂起伏多变坡面的雨洪运动为数值算例,进行了数值检验并与忽略惯性项的扩散波模型进行了对比分析。结果表明:动力波模型可以较好地模拟洪水过程,在峰现时间,洪峰水位的捕捉和退水过程等方面都表现出优良的特性;而且动力波模型在复杂坡面雨洪过程计算的适应性方面表现更佳。而扩散波模型在计算精度和稳定性方面都相对要差。虽然扩散波模型在单坡面算例中的计算精度也较高,但因受忽略惯性项的影响,退水过程有明显偏离。

Numerical study of two-dimensional hydrodynamic model for overland flood

The process of overland flood propagation caused by rainfall is complex,its reliable simulation remains to be further investigated.A two-dimensional hydrodynamic model,based on the fully dynamic shallow water equations,is developed to simulate the overland flood propagation in this paper.Inorder to conduct a numerical test and compare with diffusion wave model ignoring the inertia item,a single plane,a cascade of three planes,complicated and changeable overland flood propagation as examples of numerical simulation are selected.The results show that the full dynamic wave model can well simulate the overland flood process.It exhibits excellent properties in simulating peak time,capturing peak stage and describing recession process.The full dynamic wave model also have better performances in overland flood simulation over complicated terrain.However,the prediction accuracy and calculation stability of diffusion wave model are relatively poor.Although the diffusion wave model has a high accuracy in simulating flood propagation of a single plane,but the recession limb of it has obvious deviation due to the influence of the inertia item.