基于动力波法的高效高分辨率城市雨洪过程数值模型

High-performance numerical model for high-resolution urban rainfall-runoff process based on dynamic wave method

基于物理定律的动力波方法,提出了高效高分辨率城市雨洪过程数值模型。该模型采用Godunov格式的有限体积法数值求解二维浅水方程,输入可表征真实城市地表的高分辨率地形数据,以精确模拟城市降雨径流及内涝积水过程。同时引入图形处理器(GPU)加速计算技术,在不降低精度的条件下大幅提升计算速度。并将模型用于模拟陕西省西咸新区内涝积水过程,发现计算结果与实测数据吻合度高,五处积水面积均实现较为精确地计算。证明该模型可快速准确模拟较大范围高分辨率城市雨洪过程,且能提供分析涝灾成因及计算污染物输移的流速,克服了常规水文模型的缺陷。可见,研究对指导城市规划及可持续性城市雨洪管理如海绵城市建设具有重要的应用价值。

Based on the dynamic wave method, a high-performance numerical model for high-resolution urban rainfall-runoff process is presented in this paper. This high resolution digital elevation model （DEM） is in the framework of a Godunov-type finite volume scheme to solve the shallow water equations （SWEs）. Aimed at accurate prediction of urban rainfall-runoff and inundation process, it resolves the realistic features of urban terrain and uses a Graphic Processing Units （GPU） parallel computing technique to accelerate calculation. Validation results by modeling the Xixian new area in Shaanxi indicate that our model is reliable and efficient in accurate calculations of all the five inundation spots and gives detailed flow velocities for analysis of the causes of inundation and the pollutant transport process, useful for urban planning and storm water management.