城市洪涝仿真模型地下排水计算方法的改进

为了增强对城市地下排水的模拟能力,获取更为详细的计算结果信息,提高城市洪涝分析水平,对现有洪涝仿真模型的地下排水计算进行了改进,提出在同一模型中对排水管网采用简化和细化相结合的计算方式。简化计算采用等效体积法实现,细化计算采用建立真实管网的一维动力波方程实现,并在特殊道路通道和网格上实现地上、地下水流交换。同时,在降雨产流计算中考虑地面透水性,形成了面向城市降雨产、汇流和排水的洪涝全过程模拟模型。改进后的模型对地下排水的模拟适用性更强,计算结果更为丰富,提高了区间暴雨导致的城市洪涝模拟能力。文中以上海市蕴南控制片洪涝分析计算为例,说明改进模型可获得较好的应用效果。

Improvement of underground drainage computation method for urban flood simulation model

In order to strengthen the simulation capacity of urban underground drainage,acquiring more de-tailed results and improving analysis level on urban flooding, this paper describes an improved method for underground drainage computation based on the Urban Flood Simulation Model. A sub module combining both simplified and detailed pipe network compute is proposed, which adopts equivalent volume approach and 1D hydrodynamic equation of actual pipe network respectively for computing underground drainage,and the flow exchange position of overland and underground is set at special road passages and grids. For rain-fall-runoff, surface water permeability of each land use type is considered in hydrologic module. Through coupling these sub compute modules, the improved model is capable to simulate the whole process of ur-ban flooding, including rainfall-runoff, flowing concentration and drainage, which is more suitable to simu-late urban flooding caused by local storms. Yunnan control region in Shanghai Municipality is taken as an example to carry out demonstration research, which shows that a satisfactory simulation effect and more abundant results can be achieved.