Improvement of underground drainage computation method for urban flood simulation model

In order to strengthen the simulation capacity of urban underground drainage, acquiring more detailed 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 rainfall-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 urban flooding, including rainfall-runoff, flowing concentration and drainage, which is more suitable to simulate 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. © 2017, China Water Power Press. All right reserved.