Simulation of Urban Rainstorm Waterlogging with Bidirectional Coupling of One-Dimensional Sewer Network and Two-Dimensional Surface

Abstract:

To quickly and accurately simulate the evolution process of urban rainstorm waterlogging， a dynamic interaction method between underground sewer network and above surface was proposed， and a bidirectional coupling model of SWMM /LISFLOOD-FP was constructed to solve the two-way flow exchange and time synchronization problems. Taking the Waigaoqiao area of Shanghai as an example， the coupling model was calibrated and verified using two short-duration rainfall processes， and the simulation results of unidirectional and bidirectional coupling models were compared and analyzed. The results show that the bidirectional coupling model has a higher simulation accuracy and a better applicability in the study area. For the mild （<0.2 m） waterlogged area that accounts for more than 80 % of the submerged area， the ratio of simulated waterlogged area between unidirectional and bidirectional coupling models is 1.21. However， for moderate （0.2-0.3 m） and heavy （>0.3 m） waterlogged areas， the unidirectional coupling simulations tend to overestimate， and the ratios increase to 1.88 and 2.1， respectively. The bidirectional coupling model can effectively reveal the whole process of urban stormwater accumulation， diffusion and regression， which can be used for urban rainstorm waterlogging simulation and inference， and provide scientific basis for waterlogging control and disaster prevention.

Key words:urban rainstorm waterlogging;sewer network;bidirectional coupling;flow exchange;time synchronization