Storm Sewer Network Hydrodynamic Simulation And Urban Storm Waterlogging Analysis

Urban storm water disaster and waterlogging which give rise to seriously impacts of social and economic development and life and property security of the people frequently occurred with global climate change and urbanization process advancement in recent years. The higher intensities and shorter duration storm as well as continuously decrease of urban nature catchment area bring a lot of pressure on urban storm sewer networks, so it is great significant of studying the hydrodynamic process of sewer networks and storm waterlogging development process for scientific sewer networks planning and early warning of storm disaster.Based on the pipe network hydrodynamic model and water balance principle, the paper builds mathematics’relationship between storm sewer network and storm waterlogging, respectively by referring to previous researches and engineering demands. And then, the developed model is applied to simulate the hydrodynamic process of sewer network and storm waterlogging development and it can bring convenience for guarding against and reducing storm disaster.The stagger mesh and implicit method is used to discrete the model equations, which can guarantee the conservativeness and stability of the discrete scheme. The upwind interpolation method is employed at advection term in the kinematic equation to improve its ability to simulate complex flow problems. And the model equations is resolved by the fractional step method which makes the solving variables concentrate on the branching and boundary points through recursion relations, the method improves the computational efficiency obviously. The fourth rank Rounge-kutta method is adopted for the water balance equation. After a series of typical numerical examples verifications, the model was applied to certain storm sewer networks engineering project, which simulated the hydrodynamic process of sewer networks and waterlogging depth, inundated area and its duration at any position under storm and downstream tide combined conditions, the results can be as the basis of sewer networks design and strategic decisions.