Hydraulic Calculation Of Drainage Network And Simulation Method Of Storm Waterlogging Study

In recent years, urbanization is developing rapidly in China. Urban waterlogging was frequently happened in many cities, which has a large impact on people’s lives and productivities. The reason is that short term heavy rainfall is increasing, the design criterion of urban drainage system is at low level and daily management of drainage network is lag. Therefore, it’s necessary to apply modern computer technology to establish urban rainstorm and waterlogging model system. This system can help to simulate the position and condition of storm waterlogging in urban areas, which provide decision makers with scientific evidence for flood control and rush emergency, and reduce loss of life and property made by flood disaster maximally.Based on predecessors’ study, this paper comprehensively applied GIS technology to build SWMM drainage network hydraulic model and build a warning and forecasting system of storm waterlogging in Haidian island, Haikou city, which based on Arc GIS Engine. The main results are summarized as follow.(1)This paper summarized the research status and common theoretical method of computation of urban rainfall runoff model at home and abroad. It also introduced the application status of the integrated technology of GIS and urban rainfall runoff model.(2)Framework of SWMM drainage network hydraulic model was studied. Meanwhile, this paper elaborated the calculation principle and methods of model including the calculation methods of surface rainfall-runoff, pipe flow transmission and surface waterlogging simulation.(3)Used in the SWMM modeling process, drainage network and underlying surface data processing methods were summarized, including generating vector data of junctions and pipeline, the tools, methods, steps of checking pipe network, the generalization of underlying surface,and important parameters calculated.(4) This paper generalized the advantages and ways of the integration of SWMM model and GIS.Then the autor proposed the calculation method of storm waterlogging and the development framework of the warning and forecasting system, so that the surface waterlogging could be calculated.(5) Through generalizing the drainage system and underlying surface, this paper constructed the SWMM model of Haidian island, Haikou city. Then the model was verified by observed rainfall and designed storms. While the author analyzed the results of node flooding, conduit surcharge and outfall flow.The study showed that the model has a certain accuracy and reliability.(6) Based on SWMM model and Arc GIS Engine, the warning and forecasting system of urban storm waterlogging in Haidian island was built. It had rich functions and could meet the most requirements of result query. Besides, the system simulated the waterlogging depth and range of study area under different rainfall conditions. And the simulated results were in conformity with the actual waterlogging situations, which proved that the calculation method of storm waterlogging was reasonable and practical.