Risk Assessment Of Waterlogging And Hydraulic Simulation Of Urban Drainage Network

In recent years, many cities of China were affected by waterlogging disasters. Urban waterlogging was frequently happened in many cities, which have a large impact on people’s lives and productivities, as well as the development of social economy and the city. Therefore, it’s necessary to apply modern computer technology and urban stormwater drainage model to establish urban rainstorm and waterlogging model system. This system can help to simulate the position and condition, and to assess the risk, 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.This paper takes the main area of Haikou city. Based on InfoWorks ICM model to build the integrated catchment drainage network hydraulic model of Haikou city, after the basic data were processed by ArcGIS. The principal results are summarized as follows.(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 research methods of waterlogging problem and introduced three main ways of waterlogging-risk assessment and the research status.(2) Framework of InfoWorks ICM model was studied. Meanwhile, this paper elaborated the calculation principle and methods of the model including the calculation methods of surface rainfall runoff, pipe flow transmission and surface of city waterlogging simulation.(3) The city’s comprehensive overview of the study area was introduced. The causes of waterlogging disaster were analyzed and summarized after investigating the waterlogging disasters in the study area.(4) This paper described the data and related data processing methods needed for model building. InfoWorks ICM model of the study area was constructed. In addition, this paper also elaborated InfoWorks ICM modeling steps, including the 1D model, 2D model, and coupled 1D-2D model.(5) Based on the InfoWorks ICM model which has been established, using real stormwater data and investigation results of related waterlogging disasters validating the model. While the author analyzed the results of node flooding, conduit surcharge, outfall flow and flooding area, submerged depth. The study showed that the model has a certain accuracy and reliability.(6) Using scenario simulation method, based, 1a, 2a, 5a, 10 a, 20 a, five different design frequency rainstorm model calculations, considering two factors, submerged depth and flooding time, to assess waterlogging risk of the study area. And, in order to visualize the performance of waterlogging risk profile of the study area, the author drew waterlogging-risk map of five different frequency design storms.