Review and Optimization of Carrying Capacity of Urban Drainage System Based on ArcGIS and SWMM Model

Abstract

With the rapid process of urbanization, the city flood problem mainly characterized by waterlogging and its hazard are becoming serious. And it has become the most urgent security matter in the world. Simulation of drainage pipe network by mathematic model is an effective measure to help manage urban drainage system. The emphasis and difficulty of land surface runoff model establishment can be the complication of surface characteristics, and the accuracy of surface characteristics directly influences the results of urban storm flooding simulation. A generalized model of pipeline network is developed in this chapter, in combination with critical data of remote sense, urban plan, as well as hydrologic. Using geoprocessing and analyzing statics model on ArcGIS, we get fundamental parameters like average slope of catchments areas and the rate of imperious area for Storm Water Management Model (SWMM). The design rainfall process is calculated by using formula of Chicago rainfall pattern and Kaifeng rainfall pattern as rainfall data of the generalized model, and the calibration of model parameters is based on objective function calibrated by runoff coefficient. This study simulated rainfall waterlogging of the generalized model in different return periods over planned area and selected representative waterlogged point to optimally analyze on the rate of imperious area of upper catchments areas as well as the design standard of lower drainage pipeline, respectively. The results show that changing the rate of imperious area of upper catchments areas makes little difference for the coming time of flood peak, but the effect on flood peak discharge is considerable. Peak flow velocity of pipeline is significantly decreasing and the coming time of flood peak is delaying in larger size pipelines. Both decreasing the rate of imperious area of upper catchments areas and stepping pipeline of lower drainage can effectively reduce frequency of waterlogging and location of water. The method coupling technical such as ArcGIS and SWMM can extract data of spatial structure and attributes in urban drainage system accurately and quickly, where analysis of simulated results and theories can be interactive. It fully simulates the generation of urban storm flood and can help forewarn potential threatened area of flooding risk, further to provide the reliable basis to make scientific decision of urban flood control and hazard mitigation.