Simulation And Evaluation Of Plan On Urban Storm Water Drainage System Based On Sponge City Concept

With rapid urbanization progress in China, the hydrology balance was destroyed in regional scale. Problems such as water scarcity, rainwater loss, rainstorm and flood disasters in the cities need to be solved during the development progress of cities. Thus, the cutting-edge concept of ?Sponge City? was brought forward. The core of Sponge City Concept is to deal with urban rainwater problems, so that the city could adapt to changes in environment by itself, and be resilient to natural calamities.In this paper, firstly, the implication, the key issues and the main related technologies were discussed. The effects of reducing runoff, the merits and drawbacks, and the application conditions of Low Impact Development technologies, propulsion pipes and deep tunnel were analyzed and compared comprehensively by literature review methodology.Secondly, the background and the present hydrology condition of the study area were introduced. Modeling of the present stormwater system of the study area was developed in Infoworks ICM software based on related data. In order to discuss the application of the Sponge City Concept, according to the modeling results of the present stormwater system under different rainfall intensity and different rainfall pattern, three optimization plans were developed: the LID plan, the propulsion pipes plan, and the deep tunnel plan. Modeling results of the three optimization plans under rainfall events in different rainfall intensity and different rainfall patterns were analyzed and compared with the modeling results of the original storm water system, in terms of volume of runoff, effects of reducing runoff, time parameters of runoff. Drainage ability of the stormwater system in the whole study area was assessed under three plans.Finally, using Fuzzy Analytic Hierarchy Process(FAHP) methodology, initial evaluation system was built in order to evaluate the optimization plans comprehensively, taking into account of environmental factors, economic factors, and social factors. Thus, the results of this study would provide some insights for the discussion and practice of Sponge City Concept.