Study On Reconstruction Of Rainwater System In Residential Area Based On LID

The rapid development of urbanization directly led to changes in the nature of theunderlying surface of the city. The increase of impervious surface area affected the hydrological cycle of the original city. The peak flow increased, the time of flood peak appeared earlier and the water quality of runoff was affected. In recent years, the major cities like Beijing Wuhan suffered a lot from domestic waterlogging disasters,which is a serious threat to people's lives and property.This paper starts with the concept of low impact development(LID) and sponge city,introduces the current situation and difficulties of domestic and foreign drainage system, and puts forward a method to rebuild the rainwater system of residential area based on low impact development. Surface runoff, and reduce the pressure of pipe network, and the direction of the application of various LID technical measures were divided, to the future project to provide a reference for the selection of technical measures.Based on the Storm water management model(SWMM), the construction method of the hydraulic model of the pipe network is introduced, including the generalization of the study area, the selection of the runoff, the confluence and the infiltration model, and the selection of the model parameters. The model mechanism and parameter selection range of LID module in SWMM software are introduced, and theoretical support is provided to the reconstruction method.Finally, the selection of the existing residential district of Tongshuwang village,Zhengdong New District, the effect of the transformation method validation. The existing rainwater pipe network and the reconstructed rainwater pipe network model were established,and the precipitation of 0.5a, 1a, 3a, 5a, 10 a were simulated. The surface runoff and rainwater pipe network were simulated after the precipitation was simulated. Flow condition and pipe network load. Through the comparison of output data, it can be concluded that the LID transformation can obviously reduce the surface runoff and reduce the pressure of the pipe network.The main results are as follows:1. By analyzing the current situation and predicament of drainage system and combining with the concept of low-impact development, this paper puts forward the method ofreconstructing rainwater in residential area based on low-impact development, that is,reducing the surface runoff by adding LID technique.2.The SWMM software is used to establish the rainwater reconstruction model for the residential area. The method and the selection principle of the model are introduced, which provide a theoretical basis for the practical application.3.Based on the reconstruction of Tongshuwang village in Zhengdong New Area, a rainwater model was established, which proved that the low-impact development technique could reduce the surface runoff and delayed the arrival time of flood peak. From the source control and reduction of urban waterlogging.4.It is proved that by adding LID technical measures, the drainage capacity of residential area can be improved without changing the existing pipe network, and the waterlogging threat caused by heavy rain can be reduced obviously.