Research On The Optimization Of Low-impact Development Schemes In Residential Areas Based On SWMM Mode

In recent years,China’s industrialization and urbanization have accelerated,resulting in changes in the permeability of urban underlying surfaces.At the same time,global climate change has greatly increased the possibility of extreme rainstorm disasters,further exacerbating the severity of my country’s urban waterlogging problem.To alleviate this situation,China has proposed the concept of "sponge city",which aims to reduce urban waterlogging by adopting low-impact development measures(LID).However,there is still a lack of systematic studies to evaluate the effectiveness and applicability of LID measures for urban waterlogging.At the same time,as an important tool for urban hydrological simulation,the SWMM model has difficulties in displaying the submerged range and depth,which has triggered further research needs.This paper expounds in detail the basic principles,components and parameters required for the modeling process of the SWMM model,and describes the basic situation of the geographic information system(GIS).On this basis,the paper establishes hydrological models through various software through detailed analysis of topography,meteorological environment and hydrogeological conditions in the research area.This paper analyzes and evaluates the runoff and node overflow in the undeveloped state of the study area.At the same time,in accordance with the requirements of relevant regulations and local planning,the LID layout scenario was simulated,and the runoff and node overflow conditions before and after the development of the LID in the study area were further analyzed.The three LID combination schemes designed can significantly reduce the peak and flow.Under the rainfall scenario with a small return period,the control effect of LID on runoff is more significant.The SWMM model has the disadvantage of being difficult to visually display the submerged range and submerged depth,and existing studies often use the overload depth of nodes to replace the submerged depth of catchment areas,which has certain problems.In order to solve these problems,this paper adopts the one-way coupling of LISFLOOD-FP model and SWMM model to realize the visual display of submerged range and depth.By comparing the simulation results under different return periods,the submerged range and depth before and after the renovation are effectively displayed.Through the comprehensive application of SWMM model and LISFLOOD-FP model,this paper supports the construction of sponge city from the scientific level.The research results are of great significance for solving the urban waterlogging problem and improving the urban ecological environment,and also provide useful reference and guidance for the theory and practice of sponge cities.