Research And Application Of Applicable Technologies For Sponge Transformation Of Old Residential Areas Based On SWM

In the construction of sponge city,the area of construction district occupies a large proportion in the construction of sponge city in our country.However,the number of existing old districts in our country is still more.Under the background of the vigorous development of old district transformation in our country,the sponge transformation is an important part of the organic renewal of old districts.It is of great significance to alleviate waterlogging problem,reduce water pollution,restore urban hydrological cycle and realize rainwater resource utilization.However,in the process of reconstruction,there are often backward infrastructure,mixed land functions,space constraints and other problems,so more scientific guidance is needed.Therefore,how to realize the sponge transformation in the old residential areas,especially how to realize the regulation and utilization of rainwater,has become an important content of sponge city construction.This article summarizes the cases of sponge transformation in old residential areas both domestically and internationally,and based on the shortcomings of sponge transformation in old residential areas in China,proposes applicability technologies for roof transformation,drainage network and road surface transformation,green area transformation,and slope residential area transformation for different types of sponge transformation in old residential areas.Select an old community that meets the conditions,establish a SWMM(Storm Water Management Model)model based on its natural situation and actual situation,and select relevant parameters.Use the SWMM model to analyze the current rainwater and flood treatment capacity of the research community.Through data analysis,it is found that the main problems currently existing in the research community are that the underlying surface is mostly poorly permeable roofs and concrete asphalt pavement,and the water storage and retention capacity of green belts is poor,Lack of rainwater storage and utilization facilities in the community.Based on the existing main problems and renovation conditions of the old residential area,this study selected several sponge renovation technologies such as rainwater disconnection renovation technology,sunken green space,permeable pavement,and rainwater buckets to design a sponge renovation plan.SWMM software was used to conduct numerical simulation,analyze the simulation results,evaluate the renovation effect,and study its applicability.The following research results were obtained:(1)Using a single LID(Low Impact Development)facility and a combination of LID facilities can improve the drainage network capacity of the community under heavy rainfall conditions,including runoff reduction capacity: LID combined facilities>permeable pavement>sunken green space;Improvement capacity of infiltration capacity: LID composite facilities>permeable pavement>sunken green space;Peak flow reduction capacity: LID combined facilities>sunken green space>permeable pavement.(2)After comprehensive analysis of the simulation results,it can be seen that the rain flood control effect of various measures decreases slightly with the increase of rain intensity.The rain flood effect of using a single LID facility is relatively limited,while the effect of using a combination of LID facilities is the best,which can more fully utilize the advantages of the three commonly used LID facilities selected.(3)LID combined facilities can effectively slow down the formation rate of water accumulation on the road surface and reduce the possibility of waterlogging in the community by improving the permeability of the underlying surface and adding rainwater storage facilities to alleviate the pressure of the drainage network,significantly reducing the number of overloaded nodes,controlling the maximum overload time,and reducing the water level at the outlet.(4)For this type of old residential areas oriented towards the goal of sponge city reconstruction,selecting these commonly used LID facilities and adopting technical measures related to sponge city construction such as "infiltration,stagnation,storage,purification,utilization,and drainage" can effectively achieve the reconstruction goal and achieve good reconstruction results.The relevant research conducted in this article can also provide a certain theoretical reference for the sponge transformation of similar residential areas.