Research On Rainwater Environmental Renewal Design Of Old Residential Areas In Changchun City Based On Flood Resilience

At present,with the rapid development of Chinese cities,the global climate problem is becoming more and more serious.Extreme weather occurs frequently.Urban waterlogging has become a serious obstacle to urban development.At the same time,there are some old communities that have long been built,backward infrastructure,poor landscape environment,rainwater discharge by obstacles,low service level,has been unable to meet the needs of residents for living in a better living environment,urgently need to improve the function of the transformation,when heavy rainfall occurred in the city,the old community waterlogging problems,greatly affecting the normal life of residents.In view of the above problems,this paper uses control variable method,simulation experiment method,literature review method,field research method,etc.,to analyze the existing problems in the old residential district that needs to be reformed at present.From the perspective of flood resilience,combining relevant concepts at home and abroad,referring to relevant cases and summarizing experience,it establishes the rainwater generalization model of different residential district types based on SWMM.Relevant reconstruction guidance schemes are proposed,and different proportions of low-impact development facilities are selected for matching.The effects of different reconstruction schemes on rainwater retention under different rainfall recurrence periods are analyzed,and the reduction capacity of the old residential area after reconstruction on rainwater runoff is explored.Through the simulation experiment,the runoff of rainwater can be effectively alleviated and the flood bearing toughness can be improved.Through the simulation transformation,the following conclusions are drawn: the longer the rainfall return period,the greater the intensity of the rainstorm,so the greater the runoff.Under the rainfall conditions of different recurrence periods,the reduction rate of surface runoff of different schemes reached 39%-50%,and the average water level height of rainwater Wells decreased 0.1m to 0.2m,which fully proved that the simulation design was effective,and different schemes could reflect the flood bearing toughness of residential areas.Finally,Yuguang Community of Changchun City was introduced as the object of transformation.During the transformation,the layout of lowimpact development facilities,residents’ activity space and the application effect of landscape greening in the residential area were transformed in accordance with the principles of ecological suitability,feasible transformation,people-oriented and economical transformation.The results of transformation were summarized and the shortcomings of transformation were put forward.