Study On Outdoor Space Design Of Existing Settlements Under The Target Of Stormwater Management

In February 2016,"Several Opinions of the Central Committee of the Communist Party of China and the State Council on Further Strengthening the Management of Urban Planning and Construction" pointed out that it is necessary to promote the comprehensive improvement of old residential areas in an orderly manner.There are a large number of old settlements in Dalian.The settlements built in the 1980 s and 1990 s accounted for a large proportion.The settlements have not yet reached the service life.However,they were limited to the technical factors and economic conditions at that time.The developed community has long been unable to adapt to the current urban environment.Many old residential areas have experienced the phenomenon of “heavy rain and drought after rain”.It is difficult to meet the needs of residents regardless of their own functions or their carrying functions.The drainage conditions and the quality of the space environment in the outdoor space of the residential area are imminent.However,the demolition of drainage facilities in the residential areas in use will not only consume a lot of manpower and material resources,but also affect the residents of the settlements.In this context,this paper proposes to introduce the concept of rainwater management in the outdoor space renewal of existing residential areas,which will effectively improve the stormwater management capacity of old residential areas and achieve the purpose of improving the environmental quality of residential areas and replenishing groundwater resources.At the same time,it can also avoid large-scale demolition and reform in the process of residential area reconstruction,and reduce the impact on residents’ lives.This paper takes the existing residential areas built by Dalian in the 1980 s and 1990 s as the research object,and takes the outdoor space environment as the foothold,sorts out the common problems existing in different types of underlying surfaces of existing settlements,and summarizes the management of rain and flood.Based on the related application of technical measures and different underlying elements,the design strategy of outdoor space transformation under the guidance of rainwater management is proposed.On this basis,the typical design is combined with the typical community and verified by SWMM simulation software.details as follows:Firstly,using the method of literature research,through the summary of the existing residential area transformation at home and abroad and the development history of the rainwater management system,the achievements and shortcomings of the outdoor space renewal and rainwater management construction in the existing residential areas in China are analyzed.Secondly,select 20 existing residential areas in the downtown area of Dalian to conduct a large number of actual surveys,and sort out the four spatial design elements of old residential buildings,roads,green spaces and venues,and analyze the outdoor Functional quality issues and stormwater problems in space.Then,the current mainstream rainwater management technical measures are elaborated,and the combination of four spatial design elements and rainwater management technical measures in residential areas is summarized.On this basis,based on the "life circle" as the scale,according to the typical problems of different "living circles",the strategies and methods for the transformation of buildings,roads,green spaces and sites are proposed.Finally,taking Dalian Liuliu Community as a typical object,combined with the investigation,the outdoor space environment is updated,and then SWMM simulation software is used to simulate the effect of rainwater management technical measures to verify the feasibility of relevant strategies and technical measures.And verify the effect of the combination of different technical measures,and make secondary feedback on the updated design.In the process of transformation of existing settlements,while improving the renovation standards and quality of the old residential areas,in addition to the existing defects in the management of existing residential areas in the rainwater and floods,the functions of collecting,regulating,and purifying rainwater are added to the renovation.Among the elements,the realization of the function of the outdoor space elements of the residential area is realized,and the comprehensive value of the existing residential areas is improved,which has a strong guiding significance for the transformation design of the existing outdoor space.