Research On Climate Adaptability Design Of Xi’an Urban Life Service Street

Service-oriented street is a compound space integrating public communication and traffic,and it is an outdoor public space closely related to people’s daily life.As a typical hot summer and cold winter area in Xi ’an,the hot and rainy summer and cold winter climate bring discomfort to citizens’ travel.Therefore,it is particularly important to analyze the spatial form elements of life-service street to balance the climate demand in winter and summer.This paper takes Xi ’an urban life service street as the research object,and makes an in-depth analysis from the perspective of climate adaptive design.Firstly,it combs the basic theory of the influence of the spatial form elements of life-service street on microclimate;Secondly,the service-oriented streets in Xi ’an city are investigated,and statistical analysis is made from six aspects: street direction,road width form,width,aspect ratio,tree-lined space form,and street tree species.Combined with the effect of street form elements on microclimate,the design idea of giving priority to sunshine in winter and shading in summer is put forward.Further analyzing the climate adaptability of Xi ’an urban life service street in winter and summer,it is found that there is insufficient sunshine in winter in the east-west direction of standard street valley and deep street valley,and in the north-south direction of deep street valley,so Jiandong Street,Tongyi Lane,Jiaoda Street and Gongyuanmen are selected for the measurement and simulation analysis in winter and summer.Finally,the climate adaptability design strategy is put forward from the building interface,tree-lined space,street tree species,bottom interface pavement and rest facilities along the street,and the climate adaptability optimization design of four typical life-service streets is carried out,and the feasibility of the scheme is verified by software.Through the above research,the research conclusions are as follows:(1)Xi ’an urban life service-oriented streets are mainly east-west,north-south.The height of buildings along the street from east to west and the spacing of openings between buildings on the south side are the main factors affecting the sunshine environment.Priority should be given to the interface of buildings along the street on the south side to meet the demand of sunshine in winter.The height of buildings along the street on the south side should not exceed 3F,that is,9m,and the number of living service streets and openings on the south side should be limited.To the north-south street,the building height on both sides of the street is the main factor affecting the sunshine environment.The building height on the east side of the street should not exceed 4F,that is,12 m,and the building height on the west side should not exceed 2F,that is,6m.(2)The aspect ratio is one of the main factors that affect the microclimate environment of the street.In Xi ’an,the width of service-oriented streets for urban life is about 20 m,and the buildings along the streets are mostly residential buildings.According to the analysis,low-rise buildings with less than 3 floors have little influence on winter sunshine,and multi-storey buildings with 4-6 floors can be adjusted by limiting the height and retreating a certain distance.Attention should be paid to the opening size and number of buildings along the south side of the east-west street.100 m high-rise building is not recommended as a service-oriented street building in Xi ’an.If this situation cannot be avoided,the width of street can be appropriately reduced to improve the sunshine in winter.(3)Street tree-lined spatial form and street tree species can obviously regulate the microclimate environment.Deciduous trees should be selected for street trees in Xi ’an city’s service-oriented streets.The "two-row" open type of tree-lined space is better than the "single-arch" closed type,which can eliminate high temperature and automobile exhaust in time in summer.Street trees should choose tree species with large crown width,low height under branches and large leaf area index,such as Platanus acerifolia,Sophora japonica,Koelreuteria paniculata and Melia azedarach.