The Influence Of Living Street Greening On The Microclimate And Design Strategy In Xi'an

The world today is experiencing the fastest urbanization process in history,and the urban climate has been severely negatively affected.In the city,the street area occupies one third of the urban land area.Therefore,the pros and cons of the urban street greening landscape will directly affect the overall climate environment of the city.Living street greening,as the urban green space with the highest frequency of people's daily life,plays a vital role in satisfying people's physical comfort and psychological needs.The impact of graduate students' active street green space on the street microclimate is of great significance for improving the microclimate conditions of the entire city.Through literature research,it has been found that there are two main methods for predecessors to study urban street afforestation: the first,on-site measurement(using microclimate testing instruments to measure street environment)and the questionnaire;the second,using microclimate numerical simulation software(ENVI-met,Fluent,CFD,etc.)simulate and analyze the streets on the ground.In comparison,the use of microclimate numerical simulation software to analyze and analyze the street greening microclimate environment saves manpower and material resources,and can repeat the experiment,so it is favored by more and more scholars.This paper combines two research methods of actual measurement and numerical software simulation to make a comprehensive assessment of the outdoor microclimate environment(including wind environment,microclimate and wet environment)of Xi'an urban living streets.First of all,survey and summarize the living street space form and greening status in Xi'an main city area,and get the typical space form of Xi'an living street,greening tree species and layout form.Then select the typical street space with abundant greening types for field research,analyze the status of street microclimate under the influence of different types of street greening space,and get the influence mechanism of urban street greening on the microclimate environment in Xi'an.Finally,combined with field research,street tree species,greening layout and plant configuration structure are selected as the street greening elements that affect the street microclimate environment,and the greening variable simulation is carried out,and the rationality and scientificity of the microclimate numerical simulation model are also verified.Studies have shown that: 1.Among the landscape garden elements that affect the microclimate of urban streets,greening has a significant cooling and moisturizing effect on the street environment;and the combination of street tree green belts and roadside greening is superior to a single street tree Greening,the addition of roadside green belts can reduce street temperature by about 1.12? in summer;Second,the improvement of the complex greening configuration on street microclimates is better than street spaces with only trees or no greening,planting trees,shrubs and grass for greening Compared with the ungreened street space,the temperature is 1.16? lower,and the humidity is increased by 2.22%;Third,the sidewalk trees choose dense and shaded greening tree species.The higher the leaf area density,the better the street temperature improvement.The decrease of temperature in the street is about 1.14?.