Study On The Influence Of Residential Green Space Distribution On Microclimate And Particulate Matter In Mountain City Based On Numerical Simulation

The microclimate environment of urban residential area has a close influence on the daily life of urban residents,and the green space layout of residential area is an important part of urban blue-green landscape and ecological service system,it plays an important role in alleviating urban heat island and reducing particulate matter concentration.Therefore,it is very important to know the distribution of green space and its influence on micro-climate and particulate matter in real-time and accurately for coordinating the relationship between human needs and ecological carrying capacity.Previous studies have paid little attention to the overall situation of high-density residential buildings in mountain cities,there are few studies on coupling analysis of microclimate,particulate matter and green space distribution in mountainous urban residential area by using ENVI-met numerical simulation method.The residential areas of Tuanjiexiang,Xingshilu and Songbiandian in Guiyang province are taken as research objects.The Quantitative analysis method of combining field measurements with ENVI-met is used to summarize the status quo of residential areas and the layout of green space,to explore the impact of green space layout in urban residential areas of Guiyang on particulate matter and microclimate,to analyze their changes in high-density building enclosures,parallel enclosures and green enclosures under the layout and plant configuration structure,using numerical simulation to show the effects of different green space layout on microclimate and PM¹⁰,PM^2.5,based on the comparison of simulation results,plane comparison and plant configuration,a strategy for optimizing the layout of green space in Guiyang residential areas was proposed.Based on the field data of microclimate,green space layout and particulate matter concentration in residential areas,and ENVI-met simulation,the results show that:（1）the environment in the existing old residential areas in Guiyang city is poor,showing the characteristics of high-density buildings and low greening rate,the green space has poor penetration and continuity,high particle concentration and low diffusivity.（2）the residential areas with high building shading have obvious cold island effect,the smaller the area between buildings,the better the cooling effect when the building distribution is the same;the high-density building enclosure leads to a more stable microclimate and particle concentration;However,the diffusivity of particulate matter is low,and the human comfort is low.（3）although the layout of green enclosing type has the advantages of stable microclimate and lower concentration of particulate matter,the high density of plant structure will lead to slow cooling and poor diffusion of particulate matter in the site,it is not suitable for residents’recreation,and the parallel green space has the best dispersal ability of particulate matter,but the microclimate and particulate matter concentration are most influenced by the outside world.（4）the structure of trees and plants with large crown and high density is not suitable for the residential area of Mountain City,while roof greening,vertical green space,strip green space and dot green space can reduce particles and reduce the occupation of plane space,increase the consistency and quantity of green space patches,it plays a significant role in cooling and humidifying,and is suitable for the layout planning of green space in mountainous urban residential areas.