| As the main place of urban green space system and residents’ daily activities,community parks play an important role in improving the microclimate of the built environment and the diffusion of PM2.5 concentration in the park and surrounding residential areas.The scientific and reasonable layout of green space landscape pattern can promote Maximize the ecological benefits in the green space of community parks and the built environment of surrounding residential areas.Taking Xi’an as an example,this paper selects community parks as the research object,studies the characteristic elements of its green space landscape pattern,explores its influence on the PM2.5 concentration inside the community park,and proposes and verifies the optimization strategy of the community park green space landscape pattern.The specific research results are:First,through data analysis,the background of the study area and the temporal and spatial distribution characteristics of PM2.5 concentration were explored,and the data from 2010 to 2021 in the central urban area of Xi’an found that the concentration of PM2.5 was the highest in winter and the lowest in summer;the concentration of PM2.5 in 2021 The cluster analysis of the data shows that the concentration of PM2.5 in the central city of Xi’an is generally high in winter,and in most areas of the central city in summer.It can be seen that the problem of PM2.5 pollution in the central city of Xi’an is still serious.Meteorological factors have a significant impact on the distribution and diffusion of PM2.5 concentration in the central urban area of Xi’an.Temperature has a significant positive correlation with PM2.5 concentration,while precipitation,wind speed and relative humidity have a significant negative correlation with PM2.5 In addition,the distribution relationship and characteristics of 143 park green spaces and residential areas in the central urban area of Xi’an were investigated,and the screening basis was proposed,and 59 community parks were selected as research objects to study the impact of community park green space landscape pattern on PM2.5 Concentration effects.Second,based on the landscape pattern theory,select the landscape pattern index suitable for community park green space,use GIS and Fragstats spatial pattern analysis technology to calculate the landscape pattern index and extract the PM2.5 concentration data in the community park.Through correlation and factor impact analysis,the impact relationship between community park green space landscape pattern and PM2.5 concentration in winter and summer was explored,and it was concluded that the community park green space landscape pattern index had a significant impact on PM2.5 concentration,among which The four most influential landscape pattern indices are CA(patch area),NP(patch number),AI(patch aggregation),and SHAPE-AM(shape index).Third,the ENVI-met ideal model of single-factor community parks was established through the four landscape pattern indexes with strong influence factors on PM2.5 concentration.The number of patches(16 patches),the smallest aggregation degree(99.46)and the largest shape index(1.31),corresponding to the lowest 24h average PM2.5 concentration in the built environment of the community park model and the residential area around the community park;and In winter,the temperature and relative humidity are the highest and the wind speed is the lowest;in summer,the temperature is the lowest,the relative humidity is the highest and the wind speed is the lowest.Therefore,an optimization strategy for the green space landscape pattern of the community park green space patch area.number of patches,aggregation degree and shape index is proposed.Fourth,select the case community park,and based on the proposed optimization strategy,select the typical pollution season and winter to optimize and verify the area,quantity,aggregation degree and shape index of the green patch in the case community park,and use the ENVI-met model to analyze the case community park The PM2.5 concentration and microclimate factors in the built environment of the park and surrounding residential areas before and after optimization changed,and the 24h average PM2.5 concentration inside the optimized community park decreased by 2.57μg/m~3,0.17μg/m~3,and 0.17μg respectively/m~3 and 1.13μg/m~3,the 24h average PM2.5 concentration in the built environment of the surrounding residential areas decreased by0.23μg/m~3,021μg/m~3μ0.26μg/m~3 and 0.31μg/m~3 respectively,and the temperature and relative humidity both decreased Ther e is an increase.and the wind speed has weakened Therefore,the feasibility of the community park green space optimization strategy in regulating the PM2.5 diffusion concentration and microclimate factors in the built environment of its interior and surrounding residential areas is further demonstrated.In this paper,through quantitative analysis and optimization research on the relationship between the landscape pattern of community park green space and PM2.5 concentration in the central urban area of Xi’an,the relationship between the characteristics of the landscape pattern of community park green space and PM2.5 is clarified,and the verification and regulation of PM2.5 concentration is proposed The design strategy and feasibility of distribution,to achieve the goal of improving the air quality of the built environment of community parks and surrounding residential areas,and providing a pleasant living environment.The research results can provide a reference for the layout planning,construction and optimization of the green space system of community parks in Xi’an,and provide scientific guidance for the planning and design of the urban green space system. |
PDF Full Text Request