Optimization Of Plant Community In Cold City Park Based On Outdoor Thermal Comfort Evaluation

The rapid advancement of the urbanization process has triggered urban heat island problems.How to improve the heat island problem in cities and strengthen the living environment of human settlements has become particularly important.Urban park green space is an important part of the urban green space system and has a variety of ecological functions,such as improving air quality,reducing temperature,increasing humidity,and regulating the microclimate environment.Because the regulation of urban park green space on the local microclimate is affected by many factors,the previous research on only one garden element is still very weak.In this study,Guli Park,Shangzhi Park and Zhaolin Park in Harbin were taken as the research objects.Through field observation and on-site measurement,combined with Rayman1.2,IBM SPASS and other software,the spring,summer and autumn of different plant communities in the urban park green space,the changes of microclimate factors and human comfort in three seasons were evaluated and analyzed to explore the ecological differences,diurnal variation patterns and their impact on human comfort between local microclimate environments created by different plant communities in urban park green spaces influences.The main research contents and conclusions of this study are as follows:(1)This article first combs and summarizes the relevant conceptual angles of urban parks,plant communities,microclimate and human comfort,then use on-site research and microclimate data measurement and other methods,the microclimate data of 16 plant communities in three park green areas in Harbin city in spring,summer and autumn were measured,and use Microsoft Excel software to carry out simple standardization of the collected data in the early stage.Quantitative analysis and comparison of the diurnal variation of microclimate factors of plant communities in three seasons.(2)Physiologically equivalent temperature was used to evaluate human comfort in the plant community.In spring,the human comfort of different plant communities accounted for 10.23% in the "comfort" feeling,73.86% in the "slightly cool" feeling,and 15.91% in the "cool" feeling.In summer,the comfort of various plant communities is mainly "comfortable" and "slightly warm",of which 48.86% are "comfortable".In autumn,the plant community's comfort level is divided into four types: "extremely cold","cold","cool",and "slightly cold".The percentage of feeling "cold" is as high as 50.57%,followed by 36.93% "cool" feeling.(3)According to the correlation analysis between the thermal comfort of plant communities and microclimate factors,it can be seen that the thermal comfort of plant communities in the three seasons of spring,summer and autumn is positively correlated with air temperature and solar radiation,and negatively correlated with relative humidity.There is no significant correlation with the instantaneous wind speed.The correlation between the thermal comfort value of the plant community and the number,density,and canopy of the community is ranked as species number>density>canopy density;among them,there is a very significant correlation with the number of species(P<0.01),with density,canopy the degrees were significantly correlated(P<0.05).(4)Provide optimization strategies and suggestions for the allocation of greenbelt plant communities in Harbin park,such as different plant community allocation strategies for the three seasons of spring,summer and autumn;put forward the hierarchy and scheme of planting structure suitable for Harbin park green space plant,and put forward rational suggestions for improving local microclimate environment.This will further improve the microclimate human comfort of the greenbelt plant community in Harbin park,make the urban park greenbelt planting design more scientific and reasonable,meet the needs of citizens outdoor human comfort in different seasons,and promote the realization of the "livable city" goal.