Study On Microclimate And Thermal Comfort Of Green Space In Urban Parks In Winter And Summer

In recent years,global climate change has intensified,with the "heat island effect",extreme weather,deadly heat waves and many other environmental problems occurring frequently.As China’s urbanization process continues to advance,the scale of cities continues to expand,the urban population increases dramatically,and the urban thermal environment deteriorates,the demand of modern urban residents for a healthy and comfortable outdoor environment increases dramatically.As an important part of the urban green space system,park green space plays an important role in regulating the urban thermal environment and other aspects.In this study,four comprehensive parks,Zhongshan Park,Haipohe Park,Licun Park,and Olympic Sculpture and Culture Park,were selected as research objects to investigate the effects of different microclimate factors on human thermal comfort in winter and summer in Qingdao,a typical seaside city with a north-temperate maritime monsoon climate.Based on real-time monitoring of microclimate factors and subjective thermal comfort questionnaires,thermal sensory voting(TSV),thermal comfort voting(TCV)and thermal preference voting of microclimate parameters were analyzed.Physiological equivalent temperature(PET)was selected as the thermal comfort evaluation index.The main research contents and results of this study are as follows:(1)In this paper,we first sorted out and summarized the concepts related to thermal comfort,microclimate,urban parks and urban green spaces,and then measured the microclimate data of 27 green spaces in four comprehensive parks in Qingdao in winter and summer seasons by using real-time monitoring of microclimate factors and subjective thermal comfort questionnaires,and used Microsoft Excel software to conduct the collected data The data collected were standardized using Microsoft Excel software,and the daily change patterns of microclimate factors in green spaces in winter and summer were quantitatively analyzed and compared respectively.The effect of different canopy shading materials on solar radiation intensity was different,and the solar radiation intensity G was ranked as no shade space > deciduous plants ≥ evergreen plants.(2)The physiologically equivalent temperature index was used to evaluate the human thermal comfort in green space.seven levels of ASHRAE thermal sensory scale were applied to Qingdao area.Thermal comfort voting(TCV)is closely related to thermal sensory voting(TSV),and the results of these two questions are similar.Solar radiation(G)and temperature(Ta)are critical to TSV and TCV in both winter and summer,but relative humidity(Rh)affects TSV and TCV only in summer,and wind speed(Va)is harmful to TSV and TCV in winter,but people’s preference for wind speed increases in summer.The correlation analysis between human thermal comfort and climate factors in green spaces showed that canopy characteristics(D/H)and sky visibility factor(SVF)had important effects on microclimate and thermal comfort,and SVF had the strongest correlation with G,with a coefficient of 0.377 in winter and 0.624 in summer.thermoneutral temperature was 15.5°C in winter and 22.6°C in summer,and thermal neutral temperature range was 8.4-22.7°C in winter and 17.4-27.8°C in summer.Thermoneutral temperature and thermoneutral temperature range are influenced by multiple factors such as climate zone,environment,latitude,and age.(3)The design techniques are proposed to improve and optimize the thermal comfort of green spaces in Qingdao city parks,such as different shading design strategies should be adopted in the same space in winter and summer seasons respectively;it is suggested to use as many permeable hard pavers or hard pavers combined with green spaces as possible under the conditions;adjust the plant configuration form and spatial organization to increase the obstructing effect of plants on wind.This study investigates the relationship between different green space microclimate factors and residents’ outdoor thermal comfort in Qingdao comprehensive parks by combining real-time monitoring of green space microclimate factors and subjective thermal comfort questionnaires,in order to improve the green space microclimate and human thermal comfort in Qingdao city parks,optimize the green space planting design of city parks scientifically and reasonably,meet the public’s outdoor human thermal comfort demand in different seasons,and promote the outdoor thermal comfort of Qingdao city parks.The aim is to improve the microclimate of green space and human thermal comfort in Qingdao city parks,to optimize the green space planting design in Qingdao city parks scientifically and reasonably,to meet the outdoor human thermal comfort demand of citizens in different seasons,to promote the sustainable development of the city,and to contribute to improving the quality of life of urban residents.