Study On The Cooling Effect Of Greenery Combination On The Residential Areas In Hot Summer And Cold Winter Zone

With the development of urbanization and the intensification of global warming,the urban heat island(UHI)problem is becoming more and more serious.The thermal comfort continues to decrease,which has seriously affected the life and even the health of urban residents.The vegetation is considered as one of the most effective measures to alleviate the UHI effect,especially for the built-up areas of cities.However,the current research on the thermal benefits of urban greening focuses on the cooling effect of a single greening type,ignoring the cooling effect of the vegetation combinations on the urban thermal environment,but in reality,green space planning and design often use the vegetation combination,rather than just planting a single vegetation type.Therefore,under the climate conditions of continuous high temperature and humidity in the hotsummer and cold-winter climate zones,it is important to study the interrelated effects between vegetation combinations and urban thermal environment to improve urban thermal comfort in summer and improve the quality of the urban living environment.To address these problems,this paper starts from the residential quarter and takes Changsha city,which is located in the hot summer and cold winter climate zone,as the research area,takes the green space as the research object.This research constructs a multi-scenario residential green space model using the ENVI-met model.This study quantitatively evaluates the main elements of green space planning and design,such as vegetation combination,vegetation combination ratio,and the cooling effect of vegetation combination layout.To realize a seamless connection between the climate regulation effect of green areas and the planning and design of green areas in a residential quarter,the paper aims at maximizing the climate regulation effect of green areas based on the limited green areas in settlements through effective planning and design of green areas,to improve the thermal environment of settlements in summer and enhance the thermal comfort of residents in settlements more effectively.Firstly,this paper verifies that the green space factors(different green space combination patterns,green space combination ratios,and green space combination layouts)have different effects on the cooling effect using field measurements,and verifies the feasibility and applicability of the ENVI-met software applied to the study of the effect of green space combination on the thermal environment in hot summer and cold winter areas by combining with statistical analysis methods,to provide a new way of thinking and design for the residential green space planning in hot summer and cold winter areas.Secondly,based on the spatial layout of a typical multi-story residential area in Changsha,ENVI-met software was used to quantify the cooling effect of different greenery combinations in the residential area,and to determine the best greenery combination mode that can effectively improve the thermal environment of the residential area in summer.Finally,the impact of different greenery combination layouts on summer cooling is quantified and the layout pattern of greenery combination that can effectively improve the outdoor thermal comfort of residential areas in summer is proposed to provide practical scientific guidance for residential green space planning and construction.