Optimization Of Green Spaces Design For High-rise Residential Areas Based On Human Thermal Comfort Assessment

One of the most obvious features of the urbanization process is the "urban heat island" effect,which has led to a series of urban problems.The large-scale construction of cities and towns has led to fundamental changes in the nature and structure of their substrates.The artificial surface layer,represented by concrete and asphalt,is a strong absorber of short-wave solar radiation,while the accumulated heat is transmitted outwards in the form of long-wave radiation,leading to a rapid rise in surface temperature.Numerous researchers have demonstrated that green spaces can effectively improve urban microclimate,create cool and comfortable urban spaces and reduce urban energy consumption.However,in the actual construction and planning of urban green spaces,functionality,and aesthetics are the primary considerations.Residential green spaces are an important part of the urban green space system,and their proportion of land area and the quality of greenery directly determine the quality of the living environment.At present,there are few documents and standards that can directly and accurately guide the planning and design of residential green spaces from the perspective of their ecological benefits.Therefore,this paper takes the improvement of the outdoor thermal environment of residential areas in Nanjing as the starting point.By analyzing the characteristics of residential areas in the city and combining them with field research,the paper uses microclimate simulation software to verify the meteorological data and simulate the actual sites to explore the optimal design strategy of residential green areas based on the improvement of human thermal comfort.The main research work of this paper is as follows:In the first part,a literature review and analysis of the relationship between green space and microclimate in residential areas at home and abroad are presented,and the concepts of urban microclimate,thermal comfort evaluation index as well as green space in residential areas are sorted out.In the second part,the current situation of the built-up residential areas and residential green spaces in Nanjing is analyzed and summarized through government data and previous studies.Based on the recent urban development in Nanjing,the number of high-rise residential areas with ranks and columns has dominated in the last two decades.Therefore,three typical high-rise residential areas in Nanjing are selected for this study,and their meteorological monitoring and overall environment are examined in the field.In the third part,based on the measured meteorological data and the overall layout of the residential areas,microclimate simulation software was used to model the sites of the residential areas within the study area,and the accuracy of the actual sites and models was verified through the temperature and humidity data obtained from the simulations.On this basis,the microclimate elements affecting the thermal environment of the residential area are further investigated using numerical simulation techniques,large uncomfortable areas of the site are extracted,and feasible design strategies are proposed in conjunction with the existing problems of the residential area green space from the research.In the fourth part,the study proposes specific green space design solutions for each residential area,combining the optimal design strategies proposed above,simulating different tree canopy coverage scenarios,optimizing the green space layout and plant configuration,and updating the design of some landscape nodes.Based on the simulation results,tree canopy coverage thresholds are derived for each high-rise residential area at different building heights,which can provide a theoretical basis for future residential area green space planning and design.Furthermore,the use of plants to create a reasonable green space not only enhances the quality of the living environment and relieves the heat stress of residents when they are outdoors in summer,but also helps to reduce energy consumption to a certain extent,which is in line with the sustainable development of society.The research methods and green space design strategies used in this paper can provide references for research on the mitigation of outdoor thermal conditions in residential areas in summer and the enhancement of human thermal comfort,and add a new perspective to the practical planning and design of residential green spaces in the future.