Thermal Environment Evaluation And Optimization Strategy Of LCZ Based On Human Thermal Comfort

In recent years,the heat wave of urban construction in summer has changed the health of urban residents.Complex urban forms have different effects on urban thermal environment,and each urban form has its corresponding microclimate characteristics.It is helpful for planners and decision-makers to find out the prominent problems in the city,put forward planning improvement measures,and improve the level of residents' outdoor activities.Therefore,in order to distinguish the complex urban form,this paper uses the local climate zoning(LCZ)model to systematically and finely study the differences of urban internal thermal environment,and takes the residents' subjective feeling of thermal comfort as the evaluation standard,quantitatively evaluates the outdoor thermal environment quality under different urban forms based on human thermal comfort index,and studies and analyzes the impact of different LCZ urban forms on human thermal comfort influence.In order to provide more effective climate and environmental regulation strategies for urban design and planning,this paper superimposes the spatial information and the evaluation results of urban thermal environment into a graph,so as to find out the urban climate sensitive areas,and puts forward the improvement measures of thermal environment based on urban geospatial information.In view of the above objectives,this paper has carried out three parts of research and analysis:(1)using the combination of remote sensing discrimination and building vector data analysis to establish the urban local climate(LCZ)map,analyze the distribution of urban internal spatial morphology,and quantitatively and finely study the characteristics of urban thermal environment under different spatial morphology;(2)using the combination of field data monitoring and questionnaire survey,the LCZ map is established The model is applied to the study of thermal comfort.Objective to explore the differences of subjective thermal sensation of urban residents in different spatial forms,and to establish the human thermal comfort models under different LCZ categories;(3)the WRF-UCM calculation model is used to simulate the current situation of urban thermal environment,and the thermal environment information is superimposed and analyzed based on the human thermal comfort evaluation system,the urban climate analysis map and planning suggestion map are established,and the urban optimization measures are analyzed Evaluation.According to the spatial distribution of the city,lcz4 and lcz5 account for the highest proportion in the main urban area of Wuhan.LCZ classification system can distinguish the thermal environment characteristics such as surface temperature,air temperature,wind speed and relative humidity significantly.In different LCZ categories,residents' perceptions and preferences of climate factors such as temperature,wind speed,relative humidity and radiation temperature are significantly different.The higher the density,the more sensitive the residents are to the changes of temperature and relative humidity,and the lower their preferences for temperature,the lower the density,the higher their perceptions of wind speed,and the more sensitive they are to the changes of wind speed;the higher the density,the lower their tolerance of night humidity,and the higher their humidity The preference is high.In urban areas,the temperature of neutral heat sensitive pet of different LCZ types from small to large is lcz5 < lcz6 < lcz4 < lcz2 < lcz3 < lcz1,and the temperature range is 24.1-28.8 ?.The neutral temperature of natural surface(lczd,lczg)is 25.9 ? and 26 ? respectively.In most LCZ categories,the comfortable temperature of residents is higher than the neutral thermal temperature,and the acceptable temperature is slightly higher than the neutral temperature.In the construction of different LCZ types of empirical models in Wuhan City,the human thermal voting(TSV)empirical models under 8 types of urban spatial forms are established.According to the established empirical model of human thermal sensitivity,the evaluation of urban thermal environment is carried out and the evaluation results are illustrated.The four level urban climate planning zoning is studied and planned.The urban climate protection zone is set up and the urban ventilation duct is planned to improve the urban internal thermal environment.According to the optimization measures,the simulation results show that the TSV in the main urban area is significantly reduced,and the duration of daytime high heat pressure is also shortened.In conclusion,taking Wuhan City as an example,this paper draws the map of local climate zone(LCZ)of Wuhan City Based on WUDAPT platform and urban vector data to identify the characteristics of thermal environment change under different LCZ zones.The thermal comfort model of outdoor adaptive human body in summer based on local climate partition was established,and the characteristics of thermal comfort environment of outdoor activity personnel in different LCZ areas of Wuhan were analyzed.The human thermal comfort evaluation system is applied to the evaluation and optimization of urban thermal environment,and the different planning levels and optimization strategies for urban climate division are summarized.The research results are of great reference value for improving outdoor thermal comfort in local climate areas through urban planning and design.