Study On The Spatial Form Of Residential Area Based On The Optimization Of Outdoor Thermal Environment

The process of urbanization and construction has been accelerating,and urban construction activities in different dimensions have led to the deterioration of outdoor thermal environment.It has been established that different forms of building masses affect outdoor microclimate,but its comprehensive impact on outdoor thermal environment is still controversial and ambiguous because the impact of building spatial forms on outdoor thermal environment may vary in different time periods and seasons.Currently,residential land,as the largest contributor to the heat island effect,has become the focus of research to quantify the outdoor thermal environment effect of spatial morphology of residential areas in different dimensions and seasons in an integrated manner.This thesis firstly constructs the correlation indexes between the spatial morphology of buildings in residential areas and outdoor thermal environment,separately discusses the research related to the spatial morphology indexes of different dimensions and outdoor thermal environment parameters,and summarizes the characteristics of outdoor thermal environment effects of various morphology indexes and their research limitations.After that,we conducted field research on 15 residential areas with different spatial morphology in the Tongshan District of Xuzhou City,and the spatial morphological indicators of residential areas were measured on site and supplemented with map data to calculate the spatial morphological indicators of residential areas at each measurement point,while the outdoor thermal environment data of residential areas in different seasons and different time periods(morning and afternoon),including air temperature(T_a),land surface temperature(LST),mean surface temperature(MST)and relative humidity(RH),were investigated by mobile observation method.This thesis intends to analyze the spatial morphological factors related to outdoor thermal environment in the study area,in order to explore the spatial morphological design strategies of residential areas based on the perspective of thermal environment optimization.Firstly,this thesis explores the relationship between spatial morphological indicators of residential areas and outdoor thermal environment parameters through correlation analysis;secondly,based on hierarchical analysis,we explore the individual and joint contribution of spatial morphological indicators of residential areas to outdoor thermal environment parameters;we use systematic cluster analysis to classify spatial morphological indicators of residential areas into three categories,namely,three-dimensional structure factor,heat source area factor and three-dimensional visual factor;subsequently,we explore the individual and synergistic contribution of the three categories to outdoor thermal environment parameters through redundancy analysis.We explore the individual and synergistic effects of the three types of factors on outdoor thermal environment parameters;meanwhile,we further clarify the main contributing indicators through stepwise regression;finally,we explore the threshold intervals of outdoor thermal environment parameters and spatial morphology indicators,and analyze the optimization trend of spatial morphology of residential areas in the study area.The conclusions of the study are as follows:(1)The outdoor thermal environment of residential areas is the result of the joint action of several spatial morphological indicators,not determined by a single indicator.For T_a,BH,FAI,SVF and BD are the main influencing factors in summer and autumn,and H/W,FAR and FAI have the strongest effect on T_a in winter;for LST,BD is the main influencing indicator in summer,BD,SVF and FAR have the strongest effect on the distribution in winter,and FAI,BH and FAR are the main influencing factors affecting LST in autumn;in addition,the influencing MST the main indicators are FAI,BD and SVF;for RH,the main influencing indicators in summer and autumn are BH,FAI,SVF and BD,and H/W and BD are the main influencing indicators for RH in winter.(2)The outdoor thermal environment effect of spatial morphology in residential areas is temporally heterogeneous,with variability in the pattern of effects at different times of the day due to changes in solar radiation and weather conditions.Morning weather changes are more stable,with structural factors playing a major role in T_a and area factors and visual factors playing a weaker role.The spatial morphological indicators generally explain more of the LST and MST in the morning than in the afternoon,with the area factor having the highest contribution.The spatial contribution of the structure factor to RH was greater in the morning than in the afternoon hours,and the spatial contribution of the area and visual factors was lower than in the afternoon.In the afternoon hours,the significant enhancement of solar radiation causes changes in the energy flow of spatial forms,among which T_a in summer and autumn mainly shows the area thermal effect,and T_a in winter is affected by the combined effect of structural and area factors;in addition,the total joint contribution of the three types of indicators to T_a in autumn increases significantly in the afternoon,among which SVF and BD play a major role,indicating that the construction capacity and spatial permeability of residential building groups The degree of spatial permeability plays a dominant role.In terms of LST,the individual contribution of spatial morphology indicators to LST is significantly lower than that in the morning,but the total joint contribution is significantly higher than that in the morning.In addition,spatial morphology has a similar pattern of influence on MST as LST,with the highest contribution of SVF to MST.(3)The outdoor thermal environment effects of spatial forms in residential areas have seasonal differences.Due to the different energy states of substrate and building space in different seasons,the structural factor and area factor contribute more to T_a in winter than in summer and autumn,while the visual factor explains the highest degree of T_a in autumn.Among them,the structural factors have similar influence patterns on summer and autumn,and the indicators with higher contribution rates are BH and FAI.for LST,the contribution rates of each spatial morphology indicator are higher in autumn and winter than in summer;the area factor contributes significantly more to LST in winter than in other seasons because heating enhances the role of building surface heat source;in addition,SVF plays a dominant role in winter.For MST,the visual factor has the highest contribution in winter;the structural factor generally contributes more in winter than in summer,and the area factor explains more in autumn than in summer;for a single index,BD has high contribution in summer,autumn and winter,and H/W has a higher role in autumn than in summer.For RH,the structural factor has a greater effect on winter than summer.(4)Threshold values of spatial morphological indicators for residential areas based on the optimization of summer and winter thermal environments,and the threshold intervals for each indicator that can take into account summer cooling and winter warming are as follows:the threshold interval for SVF is 0.47～0.50;the threshold interval for FAR is 2.31～2.39;the threshold interval for CAR is 0～1.71;the optimization threshold for FAI is 0～1.10 or higher than 4.88;The threshold interval for BD was 0.51～0.54 or 0～0.22.Finally,based on the findings of the study,optimization strategies are proposed and applied to the design with the goal of optimizing the outdoor thermal environment of residential areas.The findings of this thesis provide a theoretical basis for quantifying the outdoor thermal environment effect of buildings and promote the research related to accurately quantifying the outdoor thermal environment effect of spatial forms in residential areas.There are 88 figures,42 tables and 131 references in this thesis.