Impact Analysis Of Land Surface Temperature Based On Building Structure In Beijing

Buildings are one of the main contributing factors of the urban heat island effect.To explore the influence of urban buildings on the thermal environment and put forward the measures to optimize the thermal environment is an important way to alleviate the urban heat island effect.Taking Beijing as the research area,this study uses Landsat8 images and building vector data to explore the influence of building spatial structure on thermal environment in Beijing.Firstly,the land surface temperature is inverted based on the radiation transmission equation method,and the thermodynamic grade is divided,so as to analyze the land surface temperature distribution characteristics of Beijing.Secondly,the spatial structure of buildings in Beijing is described by four indexes: building density,building height,building plot ratio and sky view factor,and then the distribution characteristics of the spatial structure of buildings in Beijing are analyzed.Finally,statistical analysis,correlation analysis and linear regression analysis are used to quantitatively analyze the influence of the spatial structure of buildings on the thermal environment in Beijing.Through the above research,the following conclusions are mainly drawn:(1)In 2015,the land surface temperature in Beijing was mainly medium temperature area and sub-high temperature area,and the distribution and area ratio of low temperature area and sub-low temperature area were similar,and the land surface temperature distribution law had seasonal differences.There is a difference in the distribution of thermal levels within each loop.(2)The number of buildings in Beijing increased from the second ring road to the fifth ring road in 2015.The research area is dominated by medium density and relatively high density buildings.The proportion of low-density and high-density buildings in each ring line from the second ring road to the fifth ring road has increased,while the proportion of medium-density buildings has decreased.The research area is mainly composed of low-rise and multistorey buildings,with the middle and high-rise buildings,high-rise buildings and super-high-rise buildings accounting for the largest proportion in the third ring road.The research area is dominated by buildings with low floor area ratio and lower floor area ratio,while buildings with medium floor area ratio,high floor area ratio and high floor area ratio take up the largest proportion in the third ring road.In the study area,the sky view factor in open areas such as parks,water bodies and open spaces is relatively large.In areas with different building heights and high building density in residential areas,as well as narrow roads and open areas surrounded by buildings,the sky view factor is relatively small.(3)The average land surface temperature of buildings in Beijing in 2015 is higher than the overall average of the study area.The standard deviation of the surface temperature of buildings in summer is greater than that in winter,and there is a larger temperature gap.(4)There is a significant correlation between building density,building height,building floor area ratio and sky view factor with land surface temperature.Among them,there is a positive correlation between building density,sky view factor and land surface temperature,which are 0.237 and 0.110 in summer and 0.096 and 0.146 in winter,respectively.There is a negative correlation between building height and building volume ratio and land surface temperature,which are-0.317 and-0.162 in summer and-0.405 and-0.273 in winter,respectively.The linear regression results show that the temperature increase effect of building density in summer is greater than the temperature decrease effect of building height,building volume ratio,and sky view factor.The regression coefficient is 0.581.Winter building density and land surface temperature have a weak cooling effect.The cooling effect of building height is higher than the cooling effect of building volume ratio and the heating effect of sky view factor,and the regression coefficient is-0.322.