Study On The Influence Of Urban Spatial Structure On Urban Thermal Field

The buildings are the one of the main factors that intensify the urban heat island effect.Optimizing the spatial layout of buildings is of great significance to alleviating the urban heat island effect.This paper took the central city of Jinan as the research area,and explored the impact of urban spatial structure on the urban thermal field based on two spatial scales of 600m×600m and 1200 m × 1200 m.First,the radiant transfer method was used to retrieve the land surface temperature from Landsat 8 remote sensing image of Jinan's central urban area to analyze the spatial distribution of Jinan's summer urban thermal field.Then,this research took the buildings as the main research object,and established building spatial distribution indicators based on three dimensions.Then,this research took the buildings as the main research object,and established building spatial distribution indicators based on three dimensions: one-dimensional height,two-dimensional plane,and three-dimensional space,and combined the urban greening ecological indicators to build an urban spatial structure indicator system.Then it was quantitatively expressed.Thirdly,using methods such as Pearson correlation coefficient and bivariate global spatial autocorrelation analysis to study the correlation and spatial correlation between urban spatial structure indicators and urban surface temperature,and using stepwise regression analysis methods to explore the quantitative relationship between them.Based on this,the influence of urban spatial structure on urban thermal field was analyzed.Finally,the spatial correlation,agglomeration characteristics and spatial differences between the surface temperature and the spatial structure indicators of each city were explored by using the analysis method of bivariate local spatial autocorrelation.Based on this,the spatial heterogeneity of the influence of urban spatial structure on the urban thermal field was discussed.The main research conclusions were as follows:(1)The average surface temperature in summer in the central city of Jinan was between 25.1? and 43.7?,the temperature difference between east and west was not obvious,the temperature difference between north and south was large,and the surface temperature in the north was higher than that in the south.The distribution of areas with higher mean surface temperature was generally similar to the distribution of buildings,and the distribution of areas with lower mean surface temperature was generally similar to that of Jinan's green space water bodies.(2)In the study of different spatial scales,the impact of urban spatial structure indicators on the urban thermal field was different.Among them,the land surface temperature had the most significant positive correlation with the summation of building base area,building density,the summation of building volume,and floor area ratio in this area.The correlation coefficient R value and Moran's I value were both greater than 0.3.There was a significant negative spatial correlation between the surface temperature and the absolute height of the buildings,the mean value of DEM,and the area of outdoor activities in this area and adjacent areas.The correlation coefficient R value and Moran's I value were all less than-0.3.In the small space scale,the three indicators such as the mean value of DEM,the standard deviation of building height,and the outdoor activity area ratio had the strongest explanatory power for the surface temperature.In the medium space scale,the three indicators of the mean value of DEM,the standard deviation of building base area,and the floor area ratio had the strongest explanatory power of the surface temperature.(3)In the research of different spatial scales,the influence of urban spatial structure indicators on the urban thermal field was spatially heterogeneous.Among them,in the southern part of the city center,the southern part of the Lixia district,and the central part of the Licheng district,these areas with higher altitudes and higher terrain undulations had the most significant low-high accumulation of surface temperature and one-dimensional height indicators,which indicates that the terrain height had a significant effect on the surface temperature.In the areas at the junction of Huaiyin district,Tianqiao district,Shizhong district and Lixia district,where the two-dimensional and three-dimensional spatial index values of buildings were relatively large,the surface temperature was more comparable to that of most two-dimensional and three-dimensional spatial structure indexes.They had a relatively significant high-high agglomeration distribution.Areas with significant spatial correlation between surface temperature and ecological greening indicators were mainly distributed in areas with more urban ecological greening areas.Areas with significant spatial correlation between surface temperature and ecological greening indicators were mainly distributed in areas with more urban ecological greening areas.Urban ecological greening had a certain impact on lowering the surface temperature.The main reason for the large differences in temperature in areas where ecological greening was more widely distributed was the different density of buildings.It showed that the two-dimensional and three-dimensional indexes of buildings had a certain degree of influence on the urban thermal field,and their influence was spatially different.