| With the development of urbanization,changes in land cover have brought great changes to the urban thermal environment.Many scholars have conducted research on the characteristics of changes in the thermal environment and the impact mechanism of land cover.However,most of the research still remains at a single point.The impact of factors on the surface thermal environment is rarely explored on the mutual interference between multiple factors.In addition,a large number of studies have been conducted on the impact mechanism on the scale of the city as a whole or the standard grid,but it has a great impact on the micro-scale of the community that reflects the urban spatial pattern.Lack of attention.This study takes the urban built-up area within the 5th Ring Road of Beijing as an example.The building group enclosed by the road network is used as the research unit to study the distribution characteristics of surface temperature,buildings and vegetation in the area,and analyze the differences between buildings and vegetation.The correlation between ground surface temperature,through studying the influence of building distribution characteristics on vegetation cooling effect,analyzes the mutual interference between vegetation and buildings that affect ground surface temperature,and further explores its influence mechanism,in order to expect this The research results can provide scientific reference for urban planning and urban design from the perspective of urban heat island mitigation and human settlements health.The main findings are as follows:(1)The spatial distribution of ground surface temperature,buildings and vegetation has a certain corresponding relationship.According to the ring line division of Beijing's built-up area,from the 2nd ring to the 5th ring,the building density in the study area decreases ring by ring,the surface temperature decreases ring by ring,the vegetation distribution(normalized vegetation index)increases ring by ring,and the building height Low-rise buildings(with floors less than or equal to 3 floors)are mainly used in the 2nd and 4th ring roads,and the middle and high-rise buildings are mainly used between the 2nd and 4th ring roads.(2)Building density,building height and vegetation are all related to ground surface temperature.There is a positive correlation between building density and ground temperature,and the slope of the linear regression curve between building density and ground temperature is affected by the height of the building.The normalized vegetation index has a negative correlation with surface temperature,and the slope of the regression curve between vegetation and surface temperature is affected by the distribution of vegetation itself.There is a weak positive correlation between building height and ground temperature.(3)The cooling effect of vegetation is different under different architectural features.Compared with the vegetation distribution,when the building density is low,the vegetation cooling effect changes simultaneously with the vegetation distribution.The vegetation cooling effect is stronger when the building density is middle,and the vegetation cooling effect is stronger or weaker when the building density is higher.(4)The influence of building characteristics on vegetation cooling effect is mainly affected by wind environment.When the building density is low,the wind speed will be less affected,and the vegetation cooling effect will change simultaneously with the vegetation distribution.When the building density increases,the wind speed inside the building increases,which promotes the cooling effect of vegetation and heat evacuation.When the building density is large enough,the wind speed is blocked and reduced,and the cooling effect of vegetation is correspondingly weakened.However,when the distribution of buildings conforms to the wind direction of the wind environment,the wind speed will not be blocked and the cooling effect of vegetation will not be weakened. |
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