Effects Of Urban Landscape Pattern And Connectivity On Land Surface Temperature

Urban surface temperature is the core of urban space thermal environment.The change of urban landscape pattern has significant influence on urban thermal environment.Therefore,the research on the driving force and driving mechanism of urban thermal environment is the key to analyze the spatiotemporal variation of urban thermal environment.In this study,the central urban area of Fuzhou is taken as an example.The surface temperature evaluation index system from 2003 to 2019 were identified using correlation and multicollinearity tests based on surface landscape pattern and connectivity index,referring to the land cover type interpretation results of Landsat remote sensing images.Finally,geographically weighted regression model was used to study the spatiotemporal response characteristics of land surface temperature in order to provide a scientific basis for urban planning and urban thermal environment regulation.During the study period,the overall change range of surface landscape was small,and the change rate of construction land was the fastest,followed by bare land,green land and water.Construction land is mainly transformed from green land.With the increase of area,the shape of patches becomes more regular and the degree of aggregation also improves.The green patches were segmented continuously,the degree of aggregation decreased,and the degree of fragmentation and shape complexity increased significantly.During the past 16 years,the overall landscape fragmentation of Fuzhou city center has been deepening,and the spatial distribution tends to be balanced.The four districts of Taijiang,Gulou,Jin 'an and Cangshan in Fuzhou and the riverside area of Minhou County are the most significant hot spots in the daytime,and the Cangshan district gradually develops into an extremely high temperature area.In addition to Taijiang,Gulou and Jinan districts,which maintain extremely high temperature distribution,Langqi Island in the eastern part of Mawei District also shows a heat island effect area at night.In spring,summer and autumn,the heat island effect increased gradually in the daytime,with the most prominent effect in summer,followed by autumn and spring,and the influence range of the heat island effect in winter decreased gradually.The distribution of heat island at night is more dispersed,especially in autumn and winter,there are a lot of sporadic distr ibution phenomenon.In addition,the dominance of patches was greater in low and medium temperature regions,and the shape of patches in high temperature,high temperature,low temperature and low temperature regions was more complex.The thermal plaque aggregation index of extremely low temperature and extremely high temperature regions was the highest.The fragmentation degree,aggregation degree and connectivity of green land and construction land have a great influence on land surface temperature,and the influence of each influencing factor on land surface temperature has a significant spatial heterogeneity.The green space aggregation degree in the south of the study area has a strong negative effect on the surface temperature,and it is most significant in summer.Construction land agglomeration degree in the middle and north has a great positive effect on LST,and it is stable in each season.In terms of landscape connectivity,the connectivity index of green space,water and construction land is negative ly correlated with LST,while the connectivity index of water and construction land has a positive effect on LST.At night,the contribution degree of each influencing factor to LST was obviously weakened.