| The urban heat island(UHI)effect,as the most direct climate response result of urbanization,presents a major sustainability challenge for cities.The thermal comfort and standard of living of urban residents significantly affected by UHI.The transformation from natural landscape to man-made landscape is the direct cause of the formation of UHI effect,so urban landscape structure plays a decisive role in the intensity of UHI.However,there still have a gap between previous studies which have found that the landscape components and spatial patterns differently influence on the intensity of UHI in different cities.Therefore,in order to adapt to and improve the increasingly severe thermal environment of cities,it is necessary to deeply explore the impact of urban landscape construction on land surface temperature(LST),and quantify its scale effect and neighborhood effect.This study selected five cities(Beijing,Shanghai,Chongqing,Changsha and Changchun)in different geographical areas as this study area,Landsat8 images(resolusion ratio is 30 m)were used to analyze the influence of landscape construction on LST in summer,and the regulation ability of itself and neighborhood landscape on LST in different scales(grid size and neighbor range)was explored.The results of this study show that:(1)Under the influence of other landscape components,the sensitivity of LST to landscape components was significantly different in five cities.When other landscape components are controlled,vegetation alleviates 40%-60%of the warming effect of buildings while surface moisture intensifies or reduces it depending on climate conditions.(2)LST is affected by its own(endogenous)and neighbor(exogenous)landscape,and the influence of endogenous landscape features(Eendo)on LST can be described consistently across all cities as a nonlinear function of grain size(gs)and neighbor size(ns)(Eendo=?nsgs-0.5,where ? is a city-specific constant)while the influence of exogenous features(Eexo)depends only on neighbor size(Eexo=?-?ns0.5,where ? and ? are city-specific constants).In addition,a simple relationship describing the relative strength of endogenous and exogenous impacts of landscape features on LST was found(Eendo>Eexo if ns>kgs2/5,where k is a city-specific parameter;otherwise,Eendo<Eexo).(3)LST is also affected by the spatial pattern of landscape features,which is deeply affected by the proportion of landscape features.When the proportion of buildings is large,the landscape pattern has a weak impact on LST.When the proportion of vegetation is large,LST can be effectively reduced by increasing the patch area,enhancing the degree of aggregation,reducing the degree of patch fragmentation and the complexity of patch edge,no matter for green space or buildings.This indicates that green space and architecture,as the main landscape components of the city,are complementary in spatial distribution,so the influence of spatial pattern characteristics of the two on LST is similar.This study shows that the regulation effect of urban landscape structure on LST is deeply influenced by the research scale and the neighborhood landscape,and further reveal a set of quantitative relations that can effectively describe the influence of landscape structure on LST on its own and neighborhood under different spatial scales.Therefore,it is very important to explore the influence of urban landscape construction on LST,so as to provide scientific theoretical basis for the optimization of landscape thermal environment. |
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