Interpreting the relationship between urban heat island (UHI) and urban vegetation is a basis for understanding the impacts of underlying surfaces on UHL The calculation of UHI intensity (UHII) requires observations f...Interpreting the relationship between urban heat island (UHI) and urban vegetation is a basis for understanding the impacts of underlying surfaces on UHL The calculation of UHI intensity (UHII) requires observations from paired stations in both urban and rural areas.Due to the limited number of paired meteorological stations,many studies have used remotely sensed land surface temperature,but these time-series land surface temperature data are often heavily affected by cloud cover and other factors.These factors,together with the algorithm for inversion of land surface temperature,lead to accuracy problems in detecting the UHII,especially in cities with weak UHII.Based on meteorological observations from the Oklahoma Mesonet,a world-class network,we quantified the UHII and trends in eight cities of the Great Plains,USA,where data from at least one pair of urban and rural meteorological stations were available.We examined the changes and variability in urban temperature,UHII,vegetation condition (as measured by enhanced vegetation index,EVI),and evapotranspiration (ET).We found that both UHI and urban cold islands (UCI) occurred among the eight cities during 2000-2014 (as measured by impervious surface area).Unlike what is generally considered,UHII in only three cities significantly decreased as EVI and ET increased (p < 0.1),indicating that the UHI or UCI cannot be completely explained simply from the perspective of the underlying surface.Increased vegetative cover (signaled by EVI) can increase ET,and thereby effectively mitigate the UHI.Each study station clearly showed that the underlying surface or vegetation affects urban-rural temperature,and that these factors should be considered during analysis of the UHI effect over time.展开更多
基金research grants from the Strategic Priority Research Program of the Chinese Academy of Sciences (XDA19040301)the National Science Foundation EPSCoR program of American (ILA-1301789)+3 种基金the National Natural Science Foundation of China (Grant Nos.41671425 and 41401504)HENU-CPGIS Collaborative Fund (JOF201701)the Key Research Program of Frontier Sciences by the Chinese Academy of Sciences (QYZDB-SSW-DQC005)the “Thousand Youth Talents Plan.”.
文摘Interpreting the relationship between urban heat island (UHI) and urban vegetation is a basis for understanding the impacts of underlying surfaces on UHL The calculation of UHI intensity (UHII) requires observations from paired stations in both urban and rural areas.Due to the limited number of paired meteorological stations,many studies have used remotely sensed land surface temperature,but these time-series land surface temperature data are often heavily affected by cloud cover and other factors.These factors,together with the algorithm for inversion of land surface temperature,lead to accuracy problems in detecting the UHII,especially in cities with weak UHII.Based on meteorological observations from the Oklahoma Mesonet,a world-class network,we quantified the UHII and trends in eight cities of the Great Plains,USA,where data from at least one pair of urban and rural meteorological stations were available.We examined the changes and variability in urban temperature,UHII,vegetation condition (as measured by enhanced vegetation index,EVI),and evapotranspiration (ET).We found that both UHI and urban cold islands (UCI) occurred among the eight cities during 2000-2014 (as measured by impervious surface area).Unlike what is generally considered,UHII in only three cities significantly decreased as EVI and ET increased (p < 0.1),indicating that the UHI or UCI cannot be completely explained simply from the perspective of the underlying surface.Increased vegetative cover (signaled by EVI) can increase ET,and thereby effectively mitigate the UHI.Each study station clearly showed that the underlying surface or vegetation affects urban-rural temperature,and that these factors should be considered during analysis of the UHI effect over time.
