Quantitative Identification of Temporal-Spatial Variations of Urban Heat Island (UHI) Effects in Changchun, China

With the fast urbanization, urban heat island (UHI) effect is becoming more and more pronounced. Identify and evaluate the temporal-spatial variations and the driving factors that are in urgent need to alleviate a series of problems caused by heat island. Changchun of Jilin province is located in northeast China, using multiperiod satellites images and other ancillary data to invert the surface temperature and acquire the surface land cover classification, then it analyzed the temporal-spatial variation of UHI effect and relation between urban developments. The temporal variations of UHI effects based on air temperature (AT) showed: the UHI was strong at night and weak in daytime; the UHI was strong in autumn and winter and weak in spring and summer; the UHI effect increased rapidly before 2015 and decreased after 2015. The spatial variations of UHI based on land surface temperature (LST) effected: The area of higher temperature zone increased, while the area of other areas declined. The strength order of the UHI effect for different land surface covering types was: building land> grassland> woodland>water area. This meant how to layout urban land use types were important, reasonable urban land planning was necessary for urban sustainable development. This study provided an important basis for counteracting the UHI effect and promoting the construction of an eco-city.