Spatial variation of urban heat island effect in Xiong’an New Area

Based on the Landsat-8 satellite remote sensing images of Xiong’an New Area, including Xiong County, Rongcheng County and Anxin County, in September 2019, the land use types were divided into five types by the supervised classification method and the land use structure characteristics of Xiong’an New Area were analyzed. The radiative transfer method was used to perform land surface temperature inversion, the surface temperature was classified according to the mean standard deviation method, and the spatial change of surface temperature and the classification of heat island intensity in Xiong’an New Area were analyzed. The point of information (POI) data were used to divide the city into functional areas and analyze the influencing factors of high temperature distribution. The results showed that among the five types of land use in Xiong’an New Area, the area of cultivated land and construction land was relatively large, accounting for 56.19% and 31.81%, respectively. The distribution of the area proportion of the five types of land use in the three counties was quite different. The overall distribution characteristics of land surface temperature in Xiong’an New Area was higher in the north and lower in the south, the range of temperature was about 21 ℃, and the variation of surface temperature in Rongcheng County was large. The area of heat island intensity grade in the three counties was different, with the largest area in medium temperature area and the smallest in low temperature area. Those that had higher proportion of heat island intensity grade area had the higher proportion of building area. The average surface temperature in different temperature areas of heat island intensity had a significant linear positive correlation with the number of POI. Different urban functional areas had different effects on surface temperature, the surface temperature of functional areas with large human activities was high, with the area of higher temperature being around the construction land, the area with lower temperature around water body, and the area with normal temperature being cultivated land and forest land.