Effects of landscape patterns on the morphological evolution of surface urban heat island in Hangzhou during 2000 – 2020

Rapid urbanization exacerbates the urban heat island (UHI) phenomenon, which significantly affects people's daily life and socioeconomic activities. In this study, using Landsat long-time series satellite images, we attempted to examine the dynamics of surface urban heat islands (SUHI) in Hangzhou from 2000 to 2020. Directional analysis, correlation analysis, and stepwise regression analysis were employed to detect the relationships between land surface temperature (LST) and landscape patterns. The results show that the changes of SUHI were mainly due to the urban expansion in suburban areas, and the intensity of SUHI in the urban center kept stable. The correlation between LST and forest was stronger over time with an increased proportion level. There was no correlation between LST and forest when the forest density was less than 20 ha/km2. However, when the forest density reached 80 ha/km2, the R2 of their correlation was 0.2921. The landscape configuration also affected the LST, and agglomerated water and forests showed a more substantial cooling effect. Compared with dense buildings, scattered buildings showed a weaker warming effect. These findings would be helpful for the current landscape configuration adjustment and future urban planning, with the promotion of sustainable development in Hangzhou.