Comparison of Surface Urban Heat Island (SUHI) at Landsat Scale in Hefei, China: Diurnal, Seasons and Drivers

The formation of surface urban heat island (SUHI) is one of the most common effects of the urbanization and its long time series analysis on fine-scale remains poorly understood. In this study, the diurnal and seasonal Landsat-scale data were obtained by using spatiotemporal data fusion (STF) method. We quantified the diurnal and seasonal SUHI and analyzed their spatial variations and possible underlying mechanisms. The results demonstrate the following: the annual mean SUHI varied markedly during the day and night, with a great deal of spatial heterogeneities. The SUHI differed greatly by season, characterized by a higher intensity in summer than in spring, autumn and winter during the day, and it is the opposite at night. Moreover, the negative correlation between land surface temperature (LST) and Normalized Difference Vegetation Index (NDVI) showed an amplifying effect of the developed areas for SUHI, while areas with a predominance of vegetation attenuated the effect of SUHI.