全球变化知识资源中心

Systematically investigating the spatial and dynamic variations in surface urban heat island (SUHI) and their relationships with vegetation is needed in the context of sustainable urban development. In this study, the regional differences in the spatial and temporal variations in SUHI intensity (SUHII) were quantified, and their correlations with vegetation activity were analyzed in Beijing during 2001-2013, based on Moderate Resolution Imaging Spectroradiometer land cover/land use, land surface temperature, normalized difference vegetation index and digital elevation model. The results show that the 13-year averaged daytime SUHII presenting obvious seasonal variations was the highest (2.61 degrees C) in urban core area and the lowest (-2.09 degrees C) in rural area. The night-time SUHII was relatively stable in season, showing the highest SUHII (2.47 degrees C) in urban core area and the lowest SUHII (-1.25 degrees C) in rural area. The annual daytime SUHII decreased apparently in urban core (-0.28 degrees C), urban (-0.10 degrees C) and rural (-0.58 degrees C) areas. The annual night-time SUHII increased weakly in urban core (0.20 degrees C), urban (0.02 degrees C) and suburban (0.08 degrees C) areas. Correlation analyses indicate that the SUHII was negatively and significantly correlated with vegetation activity except in winter days. In addition, the significant negative correlations between daytime SUHII change and vegetation change were observed except in winter. In contrast, the correlation between night-time SUHII change and vegetation change was not observed.