Urban heat island of Yangtze River Delta urban agglomeration in China: Multi-time scale characteristics and influencing factors

Abstract

Because the scale of the urban agglomeration is much bigger than that of a single city, the urban agglomeration may present different spatio-temporal urban heat island (UHI) patterns from those of a single city. Here in this paper, the multi-time scale UHI characteristics in the Yangtze River Delta urban agglomeration were investigated on the basis of remote sensing data, and the factors influencing the UHI effect were also analyzed with the meteorological data and the economic statistics. The results showed that the characteristics of temperature distribution in the daytime were more consistent with the basic definition of UHI than those in the nighttime. The monthly characteristics of UHI in the study area showed a regular movement pattern, and August was the most suitable month for the yearly UHI characteristics analyses. The yearly UHI variations coincided with the urbanization processes in the past 20 years. It was also found that in the meteorological factors, only the average temperature and the precipitation in the central region had linear relationships with the UHI areas. While the correlations between the UHI areas and various economic statistics factors were very significant.