The spatial distribution of global urban heat island intensity and the influence of urban sprawl

With significant urbanization effects, the urban heat island effect has been reported in many cities. There are many related researches on urban heat island effect in a single city or urban agglomeration. In this paper, MODIS land surface temperature products, maps of global urban extent, gross domestic product, and population data were used to analyze the relationship between urban heat island intensity and urban sprawl factors. The results showed that: (1) the distribution of global urban heat island intensity existed obviously spatial heterogeneity, and the dominant impact factor of urban sprawl on urban heat island intensity in different regions was different. (2) Urban heat island intensity mainly were related to the human activities (gross domestic product and population), while the impact of urban shape characteristics (urban area and urban shape index) were limited. Therefore, to a certain extent it may be possible to keep the urban heat island intensity down under well-organized urban sprawling. (3) Urban heat island intensity could not be fully explained by urban sprawl factors only, other factors such as climatic factors still played an important role.