Resident heat exposure in major cities in Northeastern China

The urban heat island phenomenon is one of the urban problems caused by urban expansion and changes in underlying surfaces. It makes urban residents suffer more heat stress than surrounding rural residents on ordinary days. Heat exposure depends not only on temperature but also on the spatial distribution of population. The integrated impacts of the temporal and spatial distribution of temperature and the population on heat exposure are poorly known in cities. We used open source data of land surface temperature and population distribution to conduct independent thermal exposure analysis on specific residential areas, commercial areas, factories and scenic spots in Shenyang, Changchun, and Harbin, the capital cities of the three northeastern provinces of China. Results showed that the heat exposure in areas with higher surface temperature were not necessarily the strongest. Commercial districts in cities with massive anthropogenic heat emissions were areas with higher heat exposure. Scenic spots had lowest heat exposure due to more vegetation and few built-up surfaces. This study combines urban surface temperature with occurrence of population to quantify the spatial and temporal dynamics of heat exposure in different functional areas, providing critical information to heat emergency responses in cities.

Key words ：Heat exposure index; Urban heat island ; Population; functional areas