Heat exposure inequalities in Hong Kong from 1981 to 2021

The heat exposure risks can differ for various sociodemographic groups because of the heterogeneous distribution of urban heat islands and populations across the space. This study investigates the association between the various sociodemographic attributes and their heat stress (given by the Land Surface Temperature) by the case of Hong Kong (HK) over 40 years, using census data and remote sensing temperature data. The findings reveal significant and widening differences of heat stresses based on ethnicity and first language, with Whites, English users, and overseas immigrants consistently experiencing lower heat stresses compared to other groups. The widening inequalities are related to the developments of the new satellite cities that tend to take high Land Surface Temperature, yet few migrants into these regions are within the groups above. The research demonstrates the persistent and growing thermal inequality among different sociodemographic groups in HK, highlights the vulnerability of environmental equality during the city expansion process, and underscores the considerable demands to mitigate heat stress in the newly developed regions.