Exploring spatiotemporal changes of the urban heat Island effect in high-latitude cities at a neighbourhood level: A case of Edmonton, Canada

Abstract

Urban heat exposures have increased considerably in cities around the globe due to rapid urbanization and the changing climate. This study explores the spatiotemporal variations in surface urban heat islands (SUHIs) across multiple seasons as well as the relationship between neighbourhood-level SUHI intensity and three major factors—land surface, anthropogenic heat, and population characteristics—in a high-latitude city. The study focuses on the City of Edmonton, Canada, North America's northernmost high-latitude city with a population of one million. Results showed a significant SUHI intensity increase over the past two decades during spring, summer, and winter. Neighbourhood SUHI intensity in summer significantly reduces with the increase in areas covered by vegetation (r = -0.9) and water bodies (r = -0.6), whereas intensity significantly rises with increased road network (r = 0.6) and population density (r = 0.5). Results also indicated that increasing vegetation cover in neighbourhoods by up to 20% could reduce current SUHI intensity by one-third. The study revealed that neighbourhoods with more affluent and better-educated residents experience lower SUHI intensities. The findings will help municipal planners and policymakers develop heat mitigation strategies for new and existing neighbourhoods, along with high-latitude city design structures that enhance the winter benefits of SUHIs, while reducing summer penalties.