Spatiotemporal variations and influencing factors of heatwaves in Chengdu, China

In the context of global warming and rapid urbanization, the impacts of heatwaves on urban residents and socioeconomic activities are becoming increasingly pronounced. This study examines the spatiotemporal variations and influencing factors of heatwaves in Chengdu from 1961 to 2019, utilizing methods such as trend analysis, gravity center movement, time series clustering, and GeoDetector. The findings reveal a significant increase in the frequency, duration, and intensity of heatwaves since 1994, with an average rise of 2.14 degrees C per decade, and a spatial distribution that decreases from east to west. Heatwave intensity is closely linked to temperature and elevation, as well as atmospheric factors such as the intensity of the Western Pacific Subtropical High and the Tibetan High. Notably, despite an increase in blue-green spaces in Chengdu over the past 10 years, heatwave intensity has intensified, indicating that at the city-wide scale, the effects of urbanization and global warming outweigh the climate regulation benefits of blue-green spaces. This research enhances the understanding of urban heatwaves in Chengdu and Southwest China, providing a scientific foundation for effective heatwave risk assessment and climate change adaptation strategies. Furthermore, it offers insights for other megacities confronting similar heatwave challenges.