Towards sustainable cities: A human-centric approach to evaluating urban heat island intensity responses

Urban heat island intensity (UHII) is a critical metric for assessing urban thermal environments, yet traditional approaches often lack a human-centric perspective, resulting in limited insights into human thermal stress and global variability in UHII responses to influencing factors. Addressing this gap is critical for mitigating UHII through factor regulation (regulating the scale of factors influencing UHII), thereby contributing to the development of sustainable and livable cities. In this study, we employ the Universal Thermal Climate Index (UTCI) to calculate UHII (UHII-UTCI) based on a human-centric delineation of urban and rural areas. We further evaluate UHII-UTCI responses to changes in influencing factors at a fine spatial scale. The differences in these responses are captured through three key elements: (1) dominant influencing factors, (2) response patterns—classified as monotonic increasing (Type-I), monotonic decreasing (Type-D), and downward parabola (Type-P)—and (3) regulation thresholds of the response patterns. Additionally, the spatial heterogeneity of these key elements is notable, with distinct clusters observed in eastern North America, East Asia, and Europe. These findings emphasize the urgency of adopting human-centric approach to address the growing threat of urban heat, and underscores the necessity of tailored, context-sensitive strategies to mitigate UHII in diverse global settings.