Path dependency of urban resilience to recurring COVID-19 waves : the role of initial invasion contexts and urban scaling structure

Abstract

COVID-19 variants had emerged continuously and urban resilience to their invasion often relies on whether these variants can sustain transmission within urban population—potentially leading to new outbreaks or their extinction. In this process, the urban scaling structure that governs how local places interact and collectively shape scaling-distributed mobility patterns plays a critical role. This study built a spatially explicit agent-based model to explore how the origin place of new variants can influence subsequent transmission dynamics. We found small differences in initial invasion places had path-dependent effects on resilience outcomes. Structurally more important places can facilitate the occurrence of new outbreaks. However, surprisingly, outbreaks originated in structurally less important places show more explosive early spread. This early spread advantage can be attributed to survivorship bias: invasions originating from the less favourable environments had to be more vigorous to guarantee successful breakthroughs. Nevertheless, this early spread advantage was not sustained because the more dispersed waves of early spread may lead to greater energy loss in subsequent spread progression. These findings highlight the need to pay close attention to small but critical factors in urban systems, as they can accumulate over time to trigger unexpected disruptions and shape how cities respond to future challenges.