Evaluating urban vitality and resilience under the influence of the COVID-19 pandemic from a mobility perspective: A case study in Shenzhen, China

Urban vitality is a critical metric for assessing a city's appeal, competitiveness, and sustainability. The lockdown measures enacted during the coronavirus disease 2019 (COVID-19) pandemic has imposed a substantial impact on people's mobility, yet how urban vitality has evolved and the extent of its recovery remain unclear. To address this knowledge gap, this study introduces a novel method for assessing vitality through the lens of human mobility. By combining residents' origin-destination (OD) flow data with the PageRank algorithm, our approach evaluates regional vitality by considering visitation volume, travel distance, and the architecture of the flow network simultaneously. Focusing on Shenzhen, China, as a case study, we evaluate its urban vitality from 2019 to 2023 using the OD flows extracted from mobile phone big data. Building on this evaluation, a resilience indicator is further established to measure the recovery of vitality, and the geographically weighted regression is employed to investigate the factors influencing vitality, with their spatial and temporal changes being explored. Our findings reveal that, as of June 2023, the overall urban vitality in Shenzhen has only recovered to 86% of the level during the same period in 2019, with certain districts exhibiting a continuous decline in vitality even as the epidemic subsided. The main influencing factors also present a significant spatial heterogeneity across different districts in Shenzhen. This study is expected to provide a new method to evaluate vitality dynamics and offer insights to enhance urban vitality.