How the built environment affects the spatiotemporal pattern of urban vitality: A comparison among different urban functional areas.

Urban vitality is an essential indicator of an area's capacity to promote lively social and economic activities. Urban functional areas can play different roles throughout the day, and urban vitality may exhibit significant intraday temporal dynamics. However, few studies have evaluated the dynamic vitality throughout the day among various urban functional areas or explored how the built environment influences this attribute. To bridge this gap, we assessed the vitality dynamics in intensity, variability, and night ratio. We then examined the influencing factors of urban vitality in Central Shanghai using heatmap and point of interest (POI) data. We found significant differences in the intensity, variability, and night ratio of urban vitality among different urban functional areas. The difference in vitality intensity was more significant than the variability and night ratio between weekdays and weekends. The built environment significantly affected urban vitality, but its role differed among the various urban functional areas. Overall, describing urban vitality from a dynamic perspective could improve our understanding of the differences in attracting and maintaining human activities among different urban functional areas.