Investigating the Spatiotemporal Pattern between Street Vitality in Historic Cities and Built Environments Using Multisource Data in Chaozhou, China

Historic cities serve as a crucial historical–cultural cornerstone within urban settings, and fostering its sustainable vitality has emerged as a focal point in urban research. Multisource data have advanced large-scale vitality research. Despite keen interest in the nexus between urban vitality and the built environment, the spatiotemporal intricacies influencing street vitality in smaller urban settings like ancient city are underexplored. To fill this gap, we use Chaozhou ancient cities as a case study to examine the relationship between street vitality and the built environment. Leveraging Jacobs' urban vitality theory and the 5D system, this study develops initial tools to understand ancient city vitality, focusing on density, diversity, accessibility, and the streets' spatial characteristics. Subsequently, employing a geographically and temporally weighted regression model, we delve into the spatiotemporal heterogeneity of vitality and the built environment. The research findings indicate that: (1) the association between street vitality and the built environment in historic cities exhibits dynamic variations over time and space. The impact of different built environment indicators on the vitality of the streets varies in intensity across different periods and areas. (2) Density and diversity play contrasting multifaceted and limited roles in enhancing the vitality of ancient cities. Accessibility's role in traffic attraction and navigability significantly sways vitality. The temporal nonstationary of street space characteristics is particularly pronounced. (3) The density of aged buildings, diversity of building ages, sky view ratio, and green view ratio generally show a negative correlation with the vitality of ancient cities across time and space.