Seeing Is Believing? Longitudinal Analysis of the Evolving Impact Mechanisms of Central Urban Liveliness through Multidimensional Spatial Morphology and Perception

As rapid urban expansion continues, the problem of urban hollowing has become increasingly pronounced. To mitigate the loss of spatial liveliness contributing to this issue, numerous studies have extensively examined the static relationship between two-dimensional (2D) urban spatial characteristics and spatial liveliness. However, the dynamic, longitudinal visual exploration of urban vitality from a three-dimensional spatial perception perspective remains underexplored. This study focuses on the central urban area of Guangzhou, China, employing semantic segmentation techniques to analyze street view images and quantify changes in two-dimensional urban morphology and three-dimensional perceptions, alongside the temporal dynamics of spatial liveliness. By constructing spatial autocorrelation and nonlinear regression models, we investigate the dynamic influence of multidimensional urban spatial forms on spatial liveliness. The results reveal a trend of vitality collapse in the core areas of the central city, while the noncore areas exhibit heterogeneous growth in vitality. Moreover, the study challenges the prevailing dominance of 2D physical space in defining urban vitality, demonstrating that three-dimensional spatial experiences have a more significant impact on vitality changes in central urban areas. Additionally, the combination of urban green spaces and block walkability contributes to stronger spatial liveliness in the central city, whereas spatial openness and enclosure show little correlation with urban spatial liveliness. From a planning perspective, we find that the old central areas have a closer connection to residents' experiential perceptions, suggesting that enhancing spatial familiarity and intimacy can increase visitation rates. The findings provide actionable solutions for addressing the collapse of spatial liveliness in older central urban areas.