Spatio-temporal heterogeneity in the built environment-urban vibrancy nexus of rail transit station areas and its implications for targeted management: Case study of Xi’an, China

Urban Rail Transit (URT) station areas are pivotal nodes for shaping urban structure and fostering Urban Vibrancy. However, the spatio-temporal heterogeneity of the built environment’s impact on urban vibrancy remains underexplored, as existing research predominantly relies on spatially invariant global models, which overlook how the effects of the built environment vary across geographical locations and temporal contexts. To address this gap, this study uses Xi’an Metro Line 2 in China as a case study. Employing multi-source big data, including Location-Based Service (LBS) population heatmaps and Points of Interest (POIs) at a fine-grained grid scale, we utilize a Geographically Weighted Regression (GWR) model to quantitatively deconstruct the spatially varying interactions between built environment’s variables and urban vibrancy across different time periods (morning, noon, and evening).The results first statistically confirm the significant spatial non-stationarity of the built environment’s impacts. Based on this, the study identifies three distinct vibrancy generation archetypes: (1) "endogenous service-oriented" vibrancy, driven by localized built capacity and public services; (2) "exogenous attraction-based" vibrancy, defined by city-level functional synergies and public space quality; and (3) "nodal absorption-oriented" vibrancy, characterized by the efficient absorption of commuter flows through high-density development and functional diversity.These findings empirically challenge the universal applicability of principles within Transit-Oriented Development (TOD) theory. The core contribution of this study, therefore, is its advocacy for a paradigm shift in planning-from a "prescriptive framework" that applies standardized principles to a "diagnostic framework" predicated on the precise identification of local, dominant driving mechanisms. This conclusion provides a solid scientific basis and theoretical guidance for formulating place-based and time-sensitive strategies to enhance station area vibrancy.