Spatiotemporal evolution and driving factors of urban vitality in China: Insights from grid-based quantification

The accelerating process of global urbanization has made disparities in urban vitality increasingly evident, underscoring the need for precise and systematic assessment. However, most existing large-scale studies still rely on single indicators and administrative boundaries, which constrains the fine-grained exploration of internal urban dynamics. To evaluate the spatial distribution and evolution of urban vitality, this study integrates NTL imagery and LandScan population data to construct a grid-based urban vitality index, combined with trend analysis and hotspot detection to reveal multi-scale patterns across China. The results show a 64% nationwide increase in vitality from 2012 to 2022, with regions east of the Hu Line contributing 95% of the growth. Vitality in coastal provinces increased far faster than in the 21 inland provinces, reflecting persistent spatial polarization in China’s urban development. This uneven growth further intensified disparities among core and peripheral clusters, major and secondary cities, and urban and non-urban areas, revealing a deepening imbalance in the diffusion of vitality. Multi-scale analysis identifies a 10 km threshold as critical for vitality diffusion. The Geographically and Temporally Weighted Regression model indicates that social security and household consumption are key drivers of vitality dynamics. A policy shift is replacing traditional factor-input and scale-expansion approaches with endogenous drivers that emphasize human vitality, social services, and environmental quality. This research provides a new analytical framework and solid data foundation for quantifying China’s urban vitality, offering valuable guidance for policy formulation and coordinated regional development.