Synergistic evolution and transition mechanism of urban resilience and efficiency in the Yangtze River Delta urban agglomeration, China

Balancing urban resilience (UR) and urban efficiency (UE) is essential for achieving sustainable development within China’s high-density urban agglomerations. We investigate their synergistic relationship in the Yangtze River Delta urban agglomeration, one of the world’s most densely populated regions. UR and UE between 2010 and 2022 were quantified via an integrated AHP-EWM-TOPSIS approach and the Super-EBM model. The improved Haken model was utilized to describe their synergistic relationship. Furthermore, the dynamic evolution and transition mechanisms of UR-UE synergy were examined from the perspective of spatiotemporal interactions. The key findings are as follows: (1) UR acts as the dominant order parameter driving sustainable development. (2) Synergy levels remain suboptimal throughout the study period, with a spatial distribution pattern of “core metropolitan-driven, provincial capital-synergized.” (3) Four distinct transition patterns were identified, demonstrating significant path dependency and spatial lock-in effects in synergistic state evolution. This study establishes UR as the dominant factor for sustainability in mature, high-density agglomerations. The findings advance understanding of complex system dynamics in such regions and provide a theoretical foundation for diagnosing developmental bottlenecks, designing targeted policies to optimize UR-UE synergy, and fostering sustainable development.