Water-City Coupling and Dual-Core Driven Strategy in Climate-Sensitive Metropolitan Areas

In the context of global climate extremes, the Chengdu-Chongqing region, a climate-sensitive metropolitan area, faces dual challenges of rapid urbanization and water resource security. This study develops a "climate-water-city" synergistic framework, integrating TOPSIS, standard deviation ellipse, and grey relational analysis to explore interactions between water resource carrying capacity (WCI) and urbanization quality (UQI) across 16 cities (2012–2022). Key findings include: (1) UQI improves at a 2.3% annual rate, driven by core cities, enhancing climate adaptability, while WCI fluctuates drastically (42% drop in 2022 due to extreme events); (2) coupling coordination rises from moderate dis-coordination (0.31) to primary coordination (0.65), highlighting climate variability’s role; (3) a "core agglomeration–edge adaptation" spatial pattern emerges, with peripheral areas using water-saving/ecological measures; (4) barrier analysis identifies ecological/social systems as key, reducing climate sensitivity by 25%. The proposed "dual-core synergy + axis diffusion" strategy cuts core-region risks by 18% (via cross-basin transfer/sponge cities) and designates 15% ecological buffers in peripheries. This "climate vulnerability zoning governance" model offers a scalable resilient framework, applicable to regions like the Amazon Basin. By quantifying climate elasticity’s impact, the study transcends traditional models, providing a novel paradigm for balancing development and security in climate-sensitive urban areas. It offers practical guidance for resilient planning (e.g., infrastructure optimization, sustainable water management), advancing climate resilience globally.