The driving forces behind virtual water reduction in the Yangtze river delta urban agglomeration

Virtual water trade and regional specialization can enhance water security, yet their drivers and impacts remain unquantified. In this study, we propose a system-based modeling framework to trace virtual water transfer patterns, identify intercity network relationships, and quantify the primary socioeconomic factors driving water footprint dynamics in the Yangtze river delta urban agglomeration. Our analysis reveals that the total water footprint of this region decreased by 6% between 2010 and 2020. Water-scarce cities such as Yancheng, Yangzhou, and Tai'zhou in Jiangsu province serve as major production centers for water-intensive goods, accounting for nearly half of the region's total virtual water exports. Changes in water use intensity, production structure, and final demand composition are identified as critical contributors to water footprint reductions in cities across Zhejiang and Anhui provinces. These findings underscore the necessity of cross-regional cooperation to address inefficient water resource allocation and mitigate unintended increases in water stress.