Water pollution control promotes sustainable water use in Yangtze River Economic Belt——from water footprint perspective

The Yangtze River Economic Belt (YREB), characterized by its dense population and dynamic industrial activities, is facing unprecedented challenges in balancing water resource utilization with environmental protection. Understanding the interplay between water environment and economic development is crucial for the YREB. In this study, the dynamics of sustainable state and driving mechanism for water utilization examined from a Water Footprint (WF) perspective at regional and sectoral scales from 2002 to 2017. The analysis is facilitated by a novel framework that integrates WF sustainability and equilibrium assessment for water pollution and scarcity stresses with structural decomposition analysis (SDA), based on multiregional input-output (MRIO) dataset. The results reveal that the YREB had an extremely high grey WF (GWF), approximately nine times higher than the blue WF (BWF), yet has consistently decreased by 210.00 billion m3 during 2002–2017, indicating a greater but mitigated stress from water pollution compared to water scarcity. Our analysis shows an increase in the Sustainability Index (SI) of YREB from 0.3706 to 0.4435, primarily due to the reduction in GWF. Water use equality among the three major sectors has also improved. The decomposition results highlight that water conservation and treatment technologies have the most significant impact on reducing WFs, followed by shifts in consumption patterns and adjustments in industry structure, all of which enhance the water sustainability of the YREB. This study underscores the critical role of water pollution control in ensuring sustainable water resource use, as reducing pollution loads supports responsible water exploitation, leading to improved water quality and optimized resource efficiency.