Abstract
Effective water management in large river basins requires a comprehensive understanding of policy effectiveness and regulatory frameworks. However, quantitative assessments of water-related policies remain limited. Here, we propose a novel quantitative framework for evaluating water policies in large river basins, providing an intuitive and systematic approach for decision-makers. Using the Yellow River Basin-the second-largest river basin in China-as a case study, we constructed a database of 1271 water-related policies spanning 68 cities. We assessed the completeness of nine representative policies, identifying key gaps in water environment governance. To evaluate management effectiveness, we developed a system integrating two key subsystems: water resource utilization and water environment treatment, incorporating climatic, economic, and industrial factors. Our findings reveal that water environment governance policies were more effective than those targeting water resource utilization, though their impact was delayed by one to two years. Furthermore, a risk-based analysis pinpointed critical water management challenges in each city, offering actionable insights for policy optimization. This framework provides a robust and scalable approach for assessing the effectiveness of complex water policies in large river basins, with global applicability for improving water governance.