Water security assessment and prediction for coastal Urban Agglomeration: a case study in the Pearl River Delta, east China

Water security is a critical challenge for coastal urban regions due to rapid population growth, urbanization, and environmental vulnerability. This study provides a comprehensive water security assessment and prediction of the Pearl River Delta Urban Agglomeration, one of China's most economically advanced yet environmentally vulnerable coastal regions. The Driving Force-Pressure-State-Impact-Response (DPSIR) conceptual framework was utilized to establish a water security evaluation index system, with indicator weights determined through the entropy method. The single-indicator quantification, multi-indicator aggregation, and multi-criteria integration (SMI-P) method was employed for a thorough assessment. Using a combination of coordination and hindrance degree models, we identified the key factors impacting water security. The findings reveal significant improvements in the region's water security status, progressing from slightly unsafe to generally safe between 2012 and 2021. The coupling coordination degree increased from barely coordinated to intermediate coordination, with key obstacle factors identified. Predictive analysis using the grey prediction model forecasts further improvements, with water security expected to reach 0.651 by 2026. This study offers valuable insights for policymakers to enhance water resource management practices and promote sustainable development in coastal urban regions.