A novel framework for integrated assessment of reclaimed water demand potential in China

As global water scarcity intensifies, reclaimed water has emerged as a critical sustainable alternative to conventional resources. This study develops an innovative measurement system to assess regional reclaimed water demand potential index (RDPI) in China, revealing a significant east-west disparity along the Hu Line. Using internal-external factor analysis, we identify key drivers and constraints. The results of the study show that: (1) Jiangsu and Xinjiang exhibit the highest demand potential, the RDPI in the eastern region is higher than that in the western region. (2) Kernel density analysis shows rising potential in eastern and central regions, while the west follows a multipolar pattern. From 2015 to 2023, the Gini coefficient showed a fluctuating trend of “decreasing-increasing-decreasing” with an overall downward trend. (3) The RDPI on both sides of the Hu Line is significantly constrained by the S₈ (density of reclaimed water pipes in built-up areas) and E₂ (water resources per capita) obstacle factors. External driving factors show that RDPI in western regions is mainly driven by the synergistic effects of economic detectors and industrial detectors, while in eastern regions, the impact of key polluting industries and environmental awareness is more pronounced. This study provides actionable insights for policymakers to optimize reclaimed water utilization, addressing regional imbalances and sustainability challenges.