Evaluation and Forecasting of Water Sustainability in China Under Shared Socio-economic Pathways

Water resources play a fundamental role in maintaining ecosystem well-being and supporting socio-economic progress. Nevertheless, the water sustainability confronts unprecedented challenges exacerbated by climate change and human interventions. This research establishes a comprehensive evaluation framework aligned with the United Nations’ Sustainability Development Goals (SDGs) to assess water sustainability across 30 Chinese provinces, municipalities, and autonomous regions (excluding Xizang, Hong Kong, Macao and Taiwan). By integrating natural, economic, and social factors, this research elucidated the spatiotemporal evolution patterns of water sustainability from 2010 to 2020, and projected future trajectories under diverse socio-economic pathways (SSPs) for 2030 and 2050. The main findings include: 1) China’s water sustainability demonstrated gradual improvement during 2010–2020, yet baseline levels remain suboptimal for achieving SDG targets in 2030. Projections suggest significant enhancements by 2050, particularly under the SSP1-2.6 sustainability-oriented scenario. 2) Persistent regional disparities are evident, with acute sustainability deficits observed in densely populated, intensively cultivated northern and the arid northwestern territories. These disparities are projected to attenuate by 2050. 3) Natural ecological processes emerge as the dominant contributor to water sustainability, with projected growth potential. Economic processes constitute a secondary driver, while social dimensions exhibit more limited influence, both displaying heterogeneous developmental trajectories. 4) SDG 6.4 (Water Use Efficiency) demonstrates the highest implementation efficiency, whereas SDG 6.3 (Water Quality) and SDG 15.1 (Terrestrial Ecosystem Conservation) require urgent policy interventions. This study demonstrates the applicability of the proposed SDGs-aligned framework in diagnosing China’s water sustainability challenges, providing actionable insights for regional policy prioritization. The interdisciplinary methodology bridges scientific analysis and governance strategies, enabling robust decision-making under complex future uncertainties.