Hydroclimatic variability and socio-hydrological adaptation in the Yiluo River Basin (2013–2023) of China
Climate change and urbanization are intensifying pressures on the sustainable development of water-scarce regions. Exploring adaptive management strategies and models is therefore critical. While previous studies have applied socio-hydrological balance theory, synergetics, or random forest separately, to our knowledge, this study is the first to integrate all three methods into a unified framework for analyzing stage-based adaptive mechanism in a single basin. Furthermore, the proposed ‘Pressure-State-Response-Regulation-Pressure’ feedback cycle provides a novel conceptual model for understanding self-regulation in socio-hydrological systems. This study focuses on China’s Yiluo River Basin, integrating the socio-hydrological balance framework, synergetics theory, and random forest models to assess adaptive development pathways in the context of evolving socio-hydrological cycles. Key results from the period 2013–2023 indicated: (1) Mann–Kendall trend tests and Sen’s slope estimation analysis indicated that the hydrological variables in the Yiluo River Basin still did not show a significant trend. (2) Trend tests for 19 social hydrological cycle indicators suggested that the water usage for daily life and ecological environment showed an increasing trend, while industrial water usage showed a decreasing trend (P < 0.05), and wastewater discharge showed a decreasing trend (P < 0.05). It can be seen that the social hydrological cycle in the Yiluo River Basin in the past 10 years has presented different characteristics from the changes in water resources. (3) Although the key potential factors for the adaptability of water resource systems have been constantly changing over different periods, there has been an increasingly orderly evolution of the socio-hydrological balance. Synergy‑degree analysis further demonstrated the indicators with higher compatibility with the water resource system have increased from 5 to 11 in the study period. (4) The dominant statistically important predictors evolved dynamically: initially integrated and domestic water conservation, then industrial water saving, followed by combined industrial-agricultural water saving, and ultimately, unconventional water utilization. (4) Adaptation operates through a “Pressure–State–Response–Regulation–Pressure” feedback mechanism.