Three-dimensional assessment of watershed health resilience and low-resilience risk analysis under the coupling of water resources, ecosystem and Socioeconomic systems

Watershed resilience under compounded climate variability and intensifying human disturbances has become a critical prerequisite for sustainable development in semi-arid inland basins. This study developed a spatially explicit watershed health resilience (WHR) framework that integrates three resilience dimensions (resistance, restoration, and adaptability) within the water resources, ecosystem, and Socioeconomic subsystems. Using the upper Xilin River Basin (XRB) as a case study, this study constructed a grid-based indicator system and quantified WHR dynamics during 2010–2023 based on multi-source hydro-climatic, remote sensing, and Socioeconomic datasets. The obstacle degree model and GeoDetector were employed to diagnose key constraints and attribute spatial heterogeneity, while KDE-based marginal estimation and copula models are used to characterize dependence structures and joint and conditional low-resilience risks among subsystems. WHR exhibits persistent spatial heterogeneity, with stable low-resilience clusters along the main river course, tributary confluences, and the reservoir-affected reach, whereas upstream areas remain consistently higher. Basin-averaged WHR increases from 0.41 (2010) to a peak of 0.59 (2021). Obstacle analysis reveals that the water resources subsystem constitutes the primary bottleneck, mainly constrained by the surface runoff restoration coefficient and the seasonal rebound amplitude of groundwater level. GeoDetector demonstrates that vegetation-water coupling factors are the main drivers of WHR spatial heterogeneity, led by seasonal rebound amplitude of NDVI and water use efficiency. Copula-based analysis indicates the strongest lower-tail dependence and the highest joint low-resilience risk for the water resources-ecosystem pair, suggesting a higher likelihood of co-failure under adverse states. This framework supports resilience-oriented hotspot targeting and cross-subsystem risk-informed watershed management.