Coupling dynamics of human-environment systems in the large lake basin: Spatiotemporal interactions and driving mechanisms of ecosystem services and human footprint intensity

• Opposing ESs-HFI dynamics emerge: ESs contract upstream vs HFI hotspots cluster downstream. • Polarized CCD pattern with degradation in transitional zones between stable ecological barriers and urban cores. • Synergistic eco-development systems amplify nonlinear HES coupling via carbon-water-NDVI synergy and GDP-population pressure. • Spatial statistics-CCD-XGBoost-SHAP integration offers replicable framework diagnosing lake basin sustainability. High-intensity human activities are reshaping the pattern of ecosystem services (ESs) and threatening the sustainability of human–environment systems (HES) in large lake basins. To elucidate the coupling mechanisms of such systems, this study constructs a model based on ESs and human footprint intensity (HFI). First, the Sen-MK trend and center-of-gravity migration models are used to characterize the spatiotemporal dynamics of the system. Next, exploratory spatial data analysis (ESDA) is combined with the coupling coordination degree (CCD) model to examine the spatial dependence structure and the coupled evolution patterns of the HES. Finally, the XGBoost-SHAP machine learning framework is applied to reveal the nonlinear interaction mechanisms among key driving factors. Using the Dongting Lake Basin as a case study, the results show the following. First, between 2000 and 2020, ESs and HFI exhibited significant spatial mismatches. The total ESs initially declined and then rebounded to 33 %, concentrating in upstream areas. In contrast, high HFI zones expanded from 13 % to 25 %, continuously clustering in downstream urban regions. Second, the HES exhibited a typical “contraction in the middle, expansion at both ends” pattern. Medium-coordination zones decreased by 10.9 %, while low-coordination zones increased by 135 %. Upstream ecological barrier areas and downstream urban clusters remained relatively stable, whereas the coordination in midstream transitional zones significantly deteriorated. Third, carbon storage, NDVI, and water yield constitute the ecological gain system of ESs, while population and GDP form the development pressure system. Significant synergistic enhancement exists among ecological elements, amplifying their positive effects on system coupling. Overall, the sustainable development of HES requires a comprehensive basin assessment and a systems coupling perspective. This study provides a scientific basis for hierarchical governance in large lake basins.