Basin-scale coupling between water-resource protection priority areas and urban–agricultural–ecological configuration typologies: Evidence from the Dongting Lake Basin, China

Climate change, urbanization, and intensified resource development are increasing pressure on freshwater systems and creating a need for spatially differentiated basin-scale protection. This study develops an integrated evaluation-configuration-diagnosis framework for the Dongting Lake Basin (DLB) from 2000 to 2023. A Water Resource Protection Importance Index (WRPI) and multiscale sensitivity analysis were used to identify stable high-demand areas. Class-level aggregation indices (CLUMPY) characterized the aggregation of urban, agricultural, and ecological spaces and identified stable spatial configurations. Spatial overlay delineated coupled priority areas, while an obstacle-degree model diagnosed municipal-level constraint structures. Stable high-demand areas were concentrated in the southern and southwestern basin, and their core distribution remained consistent across grid scales. In the urban-agricultural-ecological sequence, Low-Low-Low (LLL) and Low-High-High (LHH) were the dominant stable configurations, accounting for 40.99% and 31.62% of the total stable-configuration area, respectively. Overall, 90.96% of stable high-demand areas overlapped with stable configuration units, with LLL and LHH jointly accounting for 71.08% of the total overlap. The WRPI obstacle structure remained stable over time and was dominated by constraints related to Water Resource Conditions and Water Resource Development Potential, although their relative importance varied among municipalities and configuration contexts. Integrating municipal obstacle structures with stable configurations connected basin-scale priority assessment with specific spatial implementation contexts. The framework supports spatially targeted and differentiated water-resource governance in the DLB and provides a transferable workflow for other large basins.