Field-constrained and robustness-aware assessment of potential groundwater disturbance from deep coal mining: Coupling fracture-zone development, aquitard safety and aquifer hydraulic sensitivity

Traditional deterministic zoning methods for groundwater impact induced by deep coal mining fail to characterize mining-induced groundwater responses and ignore zoning uncertainty, leading to unreliable results. To address this problem, this study develops a field-constrained and uncertainty-aware framework for groundwater impact zoning based on a coal mine in Ordos, Inner Mongolia. Field measurements are adopted to determine the height of the water-conducting fracture zone (WCFZ). Key indicators including the depth-to-thickness ratio, vertical protection distance of aquitard, and aquifer hydraulic sensitivity index are selected and integrated into a groundwater disturbance index via seam-specific entropy-weight TOPSIS. Each seam is then independently classified by one-dimensional K-means. Weight perturbation and Monte Carlo simulations are conducted to verify model robustness and quantify zoning uncertainty. Field tests reveal that the measured WCFZ heights (79.6–83.0 m for panel 21104 and 80.0–81.4 m for panel 21404) are considerably higher than empirical estimates. Zoning results show that Level III–IV potential-disturbance zones account for 23.47% and 35.68% of the 2-1# and 2-2# seam domains, respectively. Uncertainty analysis verifies that the continuous spatial ranking is more stable than discrete boundaries, with mean rank correlations remaining 0.979 and 0.975 and mean baseline-class retention reaching 90.99% and 83.71%. Furthermore, a potential transition from aquitard barrier-dominated protection to coupled barrier-aquifer sensitivity protection is suggested in coal mining groundwater systems. The proposed framework clarifies the potential response mechanism of groundwater to deep coal mining and distinguishes impact magnitude from classification robustness, providing a reliable scientific basis for spatially differentiated water-preserved mining.