Groundwater System Evolution and Sustainable Management in Energy Bases: A Case Study of Ejin Horo Banner Hilly Region

Addressing water resource constraints in arid energy bases, this study employs a calibrated 3D groundwater flow model to systematically assess groundwater dynamics in Ejin Horo Banner’s hilly region (Ordos, China). Key findings reveal: (1) Total annual groundwater resources amount to 10,841.331×10⁴m³ with marked spatial heterogeneity (Zone I: 2,965.947×10⁴m³ to Zone VI: 420.844×10⁴m³); (2) A water deficit of -1,090.647×10⁴m³/a indicates unsustainable exploitation, where rainfall infiltration dominates recharge (64.15%) and groundwater extraction constitutes 64.63% of total discharge; (3) Simulations (2020–2026) project persistent groundwater decline, with maximum cumulative drawdown reaching 3.7m in Zone V by 2025, and an additional 1.5m by 2026; (4) The dual-driver mechanism combines seasonal fluctuations (wet-season rise/dry-season decline) with long-term mining-induced depletion. We propose zone-specific management strategies: strict extraction control in Zone V, enhanced rainfall infiltration utilization, and a water-energy nexus governance framework, offering a scientific paradigm for sustainable water management in ecologically fragile energy hubs.