Enhancing Drought Resilience in Combined Surface Water and Groundwater Supply Areas with a Hedging Policy Triggered by Drought-Limited Water Level

To address the increasing frequency and severity of droughts worldwide, water resource management strategies should prioritize enhancing resilience and adaptability to drought and water shortages. This paper focuses on water resource management issues in drought-prone areas with diversified water supply structures. It proposes and validated a framework to enhance the drought resilience of combined surface water and groundwater supply systems. Based on the concept of risk hedging, the framework constructs a combined water supply model of surface water and groundwater using General Water Allocation and Simulation Model (GWAS). It refines the calculation of drought limit water levels for each water source and their operational strategies. This study applied the framework to a typical drought-prone area in the North China Plain. It evaluated the effect of drought-limited water levels and their operation strategies on drought resilience of the water supply system based on the analysis of the overall drought resilience of various local water sources. The results indicated significant improvements in the reliability, resiliency, and vulnerability of the combined surface water and groundwater supply area during dry years. This framework optimizes the spatiotemporal distribution of water resources, transforming continuous extreme damage into milder wide-shallow damage, accelerating the speed of system restoration of water supply, and effectively mitigating extreme water shortages at the end of dry years. The research provides new insights and methods for water resource management in drought-prone areas, highlighting its importance for enhancing drought resilience and achieving stable, sustainable water resource utilization.