Strategic Repurposing of Abandoned Cropland for Aquifer Recharge and Renewable Energy Boosts Water-Food-Energy Sustainability

The increasing demands for food and renewable energy are placing unprecedented pressure on water and land resources, a challenge further exacerbated by climate-induced declines in surface water availability. Globally widespread cropland abandonment presents a unique opportunity for strategic, multi-benefit land repurposing to enhance sustainable water, food, and energy management. Managed Aquifer Recharge (MAR) offers a promising strategy to augment groundwater supplies for agriculture and ecosystems, while water-efficient variable renewable energy (VRE), such as wind power and solar photovoltaic (PV), offers potential to reduce surface water use for hydropower, allowing more water allocation for irrigation and MAR. Despite these promising synergies, the large-scale feasibility and socio-economic value of integrating MAR and VRE development on abandoned cropland remain unclear. In this study, we develop a multi-scale spatial optimization framework to identify priority locations for MAR and VRE expansion, aiming to enhance water, food, and energy security, particularly during droughts. We evaluate the benefits and trade-offs of repurposing global abandoned cropland under various strategies (i.e., MAR only, VRE only, and integrated MAR-VRE) across different climate conditions and spatial scales (local, regional, and global). Our findings highlight that multi-objective spatial optimization and cross-scale coordination are crucial for maximizing synergies and minimizing conflicts between MAR and VRE development. Our study reveals the untapped potential of abandoned cropland for water and energy expansion and proposes a scalable framework to support multi-benefit land management strategies that boost water-food-energy sustainability.