Harnessing rainwater for dryland agriculture: a review of harvesting and managed recharge strategies
Abstract
Arid and semi-arid regions, encompassing nearly half of Earth’s land surface, face escalating water scarcity due to precipitation variability, high evaporative demand, and climate change-induced extremes. While groundwater has historically buffered surface water deficits, widespread overexploitation has precipitated aquifer depletion, land subsidence, and water quality deterioration. Conventional irrigation practices—characterized by low water-use efficiency and weak governance—exacerbate these pressures. This review synthesizes principles and multi-scale applications of rainwater harvesting (RWH) as a strategic complement to conventional water management. It examines technical synergies between decentralized RWH systems and managed aquifer recharge (MAR), demonstrating their combined potential to alleviate stress on overexploited groundwater reserves. We address four objectives: (1) analyzing how increasing precipitation variability and extreme climatic events destabilize agricultural systems and exacerbate water risk; (2) evaluating technical and managerial inefficiencies in conventional irrigation; (3) highlighting cascading environmental, economic, and social costs of groundwater overdraft; and (4) proposing an integrated RWH–MAR framework to enhance water availability, improve ecosystem resilience, and contribute to sustainable agricultural intensification. Our findings show that integrating RWH with efficient irrigation, agroecological practices, and supportive governance can significantly improve water-use efficiency and system resilience. Advancing this approach requires a paradigm shift treating rainwater as a managed resource within a unified hydrological cycle. We conclude that revitalizing rainwater harvesting constitutes a cornerstone for building sustainable agricultural systems and ensuring food security under increasing climatic uncertainty. Key advantages of our integrated framework include: (i) reduced reliance on energy-intensive groundwater extraction; (ii) enhanced water availability during critical crop growth stages; (iii) improved groundwater quality through natural filtration mechanisms; and (iv) strengthened institutional capacity through participatory governance and community engagement.