Mapping the Spatiotemporal Evolution of Virtual Water Flows in Global Maize Cultivation

Water scarcity is among the most urgent global challenges, with agriculture responsible for nearly 70% of freshwater withdrawals. Accurate accounting of water use across sectors is essential for effective policy design, yet conventional assessments often capture only direct irrigation while overlooking indirect water embedded in supply chains. To address the limitation, this study focuses on maize—a globally significant staple crop—and employs a dynamic input–output model to quantify its direct and indirect water use (known as virtual water) at global, national, and sectoral scales from 2005 to 2020. Our results show that, first, maize's virtual water use is highly uneven: the Americas and Asia dominate global flows, with the United States sustaining its role as the largest net exporter, while contributions from middle‐income countries such as China and Pakistan are rising rapidly. Second, although Africa's virtual water remains modest, its rapid growth signals expanding maize cultivation in emerging regions. Third, virtual water is concentrated not only in agriculture but also in industries such as energy, chemicals, and metallurgy, underscoring the importance of cross‐sectoral linkages. These findings deepen understanding of global maize virtual water flows and provide a scientific basis for improving water‐use efficiency, optimizing trade structures, and fostering transregional cooperation for SDG 6.