A research team from Nanjing University of Aeronautics and Astronautics has proposed a new approach to managing the "virtual water" embedded in food production and trade, offering a better way to balance water resources across both river basins and cities.
The study, led by Liu Jinliang, a PhD student at NUAA's College of Economics and Management, was published in the Proceedings of the National Academy of Sciences (PNAS).
"Virtual water" refers to the water used to produce food. When food is traded from one place to another, the water used to produce it is effectively transferred with it, even though no physical water changes hands.
The challenge is that river basins naturally govern water resources, whereas food production, consumption, and trade are largely managed by administrative units such as cities. The team's simulations found that managing these systems separately can create new imbalances: measures that improve water distribution between river basins may increase disparities between cities, while optimizing water use within individual basins may fail to address basin-wide shortages.
To address this, the researchers proposed an integrated basin-city management framework. Their analysis shows that if 50 percent of the proposed measures were implemented, the approach could reduce disparities in water availability between river basins by 7 percent and save water equivalent to more than 80 percent of the Yangtze River Basin's annual food-related water use.
The framework provides a new tool for managing food-related water resources in China, offering insights for river basin governance and other resource-management challenges where natural systems and administrative boundaries do not align.
