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The global ties that bind water, food and climate

Tara Troy, assistant professor of water resources engineering, takes a very macro-level approach to her field of study. “You can’t think about water in isolation of climate or agriculture or energy,” she says. “All of these systems are linked. That makes a hydrologist’s job challenging, but it also means our research answers very societally relevant questions.”

Among them: How are changes in international food consumption affecting groundwater resources at home? A recent paper published in the journal Proceedings of the National Academy of Sciences spoke to the growing globalization of food and water resources and why Troy’s bird’s eye view of this system is important to help optimize the use of finite resources.

The paper, which was coauthored by Troy and by Landon Marston, Megan Konar and Ximing Cai of the University of Illinois at Urbana- Champaign, examined the way droughts have forced many American farmers to look deep underground for a source of water for crop irrigation.

According to the paper, as much as 18 percent of American cereal crops—grains like corn, rice and wheat—depend on groundwater from three significant American aquifer systems: the Central Valley, High Plains, and Mississippi Embayment. Though trillions of gallons of water sit untapped beneath the surface of the earth, it will become increasingly costly to extract that water before it eventually runs out, and continued reliance on this water could have severe effects on the global food supply, as other nations—including Japan, Taiwan and Panama—buy their cereal grains from U.S. sources that rely on groundwater.

“Under an uncertain climate future, in which rain-fed agriculture is likely to experience more droughts and extreme climate events, groundwater resources may become more valuable,” the paper says. Just how valuable? That’s still to be determined, but this new knowledge of the virtual transfers of groundwater resources, combined with an increased understanding of local production withdrawals, will empower producers, consumers, water planners, and other decision makers to balance current food and water needs while keeping an eye on future consumption.

To answer these complex, large-scale problems, Troy is seeking to identify links between systems through modeling and data analysis.

“As we continue to acquire more measurements and learn more about the interconnected processes that lead to these problems,” she says, “we’ll be able to start developing smarter, more sustainable solutions.”