In a report speculating that an African land grab could lead to future water conflicts, New Scientist magazine cites a new study by Princeton Engineering’s Ignacio Rodriguez-Iturbe examining how “virtual water” moves around the world. In an effort to secure their food supply, China, India, and Saudia Arabia are leasing water-rich tracts in sub-Saharan Africa to grow their own food rather than importing it. This is the equivalent of importing “virtual water,” according to New Scientist, since food production accounts for nearly 80 percent of annual freshwater usage.

New Scientist reports that Rodriguez-Iturbe and Samir Suweis of the Swiss Federal Institute of Technology in Lausanne have built the first mathematical model of the global virtual water trade network. To do so they drew upon the U.N. Food and Agricultural Organization’s data on trade in barley, corn, rice, soya beans, wheat, beef, pork, and poultry in 2000.

“The model shows that a small number of countries have a large number of connections to other countries, offering them a steady and cheap supply of virtual water even if some connections are compromised by drought or political upheaval,” New Scientist writes. “A much larger number of countries have very few connections and so are vulnerable to market forces.”

This results in what Rodriguez-Iturbe terms “the rich club phenonmenon,” whereby 80 percent of water flows through just 4 percent of these connections.

Read the full article here.