Groundwater depletion in semiarid regions of Texas and California threatens US food security

The nation's food supply may be vulnerable to rapid groundwater
depletion from irrigated agriculture, according to a new study by
researchers at The University of Texas at Austin and elsewhere.
The study, which appears in the journal Proceedings of the National Academy of Sciences,
paints the highest resolution picture yet of how groundwater depletion
varies across space and time in California's Central Valley and the High
Plains of the central U.S. Researchers hope this information will
enable more sustainable use of water in these areas, although they think
irrigated agriculture may be unsustainable in some parts.
"We're already seeing changes in both areas," said Bridget Scanlon,
senior research scientist at The University of Texas at Austin's Bureau
of Economic Geology and lead author of the study. "We're seeing
decreases in rural populations in the High Plains. Increasing
urbanization is replacing farms in the Central Valley. And during
droughts some farmers are forced to fallow their land. These trends will
only accelerate as water scarcity issues become more severe."

Read the whole story: http://www.sciencedaily.com/releases/2012/05/120528154857.htm