Water securityUsing satellites to measure vital underground water resources

Published 20 July 2018

The availability of water from underground aquifers is vital to the basic needs of more than 1.5 billion people worldwide. In recent decades, however, the over-pumping of groundwater, combined with drought, has caused some aquifers to permanently lose their essential storage capacity. Scientists are using the latest space technology to measure this precious natural resource.

The availability of water from underground aquifers is vital to the basic needs of more than 1.5 billion people worldwide.

In recent decades, however, the over-pumping of groundwater, combined with drought, has caused some aquifers to permanently lose their essential storage capacity.

With the hope of providing better tools to water resource managers to keep aquifers healthy, scientists funded by the National Science Foundation (NSF) and affiliated with Arizona State University (ASU) and the Jet Propulsion Laboratory (JPL) are using the latest space technology to measure this precious natural resource.

“Periods of drought have long-term effects on groundwater supplies and create major challenges for groundwater management,” says Maggie Benoit, a program director in NSF’s Division of Earth Sciences, which funded the research. “Now, scientists are developing new methods of monitoring groundwater levels using satellite-based measurements of Earth’s surface, providing a more comprehensive picture of the health of our nation’s groundwater resources.”

The researchers have focused their efforts on one of the world’s largest aquifer systems, located in California’s Central Valley, measuring both its groundwater volume and its storage capacity. The results of their findings are published in the American Geophysical Union journal Water Resources Research.

Peering underground from space
NSF notes that California’s Central Valley is a major agricultural hub covering an area of about 20,000 square miles. It produces more than 25 percent of U.S. agriculture, at an estimated value of $17 billion per year.

The Central Valley aquifer system provides water for people and wetlands, supplying about 20 percent of the overall U.S. groundwater demand. Because of drought and the increase in the human population this aquifer serves, it is ranked one of the most stressed in the world.

While past studies on water resources and drought have focused mainly on low-resolution or local scale measurements of groundwater dynamics, the research team for this study, which includes ASU scientists Chandrakanta Ojha, Manoochehr Shirzaei and Susanna Werth, and Donald Argus and Thomas Farr from JPL, took a more high-tech route.