Satellite Data Gives Scientists New Look at Underground Water Sources

There may be a new way to monitor underground water sources. Scientists have managed to find a way to use satellites to accurately measure levels of water stored hundreds of feet below ground. The findings could be huge for ground water management in the future.

Groundwater is important to our freshwater systems. In fact, it provides 25 to 40 percent of all drinking water worldwide. It's also the primary source of freshwater in many arid countries. Needless to say, managing this resource is important, despite the difficulty in estimating availability predictions.

Until now, the only way a water manager could gather data about the state of water tables in a watershed was to drill monitoring wells. This process in particular is both time and resource intensive, especially for confined aquifers. That's why scientists decided to see if there was another way to monitor water levels.

The researchers decided to look to the sky. Satellites can use electromagnetic waves to monitor changes in the elevation of Earth's surface to within a millimeter. In theory, this means they could be mined for clues about groundwater. The technology, which is called Interferometric Synthetic Aperture Radar (InSAR), has previously been used to collect data on volcanoes, earthquakes and landslides.

The researchers used InSAR in order to make measurements at 15 locations in Colorado's San Luis Valley. This allowed them to compile water-level measurements for confined aquifers at three sampling locations that matched the data from nearby monitoring wells.

"If we can get this working in between wells, we can measure groundwater levels across vast areas without using lots of on-the-ground monitors," said Jessica Reeves, one of the researchers, in a news release.

The findings could be huge for future groundwater monitoring activities. As satellite data improves, scientists and monitors could use the information in order to estimate how much water is available in a certain region in order to better manage the resource.

The findings are published in the journal Water Resources Research.