Satellites find that snow didn’t offset southwestern US groundwater loss

A recent study using satellite data has revealed that the southwestern United States did not experience a significant rebound in groundwater levels despite above-average snowfall in the region. The findings, published in the journal _Water Resources Research_, suggest that the region’s groundwater reserves continue to decline, posing a significant threat to the long-term sustainability of its water resources.

The southwestern United States, which includes states such as California, Arizona, and Nevada, has been experiencing a prolonged drought in recent years. The drought has had a devastating impact on the region’s agriculture, ecosystems, and water resources. In an effort to mitigate the effects of the drought, scientists have been monitoring the region’s groundwater levels using satellite data.

The study, led by researchers from the University of California, Irvine, used data from NASA’s Gravity Recovery and Climate Experiment (GRACE) satellites to track changes in groundwater levels across the southwestern United States. The GRACE satellites, launched in 2002, use gravity measurements to detect changes in the Earth’s mass, including the movement of water underground.

The researchers analyzed GRACE data from 2003 to 2019 and found that despite above-average snowfall in the region during the 2016-2017 winter season, groundwater levels did not significantly rebound. In fact, the study found that groundwater levels continued to decline at a rate of approximately 1.5 centimeters per year.

The lack of rebound in groundwater levels is attributed to several factors, including increased water pumping and human consumption, as well as changes in land use and climate patterns. The study’s lead author, Dr. Jay Famiglietti, noted that “the snowpack in the southwestern United States is not as effective at recharging groundwater as it once was, due to changes in climate and land use patterns.”

The findings of this study have significant implications for water management in the southwestern United States. Groundwater is a critical component of the region’s water supply, and its depletion can have devastating consequences for agriculture, ecosystems, and human consumption. The study’s authors suggest that policymakers and water managers must take a more proactive approach to managing the region’s water resources, including implementing more efficient irrigation systems and promoting water conservation practices.

Furthermore, the study highlights the importance of continued monitoring of groundwater levels using satellite data. The GRACE satellites have provided invaluable insights into the region’s groundwater dynamics, and future satellite missions, such as the GRACE-FO mission launched in 2018, will continue to play a critical role in tracking changes in groundwater levels.

In conclusion, the study’s findings serve as a stark reminder of the need for sustainable water management practices in the southwestern United States. As the region continues to grapple with the impacts of drought and climate change, it is essential that policymakers and water managers take a proactive approach to managing its water resources, including implementing more efficient irrigation systems and promoting water conservation practices. By doing so, we can ensure a more sustainable future for the region’s water resources.