Nav: Home

Measuring impact of drought on groundwater resources from space

March 19, 2019

A team of ASU scientists has been using the latest space technology, combined with ground measurements, to assess the health of one of the nation's most important sources of underground water, a large aquifer system located in California's San Joaquin Valley.

The team, comprised of School of Earth and Space Exploration researchers Chandrakanta Ojha, Susanna Werth, and Manoochehr Shirzaei, focused on the San Joaquin Valley's most recent drought period, from 2012 to 2015, measuring both groundwater loss and aquifer storage loss. The results of their findings have been recently published in the Journal of Geophysical Research.

With the hope of providing water resource managers with better tools to help keep aquifers healthy, the research team is developing new observation techniques to monitor groundwater and storage capacity of this important California aquifer.

They are using a unique combination of data from the NASA GRACE satellites, the Global Navigation Satellite System (GNSS), Interferometric Synthetic Aperture Radar (InSAR) from the European Space Agency's Sentinel 1 satellite, extensometers, and ground level records.

The results of the recent study, which is a follow up to their 2018 published research on the 2007-2010 drought in California's Central Valley, show an alarming loss of ground water each year of the 2012-2105 drought and, more importantly, an overall permanent loss of storage capacity in the San Joaquin Valley aquifer.

"Using high-tech Earth-orbiting satellites, we can see that groundwater overdraft in a large part of San Joaquin Valley has caused the permanent compaction of clay layers, resulting in rapid ground sinking of up to almost 12 inches per year," says co-author Shirzaei. "Through our research, we measured the amount of permanent compaction in the aquifer and we can now calculate the amount of water loss that has caused this compaction."

While the space and ground data showed an average groundwater loss of 1600 billion gallons (6.1 cubic kilometers) for each year of the drought (close to the total equivalent of the volume of Lake Powell in Arizona), the data also indicate that the aquifer system has permanently lost up to three percent of its storage capacity from 2012 to 2015.

"The lost groundwater storage capacity cannot be recovered through natural recharge," explains lead author Ojha. "It's a permanent loss that will decrease the availability of groundwater needed during future droughts, potentially running wells dry and effecting both communities and agriculture."

While three percent of aquifer loss may sound small, compounded with subsequent expected future droughts, the impact could be severe. "If we have even one drought per decade, our aquifers could shrink a bit more each time and permanently lose more than a quarter of their storage capacity this century," explains co-author Werth, who also holds a joint appointment in the School of Geographical Sciences and Urban Planning.

"While the exact frequency of future droughts might be uncertain," adds co-author Shirzaei, "we know from our 2018 and 2019 analyses that up to five percent of aquifer storage capacity has already been permanently lost during the first two decades of the 21st Century."

While this research specifically focused on California, the researchers plan to continue this type of data analysis to measure aquifers health in the southwestern United states and around the world.

"Water managers may not be able to change water use right away," says Ojha, "but this study gives them the scientific knowledge and data analysis they need to implement sustainable water usage practices in the future and that may help preserve the availability of groundwater resources for decades to come.

"We cannot properly manage what we don't measure," adds Werth.
-end-


Arizona State University

Related Drought Articles:

Vinegar: A cheap and simple way to help plants fight drought
Researchers at the RIKEN Center for Sustainable Resource Science (CSRS) have discovered a new, yet simple, way to increase drought tolerance in a wide range of plants.
Lending plants a hand to survive drought
A research team led by the Australian National University has found a new way to help plants better survive drought by enhancing their natural ability to preserve water.
New rice fights off drought
Scientists at the RIKEN Center for Sustainable Resource Science (CSRS) have developed strains of rice that are resistant to drought in real-world situations.
Drought linked with human health risks in US analysis
A Yale-led analysis of health claims in 22 US states found that severe drought conditions increased the risk of mortality -- and, in some cases, cardiovascular disease -- among adults 65 or over.
A basis for the application of drought indices in China
The definition of a drought index is the foundation of drought research.
Under the Dead Sea, warnings of dire drought
Nearly 1,000 feet below the bed of the Dead Sea, scientists have found evidence that during past warm periods, the Mideast has suffered drought on scales never recorded by humans -- a possible warning for current times.
Forests worldwide threatened by drought
Forests around the world are at risk of death due to widespread drought, University of Stirling researchers have found.
How much drought can a forest take?
Why do some trees die in a drought and others don't?
Pressures from grazers hastens ecosystem collapse from drought
Ecosystem collapse from extreme drought can be significantly hastened by pressures placed on drought-weakened vegetation by grazers and fungal pathogens, a new Duke-led study finds.
Molecular conductors help plants respond to drought
Salk scientists find key players in complex plant response to stress, offering clues to coping with drier conditions.

Related Drought Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Anthropomorphic
Do animals grieve? Do they have language or consciousness? For a long time, scientists resisted the urge to look for human qualities in animals. This hour, TED speakers explore how that is changing. Guests include biological anthropologist Barbara King, dolphin researcher Denise Herzing, primatologist Frans de Waal, and ecologist Carl Safina.
Now Playing: Science for the People

#SB2 2019 Science Birthday Minisode: Mary Golda Ross
Our second annual Science Birthday is here, and this year we celebrate the wonderful Mary Golda Ross, born 9 August 1908. She died in 2008 at age 99, but left a lasting mark on the science of rocketry and space exploration as an early woman in engineering, and one of the first Native Americans in engineering. Join Rachelle and Bethany for this very special birthday minisode celebrating Mary and her achievements. Thanks to our Patreons who make this show possible! Read more about Mary G. Ross: Interview with Mary Ross on Lash Publications International, by Laurel Sheppard Meet Mary Golda...