Earth  ID: 12950

A Map of Freshwater

Story by Ellen T. Gray | Visualizations by Trent L. Schindler Released on August 13, 2018
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Fifteen years of satellite data show changes in freshwater around the world.
Freshwater is found in lakes, rivers, soil, snow, groundwater and ice, and is one of the most essential of Earth's resources, for drinking water and agriculture. However, the distribution of freshwater around the planet is changing. Researchers used a pair of satellites called the Gravity Recovery and Climate Experiment, or GRACE, to track freshwater movement over the last fifteen years. The twin GRACE satellites were launched in 2002 as a joint mission between NASA and the German Aerospace Center (DLR). The two satellites precisely measured the distance between themselves to detect changes in Earth's gravity field caused by movements of mass on the planet below, caused by shifts in water and ice. They found that some regions' water supplies are relatively stable, others experienced increases or decreases. Climate change has driven freshwater loss from the ice sheets at the poles, which has implications for sea level rise. Other areas saw groundwater depletions because of humans using water for irrigating crops or increases due to higher amounts of rainfall because of natural variability. Watch the video to learn more.
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NASA satellite observations combined with maps of human activities show where freshwater levels are changing and why.
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The researchers found that a combination of natural and human pressures can lead to complex scenarios in some regions.
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In northwestern China, freshwater is complex with glaciers, rivers, agriculture, and groundwater. Overall it shows a loss of freshwater.
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The Okavango Delta shows an increase in freshwater between 2002 and 2010, likely due to natural variability.
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A true color satellite image of California shows drought in the region which corresponds with decreases in freshwater reserves.
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In spring 2018, NASA launched a satellite pair, GRACE Follow-On, to continue studying water movement around the planet.
 

Source Material

GRACE 15-Year Groundwater Trends
For 15 Years, GRACE Tracked Freshwater Movements Around the World

For More Information

NASA.gov

Story Credits

Lead Visualizer/Animator:
Trent L. Schindler (USRA)

Lead Producer:
Kathryn Mersmann (USRA)

Lead Scientist:
Matthew Rodell (NASA/GSFC)

Lead Writer:
Ellen T. Gray (ADNET Systems, Inc.)

Writer:
Alexandra Calloway (Experiential Learning Program, UMD)

Please give credit for this item to:
NASA's Scientific Visualization Studio

Short URL to share this page:
https://svs.gsfc.nasa.gov/12950

Mission:
Gravity Recovery and Climate Experiment (GRACE)

Keywords:
SVS >> HDTV
SVS >> App
NASA Science >> Earth