GREENVILLE, N.C. (WNCT) — Less than 1% of fresh water on the planet is available for human consumption but still keeps over 7 billion people alive.
A recent study by NASA looked at all the freshwater bodies on Earth and found out humans have a lot more of an impact than expected.
In order to investigate human impact on freshwater sources, NASA scientists completed the first-ever global survey of water levels in both natural and man-made freshwater bodies. Monitoring water storage and its variation is extremely important to understand the local water processes and global water cycle.
NASA scientists were able to do this using the ICESat-2 – a highly precise satellite measuring surface height that can assess ponds and reservoirs that were once too small to be examined. Scientists used these height measurements to study more than 227,000 freshwater bodies over 22 months to see how water levels changed.
They typically vary with season, filling up during rainy periods and draining when it’s hot and dry. However, NASA researchers found humans were impacting water storage much more than anticipated.
During the study, the water level of human-managed reservoirs fluctuated significantly more than natural bodies of water, nearly quadruple the amount! Earth’s lakes and ponds shifted about 8.6 inches on average seasonally, while man-made reservoirs varied over 33 inches.
Researchers also found regional patterns as well, with reservoirs in the Middle East, Southern Africa, and the Western US varying most, while fluctuation in natural lakes and ponds are highest in tropical regions.
This study provided a really valuable baseline of how humans are changing the water cycle at a global scale. Hopefully, it will help humans find sustainable ways to increase the availability of freshwater for future generations.