FORT WAYNE, Ind. (WFFT) — America's rivers are changing colors according to a recent study.
Rivers can be various shades of blue, green, brown and yellow.
Water color is linked to water quality.
It also relates to the amount of sediment, algae and dissolved organic carbon is in the water.
The researchers analyzed over 230,000 NASA satellite images.
Using satellite images, the group of researchers compared rivers colors from 1984 to 2018.
One third of tens of thousands of mile-long river segments in the United States have changed colors in the last 35 years.
When you draw a river, it should be blue. Only about 5% of U.S. river mileage is considered blue today. The changing colors of rivers could possibly become a new indicator of river health, say researchers >>> https://t.co/NELTYxT6Fb via @AP pic.twitter.com/19du07950e
— MilwaukeeRiverkeeper (@mkeriverkeeper) January 12, 2021
Over 11 thousand miles of rivers became greener during this time.
56% of observation were dominantly yellow, with another 38% were dominantly green.
Yellow rivers mean that they have lots of soil in them.
Algae in rivers lead to their color becoming green.
The shift to greener rivers happened mostly in northern and western states.
A shift to yellow rivers has occurred in eastern states and around the Mississippi River.
Only about 5% of U.S. rivers are considered blue.
Changes in river colors have a few major causes.
Farm fertilizer run-off, dams, efforts to fight soil erosion and climate change were the major causes according to the study authors.
Climate change increases water temperature and rain-related run off.
You can read more on the study here.