We here at WDRB get a lot of comments about the color of the Ohio River. The great debate: is it brown or is it blue? A new article accepted to the Geophysical Research Letters through he American Geophysical Union says the color matters, and it's something worth watching. Researchers examined nearly 235,000 LandSat satellite images of U.S. rivers (that are more than 60 meters wide) between 1984 and 2018.Â
Based on their research, most rivers can appear as shades of blue, brown, green and yellow. The research team found the dominant shade of one third of American rivers "changed significantly" between 1984 and 2018. It's important to watch rivers change color because it can signal some sort of "rapid environmental change" and help give us a better understanding of rivers in general. Some of those environmental changes specifically mentioned in the study could be changes in algae, sediment, or dissolved organic carbon in the water.Â
The study also found that some rivers normally change color with the seasons. Based on the supporting information with the article, the Ohio River through our area was one of the rivers they studied. During the spring the Ohio River sees a "red-shift" which would likely make it look more brown to us. Simply observing that the river changes color should not be alarming. This research shows us we should use that opportunity to figure out why the color shifted; that could be as simple as "it normally shifts a bit this time of year." The answer may not be as readily apparent, though, which is when it would be important to study more about what's in the water.Â
