Rivers in America are going through a noticeable change

A study says that only about 5% of rivers across the country are actually blue

A new study explains why keeping rivers clean and healthy is important.

When many of us think about the environment, we might be able to see the colors of the landscape. Green in the trees, white puffy clouds and flowing, blue rivers may come to mind.

However, a new study says that America’s rivers are changing colors. And unlike the leaves in autumn, this change is not good.

A study in the journal “Geographical Research Letters” says nearly one-third of America’s rivers have noticeably shifted color -- turning green and red. Research examined 230,000 NASA satellite images over 35 years to see the colors change.

The study says that only about 5% of rivers across the country are actually blue, which the general public usually equates with pristine water. Most rivers look yellow because of the soil that the water picks up. But the study found that nearly 28% of rivers are green, which means there is the presence of algae. When that algae forms, it causes oxygen loss, which can produce toxins.

The study says that the main culprit for the color change is run-off from industries, particularly farming.

But, the study also shows that there is a way to reverse the course. Techniques to prevent soil erosion along rivers -- such as planting trees on riverbanks -- can help filter out chemicals flowing into our water. It also points to using fewer harmful chemicals as well.

Scientists -- even those outside of the study -- say the changes it shows are important. For the first time, environmental scientists say that we will be able to look for early warning signs in the health of our water based on what we can physically see.

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About the Authors:

RJ Marquez has been at KSAT since 2010. He's covered a variety of stories and events across the San Antonio area, and is the lead reporter for KSAT Explains. He also covers the Spurs for on-air and digital platforms. You can see RJ regularly on KSAT Explains and Good Morning San Antonio.