NASA Satellite Images Show Blue US Rivers Turn Yellow and Green, Here’s Why

While the examine did detect areas the place human exercise could also be affecting the color of some rivers, these modifications could not essentially be everlasting.

Having examined some 235,000 satellite tv for pc photos taken between 1984 and 2018 by way of Landsat, a joint-programme between NASA and the US Geological Survey, a crew of scientists has established {that a} third of the rivers within the United States have exhibited a major change in color over the past three and a half a long time, Live Science stories.

According to the media outlet, over half of the photographs in query displayed rivers “with a dominant hue of yellow”, a 3rd of the photographs “were mostly green”, and solely 8 p.c of the river footage turned out to be “mostly blue”.

During the course of their examine, the analysis crew collected “16 million measurements” over the 34-year interval on about 108,000 kilometres of rivers over 60 meters vast within the United States.

With a river’s coloration normally being decided by the “amount of suspended sediment, algae, pollution or dissolved organic matter in the water”, the media outlet notes that river water tends flip inexperienced “as more algae blooms, or when the water carries less sediment”, whereas the color yellow seemingly implies that the river carries extra sediment.

The examine additionally established that about 55 p.c of those rivers assorted in color however with out exhibiting any clear pattern, and a 3rd of the rivers modified their color; the color of 12 p.c of the rivers in query remained fixed.

And whereas satellite tv for pc imagery did show areas the place human exercise, reminiscent of “dams, reservoirs, agriculture and urban development”, could also be affecting the color of some rivers, such modifications could not essentially be everlasting, the media outlet provides.


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