Over the years, you must have come across a number of news reports on rivers changing colors, sometimes yellow, sometimes green. Now scientists in America have come together to study the onions that have occurred in the country.
Recent research published in the journal Geophysical Research Letters examines this issue in the U.S., where one-third of the country’s rivers have changed color over the past 36 years from blue to yellow or green. Researchers John Gardner, Xiao Yang, Simon Topp, Matthew Ross, Elizabeth Altenau and Tamlin Pavelsky came together to prepare an interactive map that followed a change in river colors over the years.
The six scientists analyzed more than 235,000 satellite images, spanned over 34 years between 1984 and 2018 – from the National Aeronautics and Space Administration (NASA) and the US Landsat Geological Survey (USGS) program.
Researchers have explained that rivers are among the most endangered ecosystems in the world and we still do not have a clear understanding of their changing ecology as most are rare. sampling. Water color change is also an overall feature that determines water quality.
The paper’s lead author, Gardner, who is also a postgraduate researcher in a global water laboratory at the University of North Carolina, explained that the color of rivers can be blue, green, yellow and brown. its quality. The color can also be a sign of the presence of sediment, algae and organic organic carbon. Researchers said the human eye can act as an instrument that differentiates water quality based on its color.
Explaining the need for this research, scientists noted that while several studies have shown that some rivers are unsuitable for human consumption due to their severity, little has been found. study the color of the river when it comes to gradual change over time. Thus, using data provided by satellites that have monitored this change in color of rivers, scientists have found that rivers have a specific seasonal pattern in color that changes with its flow.
Their study also found that the strongest color in a third of rivers has changed significantly. Scientists said that the change in color of river water also indicates a rapid change in the environment. Talking to Living Science, Gardner said, most rivers are gradually changing and the change is not obvious to the human eye. However, he said the fastest-changing areas are more likely to be man-made.