The Color of Rivers

The color of a river is one of the oldest methods of determining the health and quality of its water. The Gardner Hydrology Lab has now updated this ancient methodology using the tools of the space-age. The Lab has used Landsat satellite imagery from 1984-2018 to measure the colors of rivers in the USA in order to help to determine their health and quality.

The Color of US Rivers is an interactive map which shows the most common color of American rivers from 1984 to 2018 - as determined by remote satellite sensing. If you click on an individual river on the map you can view graphs showing the full color distribution of the river recorded over the last 35 years. The map includes visualizations of the long-term trend in color distribution and the short-term seasonal trend. 

The Gardner Hydrology Lab analysis examined U.S. rivers over 60 metres in width. The analysis discovered that over a third of American rivers have seen a significant color shift in the last 35 years. The color of rivers can be altered by the amount of sediment, algae, and dissolved organic carbon in the water. This methodology of using satellite imagery to measure the change in colors of rivers can be used to remotely pinpoint rivers which are undergoing rapid environmental change.