Bouts of intense drought and rainfall are hurting water quality in rivers around the globe, according to a sprawling new analysis.
For the study, scientists looked at 965 case studies, tracking how extreme weather impacted rivers on every habitable continent. They found that water quality dropped during 51 percent of floods and rainstorms, as fertilizer runoff poured into rivers and streams.
Water quality also fell during 68 percent of droughts and heat waves. While a drop in flow meant there was less runoff, it also meant there was less water available to dilute contamination, such as pharmaceuticals from urban wastewater. Overheated rivers also had higher levels of salt.
Read more at Yale Environment 360
Image: The Mississippi River during a drought, January 2013. (Credit: USDA)