Dartmouth College – January 7, 2021
The number of “extreme streamflow” events observed in river systems have increased significantly across the United States and Canada over the last century, according to a study from Dartmouth College.
In regions where water runoff from snowmelt is a main contributor to river streamflow, the study found a rise in extreme events, such as flooding.
In drought-prone regions in the western and southeastern U.S., the study found that the frequency of extreme low-flow events has also become more common, particularly during summer and fall.
The research, published in Science Advances, analyzed records dating back to 1910 to confirm the effects of recent changes in precipitation levels on river systems.
“Floods and droughts are extremely expensive and often life-threatening events,” said Evan Dethier, a postdoctoral researcher at Dartmouth and the lead author of the paper. “It’s really important that we have good estimates of how likely extreme events are to occur and whether that likelihood is changing.”