What other factors other than atmospheric rivers contribute to flood risks? This is what a recent study published in the Journal of Hydrometeorology hopes to address as a team of researchers led by the Desert Research Institute (DRI) in Reno, Nevada investigated how soil moisture contributes strengthens atmospheric rivers, resulting in a greater flood risk. This study has the potential to help researchers, climate scientists, legislators, and the public develop more efficient disaster preparedness strategies, specifically regarding flooding risks.
For the study, the researchers analyzed data from more than 43,000 atmospheric river storms from 122 U.S. West Coast watersheds that occurred between 1980 and 2023. The goal of the study was to ascertain factors that contributed to increased flooding during atmospheric river storms. In the end, the team found that soil moisture contributed between 2 to 4.5 times increased flood peaks during atmospheric river storms.
“The main finding comes down to the fact that flooding from any event, but specifically from atmospheric river storms, is a function not only of the storm size and magnitude, but also what’s happening on the land surface,” said Mariana Webb, who is a PhD Candidate at DRI and the University of Nevada, Reno and is lead author of the study. “This work demonstrates the key role that pre-event soil moisture can have in moderating flood events. Interestingly, flood magnitudes don’t increase linearly as soil moisture increases, there's this critical threshold of soil moisture wetness above which you start to see much larger flows.”
This study comes as climate change continues to ravage the planet with more frequent and intense weather events, including atmospheric river storms.
What new connections between soil moisture and flood risks will researchers make in the coming years and decades? Only time will tell, and this is why we science!
As always, keep doing science & keep looking up!
Sources: Journal of Hydrometeorology, EurekAlert!
Image Credit: DOE Office of Science
