Researchers at Princeton have projected that climate change will markedly impact river basin flooding across the United States during the 21st century. Specifically, the researchers found that projected variations in temperature and precipitation are expected to drive increased flooding in the Northeast and Southeast, particularly along the Eastern Seaboard. Flooding will generally decrease in the Southwest and the Northern Great Plains in areas including Montana and the Dakotas. This research is detailed in a recent paper in Nature Communications.
While most analyses examine the historical record and look for trends in data moving through the present and into the near future, the researchers took a different approach.
“If all you do is look at the past and assume the future is just the same as what happened before, you will run into potential issues because of climate change," said Gabriele Villarini, a professor of civil and environmental engineering and Princeton’s High Meadows Environmental Institute.
The researchers focused on understanding the processes that led to the year-to-year changes in flooding, and broke causes of flooding down into the two most important climate factors: seasonal temperature and precipitation.The researchers did extensive modeling on how each seasonal component affected flooding. They then factored each component into a statistical flood model using data for both concurrent and lagged seasons to account for antecedent conditions such as soil moisture conditions and snowmelt.
Their model of future projections is one in which the signal of change becomes stronger and more detectable for increasing greenhouse gas emissions, pointing to the impacts of anthropogenic climate change on this hazard.