Midwestern US states are getting soaked by rise in damaging floods

Maria Galluci in the International Business Times: The U.S. Midwest is getting soaked. Damaging floods are hounding the region with increasing frequency, leading to billions of dollars in agricultural losses and displacing thousands of people, a new study found. Scientists say the trend will likely get worse in coming decades as the effects of climate change accelerate.

Fourteen states in the Midwest and surrounding area saw “increasingly more frequent flood episodes” from 1961 to 2011, according to a University of Iowa study published Monday in the journal Nature Climate Change. Researchers pored over daily geological reports from 774 stream gauges, and found that about a third of stations experienced increasingly frequent flooding. Only 9 percent of stations showed a decrease in flood events.

“There was a feeling that these flood events have been increasing, but the question was, Is it just our perception of the recent past vs. present?” Gabriele Villarini, an engineering professor at Iowa and the report’s lead author, said. “So that’s when we decided to do this analysis.”

Five major floods have pummeled the Midwest region over the past two decades, including a record 2008 disaster in Cedar Rapids, Iowa, that caused up to $6 billion in flood-related damage and forced 25,000 people from their homes...Nationwide, many states have also seen a rise in “nuisance flooding,” the minor events that shut down roads down and clog storm drains but aren’t particularly dangerous, the U.S. National Oceanic and Atmospheric Administration reported last fall....

Villarini said the increased frequency of Midwest floods is largely the result of changes in regional temperatures and rainfall patterns. In the northern states, the spring season has become steadily warmer over the past few decades, while at the same time, snowmelt -- the watery surface runoff caused by melting snow -- has also increased. In other areas, heavy rainfall events are happening more often, leading to more frequent flooding.

...But he noted that the findings are consistent with how climate scientists generally believe global warming is affecting the hydrological cycle. As the atmosphere warms up, it can retain more moisture; all that added vapor, in turn, can lead to more intense and frequent precipitation. In the Midwest, that could lead to more “erosion declining water quality and negative impacts on transportation, agriculture, human health and infrastructure,” according to the National Climate Assessment, a sweeping 2014 report by the White House....

Cedar Rapids in a 2008 flood, shot by Matt Herzberger Matt Herzberger, Wikimedia Commons via Flickr, under the Creative Commons Attribution-Share Alike 2.0 Generic license