Researchers Wei Zhang (Left) and Gabriele Villarini (Right) via The University of Iowa IIHR
Elizabeth Miglin | March 18, 2021
Climate scientists at the Iowa Institute of Hydraulic Research (IIHR) found rising greenhouse gas concentrations caused by human activity have increased the frequency of flooding in Iowa and the midwest.
Led by IIHR researchers Wei Zhang and Gabriele Villarini (IIHR director), the study focused on the weather type known as the “Midwest Water Hose” (MWH). The MWH carries moisture from the Gulf of Mexico to the midwest where the moist air meets cold dry air from the north. More than 70 percent of total precipitation in Iowa during the first five months of 2019 is accredited to this weather system.
Results from the CMIP6 climate model used in the study showed natural climate variations were unable to explain why the MWH has been occurring more frequently over the past 40 years. However, when Zhang and Villarini accounted for rising greenhouse gas concentrations the model reproduced the increase in the occurrence of the MWH.
Flooding along Iowa’s eastern and western borders in 2019 resulted in $1.6 billion in damages, according to the Des Moines Register. “…This type of flooding in this region is expected to become even more likely in the future if we do not take immediate actions to cut greenhouse gas emissions” said Zhang.
The damage caused by floods often impacts communities for years to come. “We still are seeing the very real impacts of the 2008 flood in effect over ten years later, because of the level of damage to university and city infrastructure,” Iowa City Assistant City Manager Ashley Monroe said to the Daily Iowan.
The study was published on March 1st in the scientific journal Philosophical Transactions of the Royal Society, Mathematical, Physical, and Engineering Sciences.