Coastal Flooding From Tropical Cyclones On The Rise In NC

Sep 19, 2019

Hurricane Florence brought record-breaking rain to parts of Southeastern North Carolina in 2018.
Credit Courtesy of NASA

Coastal flooding from hurricanes and other tropical storms is getting worse, according to a recent study by researchers at the UNC-Chapel Hill Institute of Marine Sciences in Morehead City. Scientists looked at more than 120 years of data on tropical cyclones and rainfall in North Carolina. They found six of the wettest events occurred in the last 20 years. Hans Paerl, the study's lead author, says statistical analysis shows that’s more than just a string of bad luck.

“It turned out that the chance of having six of those events occur in the last 20 years, against the total data set, was about 2%, so it’s obviously a trend and not a random occurrence," he said.

The study's authors say this trend of more heavy rains and coastal flooding could destabilize the region's ecology. Major flooding can trigger harmful algae blooms and low oxygen levels in water, conditions that may linger for a year after a big storm.

“When we get this increased frequency, the system may be still recovering from a previous event, and that is really of concern because it means that the system is unstable for quite a long period of time,” said Paerl.

The long-term impact of those changes is not yet known, he said, but it could impact the habitat of a wide range of species.

To prepare for heavy rains and flooding, Paerl said North Carolinians need to increase environmental protections for waterways to help protect coastal habitats. Ultimately, he said, humans must limit greenhouse gas emissions from a wide array of sources to limit further warming of the atmosphere. 

“We have to live with the climate that we currently have and the climate changes that are occurring.” said Paerl. “Minimizing the emissions of greenhouse gasses will at least slow down some of this warming and potentially, linkage to the increased storm events that are occurring.”