There has been an increase in the number and the intensity of tropical storms that have battered coastlines around the world. As storms continue to form in the world’s oceans, researchers are studying the broader trends in the storms that have hit the eastern shores of the United States over the last 120 years.
Tropical cyclones are rotating storms that bring strong winds and rains and often increase in strength to turn into typhoons or hurricanes. Researchers with the University of North Carolina’s Institute of Marine Sciences have studied tropical cyclones that have impacted North Carolina in a 120 year period. They found that six of the seven storms that dumped the most rain on the state’s coastline occurred within the last 20 years.
The Impact of Storms on Coastlines
One storm can have a major impact on a coastline, and multiple storms can dramatically change the geography and ecology of a storm-prone location. River estuaries, wetland areas, bays, and other parts of the coast are home to unique plants and animals that can feel the effects of these storms.
Researchers don’t yet know how multiple massive storms can affect these vulnerable ecosystems. These storms have the potential to impact not only vulnerable plant and animal populations, but have human implications as well. Hurricanes and tropical cyclones have caused flooding, property damage, and shut down cities for weeks or months at a time as people fight to rebuild their lives. As storms increase in frequency and intensity, humans and animals have even less time to recover.
Long Term Effects of Frequent Storms on Coastlines
During a storm, the coastline is battered by heavy winds and rains. As the storm moves inland, rain continues to fall. As flooding and rainfall occurs further inland from the coast, soil, sediment, chemicals, and other pollutants flow back into the rivers and ocean. These chemicals build up in coastal areas and can affect the habitats of people, plants, and animals.
These chemicals can also be a factor in recurring algal blooms. These blooms can deplete oxygen levels in the water, which decreases the number of marine plants and animals that can thrive there. Research shows that it can take months or years for watersheds to regain their natural balance; this time frame can be compromised by storms impacting close together.
Researchers are working to put together a complete understanding of the impact these storms have had on North Carolina. Eventually this work could be used to protect valuable habitats via conservation efforts and continued monitoring of water quality before, during, and after major storms.
Paerl, H. W., Hall, N. S., Hounshell, A. G., Luettich, R. A., Rossignol, K. L., Osburn, C. L., & Bales, J. (2019). Recent increase in catastrophic tropical cyclone flooding in coastal North Carolina, USA: Long-term observations suggest a regime shift. Scientific reports, 9(1), 10620. https://doi.org/10.1038/s41598-019-46928-9
Paerl, Hans. More frequent and intense tropical storms mean less recovery time for the world’s coastlines. 1 October, 2019. Retrieved from https://theconversation.com/more-frequent-and-intense-tropical-storms-mean-less-recovery-time-for-the-worlds-coastlines-123335