Hurricanes Charley, Frances and now Ivan have brought flooding and widespread destruction to communities in their paths, as well as misery to many of the residents living there.
But researchers at Duke University's Nicholas School of the Environment and Earth Sciences and its Program for the Study of Developed Shorelines (PSDS) say such storms also bring vital benefits to the coastal environment itself.
"The big changes that occur in barrier islands often occur during hurricanes," said Orrin H. Pilkey, James B. Duke Professor Emeritus of Geology at the Nicholas School of the Environment and Earth Sciences at Duke, and director of PSDS.
"Barrier islands need hurricanes for their survival, especially at times of rising sea levels such as now. It's during hurricanes that islands get higher and wider," he said. "From a purely natural standpoint hurricanes are a blessing for islands, even though they're a curse for people who live there."
Pilkey has lectured and written for years about the effects of human development and natural forces on barrier islands. His co-authored books, including this year's "Living with Florida's Atlantic Beaches," 2003's "A Celebration of the World's Barrier Islands," and 1979's "The Beaches are Moving," have promoted the scientific knowledge that barrier islands are dynamic structures that grow, shrink and migrate over time in response to the ocean and weather.
A. Brad Murray, assistant professor of geomorphology and coastal processes at the Nicholas School, studies how the wave-driven transport of sand influences the way the coastline and barrier islands evolve. He's found that alongshore transport of sand, which occurs largely during storms, can cause erosion at some spots and beach buildup at others, depending on the angle from which the waves approach. Even as hurricanes are eroding oceanside beaches, their powerful wind and waves often deposit more sand onto the back side of barrier islands.
"If you don't let this periodic overwash happen, the island gets skinnier and skinnier" and might disappear beneath rising sea levels, Murray said.
The transient nature of barrier island geology is a fact that's often lost in the rush to rebuild communities in a hurricane's wake, said Andrew Coburn, associate director of PSDS. "Emotions are understandably running high. There's a perceived need to rebuild every home and structure that was lost. But that's often not feasible on an island."
If we are going to build along the beach, one approach would be for communities to invest their resources in geologic-based hazard mitigation, which makes use of natural features to help reduce the likelihood of future losses.
"Geologic-based hazard mitigation is a way for us to live with the coast, not just at or on the coast," Coburn explained. "It involves maintaining the natural protective features of the coast -- things like native vegetation, natural dunes and the original elevation of oceanfront lots -- while prohibiting construction that increases the likelihood of damage."
Unfortunately, that's often easier said than done. "We know that roads that run perpendicular to the shoreline or go right up to the beach act as conduits for storm surge, so we shouldn't build or rebuild them," Coburn said. "Yet you find them in nearly every oceanfront community."
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