Wednesday, May 30, 2012

Gulf coast vulnerable to extreme erosion in Category 1 hurricanes

US Geological Survey: Seventy percent of the Gulf of Mexico shoreline is vulnerable to extreme erosion during even the weakest hurricanes, according to a new report by the U.S. Geological Survey released just prior to the start of the 2012 hurricane season.  

USGS scientists used state-of-the-art modeling to determine the probabilities of erosion, overwash and inundation during direct hurricane landfall for sandy beaches along the entire U.S. Gulf Coast shoreline. 

The research is expected to help emergency managers at local, state and federal levels as they prepare for hurricane events in this and future seasons. Planners will be able to determine how different categories of hurricanes would impact their beaches and surrounding communities, helping them better protect lives and property.  The report also includes an interactive map that allows users to focus on different parts of the Gulf Coast shoreline to view how the probability of erosion, caused by waves and storm surge, will vary depending on hurricane intensity.  

... "Beaches along the Gulf of Mexico are extremely vulnerable to erosion during hurricanes, in part, because of low elevations along the coast," said Hilary Stockdon, a USGS research oceanographer and lead author of the study.  "For example, the average elevation of sand dunes on the west coast of Florida is eight feet. On Florida’s Atlantic coast, the average is 15 feet." ... During category-1 hurricane events on the Gulf Coast, wave height and storm surge combine to increase water levels at the shoreline by 14 and a half feet higher than their normal levels.

"People continue to build communities in coastal areas that shift and move with each passing storm," said Stockdon. "This model helps us predict the potential impact of future storms and allows us to identify where the most vulnerable areas are located along the coast."...

In Gilchrist, Texas, the Gulf of Mexico shoreline showing the effects from Hurricane Ike. A view from the deck of a house that survived the destruction. Jocelyn Augusitno/FEMA

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