Coastal Change Hazards: Hurricanes and Extreme Storms

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Coastal Change Hazards

Assessing Coastal Vulnerability to Extreme Storms:

Extreme Storms

Storm-Induced Coastal Change

Storm Impact Scale

Storm Response Activities:

Lidar

Aerial Photography

Ground Surveys

Extreme Storm Impact Studies:

Hurricanes:

2008 - Gustav, Ike

2005 - Wilma, Rita, Katrina, Dennis

2004 - Jeanne, Ivan, Frances, Charley

2003 - Isabel

All Years (1996-2008)

El Niño:

1997-98 El Niño

Northeasters:

1998 Assateague Island

Historical Storms:

Hurricane Camille (1969)

Publications

Storm-Impact Scale

Overwash Regime

Overwash Regime
cartoon illustration of overwash regime

Net onshore transport order 100 meters

If wave runup exceeds the elevation of the dune, or in the absence of a dune, the beach berm, the system will be overtopped, transporting sand landward. This is a net change contributing to the migration of the barrier island landward.

Impacts of the Overwash Regime

Below are overwash deposits near Rodanthe, North Carolina, after Hurricane Dennis (1999). The sand was transported landward by wave runup overtopping the dune. In both photographs at right, wave runup overtopped the highest part of the system during a storm, resulting in net sand transport landward forming overwash fans.

Photograph of excavated overwash deposits left by Hurricane Dennis.

Overwash deposits near Rodanthe, NC after Hurricane Dennis (1999), which made landfall in early September 1999. Large overwash deposits were also observed following Hurricane Dennis (1999) in Buxton, NC.

photograph of overwash in North Carolina following Hurricane Dennis

September 1999, Hurricane Dennis, Core Banks, NC. [larger version]

photograph of overwash in Virginia following a strong Northeaster

February 1998, Northeaster, Assateague Island, VA. [larger version]

Refer to the Hurricane Katrina web pages, for photographs and lidar images of hurricane-induced overwash on Dauphin Island, AL.

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Page Last Modified: December 23, 2008 @ 11:45 AM (JSS)