Shoreline and Sediment Dynamics of the Central Outer Banks Barrier Island System, North Carolina, USA

Barrier island systems are found around the world, and in many areas these dynamic systems pose major management challenges. The Outer Banks of North Carolina is a long, narrow barrier island complex (~320 km long and mostly [ view full abstract ]

Barrier island systems are found around the world, and in many areas these dynamic systems pose major management challenges. The Outer Banks of North Carolina is a long, narrow barrier island complex (~320 km long and mostly <2 km wide) that shelters the vast Albemarle and Pamlico sounds from the open Atlantic Ocean. Forming the seaward boundary for the second largest estuarine system of the United States, this slender geological structure is dynamic, morphed by powerful storm waves and persistent currents. The central Outer Banks, defined here as extending from Nags Head to Cape Hatteras, including the Bodie Island peninsula, Oregon Inlet and northern Hatteras Island. Except for a few communities spaced along it, much of the island is federally managed land, including Pea Island National Wildlife Refuge and the Cape Hatteras National Seashore. Receiving over 2 million visitors annually, communities along this stretch serve as an important economic engine for the State and are a key part of the cultural fabric and history of Dare County. A critical challenge for this area is maintaining access along it and to the sea, with significant sediment deficits in some areas and surpluses in others. Long-term erosion has occurred along portions of the ocean and estuarine shorelines. Locally, ocean erosion has exceeded 4 m y-1, and episodically Highway 12 has been made impassable. Conversely, sedimentation has been problematic in navigational channels, including Oregon Inlet and the Rodanthe emergency ferry channel. Nourishment and dredging efforts have occurred at various locations in the system, and future efforts and potential sand resources are being evaluated. Several recent and ongoing studies of the offshore, oceanfront, inlet history and back-barrier changes give a holistic and quantitative perspective on the system. Governing natural processes and human efforts influencing the region are reviewed and discussed.