A UNIQUE LOOK AT OREGON INLET, NC USA

摘要

Oregon Inlet (01) in North Carolina (NC), the only inlet along a 170 km stretch of coast, supports an active commercial fishing and recreational boating industry. Severe erosion, because of the ongoing migration of 01, resulted in NC constructing a terminal groin to prevent the highway from being severed from the south side of the OI bridge. Construction of this structure provided a unique opportunity to monitor and assess project impacts which could be directly related to the twin jetties which are proposed for this site. The monitoring program included a directional wave gauge, aerial photography, and semi-annual sled-surveys extending 6 km north and south of the inlet. The terminal groin returned the shoreline to its pre-1986 position and has successfully protected the highway abutment to the bridge through many severe storms. This paper presents the results of 6 years of monitoring the morphologic changes. The results document how the coast has adjusted to the construction, a multi-year wave climate reversal, and placement of 1.5 million m3 of dredged material on the beach. The surveyed area generally lost material both on the up and downdrift sides, much of which apparently has been deposited in the inlet. The effect of these changes on the coast and the inlet's stability are discussed.