LONG-TERM SHORELINE POSITION MONITORING AND PREDICTION, PEA ISLAND, NC

Abstract

Pea Island is a barrier island located on the Outer Banks of North Carolina, with Oregon Inlet to the north and Hatteras Island to the south. The northern end of the island is stabilized by a terminal groin, constructed between fall of 1989 and spring of 1991. Since 1990, approximately 10 km of shoreline downdrift (south) of the inlet has been monitored via aerial orthophotography every two months. In 2010, the monitoring area was expanded to approximately 21 km downdrift of the inlet. Shoreline position was historically drawn, and later digitized, as the visible wet-dry line on the orthophotos. These data, as well as available historical shoreline position information, were used to develop a robust shoreline position database to monitor changes and predict future shoreline behavior. Predictions of shoreline positions are of interest to coastal managers and state transportation authorities, whose obligation to maintain a transportation corridor along the barrier island necessitates careful planning. The aim of the present study is to evaluate the accuracy of shoreline forecasts made based on linear regression with a prediction interval, and their applicability to coastal planning and management.