BLUFF POINT—AN EXAMINATION OF A FETCH-LIMITED BARRIER ISLAND IN THE CHESAPEAKE BAY

Bluff Point is a dynamic, spatially heterogeneous, undeveloped shoreline along the western shore of the Chesapeake Bay. This area comprises two types of fetch-limited barrier islands as described by Pilkey (2009)—classic and marsh fringe barriers and a mainland beach backed by forest. This area also provides a unique opportunity to study shoreline changes in a region that is experiencing accelerated rates of sea level rise. According to data from nearby NOAA tide stations, sea level near this site is rising at a rate of 3.5-5.0 mm/yr, whereas eustatic sea level rise is only 2.0 mm/yr over a similar time period (IPCC 2013). In this study, the shoreline was classified using historical aerial photos and erosion rates were calculated using the USGS Digital Shoreline Analysis System extension for ArcGIS. The data was employed to describe and analyze morphologic changes so the physical processes affecting each region could be better understood.

Between 2002-2009, erosion rates along the classic barrier averaged 3.1 m/yr, while along the marsh fringe barrier the erosion rate averaged 2.7 m/yr. The forested shoreline between these two islands had an average erosion rate of 4.0 m/yr between 2002-2013. The classic barrier and forested shoreline are eroding more quickly than the marsh fringe barrier. The marsh at the southern end of the island may be stabilizing the beach. A better understanding of the morphologic changes at Bluff Point will help resource managers provide more effective planning for fetch-limited coastlines as these areas will likely experience more development pressure in the future, and provide a better understanding of changes likely to be seen in other areas as sea level rise accelerates over the next century.