HISTORICAL SHORELINE CHANGES AND MORPHODYNAMICS OF PARRAMORE ISLAND, VIRGINIA (1852-2006)

摘要

Using National Ocean Service topographic sheets and global positioning system shoreline position surveyss historical shoreline changes of Parramore Island, Virginia, are quantified between 1852 and 2006 to address long- and short-term trends in shoreline movement Quantitative analyses of twelve high water line (shoreline) positions indicate the shoreline is retreating at increasing rates in the short term (decadal) when compared with long-term trends (centennial). In particular, the behavior of the outer shoreline changed from clockwise rotational instability to sustained retreat Parramore's entire outer shoreline (Cells 3, 4, and 5) experienced a retreat rate of -3.6 m/yr over the long term (1852-2006) and -8.8 m/yr over the short term (1998-2006). The short-term rate changes indicate that the processes controlling shoreline trends, e.g., overwash to the south and inlet dynamics to the north, have intensified and/or changed relative to the long-term.