THE EFFECTS OF SUPERSTORM SANDY ON COASTAL MORPHOLOGY: GREAT KILLS, STATEN ISLAND, NEW YORK

The purpose of this study is to monitor and quantify the effects of Superstorm Sandy on Great Kills, a coastal unit located within Gateway National Recreation Area in Staten Island, New York.

Three principal types of data are employed to determine changes in the study area’s morphology: Shoreline position (1D data), coastal topography (2D profile data), and calculated areal volume (3D elevation data). Data comparison between conditions pre-Sandy, immediately post-Sandy, and currently allow for measurements and visualizations indicating the degree of alteration and successive beach recovery.

Seasonal spring and fall GPS data collection provides datasets of sub-meter accuracy that record shoreline displacement. Then, the USGS Digital Shoreline Analysis System program was applied to determine shoreline change rates. Geodetic grade GPS equipment collected profile and areal data at centimeter accuracy, leading to individual profile comparison between collection periods, and the creation of digital elevation models (DEMs) for the purpose of sediment volume calculations.

At Great Kills, immediate comparisons between (2D) profile data pre- and post-Sandy reveal slumping of a once dominant cliff face to form a gently sloping beach face. Comparisons of DEMs reveal lower elevations as well as sediment loss in several portions of the study area.

Methods employed in this study are reproducible under protocols defined by the Northeast Coastal & Barrier Network, that provide a template for topography examination and sediment change calculation in areas of similar interest. Information produced within these constraints is applicable to a larger body of knowledge regarding an improved understanding of effects of large-scale storms on coastal environments.