GEOMORPHOLOGICAL MAPS INCORPORATING IMPACTS OF HURRICANE SANDY AT FIRE ISLAND NATIONAL SEASHORE, GATEWAY NATIONAL RECREATION AREA, AND ASSATEAGUE ISLAND NATIONAL SEASHORE: RESEARCH AND MANAGEMENT APPLICATIONS

The restructured topographical configurations resulting from Hurricane Sandy’s surge and waves provided an impetus to revise and update existing geomorphological maps for Fire Island National Seashore, Gateway National Recreation Area, and Assateague Island National Seashore. Drawing on orthophotos and LiDAR data sets collected soon after the October 2012 storm, the updated maps for these three national parks depict the variety of geomorphological responses to the storm-induced physical processes.

Having developed a consistently applicable methodology to discriminate landform boundaries utilizing spatial patterns of elevation and relief derived from the post-storm data sets, a categorization of coastal geomorphological features was established based on three criteria: 1) surficial expression within the landscape, 2) developmental processes associated with formation, and 3) the relative temporal stages of barrier evolution. The juxtaposition of the consistently-categorized maps highlights repeated sequences in the development of barrier systems, including the response to major storm events. Moreover, because each site is situated at different points along the spectrums of sediment supply and wave/tidal energy regimes, there is some variation in the resulting site-specific patterns of feature magnitudes and continuities.

In the cases of Gateway and Fire Island, the identical methodology and criteria for geomorphological categorization was applied to create both the updated and the original maps. Thus, these two maps recorded the dimensions and vectors of change caused by Hurricane Sandy, whereas the Assateague Island post-storm map –the first map created with this classification scheme– provided a detailed process-based portrayal of the highly dissected topography. As a result, the maps become a tool both for the establishment of the geotemporal comparisons and for the analysis of surface evolution basic to appropriate resource management in the parks.