Metrics of resilience and recovery in Breezy Point Tip, 2015-2016: Jamaica Bay Unit, Gateway National Recreation Area

Psuty, Norbert; Ames, Katherine; Habeck, Andrea; Haussner, Elizabeth; Schmelz, William; Butler, Kelly; Greenberg, Joshua

This report contains linear, elevation, and volumetric feature changes at Breezy Point Tip, a site at the western portion of Breezy Point Spit, Jamaica Bay Unit of Gateway National Recreation Area. Surveys were conducted from the winter of 2015 to the fall of 2016, and the analysis includes two LiDAR datasets from August 2010 and November 2012 to capture the effects of Hurricane Sandy. The focus of this report is on the resilience and recovery of the beach and dune system along Breezy Point Tip. The analysis provides metrics of shoreline displacement, dune crest displacement, site elevation change, and site volumetric change. At Breezy Point Tip, shoreline change was variable throughout the survey period; there was a large seaward displacement directly post-Sandy followed by smaller landward and seaward displacements seasonally. Between the first and last GPS surveys there was a seaward displacement of the shoreline in the eastern portion of the site, and landward displacement in the western portion near the jetty. In the period 2010-2012, the foredune was completely eroded by Hurricane Sandy. The foredune crest position had not recovered to the 2010 position during the latest survey period, but had remained stable in the new post-storm inland location. The topography at Breezy Point Tip from 2010 to 2012 showed volumetric gain low on the beach and loss higher on the beach, with major volumetric loss in the dune feature. The geomorphological recovery in the Post-Hurricane Sandy period had the same trend of volumetric gain in the beach feature and variable change in the dune feature. Whereas the whole site had regained more volume than was lost during the 2010 to 2012 period, the majority of this gain was in the beach feature and the dune feature had not regained volume that was lost due to Hurricane Sandy. Despite two major storms from 2010 through 2012, the beach feature gained volume during the survey period. A beach nourishment project updrift of the site potentially contributed to this gain. Both the foredune crest displacement and volumetric change showed that the foredune feature at Breezy Point Tip had not reoccupied the 2010 pre-storm foredune location and had not regained lost volume, but instead remained relatively stable in the post-storm location during the survey period. The beach feature and dune feature persisted throughout the survey period, showing resilience in the topographic system.

Metrics of resilience and recovery in Breezy Point Tip, 2015-2016: Jamaica Bay Unit, Gateway National Recreation Area

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