Beach Change Envelope - Coastal System Change at Fire Island, New York

Science Center Objects

Given the unique challenges in quantifying the extensive, yet variable impacts of Hurricane Sandy at Fire Island, we used a time series of beach profile data at Fire Island, New York, to define a new contour-based morphologic change metric, the Beach Change Envelope (BCE).

The BCE represents the portion of the upper beach that is likely to undergo direct storm wave impacts and respond in the subsequent days, weeks, and months after the events. Changes in BCE width and BCE height are extracted from the pre- and post-Hurricane Sandy profile time series and found to coincide well with established states of recovery. By capturing and tracking these distinctive changes in upper beach morphology at each state, the BCE offers a new way of characterizing beach response and recovery cycles at Fire Island and similar sandy coastal settings.

 

Beach profile schematic

Beach profile schematic showing positions of BCE metrics including Zu, Zl (calculated BCE bounding values), BCE width, and BCE height which is calculated by comparing the BCE portion of the profile to a planar profile surface (solid red line). Credit: Owen Brenner , USGS

 

Examples of observed beach morphology changes and beach profile data

Examples of observed beach morphology changes (A) and beach profile data highlighting the BCE morphology at each post-storm recovery stage (B). Credit: Owen Brenner , USGS

 

Conceptual beach profiles

Conceptual beach profiles illustrating how BCE captures distinct values of BCE height and BCE width at each of the four recovery states. Credit: Owen Brenner , USGS

 

Alongshore BCE recovery state progression from October 2012 to September 2015

Alongshore BCE recovery state progression from October 2012 to September 2015 showing general trend of post-Sandy recovery along western and central Fire Island. Credit: Owen Brenner , USGS