A millennium-long management perspective for promoting the geological-social resiliency of barrier islands: a preliminary proposal for Fire Island, NY

Abstract

Barrier islands, such as Fire Island, NY, are complex geological-social systems, driven by mesoscale (centuries/ millennia) processes. The natural resiliency of these thin, linear landforms depends mainly on their capacity to migrate land- ward (rollover) in response to the slow, persistent rise of sea level. This happens by overwash processes during storm surges, whereby beach and dune sand on the ocean side is eroded and transferred to the island's interior and back-barrier shore. Also storm breaches and inlet formation enable the de- velopment of flood-tidal deltas, which likewise supply large volumes of sand to the backshore of barriers. If these processes are curtailed by shortsighted engineering solutions, barrier islands will lose their morphologic resiliency and either disin- tegrate or drown in place. The ideas in this paper argue for a millennial management perspective for Fire Island, based on not interfering with the process of rollover over geologically significant spans of time. To be effective, people will need to think about adapting to continual change on a system level, rather than relying on conventional, short-term engineering so- lutions to a local erosion problem, a management strategy that will compromise the morphologic integrity of Fire Island as sea level continues to rise for the foreseeable future.