Reactionary fence installation for post-Superstorm Sandy dune recovery

Abstract

Dunes are invaluable to coastal areas as dynamic buffers to erosion during high tides and storms, but do not accrue naturally in developed areas without assistance. Wood paling fencing is commonly used to cultivate dune development and thereby increase the protection afforded to coastal areas. In 2012, Superstorm Sandy devastated the mid-Atlantic, especially New Jersey where many areas are still recovering. At Island Beach State Park, NJ parts of the primary dune system were destroyed and efforts were made to rebuild these areas as an emergency response. These efforts consisted of the installation of fencing in straight and zigzag patterns to catch-windblown sand and rebuild dunes. We collected field measurements of the short-term vertical sand accretion of recovering fenced localities and non-destroyed established dunes receiving no management intervention. We also collected 1.5 m cores to examine particle size after sieving in a Ro-Tap cascade shaker. There was high stochasticity among weekly changes in dune height and fence configuration affected growth rates. Zigzag fenced areas increased in height over time whereas straight fenced dunes did not. The sand composition of the dunes varied with height such that coarse sand decreased with height whereas finer sediments increased. At the initial stage of recovery fencing configuration seems to be an important factor in determining dune growth and assessing particle size can give insight into the means of sand transport. These results have implications for coastal management and restoration aimed at accruing the most sand in least time for immediate post-storm recovery efforts