Sand Fences in the Coastal Zone: Intended and Unintended Effects

Abstract

Sand-trapping fences modify the character of the coastal landscape and change its spatial structure, image, and meaning. This paper examines the relationship between these changes and fence usage at the municipal level, where most decisions about fence deployment are made. Use of fences in 29 municipalities on the developed coast of New Jersey is examined over a 6-year period. Interviews with municipal officers indicate that wooden slat sand-trapping fences are used primarily to build dunes to provide protection against wave uprush and flooding, but they are also used to control pedestrian traffic and demarcate territory. These uses result in changes in landforms and habitats. An aerial video inventory of fences taken in 2002 indicates that 82% of the shoreline had fences and 72% had dunes. Single and double straight fence rows are the most commonly used. Fences are often built to accomplish a specific primary purpose, but they can cause many different and often unanticipated changes to the landscape. The effects of a sand fence change through time as the initial structure traps sand, creates a dune that is colonized by vegetation, and becomes integrated into the environment by increasing topographic variability and aesthetic and habitat value. Sand fences can be made more compatible with natural processes by not placing them in locations where sources of wind blown sand are restricted or in unnatural shore perpendicular orientations. Symbolic fences are less expensive, are easy to replace when damaged, are less visually intrusive, and can be used for controlling pedestrian access.

Terrestrial LiDAR monitoring of coastal foredune evolution in managed and unmanaged systems

“…At the FRF, accretion was focused on the heavily vegetated portion of the dune (72 < x < 80 m), suggesting that trapping by vegetation was the primary capture mechanism. In contrast, at Nags Head, the major accretion in the first 4 months of monitoring occurred along the upper beach and within the fence zone (red and blue lines, Figure ), in accordance with Grafals‐Soto and Nordstrom () and Anthony et al . ().…”

The Role of Large Woody Debris in Beach‐Dune Interaction

“…After burial, aeolian sand was able to travel nearly unimpeded across the backshore and onto the foredune, allowing for foredune accretion during the majority of the winter months except directly after particularly large wave events that eroded the beach and exhumed existing LWD. This rapid infilling effect has been reported for sand fences and beach wrack, consisting of sea weed, kelp, and flotsam (Grafals‐Soto & Nordstrom, ; Li & Sherman, ; Nordstrom et al, , ), but never before for LWD.…”

Aerodynamics and morphodynamics of sand fences: A review

“…In coastal areas, fences have three major applications (c.f. Kerr and Nigra, 1952;Hotta et al, 1987;Grafals-Soto and Nordstrom, 2009). The first is trapping sand to initiate foredune development perpendicular to wind (Snyder and Pinet, 1981;Hotta and Horikawa, 1990;Miller et al, 2001).…”

“…Such fences are deployed extensively in deserts, on beaches, or near some man-made structures where the need to control aeolian sedimentation is recognized. Using fences as part of a management strategy is attractive because they are usually effective, inexpensive and their effects can be seen quickly (Grafals-Soto and Nordstrom, 2009). In arid regions, fences are used to reduce sand deposition into a target system (e.g., roads, railways) or to reduce wind erosion in an area behind a fence (Dong et al, 2004(Dong et al, , 2007.…”