. Coast watch. Marine resources; Oceanography; Coastal zone management; Coastal ecology. CLOCKWISE FROM BOTTOM LEFT: This is an example of an on-grade walkway with railings. David Nash developed a float germination system for dune plants at Oak Island. Tina Pritchard was involved in the Oak Island dune project. A dune is covered with American beachgrass. New dunes form around sea oats. DUNE FEATURES Ocean sand dunes are geologic features that are in a constant state of change — some- where between building in elevation with wind-trapped sand and getting flat- tened in an extreme storm or hurri
. Coast watch. Marine resources; Oceanography; Coastal zone management; Coastal ecology. CLOCKWISE FROM BOTTOM LEFT: This is an example of an on-grade walkway with railings. David Nash developed a float germination system for dune plants at Oak Island. Tina Pritchard was involved in the Oak Island dune project. A dune is covered with American beachgrass. New dunes form around sea oats. DUNE FEATURES Ocean sand dunes are geologic features that are in a constant state of change — some- where between building in elevation with wind-trapped sand and getting flat- tened in an extreme storm or hurricane. Dunes are defined as an area landward of the active beach where dune grasses are dominant plants. It might be a classic dune shape that rises 40 feet in height and is covered with sea oats, a recent overwash terrace flattened by a hurricane where the buried sand grasses have yet to pop up through the new sand, or anywhere in between. In addition to their aesthetic benefits, sand dunes and dune vegetation can provide substantial protection from storm-induced erosion. The larger the dune, the more time it takes to be eroded by the waves, and the more protection it provides to areas further landward. If the dunes are large enough, the waves and storm surge are pre- vented from washing across the barrier island. Flooding may occur from the backside of the island but not directly from the ocean. "Even if the dune is breached and the shoreline is overwashed, the sand stored in the dunes and eroded by the storm reduces the incoming wave heights compared to areas without dunes," says Rogers. For these reasons, protecting the existing dunes and building larger dunes with dune vegetation are useful shoreline management practices. "Remember that erosion has many causes," says Rogers. "Determine what is causing your erosion before planting or building ; Areas subject to seasonal fluctuations are never good places for new dunes. In areas experienc
Size: 2940px × 850px
Photo credit: © The Book Worm / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookcollectionunclibra, booksubjectoceanography
