What does beach nourishment mean?

Answer 1

# # Nourishment restores and widens the recreational beach. # Structures behind beach are protected as long as the added sand remains. # When erosion continues, beach nourishment does not leave hazards on the beach or in the surf zone. This is a big advantage when compared with "hard" beach stabilization structures like seawalls or groins. Seawalls may protect structures behind the beach, but they almost always cause the beach in front of the wall to become narrower. If erosion breaches the seawall, then debris from the wall will be left on the beach and in the surf. Since beach nourishment only puts sand on the beach, no debris is left when it erodes. == # Beach nourishment sand often (in fact, usually) erodes faster than the natural sand on the beach. A good rule of thumb is that nourished beaches erode two or three times faster than natural beaches. Erosion rates can differ widely, however. The biggest factor for the lifetime of a nourished beach is the number of storms that affect the beach. Storms are unpredictable, so nourished beach lifetimes are unpredictable too. The amount of sand added per yard of beach length and the sand placement design determine the new beach width. Wider nourished beaches last longer. # Beach nourishment is expensive, and must be repeated periodically. Except on very small beaches, the minimum expenditure is usually $1 - $2 million dollars; larger, longer-lasting projects often cost much more (e.g., $100 million - 1 billion). # The beach turns into a construction zone during nourishment. # The process of nourishment may damage, destroy or otherwise hurt marine and beach life by burying it, squishing it under bulldozers, changing the shape of the beach, or making the water near the beach too muddy. In recent decades, a variety of plants, insects, turtles, shorebirds, and other animals have become threatened or endangered as a result of human alteration of beach environments. Many of these organisms rely on storms and other natural beach processes (such as dune formation by wind) for the creation and/or maintenance of their habitats. Because of their dependence on natural beach processes, nourishment projects can affect the survival of certain species. For example, beach nourishment can modify a beach by making it too steep and/or too compacted for sea turtles to climb up and bury their eggs. Another example involves filter-feeding marine organisms, such as certain species of clams, that are accustomed to relatively clear water. These organisms can be particularly hard hit by the extreme muddiness produced by nourishment, and they can die-off in large numbers. # The sand added to the beach is often different from the natural beach sand. It can be hard to find a perfect match. This means that the new material may have smaller or larger diameter sand grains than the natural beach. Such differences in "grain-size" affect the way waves interact with a beach. This will affect surf conditions and bars on the submerged part of the beach, and will also change the shape of the "dry beach", which is where people spread their towels and go for strolls. Fine-grained sand generally erodes faster than coarse-grained sand, so grain-size influences the replenished beach's "lifetime" (see point 1, above). " ====== === ===

Answer 2

Beach nourishment is the process of dumping or pumping sand from elsewhere onto an eroding shoreline to create a new beach or to widen the existing beach. Beach nourishment does not stop erosion, it simply gives the erosional forces (usually waves) something else to "chew on" for awhile. The waves erode the nourished sand instead of destroying houses, roads or parking lots. Because nourishment doesn't stop erosion, nourishment must be repeated to maintain the beach. This is called "beach renourishment". It's helpful to imagine that each nourishment project (i.e., an addition of a batch of sand) has a "lifetime". The project's lifetime is simply the time it takes for all the nourishment sand to be eroded away. After that time, the beach would be back to its pre-nourishment width, and would need to be renourished with sand.