Coastal Defense: Stabilization techniques

Strategies Stabilization techniques
Hard Stabilization Soft Stabilization

Stabilization techniques:

Any of the following three stabilization techniques (viz. Hard StabilizationSoft Stabilization, and relocation of threatened structures) can be adopted (based on the choice of strategy) for protection against coastline erosion and shoreline property damage: .

Hard stabilization techniques

commonly involves the construction of structures like seawalls, breakwaters, revetments, and gabions. Generally these structures are designed to absorb some or all of the impact of waves crashing along the shoreline.

This is done either at the edge of the actual beach or further out in the water to break up the incoming waves before they reach the shore.

Hard stabilization methods have been moderately successful, but often come with a considerable downside including their large financial expense, adverse effects on neighboring beaches, and degraded beach aesthetics.

Soft stabilization techniques

generally consist of depositing sand from elsewhere to supplement an eroding beach.

This process adds to the size of the physical beach and provides a greater buffer for shoreline structures. Usually the sand is gathered from other offshore deposits or inland sand source.

This process does halt the erosion temporarily, and improves recreation without all of the obtrusive environmental effects of hard stabilization. However, it has proven to be quite inefficient and again causes adverse effects to adjacent beaches, such as increased wave potency.

Over 100 beaches on the United States eastern coastline have employed this strategy, but the statistical success in unimpressive. On these beaches, 26% saw their imported sand disappear after just one year, and in only 12% of the cases did the replenished beaches last for more than five years. The average span of effectiveness for the soft stabilized, replenished beaches was only two to three years.

The other viable option is relocation of threatened structures.

Obviously this is rarely popular with private homeowners and businesses because of the expense. However this option poses minimal environmental damage and is usually a one-time expense if the relocation is done properly.

Abandonment of threatened coastline structures is another option that may be cheaper for the private landowner, but becomes a considerable public cost.

Hard stabilization, soft stabilization, and relocation are all methods that are currently being employed, but it remains unclear which of these methods, or which combination, is the best management practice for coastal erosion situations. Perhaps measures to preserve the natural remedies for beach erosion, such as the protective shoreline vegetation and coastal forests, should be factored more prominently into these methodologies.

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References:
from standard technical literature & various websites including:
http://www.wisegeek.com, http://www.japantimes.co.jp,
http://www.egr.msu.edu, http://content.answers.com,
http://dcm2.enr.state.nc.us, http://www.northnorfolk.org,
http://www.english-nature.org.uk, http://www.havant.gov.uk,
http://www.coastalplanning.net, http://www.herveybay.qld.gov.au,
http://www.unesco.org, http://www.globalsecurity.org,
http://jrscience.wcp.muohio.edu & http://www.wikipedia.org

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