Shorelines, Essay Example

A number of different techniques are used to stabilize shorelines throughout the world. This paper examines the different techniques.

Hardening Practices:  This looks at aspects of bulk heading using mainly pressure treated timbers. One of the problems here is that they normally only assimilate 20% of the waves pressure. Equally in lakeshore settings the chemicals in the timbers may leak into the water. In the United States they acquired sediment cores from Lake Anne and found “elevated levels of arsenic from the timbers” (Reston Association). Chemicals seeping into the water also have a negative impact on fish stocks and the eco system

Bio logs: These are cylindrical logs that are manufactured from coconut fibres. Usually 12 “ in diameter and 20ft long and joined together in order to form a boom. These protect the shorelines of lakes by diminishing the force of the waves that hit them Vegetative planting can go behind the bio logs thereby enhancing the shoreline and creating wildlife habitats for the shore dwellers (See illustration).

Breakwaters :  Often used to protect coastal defences. These are made of concrete blocks or stone and designed to take the full brunt of powerful waves.  They have to be constructed in deep water and are expensive to build.

Groynes: These are often constructed on long beaches in order to prevent a form of erosion called long shore drift. “They are usually made of tropical hardwoods which are more resistant to marine borers and erosion. A few are made of concrete, steel or in more recent time’s large rocks. They are built at right angles to the shore and spaced about 50-100 metres apart.” (Beagle)

Gabions:  Essentially metal cages that are filled with rocks and then used in the construction of walls as sea defences.  The gaps in the rocks absorbing the pressure of the waves that hit them. Although easy to construct the cages rust and they have a very short lifespan

Sea Walls: The major defence along coastal area to prevent coastal erosion. These are often long and expensive to build but made of concrete and have a reasonably long life expectancy.

Works Cited

Beagle, David Rayner. Coastal Management. 2001. 31 10 2010 <http://www.georesources.co.uk/coastman.htm>.

Reston Association. Shore Stabilization Techniques. 2006. 31 10 2010 <http://docs.google.com/viewer?a=v&q=cache:ZsE5fkKRspsJ:https://www.reston.org/Portals/3/Parks-Recreation-Events/Nature/Natural%2520Resources/PDF/ShorelineStabilization.pdf+Methods+for+stabilizing+shorelines&hl=en&gl=uk&pid=bl&srcid=ADGEESiAUk81hnLQqSLr7DJ>.