For many decades the approach to rapid coastal erosion was to build up sea defenses, to try and slow down or even stop the erosion. Initially the attempts were thought a success, however after some years it was realized that the power of the sea and waves could overcome any human attempts to control the power of the sea. Only could protection be a success if huge costs were going to be involved. Many methods along the coast of North Carolina have taken place in the last 50 years with many failures occurring. It is very rare to find a coastline that shows a decrease in the rate of erosion over many years after defenses are in place. In fact in places the defenses seem to have sped up the erosion process. Coastal erosion is a natural process of erosion; transportation and deposition, interfering with this balance could be to blame for the rise in erosion on the coasts of some areas. Groynes have been built out to sea in many areas of the British coastline. Their aim is to trap material and thus slow down the rate of longshore drift. However, these groynes in some areas are been blamed for the rise in erosion rates further down the coast.
In various places in North Carolina , erosion is taking place at a rate of about 2 meters per year. Along these coasts there is a strong action of longshore drift taking place. Human interference is thought to be another cause, as a result of the sea defenses put in place. A rock groyne was built at Mappleton, to create a wider beach. This in turn would help protect the coastline, by absorbing the wave energy. Then at Withernsea a concrete sea wall with a splashback and boulder riprap in front of it was created. These defenses were to cause great problems. The groin meant that material moving down the coast by longshore drift would get stuck behind the groyne. This protected the initial area as a beach was created. Although this meant less material was heading further down the coast than it had done in... Continue Reading