breaking wave back on the next incoming wave [2m]. This reduces the incoming waves’ energy, making them less likely to remove coastal materials. This greatly reduces erosion in the area [2m]. Examples of sea walls in use can be seen in Lahinch, Co. Clare [2m]. While sea walls are seen as a cheap and effective way of stopping erosion, they disrupt the natural processes of the region. This can lead to increased erosion in other areas, or the prevention of the natural movement of sand along the coast [2m]. In some cases, entire coastal habitats are destroyed.
Gabions are steel mesh cages that are filled with tightly packs stones which cause waves to spread out as they hit the coast. This reduces the wave’s energy and erosional power [2m]. Sea walls are seen as a better option than gabions, as the mesh that keeps the stones together often breaks and is expensive to replace. Groynes are low walls made from wood or cement that are designed to interrupt the process of longshore drift [2m]. They are built at right angles to the shore and allow material to accumulate and prevent the erosion of beaches. While they are effective, they deprive nearby coastal areas of natural deposition which can lead to increased erosion of these areas [2m].
Soft Structures
Soft structures are a more environmentally friendly method of coastal protection as they are used to repair damage caused by destructive waves [2m]. The most common forms of soft coastal protection are beach nourishment and sand dune repair [2m]. Beach nourishment involves adding new sand to beaches by dredging sand from offshore, which increases their thickness and width [2m]. This helps to prevent erosion of beaches and adds to their value as recreational areas [2m]. The planting of Marram grass is seen as the most environmentally friendly method of coastal protection as it does not affect other coastal areas [2m]. Planting Marram grass on sand dunes roots binds the sand together and makes it more resistant to wind erosion [2m].
Marks Awarded Impact on process identified 2m
Examination of impact best 14 SRPs @ 2m each Total 30/30
Impact on process identified (reduced erosion).
Hard and soft structures purposes and impacts clearly discussed.
