Analysis of Sea Defences
Reventment
The first sea defence is the concrete re-enforced revetment. Beside the revetment, there is also a rip-rap. Rip-rap, also known as rock armour, consist of large boulders and rocks placed to absorb the energy of waves. It is a cheap solution to deflect wave energy. The revetment are made out of square concrete blocks with holes in it. They are built in a smooth, natural curve slope to reduce the wave energy. Erosion is prevented as waves break against them with the revetment absorbing the energy. The water will get into those holes on it, which will reduce the impact of the wave, as well as drainage. A recurve wall is on top of the revetment to further reduce the energy and to 'bring' the waves back to sea. There are also evidence of erosion at the bottom of the revetment, which means that the revetment might need to be repaired constantly. They might be expensive to built but is cheap to maintain. The revetment is quite effective to prevent erosion on the land above, however it is not attractive at all.
Sea Wall
The other sea defence is the sea wall. The sea wall is made out of concrete and granite. The aim of having sea walls is to protect and shield the coast. They are effective in protecting cliffs from erosion and also act as a barrier to prevent flooding. The top part of the sea wall is a plain wall to ensure safety for people so that they won't fall down. The second part is the old sea wall, and if you look closely, there are drainage pipes built in the sea wall. When it rains, the water will go out to sea to prevent the water staying in there and causing the wall to collapse. The third part is the new sea wall that they are constructing because the old wall had been eroded due to strong backwash created when the waves 'slam' onto the wall. There are evidence of erosion at the bottom of the wall. Those eroded are usually concrete rocks because it is a weaker rock compare to granite. Even though sea walls are clearly more appealing than revetment, they are expensive to construct and maintain. They are more long lasting than revetment but maintenance will be costly.