In this Earth, about 60% of it’s population lives along coasts. But, erosion may occur along the coast and causes the land to retreat inland and affect the building along the coast. Thus, there is a need to protect them. Coastal protection measures is divided into two groups, the hard engineering and the soft engineering.
Hard engineering means the building of structures that could prevent erosion, such as Seawalls, Breakwaters, Groynes, and Gabions. In other hand, the soft engineering is a cheaper option than hard engineering and it applies knowledge of natural processes to protect the coast. Examples are Stablising coastal dunes, Planting mangroves, Beach nourishment, and by Encouraging the growth of coral reefs.
Hard Engineering:
- Groynes is a low wall build at right angles to prevent materials from being transported away by the longshore drift.
- Gabions refers to rocks that are bundled up in wired cages to prevent erosion. They are also used to protect other coastal measures such as seawalls.
- Breakwater is build normally out of granites, and placed parallel to the coast and creates a zone of shallow water between it and the coast. It protect the coast as waves will break against it rather than the coast.
- Seawalls are walls made of concrete which is located infront of a cliff and is able to absord energy from waves. Thus protecting the coast. But this way, energy from the waves will be directed downwards the seawalls, breaking it’s base and causing it to collapse.
Soft Engineering:
- Coastal dunes is a ridge of sand piled up by wind on the coast. Coastal dunes can protect human property like houses and roads against erosion. To stabilise dunes, people would have to plant vegetation such as marram grass as it would bind the sand together preventing the sand to blown inland causing damage for properties.
- Planting mangroves can help to prevent erosion as mangrove trees could bind loose soil.
- Beach nourishment is a process where a large amount of sand is added to an eroded beach. When longshore drifts occurs, sands were removed from the beach to down side of the coast, sand from the other are of the beach will be brought and deposited to the beach.
- Encouraging growth of coral reefs can protect the coast from erosion as coral reefs could reduce the speed of the waves when it reaches the shore, thus the destructive energy of the waves had been weaken or lost.
In singapore, there are no much erosion occurs in it’s coast as it is located in a sheltered area. But Singapore still needs to protect it’s coast because of it’s limited land available for development and recreation. Sentosa in Singapore, had 3 main coastal management strategies. These are breakwaters, rock armour, and seawall.
Breakwaters in Sentosa:
Rock armours is large rocks stacked in the coast. They block the waves from disruption the coast by breaking the flow and energy of the water. These are the pictures of rock armours:
As seen on the picture, this Sea wall is made by big companies such as the McConnell Dowell and Delta Marine Consultants . There are 313 vertical steel pipes being piled up along with 288 racked steel pipes
and the geography textbook
Thank You.
