Coastal Protection Measures

Hard engineering


Seawalls

to protect the coast from being eroded, people have built seawalls in front of the cliff or along the coast

It is usually made out of concrete which absorb the energy of the waves and protect the coast against strong waves, especially during the storm

however, the wave energy is directed downwards, to the base of the seawall

causing it weaken and collapse

hence, seawalls have to be carefully maintain

And it is not cheap !

Breakwaters

breakwater are built off coast but parallel to it.

It is usually made of granite

it creates a zone between shallow water and the coast itself

so that water will break against it before reaching the coast

Disadvantage: it leaves other parts of the beach unprotected.

Groynes

Built right angle to the beach

it enable sediments to build up one one side.

however, the other side will be eroded.

and the long shore drift will not be able to reach it

Thus further down the beach might me eroded away

To solve it , more groynes can be build

but IT SUPER UGLY !

Gabions

Are also used to protect river banks

also used to protect other coastal protection

e.g. seawall.

however,gabions are easily destroyed by powerful waves

The wires also rust easily due to the salt in the sea water

It is also very ugly

it has a short life span of less then 15 years

However, it is the cheapest method.

Soft engineering



Stabilizing coastal dunes

Coastal dunes are great for protecting human property that is near the coast.

examples houses and roads.

natural vegetation are found in dune to make them stable

however due to human activity, dunes have became unstable

Sands Unstable dunes can blow inland and effect people's life.

to stabilize the dunes, more vegetation can be grown.

activity also needs to be minimized

Planting Mangroves along the shore

protect the coast from erosion by strong waves and harsh wind

mangrove trees have prop or kneed roots that can hold loose soils together.

studies have shown that countries that planted mangrove suffered less during the 2004 Indian Ocean Tsunami

And thus many countries are planting mangrove

however, young mangrove are very vulnerable

thus the help of the local people is needed to help take care for these your plants

Beach Nourishment

This involves adding large amounts of sand to a beach that is being eroded

When the longshore drift bring sediments down the beach,

people bring in sands from other areas to replace the sand lost

this is a very expensive method as beach quality sand is super expensive

and regular maintenance is needed

this method can only last for about 10 years

Encourage growth of coral reef

coral reefs are masses of rock-like substance growing in shallow seas

They reduces speed of the waves approaching the coast and thus protect the beach.

however due to human activities, these reef are destroy

Water pollution made it worse for them to grow as they need clear water

Some country came up with ways to encourage growth for coral reef

e.g Malaysia ban fishing the protected area

however for these methods to work, the people have to cooperate.