Breakwaters!

Okay so since Hazwani has posted about our trip to the three sites which are;
1. East Coast Park
2.Pahlawan Beach
3.Siloso Beach

and took pictures of our visit there plus pictures of breaks waters and other stuffs/measures to prevent coastal erosion, i will post about how each of these measures prevent coastal erosion :)

The most common coastal protection that we found at all the three beaches was the breakwaters. Thus, i will be talking more about this.

Basically, breakwaters (also known as bulkheads) are usually made out of granite and are built parallel to the coast of the beach or built with one end linked to the coast. Breakwaters may be small structures and are designed to protect gently sloping beaches and may either be floating or fixed, depending on the depth of the water and the tidal range.

In Singapore, the breakwaters are mostly built with one end linked to the coast and are fixed. Fun, random fact 1. There are 24 breakwaters at East Coast Park.
Fun, random fact 2. Cost of each breakwater is estimated to be around S$1 million.

Breakwaters prevent coastal erosion by creating a zone of shallow water between itself and the coast, so that the waves will break against it before reaching the coast. This way, there would be an area of slack water behind the breakwaters, thus, reducing the impact of the waves on the coast.

However, no matter how useful breakwaters are at preventing coastal erosion, the processes of erosion and sedimentation cannot be effectively overcome at the same time as deposition of sediment at one site will be compensated for by erosion elsewhere and this phenomenon occurs whenever breakwater or a series of such structures is built along coasts. Thus, there are still some disadvantages of breakwaters.

Breakwaters are unable to provide complete coastal protection as they still leave areas of the coast unprotected due to it's small structure. This will leave the unprotected area to be prone to erosion and gradually shrink, namely due to longshore drift.

Also, over the long term of interfering with currents and the supply of sediment, deposition will occur in these waters and beaches can be built up or extended in these waters and the nearby unprotected sections of the beaches do not receive fresh supplies of sediments.
Futhermore, breakwaters are subject to damage, and over-topping by big storms can lead to problems of drainage of water that gets behind them. The wall also serves to encourage erosion of beach deposits from the foot of the wall and can increase longshore sediment transport.

Okay that's the main idea of how breakwaters prevent coastal erosion and some disadvantages of having them. Now, let's look at some of the different types of breakwaters that's available. :)

Headland Breakwaters

A series of breakwaters constructed in an "attached" fashion to the shoreline and angled in the direction of predominant wave approach such that the shoreline behind the features evolves into a natural "crenulate" or log spiral embayment.

Detached Breakwaters

As the name implies, these are breakwaters that are constructed away from the shoreline, usually a slight distance offshore. They are detached" from the shoreline, and are designed to promote beach deposition on their leeside.

Single Breakwater

Single breakwaters may be attached or detached depending on what they are being designed to protect. A single detached breakwater may protect a small section of shoreline. A single attached breakwater, may be a long structure designed to shelter marinas or harbors from wave action.


Okay! So that's all i'll post about for breakwaters! Will post about the other measures that other countries take to prevent coastal erosion in the next post! so stay tuned! :D

Nous aimons la Géographie; Diyanah