Coastal Protection Measures are important because there are some cities, such as Brisbane, Houston and many more which are located along the coast and it is estimated that about 3.6 billion people in the world live along that coast! That's a lot! Also, coasts are awesome locations as tourist attractions! However, as we all know, the coast may sometimes erode thus, affecting people who live near coast they they may need to retreat inland and also affect the infrastructure that has been built. Hence, it is important for us to find way to prevent erosion from occurring :)
There are two different types of measures that could be taken. One, Hard Engineering, and two, Soft Engineering. Hard Engineering refers to the construction of structures such as seawalls, breakwaters, groynes and gabions to protect the coast from erosion while soft engineering involves the application of knowledge of natural processes to stabilize the coast and reduce the erosion.
I will talk more about Hard Engineering in this post :)
Seawalls constructed on the inland part of a coast to reduce the effects of strong waves. They are usually made out of concrete, boulders, steel or gabions which absorbs the energy of the waters and protects the coast against strong waves, especially during storms. Also, more modern seawalls tend to be curved so that they are able to reflect the wave energy back out to sea.
Fun, random fact 3.Seawalls can be expensive to build, today costing between $4000 to $7000 per metre (£2000 - £5000 per metre)
Fun, random fact 4. There's going to be a sea wall at Singapore's Resorts World! (picture below)
Also, there are different types of seawalls available! :) here are some examples:
Curved/Stepped seawalls & Standing seawalls
Curved or stepped seawalls are designed to enable waves to break and to dissipate wave energy and repel waves back to the sea. The curve can also prevent the wave overtopping the wall, and provide additional protection for the toe of the wall.
Vertical seawalls are built in particularly exposed situations. These reflect wave energy and under storm conditions standing waves will develop. In some cases piles are placed in front of the wall to lessen wave energy slightly
Rubble Mound
A series of rubble mound-type structures such as riprap and revetment are used in less demanding settings. The least exposed sites involve the lowest-cost bulkheads, or revetments of sand bags or geotextiles. These serve to armour the shore and minimize erosion. They may be either watertight, covering the slope completely, or porous, to allow water to filter through after the wave energy has been dissipated.
Groyne is a low wall built at right angles to prevent materials from being transported away by the longshore drift as it interrupts water flow and limits the movement of sediments. All of a groyne may be under water, in which case it is a submerged groyne. The areas between groups of groynes are groyne fields. Groynes are generally made of wood, concrete, or rock piles, and placed in groups. They are often used in tandem with seawalls.
Plus, gabions are cheaper alternatives compared to coastal protection measures!
Fun, random fact 5. Gabions are also used in civil engineering, road building and military applications! :)
-In a military context, earth or sand-filled gabions are used to protect artillery crews from enemy fire.
Reinforced earth with gabions, Sveti Rok, Croatia.Nous aimons la Géographie;
Diyanah
No comments:
Post a Comment