Geography Fieldtrip Labrador Park: Group 3 - Location 3: Coastal Management

Geography

Labrador Park Fieldtrip

Our second fieldtrip of the year, Labrador Park. The objective of this fieldtrip was to observe the various man-made and also natural coastal features. What my group and I were focusing on, was coastal protection features.
The main feature to look out for at Labrador Park were seawalls.

Seawalls

Seawalls are built to reduce the effects of erosion caused by strong waves, by reflecting waves away from the coast.

However, powerful backwash of reflected waves increases the rate of erosion of beach materials, therefore the base of the seawalls are weakened. But in Singapore, the currents of the waves are not as powerful as it is at other parts of the world. For example, Hawaii, Indonesia, Penang, Hong Kong and Japan. In these countries, the fetch is much longer than that of Singapore’s fetch. The reason is because Singapore is surrounded by many other countries. Therefore the wind does not blow over a very large area of water. Hence, the wave power is adversely affected.

Another factor that influences the wave power is the presence of prevailing winds. In the case of Singapore, our prevailing winds come from the North-east and from the South-west. However, the highlands of other neighbouring countries block most of the winds from reaching Singapore. With less wind power, the wave energy would be lowered.

The Need For Coastal Management

Why?

To slow down/prevent wave erosion

Cliff erosion at Weybourne.

What will happen without coastal management?
-Features disappearing (E.g. beach, coastal dune etc.)
->tourism affected
-Erosion taking place
->Land Retreating
->Flooding
->Unsuitable for settlements (E.g. Beach resort, jetty etc.)
-Port activities affected
->Deep offshore waters -> cannot anchor
->Trade decreases

Examples of Coastal Management

Seawalls

Purpose?
To reduce the effect of wave erosion
How?
When waves hit the seawalls, the wave energy is concentrated on the seawalls. When waves reach the coast, the waves are weakened, therefore there is lesser energy left to erode the coast.

Disadvantage of building Seawalls
When waves hit the seawalls, the wave erodes the base of seawalls, causing it to weaken and need to be restructured occasionally.

Advantage
Protect the entire coast unlike breakwaters which only protect some part of the coast.

Countries Using Seawalls

East Coast, Singapore.
Butterworth, Peninsular Malaysia
Labrador Park, Singapore

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After:

Groynes

Purpose
To deal with longshore drift.

How?
When longshore drift hits groynes, this causes deposition on side of groynes facing longshore drift.

Disadvantage of building groynes
Groynes are made up of ugly structure. This affects the beauty of the beach. This indirectly affects tourism. Deposition on one side of groynes causes features unable to form. This indirectly affects tourism.

Advantage of building groynes
Groynes intercept longshore drift, causing loads and sediments to be deposited on side of groynes facing longshore drift.

Countries using Groynes
->Crescent Beach, Canada

A groyne at Crescent Beach. Surrey, BC, Canada.

Breakwaters

Purpose
To reduce effect of Wave Erosion

How?
When waves hit the breakwaters, strong erosive power is concentrated on this structure. When waves reach the coast, the erosive power is lesser, therefore wave has lesser energy for erosion, and this slows down the coast erosion.

Disadvantage of building breakwaters
This structure is built only at some part of the coast. Unprotected parts of coast will be eroded by waves.

Advantage of building breakwaters
This structure causes waves energy to be concentrated on it. When waves reach the coast, it has lesser energy for coastal erosion.

Countries using Breakwaters
->East Coast, Singapore
->Tynemouth, Australia

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