chapter 1 coasts should coastal environments matter?

CHAPTER 1

COASTSShould Coastal

Environments Matter?

CHAPTER 1 COASTSShould Coastal Environments Matter?

In this Chapter, you will explore three key questions:1.How and why are coastal environments different and dynamic?2.Why are coastal areas valuable?3.How can we manage coastal areas in a sustainable manner?

http://www.youtube.com/watch?v=abU02rmVsKA&feature=related

Watch the video on coastal erosion in Australia and answer the following questions:•How does climate change cause the coastline to slowly disappear? How does it then affect property owners?•What is the problem with building rockwalls to protect housing along the beach?•How is the government trying to slow down the pace of erosion? How effective is it?

CHECK-IN: Coastal erosion in Australia


Gateway 3: How can we manage coastal areas in a sustainable manner?

a. How can coastal areas be managed?b. What are the coastal protection measures?c. Case study: East Coast Park

Sustainable management of the coastline involves:• A series of strategies (hard and soft engineering)• Sustainable development of the coastline to

benefit present & future generations

Three approaches:• Limiting damaging activities• Protection of coastal resources• Restricting development of areas prone to natural

hazards

a. How can coastal areas be managed?

Why do you think fences are built around the sand dunes?

Limiting damaging activities•Banning vs limiting activities such as:

– Blast fishing, clearing mangroves for fish farms, dumping waste into ocean

•Constructing man-made facilities to replace natural areas.


Limiting damaging activities

Read the article about the Bunaken National Park (http://www.sulawesi-info.com/bunaken.php)and answer the following questions:1.Identify the stakeholders who have a part to play in protecting the marine life in this area.2.Think of some potential problems that the stakeholders might face with the development of the marine park


Protection of coastal resources•Preventing resources from being overexploited or overused.

– For example, setting up marine reserves to protect the fishes in areas where overfishing occurs. This is a clash of interest with local fisherman who depend on the fish stock for a living.


Restricting development in areas prone to natural hazardsWatch the following video again and explain the ‘planned retreat policy’ which the Australian government used on the beachfront property.

http://www.youtube.com/watch?v=abU02rmVsKA&feature=related


Compare Photograph A and B in terms of how you think they protect the coastline from erosive waves.

A B

b. What are the coastal protection measures?

SOFT ENGINEERING HARD ENGINEERING

Protection against erosive waves using natural processes

Construction of physical structures to protect coasts against erosive waves

a. Beach nourishment Seawalls

b. Replanting coastal vegetation b. Gabions

c. Encouraging coral reef growth c. Breakwaters

d. Groynes

e. Tetrapods


Beach nourishmentFine sand brought onto Siloso, Palawan and Tanjong beaches in Sentosa, Singapore.

Planting vegetation to stabilise sand dunesVegetation planted on sand dunes in Western Australia to hold onto the sand.Mangrove restoration in Thailand after damage of the coastline in the Dec 26, 2004 Aceh-Andaman tsunami.

What are the disadvantages of each strategy?

Encouraging coral reef growthMaldives has been operating a coral-growing programme where coral growth is sped up using solar-generated electricity.


SeawallsWalls built parallel to the coastlineabsorbs wave energy.

GabionsWired cages filled with rocks which weaken wave energy when the gabions are placed in front of the coastline.

BreakwatersBuilt parallel to coasts offshore and create a zone of sheltered water between the breakwater and the coastline. Materials are deposited within the sheltered area to form beaches.



TetrapodsConcrete structures stacked in an interlocking position, allowing water to pass through them, reducing strong backwash and dissipating wave energy.

GroynesLow walls constructed at right angles to the shore to retain sediments which are transported by longshore drift.



c. Case study: East Coast Park

Uses of East Coast Park:

•The Park was reclaimed to alleviate problem of land shortage in the 1970s

•Recreational activities such as swimming, fishing, cycling, jogging, kite-flying

•Used for sports events. Sporting facilities developed in the same area


Value of protecting coastal environment• East Coast Park’s coastline is near residential area

(100m from coastline)• Population is vulnerable to changes in coastal

environment in the long run


Measures adopted to protect the coastline

•On reclaimed land

•Hard engineering strategies (seawalls & breakwaters) were put in place to protect the coastline from coastal erosion

•4,500m seawall with a strip of pebbles, sand, clay and silt in front of it

•Two types of breakwaters used to protect the coast and create beaches: gabion and riprap breakwaters

•Large drains acting as groynes built on the foreshore

What are the problems that arose from the application of hard engineering strategies on the East Coast Park coastline?


Factors undermining the success of the coastal protection measures

•Sediments from the Johore shoal reduced due to reclamation of land at Changi for Changi airport construction

•Sinking of reclaimed land of East Coast Park due to lack of beach material; more vulnerable to erosion

•Extreme high tide events worsened erosion; sand from beaches washed landward

Responses

•Beach nourishment, breakwater reconstruction

•Constant maintenance



In this Chapter, you will explore three key questions:1.How and why are coastal environments different and dynamic?2.Why are coastal areas valuable?3.How can we manage coastal areas in a sustainable manner?

chapter 1 coasts should coastal environments matter?

Documents

coastal erosion

coastal areas valuable

coastal protection measures

coastal environments

natural areas

sustainable manner

following questions

natural hazardswatch