Coastal Problems

Flooding and erosion are two common problems along the coastal area.
These problems effect both the environment and people.
As the result of this, the coastline retreat inland and the coast become unsuitable for settlement, tourism and industry.

Coast flooding Project

The Delta Projects in the Netherlands is to control the flood. It was started in 1958 with the aim to protect the Southwestern Netherlands from floods. The coastal land has been experiencing floods in 1953 a disastrous flood took away 1, 850 lives and destroyed millions worth of property.
To solve the problems,
Dams and storm surges barrier were built to keep out seawater in times of floods.

Dams and surges

Benefits from the Delta Projects, fresh water lakes that formed behind the dams become important source of water for farming, new residential area, recreational area and roads were built.

The line red represents the dams and surges built to protect against flooding in those areas

Coastal Erosion

One measure taken place to protect the coast from erosion is to build structures such as
1. Seawalls are built on and parallel to a coast.
It protects the stretch of the coast behind it by reflecting waves away from the coast.

Seawalls

2. Breakwaters are built with one end and attached to the coast.
It help to protect the coast by breaking the force of oncoming waves at some distances

breakwaters

3. Groynes are built at right angle to the coast .
Groynes interupt the longshore drift and causes materials to deposit on side of the groynes facing the longshore drift.

Groynes

A VIDEO OF COASTAL MANAGEMENT

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People and Coast

Coastal development are for
Port activities
Coasts which are sheltered from storms and have deep waters in which ships can anchor are suitable for development as PORT.
Some are strategic location and accessible by different sea routes.
Examples the port of Singapore and the port of Yokohama in Japan.

Port of Muara

Tourism
Some coast are attractive to holiday makers.
Coasts which have crystal clear water, long stretches of wide sandy beaches and have beautiful coral reefs often developed as beach resort. Examples of coasts Pulau Langkawi & Phuket
Some coast have interesting features as headland, caves , arches, stack and cliffs. Example Twelve Apostles in Victoria, Australia

Langkawi Resort

Settlement,Industries and Farming
Land reclamation where land is in short supply, people may create additional land along the coast. Such as in Singapore and the Netherlands.
These land are used for farming activities such as cattle rearing and cultivation of crops such as wheat and barley.
Apart from that also, they use it as settlement  consist of farmhouse, villages, towns and cities.

the Palm in Dubai

LAND RECLAMATION IN DUBAI- A NEW GATEWAY

FORMATION OF SPITS AND TOMBOLOS

A Spit is a long, narrow ridge of deposited materials that extends from the mainland into the sea. An example in Brunei is Muara Spit and Kuala Tutong Spit.
When the spit is connected the island to the mainland to form a feature is called the Tombolos.

Spits & Tombolos

The long shore drift transports materials along the coast. If there is a sudden change in the direction of the coast, the longshore drift continues to transport the materials in the original direction to the deep sea
As the longshore drift enters the deep water, the materials are deposited. Over time, these materials accumulate above the water to form a spit.
The spit continues to grow with the continuous deposition of materials.
The spit join a nearby island to the mainland to form a tombolo.

formation of Spits

FORMATION OF OFFSHORE BAR

Off shore bar is a long narrow ridge of deposited materials sand can be found lying away from and parallel to a coast.

OFFSHORE BAR

When the waves approach a gently sloping coast , friction between the waves and the sea bed causes the waves to break at some distance from the coast.
Over time, more materials  are built up parallel to the coast to form ridge of sand called offshore bar.
A body of coastal water may be partially or completely cut off from the open sea by the offshore bar. The body of water is called a lagoon.

FORMATION OF BEACHES

Beach is a zone of materials accumulated along the coast.

DID YOU NOTICE THE HEADLAND ROCKS ARE THE SAME COLOUR WITH THE BEACH DEPOSITED MATERIALS? EXPLAIN HOW THE PROCESS WORKS?

A beach is formed when deposited materials carried by waves are accumulated in a zone along the coast. The materials on the beach vary in size from fine sand to pebbles . The waves sort these materials according to the weight. The finer sand deposited nearer the sea and the coarser materials further inland.

COASTAL DEPOSITION

Deposition occur along the coast due to the
Constructive waves which have a more powerful swash than backwash, more materials are deposited than eroded on such coasts.
when the coasts are sheltered from prevailing winds which protected from wave erosion and deposition of materials take place.

Storm also subsidies, the large amount of materials eroded from the coast  than transport away from the coast. Hence, these materials are deposited.

Depositional features

1. Beaches
2. Offshore bars
3. Spits and tombolos
4. Coastal dunes

COASTAL TRANSPORT

The materials that are eroded from the coast are usually transported along the coast by waves and currents before they are deposited elsewhere.

The Longshore  Drift

When waves approach a coast at an  angle, the swash brings the sediment up onto the coast at the same angle.
Due to friction and the pull of gravity, the sediment is then brought seawards by the backwash at a right angle to the coast.

LONGSHORE DRIFT MOVEMENT

The sediment is picked up again by the next wave and carried up and then down the coast again.
This repeated zig zag movement of the sediment shifts the sediment along the beach.
A long shore drift is the movement of sediment along the coast when waves approach the coast at an angle

LONGSHORE DRIFT VIDEO