Coastal Management

Rapid coastal erosion often poses a threat to the settlement, industry and recreation that has grown up along the coast and we often look to protect the coast from erosion through appropriate management of the coastal system.

There are a number of possible approached to coastal management:

1. Building Structures to defend the Coast

	*Hard Engineering* - the use of structures such as seawalls and concrete breakwaters to defend against the waves erosive power.
	*Soft Engineering* - use of natural materials to provide defence - e.g. 'beach feeding' - adding sand to beaches to replace that removed by longshore drift.

2. Pre-planning

	Restricting planning permission in areas that are under threat
	Only protecting areas of great importance

3. Do-Nothing

This is an approach often taken in areas of low-value. It is argued that coastal erosion will happen whatever and that reflecting wave energy simply enhances the problem elsewhere.

Methods of Coastal protection

Method of Protection

How does it work?

Advantages

Disadvantages

Concrete Wall, curved under the side to deflect the power of the waves.

(see photo)

	Sea walls reflect rather than absorb wave energy
	Most effective means of preventing erosion

	Most expensive (up to £2.5 million / km)
	Deflected waves often scour the base, undermining the wall (may eventually collapse)

Large boulders on the beach - lesson the force of the waves by absorbing the wave energy within the gaps between the rocks

	Relatively Cheap
	Use natural materials / rocks

	Environmentally ugly
	Can be undermined and removed by waves due to washing away of sand and shingle beneath.

Cages of boulders built into the cliff face - small rocks help to absorb the wave energy

Effective where severe erosion and cheaper than sea walls

Environmentally ugly (usually used in large numbers (see photo)

Wooden structures break the force of the waves and trap beach material behind them

(see photo)

	Much cheaper than a sea wall
	Effective at breaking the force of the waves

	Less durable than a sea wall - may need replacing quicker
	Don't give total protection to base of cliff
	Environmentally ugly (see photo)

Wooden or in some cases steel structures that stop longshore drift and build up / anchor the beach, protecting the base of a cliff

Stops longshore drift encouraging the build up of the beach and effectively reducing erosion.

Can increase erosion further down coast by stopping longshore drift and starving areas further down coast of sediment.

Build up the beach by replenishing beach material, particularly at the base of structures to provide a 'natural' solution to absorbing wave energy.

	provides natural solution
	aesthetically better solution (natural looking - difficult to tell that management is taking place).

can be expensive to keep transporting large amount of sand - sediment moved by longshore drift so will need frequent replenishment unless used with other defences.

Click to see photographs of coastal management at Overstrand (Norfolk Coast)

Case study of coastal erosion and management: Holderness Coast

Last modified: 30/03/05 Site Info / Disclaimer / Use of Photographs / Copyright / Contact Details