Coastal Management

Description: When beaches are built up using gravel/sand, protecting the area of cliffs/settlement/land behind.

Cost: £300,000 per 100 metres

Advantages: 

• Natural looking, fairly attractive
• Cheaper than many hard engineering strategies
• Increases tourism as beaches are made bigger

Disadvantages:

• Mitigates effects of erosion- not prevented.
• Not as effective as hard strategies
• Constant maintenance needed due to transportation and Longshore Drift.
• Sand is sourced from elsewhere, perhaps increasing erosion in other locations.

Sustainability: More sustainable than hard strategies, but doesn't prevent erosion and the sand sourced from elsewhere may be unsustainable.

Description: Stabilising and regenerating dunes to stop effects of erosion by planting pioneers, making paths and roping off vulnerable areas.

Cost: £200-£2000 per 100 metres

Advantages:

• Cheap and natural
• Increases tourism and provides habitiats for wildlife
• More effective at stopping erosion than flat beaches

Disadvantages:

• Not as effective as hard schemes
• People may ignore designated paths/signs
• Takes time to establish the ecosystem.

Sustainability: Low cost and restoring habitats makes this strategy extremely sustainable.

Description: Salt Marshes are created by humans as a barrier between land and the sea to increase friction and dissipate wave energy.

Cost: Varies on marsh size, but overall fairly cheap.

Advantages: 

• Cheap and natural
• Creates habitats for wildlife
• Creates a natural barrier for the land from the sea

Disadvantages:

• Takes time to establish: effects aren't immediate
• Gets damaged in stormy conditions, waves can break through.

Sustainable: Very sustainable as low cost and creates new habitats.

Description: Humans deciding on land use close to the sea and what would be least expensive to replace if lost. Retreating, allowing the sea to take over.

Cost: Free!

Advantages:

• Natural- not interfering with natural processes
• No knock-on effects elsewhere
• Free

Disadvantages:

• Not stopping erosion or flooding
• Land is lost

Sustainability: Most sustainable as not interfering at all with nature, and it's free.

Description: Type of dam which consists of a line of large gates that can be opened or closed to control the amount of water passing the dam.

Cost: Depends on project- Cardiff Bay: £200 million, Thames Barrier: £534 million

Advantages:

• Tourist attraction, can make area more attractive.
• Generates hydroelectricity/creates a harbour as byproducts. 
• Most effective form of flood/erosion defence

Disadvantages: 

• Hugely damaging to wildlife
• Can only be used on narrow stretches of estuary
• Needs constant maintanance due to silting up.

Sustainability: Most effective, but huge environmental impact and cost.

Description: Concrete wall at the top of a beach, curved faces reflect waves back into the sea and dissipate energy.

Cost: £6000 per metre

Advantages:

• Effective at stopping erosion/flooding
• Long life compared to other hard defences.
• Tourism due to promenades built on top.

Disadvantages:

• Very expensive and needs constant maintanance and repairs as sea undercuts foundations.
• Eyesore, ugly.

Sustainability: Only worth cost if there's settlements behind. Unsustainable long term as needs repairs and hughe costs.

Description: Sloping wooden planks laid against frames placed on beaches to absorb energy of incoming waves.

Cost: £3500 per metre

Advantages:

• Effective at stopping erosion

Disadvantages:

• Wood rots if exposed to water for too long.
• Eyesore
• Expensive

Sustainability: Unsustainable long term, as only cost effective if there is valuable land behind and needs constant maintenance/replacement.

Description: Huge boulders dumped at the base of a cliff, helping waves to break and absorb wave energy.

Cost: £2000 per metre

Advantages:

• Cheaper than revetments, sea walls and barrages
• More natural looking

Disadvantages:

• Rocks have to be transported by ship, often from Scandinavia, causing damage in place where they were imported from.
• Not as effective as sea walls/barrages/revetments

Sustainability: Damages place of importation, and not as effective, but cheaper.

Description: Cage filled with rocks, made into a wall by stacking the gabions. Used to protect cliffs for short term only, stops erosion.

Cost: £2000 per metre

Advantages: 

• Cheaper than many other hard strategies
• Fairly attractive

Disadvantages:

• Cages rust and rocks erode by attrition, so need constant repair/maintenance.
• Not as effective as sea walls/barrages/revetments
• Short term protection only

Sustainability: Fairly sustainable as they are cheap, but erode quickly and not very effective over long periods of time

Description: Wood fences running right angles to the sea, interrupting long-shore drift.

Cost: £10,000 per groyne, 200 metres apart

Advantages: 

• Prevents longshore dift as sediment is not moved away, slows erosion.
• Attracts tourism as it makes beach bigger, boosting economy.

Disadvantages:

• Needs constant maintenance as beach needs to be levelled out.
• Beaches further along coast get eroded quicker as no sediment arrives there.

Sustainability: Not very as further coastlines are eroded and very expensive.