Coasts:: Coastal Management - Traditional Approaches Flashcards
Hard and soft engineering.
What is hard engineering?
Hard engineering involves the building of entirely artificial structure using various materials to reduce or stop the impact of coastal processes.
Why may different stakeholders not be happy with hard engineering along the coast?
It is an unsustainable method of management:
- expensive
- require constant maintenance
- harm the environment
What is soft engineering?
Soft engineering methods try to work with the physical and natural processes within an area to protect the coast
Describe a sea wall
A concrete barrier along the coast which absorbs the energy of the waves. Some can be curved to deflect the power of the waves.
Advantages of sea walls
- very effective
- will prevent erosion
- easily made
Disadvantages of sea walls
- deflecting waves can undermine foundations
- requires maintenance and repair
- expensive to maintain
- ugly and unnatural
Cost of sea walls
£5000 per metre
Describe groynes
Wooed fences or walls made from piles of rocks built out into the sea.
How do groynes protect the coast?
They reduce the rate of longshore drift by trapping material on one side. This extra beach then protects the coast from the sea.
Advantages of groynes
- works with natural processes
- increases tourist potential
- relatively low costs
- easily repaired
Disadvantages of groynes
- can increase erosion rates further down the coast
- unattractive
Cost of groynes
£1000 per metre
£5000-£10,000 each (200m intervals)
Lifespan of groynes
30-40 years
Lifespan of sea walls
30-50 years
Describe rip-rap
Large rocks placed at the foot of a cliff or at the top of a beach. It forms a permeable barrier to the sea, breaking up the waves but allowing some water to pass through.
Advantages of rip-rap
- easy to construct and maintain
- used for recreation e.g fishing, sunbathing
- uses natural resources
Disadvantages of rip-rap
- some erosion takes place
- can be intrusive
- looks out of place with local geology
- dangerous to climb on
Cost of rip-rap
£1000-£3000 per metre