Coastal Management Flashcards
(53 cards)
How many people lived within the coastal zone in 1999?
16.9 million
How much of UK manufacturing lies close to the coast?
40%
How much of coastal land is built on?
30%
What are the reasons for coastal management? (3)
- Coastal erosion
- Coastal flooding
- Failure of previous defences
What is hold the line?
Maintain current defences
What is advance the line?
Build new defences seaward of the existing line
What is managed retreat?
Allow the coastline to retreat due to flooding and erosion but closely mange the rate and location of the retreat
What is ‘do nothing’?
Low value areas left to natural coastal processes as not deemed viable to spend on defences
What are the social factors taken into account? (4)
- Number of residents
- Use of the land
- Who is impacted if it is damaged
- Effect of downdrift land
What are the economic factors taken into account? (4)
- Value of land
- Cost of defences
- Cost of maintanance
- Value of business and connections in the area
What are the environmental factors taken into account? (4)
- Impact on surrounding land
- Current state of the coasts
- Habitats and environment concerned
- Unique landforms
What are the political factors taken into account? (4)
- What are the alternatives?
- Objections/ Opinions
- Likelihood of success
- Taking into account opinions of stakeholders
What is tangible cost benefit analysis?
When cost and benefits are known and can be given as a value
What is intangible cost benefit analysis?
Where costs may be difficult to assess but are important (e.g visual impacts)
What are the steps in cost benefit analysis? (6)
- Where is the issue?
- What are causes and effects?
- Who is affected?
- What should be done?
- IS solution technically viable and environmentally acceptable?
- What is cost benefit?
Etc
What are sea walls?
Concrete or stone walls at the foot of a cliff, or at the top of a beach. Usually have a curved face to reflect waves back to sea
What are the advantages of sea walls? (4)
- Protects high value land
- Can prevent flooding
- Long lasting
- Can reflect wave impact
What are the disadvantages of sea walls? (3)
- Eyesore to locals and tourists
- Expensive to build / maintain
- Produce strong backwash, undercutting it
What are groynes?
Timber or rock structures at right angles to the coast that trap sediment being moved by LSD, building up the beach
What are the advantages of groynes? (3)
- Very effective for building beach
- Prevents sediment moving by LSD
- Allows a natural defence to build up
What are the disadvantages of groynes? (2)
- removes a lot of sediment from downdrift
- Other beaches left vulnerable to erosion
What are gabions?
Bundles or rock in mesh cages at base of cliff to reduce impact of waves and prevent cliffs being undercut
What are the advantages of gabions? (3)
- Cheap to build and maintain (£100/ metre)
- Difficult to erode
- can eventually look natural as vegetation grows in/ over them
What are the disadvantages of gabions? (3)
- Not very effective
- Unsightly, unnatural appearance
- Ongoing maintenance required
