Coastal Management Flashcards
Why manage the coast? (3 stars)
- 23% total land area lies within 10km of the coast
- 21 million people live within the coastal zone
- 40% of UK manufacturing industry lies close to the coast
Reasons for management
Coastal erosion
Coastal flooding
Failure of former defences
Possible management stategies
Hold the line
Advance the line
Retreat the line (managed retreat)
Do nothing
Hold the line
Maintain current defences or build new ones to ensure coastline stays where it is
Advance the line
Build new defences seaward of existing line - often unnatural and expensive
Retreat the line (managed retreat)
Allow the coastline to retreat due to flooding and erosion but closely manage the rate and location of this retreat
Do nothing
Low value areas left to natural coastal processes as not deemed viable to spend on defences
Only some parts of the coast
Are defended
The aim of coastal management is to protect…
Homes, businesses and the environment from erosion and flooding
The amount of money available is _________ and so not everywhere can be defended.
We use a ____-________ analysis to chose which places are defended.
Limited
Cost-benefit
The money available is usually used to protect…
Large settlements and industrial sites, rather than smaller settlements
Name factors affecting the approach taken (5)
- Likelihood of success?
- Cost of defence?
- Value and land use
- Would it affect locations elsewhere?
- Alternatives?
CBA
Cost benefit analysis
Tangible factors
Where costs and benefits are known and can be given a monetary value
E.g house prices
Intangible factors
Where costs may be difficult to assess but are important
E.g visual impact
Tangible factors that need consideration for an accurate CBA…
Land value Business values House prices Infrastructure value Transport networks value Population
Intangible factors that need consideration for an accurate CBA…
Social attachment Visual impact Emotional impact Peoples emotional connections Historic value Ecology
Issues caused by not using CBA
Impact on locations further down coast
Waste of money
Wrong location
The steps taken by the government in organising defences
- What is the issue
- Causes and effects
- Who affected
- What done
- Environmentally acceptable?
- CBA
- Décision makers
- Effects of proposition
- Who and what affected
- Gains/losses
- What is the issue
Hard engineering
Making a physical change to the coastline using man made materials and/or structures
Soft engineering
Works with nature and natural systems to protect the coast
Hard engineering strategies (9)
Sea wall Groynes Gabions Revetments Riprap/Rock armour Tidal Barrages Tidal Barriers Offshore reefs/Breakwaters Earth Bank
Soft engineering techniques (7)
Beach nourishment Beach stabilisation Dune regeneration Managed retreat Land-use management Creating marshland Do nothing
Sea wall
Outline
Pros
Cons
Cost
Curved wall reflects wave energy + barrier to flooding
Often have a promenade for walking on
Reflect//absorbing wave energy + unnatural
£6000/m
