COASTS Bk7 - Coastal Management Flashcards
What % of the worlds population lives 60knm from the sea?
50%
Definition of mitigation
Action taken to reduce long-term impacts of coastal erosion and hazards
Definition of adaption
Actions taken to adjust to the events to limit the impacts and take advantage of the opportunities, or cope with the consequences
Definition of hard engineering
using artificial strictures to prevent / control natural processes
What are the two key aims of coastal management?
- To provide defence against + mitigate the impacts of flooding
- To provide defence against + mitigate the impacts of flooding
SEA WALL
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- £6000/m
- Prevent flooding and erosion through stopping destructive waves (hydraulic action + abrasion)
- Effective, long lasting life span, little maintenance, promenade business
- Expensive, carob footprint, aesthetically unpleasing
ROCK ARMOUR
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- £3000/m
- Used at base of sea wall to prevent undercutting. Greater SA = more friction
- Effective, long life span, little maintenance, habitat creation, recreation (fish)
- aesthetically unpleasing, carbon footprint, collect litter
GABIONS
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- £100/m
- Physical protection and increases SA
- Cheaper
- Aesthetically unpleasing, carbon footprint, break as iron corrodes
GROYNES
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- £10,000 each
- Prevent LSD, spaced at 200m intervals
- Effective, tourism of the beach
- Can cause accelerated erosion further down, dependent on material
REVENTMENTS
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- £4,500/m
- Increase friction
- Cheaper
- Access issues to the beach, not as effective
OFFSHORE BREAK WATER
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- 1.3 million each
- Large amounts of material offshore
- Effective, don’t disturb the beach
- Expensive, lots of maintenance
CLIFF FIXING
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- Driving bars into the cliff face - both stabilising and absorbing wave (slumping and rotational slip) geotextile membrane
- Cheaper materials, protection against sub aerial processes
- Expensive labour and access
BARRAGES
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- Coastal flooding - present flooding on major estuaries and other large sea let areas
- 4.
Definition of soft engineering
Natural material used to work alongside natural processes > enhancing what nature is already doing
BEACH REPLENISHMENT
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- £3000/m (dependent on volume + distance)
- Deposition - waves break further out at sea
- Protects sand dunes behind, tourism (direct and indirect employment > multiplier)
- Expensive, habitat destruction where it is dregged, upset natural processes
CLIFF REGRADING AND DRAINAGE
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- Reducing the angle of the cliff to stabilise cliff + removes excess water to avoid land slides + slumping
- Cheap, effective on clay or unconsolidated material
- Draining may dry it out too much and cause it to crumble and collapse
DUNE STABILISATION
1. Cost
2. How it works
3. Advantages
4. Disadvantages
- £2-20/m
- Planting of mariam grass, fencing, removal of non native species e.g. buckhorn
- Sustainable approach, cheap, wildlife + habitats
- Time consuming, maintenance, area may still be eroded if signs ignored
What are the two other management strategies other than hard and soft engineering and what do they entail?
- Land use management
- land liable to flood or erode
- grazing = easy to remove livestock
- recreation / tourism - Managed retreat
- removing existing land defences
- land behind to periodically flood > salt marsh creation
What is the shoreline management plan recommended by DEFRA?
- 11 sediment cells in England and Wales
- district management zones
- idea that intervention is contained within each sediment cell
- 4 options for each sub cell
1. Hold the line
2. Advance the line
3. Managed retreat / strategic realignment
4. Do nothing / no active intervention
What is the Integrated Coastal Management Zone? and what the idea idea of it?
Idea of establishing sustainable levels of economic growth and social activity, while resolving environmental, social and economic challenges and conflicts to protect the coastal environment
All coastal zones managed as a whole (actions of one area effect all the others) to provide a holistic overview (sustainable measures)
Explain the EU involvement in the Integrated Coastal Management Zone idea?
2013 - new initiative on Maritime Spatial Planning and Integrated Coastal Management
- protection of nature, aquaculture, fisheries, industries etc
- sustainable development of coastal zones managed
- ‘ecosystem-based approach’
