Costal management Flashcards
Give some examples of hard engineering
- Groynes
- Sea walls
- Rip rap
Describe how groynes work
Structures build at right angles to the coats to trap sediment moving along the beach.
Give some advantages and disadvantages of groynes
Advantages: - Not too expensive (£5000-10,000/200m) - Works with the natural processes Disadvantages: - Starves beach downdrift - Unnatural and unattractive
Describe how sea walls work
Curved sone or concrete walls which reflect the waves back into the sea
Give some advantages and disadvantages of sea walls
Advantages:
- Effective prevention of erosion
- Promenade for people to walk along
Disadvantages:
- Reflect wave energy rather than absorbing it
- Expensive to build and maintain (£6000/m)
- Unnatural looking
Describe how rock armour (rip rap) works
Large rocks form a permeable barrier breaking up the waves but still letting some water through
Give some advantages and disadvantages of rock armour
Advantages:
- Cheap (£1000-3000/m)and easy to construct and maintain
- Used for recreation (fishing, sunbathing)
Disadvantages:
- Can be dangerous to people
- Can be intrusive
Explain the process of a Cost Benefit Analysis (CBA)
Carries out before a costal management project is implemented.
Costs are estimated and compared to the potential benefits
Give some examples of soft engineering
- Beach nourishment
- Marsh creation
- Dune stabilisation
Describe how beach nourishment works
The addition of sand or pebbles to an existing beach to make it higher or wider
Give some advantages and disadvantages of beach nourishment
Advantages: - Cheap (£3000/m) and easy to maintain - Natural looking Disadvantages: - Needs constant maintenance
Describe how marsh creation works
Allowing low-lying costal areas to flood, creating a salt marsh
Give some advantages and disadvantages of marsh creation
Advantages: - Relatively cheap (variable) - Creates an important wildlife habitat Disadvantages: - Agricultural land is lost - Farmers/landowners must be compensated
Describe how dune stabilisation works
Marram grass planted to stabilise dunes
Areas fenced to keep people off newly planted dunes
Give some advantages and disadvantages of dune stabilisation
Advantages: - Maintains natural costal environment - Cheap (£2-20/m) and sustainable Disadvantages: - Time consuming to plant grass - People may respond negatively to the restrictions
Explain the process of a Shoreline Management Plan (SMP)
Detailed documents based on the activity contained within each sediment cell. Each cell is treated as a ‘closed cell’.
Name the four options considered to manage a coastline
- Hold the line - maintaining the current position (hard engineering)
- Advance the line - extending the coastline (beach nourishment)
- Managed retreat - allowing the coastline to retreat (creating salt marshes)
- Do nothing - allow nature to rake its course
Explain the process of an Integrated Costal Zone Management (ICZM)
Includes all stakeholders involved to ensure broad support.
Complete sections of coast managed as a whole to prevent human actions effecting the coast elsewhere.
Enables sustainable methods to be implemented based on the understanding of the natural costal processes.
