3.4.1 Traditional Approaches To Management Flashcards
Define hard engineering coastal management
The construction of structures designed to absorb the energy of the waves, usually made out of concrete
Outline advantages and disadvantages of groynes
How it works?
Structures built perpendicular (at right angles) to the shore. Sediment is trapped as it is transported by longshore drift. The beach builds up which absorbs wave energy
Advantages
Not as expensive as other hard engineering structures
Builds up the beach which improves tourist potential
Disadvantages
Causes sediment starvation further along the coast
Can be unattractive
Need lots of maintenance to ensure sediment isn’t getting through any holes or cracks
Outline the structure of sea walls, advantages and disadvantages of it
Structure: Walls with a curved or stepped surface that absorb and reflect wave energy
Advantages: Highly effective
Can have tourism benefits as walkways are created
Disadvantages: Very expensive to build and maintain - £6000 per metre
Are ugly and intrusive to the landscape
Outline structure of rip rap/ rock armour, advantages and disadvantages
How it works: Large concrete or granite boulders at the foot of a cliff. The spaces in between the boulders cause waves to bounce between many surfaces, reducing the energy of the wave
Advantages: Cheaper than sea walls
Used for recreation such as fishing
Disadvantages: Dangerous when people are on them
Rocks from elsewhere are intrusive to local geology
Outline structure of revetments, its advantages and disadvantages
Structure: A sloped or ramp-like structure that breaks up wave energy
Advantages: Cost-effective compared to other hard engineering strategies
Disadvantages: Need lots of maintenance
Unnatural looking
Slopes are dangerous
Outline structure of the offshore breakwater, its advantages and disadvantages
How it works?
Rock barrier a little out to sea from the shoreline. This breaks the waves and dissipates their energy before they reach the coast.
Advantages: Effective
Away from the beach so does not disrupt tourist potential
Disadvantages: Can create a navigation barrier in harbour areas
What is the difference between hard and soft engineering strategies?
Soft engineering is different from hard engineering as it works with natural processes and material
Soft engineering methods can be an integral part of the strategy to adapt to sea level change as well as coastal erosion, such as through the development of marshes
Explain how beach nourishment works, its advantages and disadvantages
How it works: Adding sand or shingle to a beach to widen it - creates more surface area to absorb wave energy
Advantages: Looks very natural
Bigger beaches are good for tourism
Relatively inexpensive
Disadvantages: Material is constantly subject to erosion and longshore drift so lots of maintenance and monitoring are needed
Dredging the seabed can have impacts on local ecosystems
Explain how cliff regrading, its advantages and disadvantages
How it works: Reducing the angle of the cliff to stabilise the slope. Drainage of water also stabilises the cliff against mass movement
Advantages: cost-effective
Disadvantages: Can look unnatural as the cliff is unnaturally flatter
This effectively creates a cliff retreat
Dried-out cliffs can collapse
Explain how dune stabilisation works, its advantages and disadvantages
How it works: Planting species like Marram grass so that the roots bind the dunes. The dunes absorb wave energy and protect the land behind them.
Advantages: Cheap and sustainable
Creates habitats for wildlife
Maintains a natural environment
Disadvantages: People walk on the dunes and damage them
Planting is time-consuming and it takes time for plant species to become established
Explain how marsh creation works, its advantages and disadvantages
How it works: This is a form of do-nothing or managed retreat. The land is allowed to be flooded by the sea and then left to become a salt marsh. This absorbs wave energy and also creates a buffer to rising sea levels and projects higher-value land.
Advantages: A cheap option
Creates important and unique wildlife habitats
Disadvantages: Agricultural land is lost which creates a need for compensation
