Coastal management Flashcards
What is hard engineering
Strategies to protect the coastline using man made constructions
What are examples of hard engineering coastal management strategies
Gabions, sea walls, groynes and rock armour
What are gabions
They are wire cages full of rocks and boulders and they absorb some energy and pressure from the waves to prevent erosion, but the wire corrodes/ rusts over time and looks unattractive
What are sea walls
Sea walls are made from durable material, such as concrete, and are designed to deflect the waves power instead of absorbing it. They are hard wearing and lost lasting but expensive and look unattractive
What is rock armour
A pile of rock boulders that absorb the energy and power and look natural bht the strong waves can cause the boulders to move and be replaced.
What are groynes
Groynes are wood or stone fences that stick out 90 degrees to the coast and stop the process of long shore drift by trapping material. They create wide beaches, which are better to protect coastlines and attract tourists, and are not expensive. Since groynes stop the transportation of sediment, the coast further down causes sediment starvation (further erosion)
What is soft engineering in coastal management
They reduce effects of flooding and erosion using natural processes
Examples of soft engineering
Managed retreat and beach recharge/ replenishment/ nourishment
What is managed retreat
Coastal defences are removed and the sea is allowed to flood into a given area. The flooded land will turn into marshland, reducing flooding and erosion on the land behind it. However, saltwater can have a negative effect on ecosystems and compensation money has to be sent to the owners of the land
What is the new name for managed retreat and why
It is renamed strategic realignment because retreat seems as though the government is doing anything
What is beach recharge
Beach recharge is moving material from the upper sections of the beach to the more vulnerable areas of the beach. It slows down waves by widening the beach, therefore reducing flooding and erosion but removing sand and shingle can damage organisms and it is expensive as it must be repeated
Why is the Holderness coast vulnerable to erosion
The strong prevailing winds, causing more destructive waves, and the cliff is made from clay, which is easy to erode, and heavy rainfall can cause mass movement
What are the 4 categories of management strategies
- Do nothing
- Strategic realignment (management retreat)
- Hold the line
- Advance the line
Explain the do nothing management strategy
Let natural processes take their course. They do this for low-value land and resistant geology
Explain the strategic realignment management strategy
Allow the coast to erode further inland and create a new line of sea defences
Explain the hold the line management strategy
Maintain the present line of coastal defence
Explain the advance the line management strategy
Build forward of the coast
What is making all coasts more vulnerable to erosion
Rising sea levels and extreme weather
What do authorities do before installing a coastal management strategy
Do a cost-benefit analysis and if the cost of protecting the land outweighs the benefit, the land will be left
What type of land is protected
Tourist places, homes, agriculture, industry and businesses
What type of grass is used in sand dunes
Marram grass and their roots hold sand together
