Describe one advantage and one disadvantage of a named hard engineering strategy
that could be used to manage erosion on the coastline at happisburgh.
[4]
Answers
Answer:
Advantages
Effective at protecting the base of the cliff.
Sea walls usually have promenades so people can walk along them.
Disadvantages
Waves are still powerful and can break down and erode the sea wall.
Expensive - approximately £2,000 per metre.
Rock armour
Rock armour on a beach
Large boulders placed at the foot of a cliff. They break the waves and absorb their energy.
Advantages
Cheaper than a sea wall and easy to maintain.
Can be used for fishing.
Disadvantages
They look different to the local geology, as the rock has been imported from other areas.
The rocks are expensive to transport.
Gabions
Rocks are held in mesh cages and placed in areas affected by erosion.
Advantages
Cheap - approximately £100 per metre.
Absorbs wave energy.
Disadvantages
Not very strong.
Looks unnatural.
Groynes
Wooden groynes on a beach in Sussex
Wooden groynes on a beach in Sussex
Wooden or rock structures built out at right angles into the sea.
Advantages
Builds a beach - which encourages tourism.
They trap sediment being carried by longshore drift.
Disadvantages
By trapping sediment it starves beaches further down the coastline, increasing rates of erosion elsewhere.
They look unattractive.