Coastal hazards and their management Flashcards
What are some types of hard engineering?
- sea walls
- gabions
- groynes
- rock armour
What are the advantages of sea walls?
- effective at protecting the base of the cliff
- sea walls usually have promenades so people can walk along them
What are the disadvantages of sea walls?
- waves are still powerful and can break down and erode the sea wall
- expensive: approx. £2000 a metre
What are the advantages of rock armour?
- cheaper than a sea wall and easy to maintain
- can be used for fishing
What are the disadvantages of rock armour?
- look different to the local geology, as rock imported from other areas
- the rocks are expensive to transport
- can gather rubbish and look unsightly
What are the advantages of gabions?
- cheap
- absorb wave energy
What are the disadvantages of gabions?
- not very strong
- look unnatural
What are the advantages of groynes?
- the build a beach
- trap sediment being carried by longshore drift
What are the disadvantages of groynes?
- look unattractive
- by trapping sediment they starve beaches further down the coastline, increasing rates of erosion elsewhere
What are sea walls?
concrete walls that are placed at the foot of a cliff to prevent erosion, they are curved to reflect the wave energy back into the sea.
What is rock armour?
large boulders placed at the foot of a cliff, they break waves and absorb their energy
What are gabions?
rocks held in mesh cages and placed in areas affected by erosion
What are groynes?
wooden or rock structures built at right angles into the sea
What are some types of soft engineering?
- beach nourishment
- beach reprofiling
- sand dune stabilisation
What are the advantages of beach nourishment?
- blends in with the existing beach
- larger beaches appeal to tourists