Cada pregunta de este test está cronometrada.
Hard engineering involves..
A 'hold the line approach' where defences are constructed to prevent or reduce erosion
Building defences which work with their natural surroundings to reduce and prevent erosion
Construction of man made coastal defences
Soft engineering involves...
Great expense to prevent any erosion from occurring by constructing coastline defences
Working with natural systems (e.g. beaches) to reduce erosion by absorbing wave and tidal energy
strategies such as sea walls, groynes and gabions
This image shows a groyne
How do groynes reduce coastal erosion?
The reduce the power of the waves by causing them to break out at sea
They trap sediment by preventing longshore drift
Trapping sediment causes a beach to build up which provides a natural coastal protection, reducing a wave's available energy for eroding the cliff face
Beach nourishment is a soft engineering approach
Sea walls often have...
A recurved shape
Heights in excess of 10 metres
No gaps within them
Drainage outlets
The image shows
Gabions
Managed retreat
Revetments
People can build offshore reefs/barriers as a form of coastal defence
Planting vegetation at the back of a beach prevents erosion by...
stopping any water from hitting the cliff face
Absorbing much of the waves energy
Holding the sandy surface together, stopping the beach from eroding
Preventing tourists from being on the beach
What is meant by cost-benefit analysis?
Working out the cost of something
Comparing the cost of a defence against the value of the area it would protect
If something should be built or not
Which of the following absorb the power of the waves?
Beaches
Sea walls
Groynes
Tourism
Which sea defence below is the most expensive per 1m?
Beach Nourishment
Por favor espera - en proceso…