Coasts - Hard and Soft Engineering Flashcards
What is hard engineering?
Methods of coastal management which involve major construction work such as seawalls and groynes.
What is soft engineering?
Methods of coastal management which work with natural processes and try to be unobtrusive such as beach replenishment and cliff regrading.
Describe rip rap and outline it’s advantages and disadvantages.
Rip Rap involves placing large rocks and boulders at the base of the cliff.
Advantages
Can be very cheap as the rocks are easy to obtain
Effective for many years
Highly visible which makes people feel safer.
Disadvantages
Large rocks make it difficult to access the beach
Some people find it unattractive and visually obtrusive
In stormy weather conditions it is of little use.
Describe recurved seawalls and outline their advantages and disadvantages.
A large wall which bounces wave energy back into the sea.
Advantages
Very visible which makes people feel safer
It is effective for a long time.
Disadvantages
Ugly which could put tourists off
Very expensive (around £3000 per metre)
Describe groynes and outline their advantages and disadvantages.
Groynes stretch from the coastline to the sea and stop longshore drift by preventing the movement of sediment up the beach
Advantages
They are effective for some time
They keep the beach in place which is good for tourists.
Disadvantages
They are very visually obtrusive
They make it difficult to walk along the beach
They stop naturally occuring processes such as longshore drift.
Describe gabions and outline their advantages and disadvantages.
Gabions are wire cages full of stones. They dissipate the wave energy before it reaches the coastline
Advantages
They are cheaper than other methods.
Disadvantages
The wire cages can easily break and become dangerous with exposed wires.
Not as effective as other forms of coastal defence.
Describe offshore reefs and outline it’s advantages and disadvantages.
Enormous boulders are placed out at sea to dissipate wave energy before it comes close to the cliff and the beach.
Advantages
It breaks wave offshore so they are less damaging to the beach and coastline
It allows sand to build up on the beach which is a good defence which dissipates wave energy.
Disadvantages
Hard to install
Not very effective in stormy conditions.
Describe beach replenishment and outline it’s advantages and disadvantages.
Beach replenishment is where sand is dredged up from the ocean floor and pumped back onto the beach to dissipate waves or brought from another source.
Advantages
Cheap
Looks natural
Keeps the beach in place for tourists
Beach good defence against coastal erosion as it dissipates wave energy.
Disadvantages
It requires constant maintenance.
There can be a lot of disruption to locals with lorries of sand regularly coming to replenish the beach.
It may effect animal and plant life.
Describe cliff regrading and outline it’s advantages and disadvantages.
Cliff regrading is where cliff is cut back to avoid slumping.
Advantages
Encourages wildlife
Can be covered with plants to prevent scrambling.
Disadvantages
Not an effective defence against erosion on it’s own; it needs other methods to work.
Some homes may need to be demolished which would be distressing for local inhabitants.
Describe managed retreat and outline it’s advantages and disadvantages.
Managed retreat is where areas of little value are allowed to flood.
Advantages
Very cheap
Creates new habitats for animals.
Disadvantages
Distressing for those that may need to move away.
