Coasts Flashcards
What is a groyne?
A groyne is a wooden or stone fence that is built along the beach, into the water. The groyne traps sand that has been transported by Longshore drift, and building up the beach. If a beach is built up then it has great natural defence to incoming waves.
One problem however is that it can cause what is known as terminal groyne syndrome, where areas further down the coastline have no sand deposited, leaving their cliffs vulnerable.
What are sea walls?
A concrete or rock barrier placed at the top of a beach. They are 3-5m high, and curved to reflect waves back to sea.
Sea walls are very effective, but also very expensive, and in the future they may need to be built higher as sea levels rise.
What is rock armour?
Piles of large boulders dumped at the foot of a cliff. The rocks force waves to break, absorbing their energy and protecting the cliffs.
What is beach nourishment?
The addition of sand or shingle to a beach, to make it higher and broader.
It is relatively cheap and easy to maintain, and increases tourist potential by making a bigger beach.
However it will need constant maintenance.
What is dune regeneration?
Sand dunes are natural buffers to the sea. However they can be damaged. Plants like Maram grass can be planted to strengthen the dunes.
This helps to maintain a natural coastal environment, that provides tourists and wildlife, and is also relatively cheap.
However storms can still cause lasting damage, and it is time consuming to plant the maram grass.
What is managed retreat?
Allowing controlled flooding in low lying areas, where the land value is low. Poor quality if grazing land for example, is nit worth the cost of protection.
Managed retreat can include carrying out no repairs to protection, allowing the tide to invade low lying areas, forming salt marshes, which are good for wildlife.
This is a cheap option and creates habitats for wildlife.
However farmers and land owners will need to be compensated.
What coastal defences were put in place along mappleton?
In 1991 nearly 2 million was spent on protecting 100 people. This was justified because of the B1242 coastal route. The scheme involved the building of rock armour and two rock groynes.
The council only gets an annual four million, so this 2 million spend was hard to justify, as many believed that the village should be allowed to disappear, though of course it is easy to say when it isn’t your home at risk.
