Coastal Management Hard Engineering

Question 1

Sea wall
(£7,000 per metre)

Answer 1

-Creates a rock barrier placed at the foot of cliffs or tops of beaches. Has a curved face to reflect the waves back into the sea! (dawlish)

ADVANTAGES
1-effective at stopping the sea
2-often doubles as a walkway for people

DISADVANTAGES
1-can look obtrusive & unnatural
2-very expensive
3-high maintenance needed

Question 2

Rock Armour/ rip rap
(£2,000 per metre)

Answer 2

-piles of large bouldersdumped at the foot of the cliff
the rocks force waves to break, absorbing their energy and protecting the cliffs.
(rip rap is more chaotic, random pattern than Rock Armour)

ADVANTAGES
1-relatively cheap
2-easy to maintain
3-often used for fishing

DISADVANTAGES
1-rocks are usually taken from another part of the coastline or abroad
2-can be expensive to transport
3-don’t fit in with the local geography
4-can be very obtrusive

Question 3

Groynes
(£750 per metre)

Answer 3

-timber or rock structures built out to sea from the coast.
-they trap sedimentbeing moved by longshore drift and enlarge the beach. The wider beach acts as a buffer to reduce wave damage

ADVANTAGES
1-creates a wider beach which can be popular for tourists
2-usuful structures for people fishing
3-relatively cheap

DISADVANTAGES
1-by interrupting longshore drift they are starving beaches further along the coastline leading to more erosion elsewhere (problem shifted NOT solved)
2-unnatural
3-can beunnatractive

Question 4

Gabions
(£500 per metre)

Answer 4

-wire cages filled with rocks that can be built to support a cliff or provide a buffer against the sea.

ADVANTAGES
1-cheap to produce and flexible final design
2-can improve drainage of cliffs
3-will eventually become vegetated and blend with the landscape

DISADVANTAGES
1-for a while they look ugly
2-cages only last 5-10yrs before rusting