Distinctive Landscape

Question 1

Old Harry and his Wife

Answer 1

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Question 2

Longshore drift

Answer 2

1)Waves follow the direction of the prevailing (most common) wind.
2) They usually hit the coast at an oblique angle (any angle that isn’t a right angle).
3)The swash carries material up the beach, in the same direction as the waves.
4)The backwash then carries material down the beach at right angles, back towards the sea.
5) Over time, material zigzags along the coast.

Question 3

Groynes

Answer 3

-Groynes are wooden or stone fences that are built at right angles to the coast.
-They trap material transported by longshore drift. This creates wider beaches which slow the waves, giving greater protection from erosion.
-New timber groynes were put in place along Swanage beach in 2005-6.
They’ve helped to stop the loss of beach material.
-However, by stopping beach material from moving along the coast, they’ve starved areas further down the coast of sediment, making them narrower.
Narrow beaches don’t protect the coast as well (more erosion)

Question 4

Sea walls

Answer 4

1)There are concrete sea walls in place along most of Swanage beach.
2) Sea walls reflect waves back out to sea, preventing the erosion of the coast.
3) But they can create a strong backwash, which removes sediment from the beach and can erode under the wall.
4)They also prevent the cliffs from being eroded, so there’s no new material to replenish the beach. This will gradually lower the level of the beach.

Question 5

Beach Replenishment

Answer 5

1)In winter 2005/2006, sand and shingle dredged from the sea bed at Poole Harbour was added to the upper parts of Swanage beach.
2) This has created wider beaches, which slow the waves and help protect cliffs and coastal properties from erosion.
3)However, it cost £5 million to replenish the beach and it will need to be repeated roughly every 20 years.