2B.11b soft engineering approaches

Question 1

beach nourishment

Answer 1

• the addition of sand or pebbles to an existing beach to make it higher or wider

PROS

• looks natural and blends in with the existing beach
• replaces sediment lost by erosion
• enlarges the beach so that it dissipates wave energy and reduces wave erosion
• increases the amenity value of beaches by adding fresh sand

CONS

• costs about £10 per m^3
• doesn’t last long esp. under winter storm conditions –> repeated frequently

Question 2

cliff regrading and drainage

Answer 2

• the restructuring of a cliff face to reduce steepness and instability
• drainage removes water to prevent landslides and slumping

PROS

• reduces mass movement
• should remain stable if the base of the cliff is protected by marine erosion

CONS

• cliff regrading costs about £1 million
• drained cliffs can dry out and lead to collapse (rock falls)

Question 3

dune stabilisation

Answer 3

• dunes can provide a natural barrier to sea level rise and storm waves but are at risk of storms, trampling, overgrazing etc.
• marram grass can be planted to stabilise dunes

PROS

• maintains a natural coastal environment
• provides important wildlife habitats
• relatively cheap and sustainable

CONS

• time-consuming to plant marram grass
• powerful storms may ensure that this approach only works for a short period of time

Question 4

soft engineering

Answer 4

this approach is designed to work with natural processes in the coastal system