2B.11B

Question 1

Name 4 soft engineering approaches

Answer 1

beach nourishment, cliff regrading, drainage, dune stabilisation

Question 2

What is soft engineering

Answer 2

• Works with natural systems to reduce coastal erosion and flood threat (less intrusive than hard engineering)
• Helps to protect vital natural ecosystem services (e.g. environmental enjoyment, food provision, nutrient cycling, filtration).

Question 3

Describe beach nourishment

Answer 3

Artificially replenish the sediment to replace that lost by erosion/LSD.

Question 4

What is the purpose of beach nourishment

Answer 4

• replace sediment lost by erosion,
  -to enlarge the beach
• so that it dissipates wave energy and reduces erosion and
• increases the amenity value of the beach

Question 5

State the costs of beach nourishment

Answer 5

• £20 million per km of beach
• Ongoing costs are high
• Sediment must not be sources from elsewhere in the sediment cell

Question 6

What is cliff regrading

Answer 6

• Regrade the cliff (a lower angle of rest) provides slope stability
• This can be further supported by hard engineering at the base (e.g. Rip-Rap/Revetments etc.).

Question 7

Pros of cliff regrading

Answer 7

• Re-vegetated to reduce surface erosion.
• In-cliff drainage reduces pore-water pressure and mass movement risk.
• Costs of £1 million per 100 m
• Can be disruptive during construction

Question 8

What is dune stabilisation

Answer 8

• Fences are used to reduce wind speeds across the dunes,
• dunes are then replanted with marram and lyme grass to stabilise the surface
• add boardwalks to reduce trmapling and educate tourists with info board

Question 9

Evaluate dune stabilisation

Answer 9

• This reduces erosion by wind and water.
• Fencing costs £400-2000 per 100 m and replanting £1000 per 100 m (1400-3000)
• Can be very cost effective in the long term

Question 10

State three bioprotection methods

Answer 10

planting mangrove forests, ecological enhancement, adding grooves and holes and natural poles

Question 11

Describe planting mangroves

Answer 11

Planting Mangrove forests in (sub)-tropical regions such as SE Asia, N Australia and SE USA – to offer protection against storm surges (equivalent to restoring salt marshes in UK by allowing periodic flooding to occur – managed re-alignment).

Question 12

Describe ecological enhancement

Answer 12

Ecological enhancement of hard engineering by encouraging species to grow on them (e.g. Seaweed blanket on Isle of Portland, Dorset, helps to buffer extreme temperature changes in concrete and keeps it moist to reduce both mechanical weathering and salt crystallisation).

Question 13

Adding groorves, holes and natural pools?

Answer 13

Adding grooves, holes and natural pools into Shaldon Seawall in Devon, to encourage barnacles and limpets to grow, thereby increasing biodiversity

Question 13

Adding groorves, holes and natural pools?

Answer 13

Adding grooves, holes and natural pools into Shaldon Seawall in Devon, to encourage barnacles and limpets to grow, thereby increasing biodiversity

Question 14

Adding groorves, holes and natural pools?

Answer 14

Adding grooves, holes and natural pools into Shaldon Seawall in Devon, to encourage barnacles and limpets to grow, thereby increasing biodiversity