Types of defences

Question 1

Define hard engineering

Answer 1

Man made structures that aim to prevent erosion
Effective at preventing erosion but high cost
Environmental impact due to use of concrete

Question 2

What are offshore breakwaters

Answer 2

Rock barrier which forces waves to break before reaching shore

Question 3

Evaluate offshore breakwaters

Answer 3

+ effective at reducing wave energy
-visually unappealing
-navigation hazard for boats
-can interfere with LSD

Question 4

What are groynes?

Answer 4

timber or rock protrusions that trap sediment from LSD

Question 5

Evaluate groynes

Answer 5

+builds up beach protecting cliff and increasing tourist potential
+cost effective
-deprives areas downwind of sediment increasing erosion elsewhere

Question 6

What are sea walls?

Answer 6

concrete structures that absorb and reflect wave energy with a curved surface

Question 7

Evaluate sea walls

Answer 7

+effective erosion prevention
+promenade has tourism benefits
-expensive to construct and maintain
-wave energy reflected elsewhere with impacts on erosion rates

Question 8

What is rip rap

Answer 8

large rocks that reduce wave energy but allow water to flow through

Question 9

Evaluate rip rap

Answer 9

+cost effective
-rocks sourced elsewhere so not local geology
-pose hazard if climbed on

Question 10

What are revetments

Answer 10

wooden or concrete ramps that help absorb wave energy

Question 11

Evaluate revetments

Answer 11

+cost effective
-visually unappealing
-need constant maintenance so added cost