Coastal Management

Question 1

How does a sea wall work?

Answer 1

A wall made out of a hard material like concrete that reflects waves back to the sea

Question 2

2 pros and 2 cons of a sea wall

Answer 2

Pro

• prevents erosion
• acts as a barrier to prevent flooding

Cons

• creates strong backwash
• expensive to build and maintain

Question 3

How long does a sea wall last? Hard or soft engineering?

Answer 3

100 years

Hard

Question 4

What is rock armour(rip-rap)?

Answer 4

Boulders that are piled up along the coast

Question 5

2 pros and 1 con of rock armour

Answer 5

Pros

• absorbs heat energy
• reduces erosion and flooding

Con
-boulders can be moved around by strong waves need to be replaced

Question 6

Is rock armour hard or soft engineering?

How long does it last?

Answer 6

120 years

Hard

Question 7

How does a gabion work?

Answer 7

Rock filled cages built at the foot of cliffs with gaps to reduce energy

Question 8

2 pros and 2 cons of gabions

Answer 8

Pros

• absorbs wave energy
• reduces erosion

Cons

• they look ugly
• short life span

Question 9

How long does gabions last?

Hard or soft engineering?

Answer 9

5-10 years

Hard

Question 10

How does revetments work?

Answer 10

Slanted structure made of concrete, wood or rocks built at the foot of cliffs

Question 11

2 pros and 2 cons of revetments

Answer 11

Pros

• absorbs wave energy
• reduces erosion

Cons

• expensive to build
• creates strong backwash that erodes under the barrier

Question 12

How long does wood and rock revetments last?

Hard or soft engineering?

Answer 12

Wooden- 10 years
Rock- 30 years
Hard

Question 13

How does a groyne work?

Answer 13

Wooden or stone fences that are built at right angles to the coast they trap material transformed by longshore drift

Question 14

2 pros and 2 cons of groynes

Answer 14

Pros

• creates wider beaches which slow waves down
• gives greater protection from flooding and erosion

Cons

• starves beaches further down the coast of sand making them narrow
• narrow beaches don’t protect coasts well

Question 15

How long does groynes last?

Hard or soft engineering?

Answer 15

100 years

Hard

Question 16

1 pro and 1 con of doing nothing

Answer 16

Pro
-no cost or labour

Con
-will flood and erode coast

Question 17

How does a managed retreat work?

Answer 17

Removing an existing defence and allowing the land behind it to flood

Question 18

2 pros and 1 con of managed retreat

Answer 18

Pros

• overtime, land will become marshland creating new habitats
• fairly cheap

Con
-people may disagree

Question 19

Is managed retreat hard or soft engineering?

Answer 19

Soft

Question 20

How does beach replenishment work?

Answer 20

Sand and shingle from elsewhere (e.g. The offshore seabed) that is added to beaches

Question 21

2 pros and 3 cons of beach replenishment

Answer 21

Pros

• wider beaches slows waves
• greater protection

Cons

• has to be repeated
• expensive
• taking material from the seabed can kill organisms like sponges and coral

Question 22

Is beach replenishment hard or soft engineering?

Answer 22

Soft

Question 23

What is hard engineering?

Answer 23

Man made structure built to control the flow of the sea and reduce flooding and erosion

Question 24

What is soft engineering?

Answer 24

Schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion