Hard and Soft Engineering Strategies Overview

Question 1

Hard engineering

Answer 1

These traditional strategies aim to slow down or prevent further erosion of the coastline taking place, usually by placing an artificial, more resistant barrier between wave action and the coast

Question 2

Concrete sea wall: advantages

Answer 2

• effective

- absorbs and deflects wave energy back to sea

Question 3

Concrete sea wall: disadvantages

Answer 3

• needs regular repair

- expensive to construct

Question 4

Concrete sea wall

Answer 4

Solid facing to a coastal wall or cliff

Question 5

Gabions

Answer 5

Rock-filled wire cages placed along a vulnerable coast

Question 6

Gabions: advantages

Answer 6

• cheaper than tetrapods

- may look more attractive than alternatives

Question 7

Gabions: disadvantages

Answer 7

• wire containers may rust + be broken under high energy conditions
• require regular repair + replacement

Question 8

Groynes

Answer 8

Wooden ‘breakwaters’ at right angles to a beach extending into the sea designed to capture longshore drift sediments to build up beach width and height

Question 9

Groynes: advantages

Answer 9

• effective at increasing a natural barrier of beach between sea and shore
• tourism amenity as wider beaches attract more visitors

Question 10

Groynes: disadvantages

Answer 10

• require maintenance and repair

- speed up downcoast erosion by robbing adjacent beaches of sand

Question 11

Soft engineering

Answer 11

The approach of soft engineering is to manipulate and modify natural systems to bring about desired consequences, rather than trying to impede or interrupt them.

Question 12

Beach nourishment

Answer 12

Replacing lost beach material from a natural store either offshore (beach rebuilding) or from downshore along a stretch of longshore drift (beach recycling)

Question 13

Beach nourishment: advantages

Answer 13

• reproduces what natural systems would do, but at a faster rate
• maintains natural shoreline without artificial intrusions

Question 14

Beach nourishment: disadvantages

Answer 14

• can be disruptive to beaches (local amenity + tourist economy) whilst engineering takes place
• regular costs accumulate over the long-term

Question 15

Beach reprofiling

Answer 15

Re-shaping the cross-sectional profile of a beach to ensure it offers maximum protective gradient and width against destructive wave action

Question 16

Beach reprofiling: advantages

Answer 16

• reproduces what natural systems would do, but at a faster rate
• maintains natural shoreline without artificial intrusions

Question 17

Beach reprofiling: disadvantages

Answer 17

• can be disruptive to beaches (local amenity + tourist economy) while engineering takes place
• regular costs accumulate over the long-term

Question 18

Living shoreline barrier

Answer 18

Planting shoreline vegetation (mangrove) or shellfish colonies (oyster reefs) to absorb wave energy between shore and sea.

Question 19

Living shoreline barrier: advantages

Answer 19

• enhances shoreline habitats

- more attractive for locals and visitors

Question 20

Living shoreline barrier: disadvantages

Answer 20

• may not adjust to rising ocean temperatures and acidity

- can be devastated by extreme storm events

Question 21

Give some examples of hard engineering

Answer 21

• concrete sea wall
• gabions
• groynes

Question 22

Give some examples of soft engineering

Answer 22

• beach nourishment
• beach reprofiling
• living shoreline barrier