Coastal engineering

Question 1

define hard engineering

Answer 1

man made structures to protect coasts from erosion by working against the natural processes

Question 2

define soft engineering

Answer 2

sustainable strategies to protect coasts from erosion by working with the natural processes like deposition and erosion

Question 3

sea wall

1. hard or soft engineering?
2. how does it work?
3. cost?
4. advantages and disadvantages?

Answer 3

sea wall 
1. hard or soft engineering? 
- hard engineering
2. how does it work?
- When a wave hits the wall it loses energy and the curved edge deflects the remaining energy back into the sea
3. cost?
- 2,000 per metre
4. advantages and disadvantages?
\+ dual purpose (provides a promenade)
\+ reduces waves energy therefore reducing erosion
\+ lasts a long time
- have to will be replaced due to climate change and rising sea levels
- very expensive

Question 4

rock armour

1. hard or soft engineering?
2. how does it work?
3. cost?
4. advantages and disadvantages?

Answer 4

rock armour
1. hard or soft engineering?
- hard engineering
2. how does it work?
- resistant rock placed around groynes to absorb high wave energy reducing erosion
3. cost?
- 2,000 per metre
4. advantages and disadvantages?
\+ effective
\+ take waves energy
\+ protect groynes which slow LSD (meaning the beach will be bigger= more tourists)
- cause more abrasion
- ugly, unattractive
- dangerous if climbed on

Question 5

gabions

1. hard or soft engineering?
2. how does it work?
3. cost?
4. advantages and disadvantages?

Answer 5

gabions
1. hard or soft engineering?
- hard engineering
2. how does it work?
- wire mesh cages placed at the base of cliffs absorb wave energy
3. cost?
- £100 per meter
4. advantages and disadvantages?
\+ reduce recession
\+ cheap
- rust very quickly (Swanage)
- need maintenance
- efficacy

Question 6

groynes

1. hard or soft engineering?
2. how does it work?
3. cost?
4. advantages and disadvantages?

Answer 6

groynes
1. hard or soft engineering?
- hard engineering
2. how does it work?
- wooden/rock barriers that trap sediment being carried by longshore drift as they reduce the waves energy
3. cost?
- £10,000 per groyne
4. advantages and disadvantages?
\+ stop LSD
\+ will still be effective even with climate change
- short lifespan
- unattractive for tourists
- can have large implications further down the coastline

Question 7

dune regeneration

1. hard or soft engineering?
2. how does it work?
3. cost?
4. advantages and disadvantages?

Answer 7

dune regeneration
1. hard or soft engineering?
- soft engineering
2. how does it work?
- Studland sand dunes are protected and replanted with pioneer species to stabilize them and prevent erosion behind the dunes
3. cost?
- medium
4. advantages and disadvantages?
\+ sustainable
\+ good for tourists 
\+ won't have large impact on environment
\+ creates habitats
- damaged by storm waves
- only a small area is protected

Question 8

beach nourishment

1. hard or soft engineering?
2. how does it work?
3. cost?
4. advantages and disadvantages?

Answer 8

beach nourishment
1. hard or soft engineering?
- soft engineering
2. how does it work?
- sand is pumped on beach to increase it’s size
3. cost?
- most expensive soft engineering strategy
4. advantages and disadvantages?
+ good for tourism (due to better looking beach)
+ blends in with natural beach
+ clearly effective as it is done regularly on Bournemouth and Poole beaches
- expensive

Question 9

managed retreat

1. hard or soft engineering?
2. how does it work?
3. cost?
4. advantages and disadvantages?

Answer 9

managed retreat
1. hard or soft engineering?
- soft engineering
2. how does it work?
- areas of the cliff are allowed to erode naturally as land value is too low
3. cost?
- very cheap (free)
4. advantages and disadvantages?
\+ not invasive to the environment
- still, an ecosystem that is being damaged due to the refusal to help it so it will erode (loss of biodiversity)
but it depends on the LAND VALUE

Question 10

Evaluate the engineering methods. Which is the most effective at reducing coastal erosion? Why?

Answer 10

soft engineering is more effective as coastal erosion is a natural problem and putting more hard engineering surfaces is just perpetuating the problem as eventually they will be eroded and fall into the sea causing more abrasion. Beach nourishment is the most effective as it builds up the beach which is good for tourism whilst the beach acts as a natural barrier between land and sea which absorbs wave energy. Although other methods are still effective this is the most sustainable and is done every year at Poole Bay therefore it must be working in the area