Hard And Soft Engineering Coastal Methods

Question 1

What is a description of a sea wall and how much do they cost

5000/metre

Answer 1

Concrete walls placed at foot of cliff to prevent erosion

Curved to reflect energy back into the sea

Question 2

What are the advantages of sea walls

Answer 2

1.Often have promenades on top- popular with tourists
2.Long lifespan - cope well with high energy waves
3.doesn’t impede natural movement of sediment

Question 3

What are some disadvantages of sea walls

Answer 3

1.can affect access to beach
2.costly to construct and maintain
3.recurved sea walls can increase erosion of beach material
4.they look ugly and destroy habits

Question 4

What is the description of groynes and how much do they cost

Answer 4

Wooden barriers constructed at right angles to prevent long shore drift

5000 each

Question 5

What are some advantages of groynes

Answer 5

1.Cheaper than other hard engineering methods
2.last up to 40 years
3.cheap to repair
4.wide sandy beach attracts tourists

Question 6

What are some disadvantages of groynes

Answer 6

1The look ugly
2.beaches down drift don’t get any material - increases erosion elsewhere
3.ineffctive during storms

Question 7

What is the description of gabions and how much do they cost

110/metre

Answer 7

Wire mesh cages filled with pebbles and rock
As water enters the cages , wave energy is absorbed and dissipated

Question 8

Ehat are some advantages of gabions

Answer 8

1.Cheap and easy to build
2.Wuick and easy to maintain
3.Last between 20-25 years
4.Overtime vegetation covers it and blends in with environment

Question 9

What are some disadvantages of gabions

Answer 9

1.When damaged gabions can be dangerous-rocks falling
2.Limited use- only used at sandy beaches as pebbles would wreck them
3.Damaged gabions can cause sea birds to get stuck

Question 10

What is the description of revetments and how much do they cost

Answer 10

Revetments are wooden slanted barriers near the back of beaches to protect the base of cliffs

2000/metre

Question 11

What are some advantages of revetments

Answer 11

1.Cheaper and less intrusive to nature than sea walls
2.Less beach material is eroded than a sea wall

Question 12

What are some disadvantages of revetments

Answer 12

1.Short lifespan- not suitable for high wave energy
2.Destroys habitats when constructed
3.Reduces input of sediment - affecting coastal system

Question 13

What is the description of barrages and how much do they cost

Answer 13

Dams built across a bay or estuary to control the flow of water

Around a billion

Question 14

What are some advantages of barrages

Answer 14

1.Can create hydroelectric power
2.Reduces flooding as it controls tidal flow

Question 15

What are some disadvantages of barrages

Answer 15

Very expensive to construct and maintain
High environmental impacts because of impact on tides

Question 16

What is the description of offshore reefs and how much do they cost

Answer 16

Old tyres and sediment placed in the intertidal zone to create an offshore reef

Waves break offshore reducing their energy

Question 17

What are some advantages of offshore reefs

Answer 17

Natural marine ecosystem is barely affected

Rocks create new intertidal habitat

Dunes are able to stabilise onshore- natural barrier to erosion

Question 18

What are some disadvantages of offshore reefs

Answer 18

May cause navigation hazard for boats

Can look like an eyesore at low tide-intangible cost

Con disrupt recreational use of beach-jet skis

Question 19

What is a description of beach nourishment and how much does it cost

Answer 19

Beach nourishment is making beaches higher and wider by importing sand or shingle

Protection against flooding or erosion by absorbing wave energy

20/metre cubed

Question 20

What are some advantages of beach nourishment

Answer 20

Cheap and retains natural appearance

Tourists like wide , big beach

Question 21

What are some district beach nourishment

Answer 21

Offshore dredging of material increases erosion in other areas

After Larger storms will require further beach nourishment

Question 22

What is the description of dune regeneration

Answer 22

Taking action to build up dunes and increase regeneration

Marram grass is planted to hold dunes together

Question 23

What are some advantages of dune regeneration

Answer 23

1.Makes barrier between land and sea - absorbs wave energy before it gets to land

2.Increases biodiversity and creates natural habitats

Question 24

What are some disadvantages of dune regeneration

Answer 24

During regeneration the land is closely monitored to ensure marram grass isn’t trampled on- costing time and resources

This means fencing off dunes

Question 25

What is the description of managed retreat and how much does it cost

Answer 25

When areas of the coast are allowed to naturally erode Usually in low value areas Have to compensate land owners

Question 26

What are some advantages of managed retreat

Answer 26

Retains natural balance of coastal system Encourages development of beaches and salt marshes- important habitat

Question 27

What are some disadvantages of managed retreat

Answer 27

People lose their livelihood if there’s industry there or farmland Donna Nook Casestudy

Question 28

What is the description of do nothing

Answer 28

Nothing is done and natural processes are allowed to continue Done with very low value land

Question 29

What are some advantages of doing nothing

Answer 29

Doesn’t interfere with coastal system and allows natural processes to take place

Question 30

What are some disadvantages of doing nothing

Answer 30

The coastline is eroded and any land in the way is destroyed, potentially destroying cultural or historical land