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Flashcards in COASTS management Deck (56)
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1
Q

why do humans intervene in natural processes?

A
  • manage the shape and profile of the coastline
  • reduce rates of erosion
  • limit the likelihood of flooding
2
Q

what are the problems with human intervention?

A

unsustainable and uneconomic

3
Q

what is the England and Wales enviro agencies criteria for coastal protection?

A
  • households at risk
  • agriculture and farming at risk
  • ecosystems/ environment at risk
  • infrastructure at risk
    these factors are all looked at in a cost benefit analysis to decide which areas will be defended and which will be left.
4
Q

what are the four options for coastal management

A

hold the line
advance the line
do nothing
managed realignment

5
Q

hold the line

A

maintain existing coastal defences

6
Q

advance the line

A

build new coastal defences further out to sea than existing ones

7
Q

do nothing

A

allow nature to take its natural corse and deal with erosion and flooding as it comes.

8
Q

managed realignment

A

allow the shoreline to move but manage retreat so it causes less damage. eg) change land use to flood farmland rather than town infrastructure.

9
Q

what factors are responsible for a change in shoreline equilibrium? (5)

A
  • supply of materials
  • energy intensity
  • consistency of shoreline geology
  • changes in sea level
  • key processes taking place
10
Q

feedback loops

A

outputs modify the inputs/ processes = output cahnges

11
Q

positive feedback (in terms of input and output)

A

outputs increase = inputs increase which causes a further increase in outputs

12
Q

negative feedback (in terms of input and output)

A

output increases which slows the inputs and processes responsible for the increased output.

13
Q

dynamic equilibrium

A

gradual shift in balance over a long period of time

14
Q

metastable equilibrium

A

episodic shifts to a new equilibrium

15
Q

steady state equilibrium

A

long term balance between inputs and outputs.

16
Q

What is the SMP?

A

shoreline management plan

  • used to address the risks of coastal evolution
  • come up with flood defence strategies in the uk
17
Q

what are hard engineering strategies used for?

A

to intercept and impede marine and coastal processes

18
Q

what are 5 examples of hard engineering strategies?

A

Groynes, sea walls, revetments, rip rap and offshore breakwater.

19
Q

what are groynes?

A

they are wooden fenses built at 90* to trap sediment (LSD)

20
Q

ADV of groynes

A
  • build up the beach = increased tourism
  • works with natural processes
  • protects the land behind from erosion
  • quite cheap
21
Q

DIS of groynes

A

-staved beaches further down the coast of sediment = more erosion and flooding

22
Q

ADV of sea walls

A
  • long lasting and effective at reducing erosion
  • can act as a promenade for tourists
  • act as a barrier to prevent flooding
23
Q

sea wall

A

large concrete wall that reflects wave energy back to sea ad protects against large waves with a recurved shape.

24
Q

DIS of sea wall

A
  • expensive to build and maintain

- creates a strong backwash which erodes under the wall

25
Q

rip rap / rock armour

A

boulders of resistant rock placed at the foot of a cliff to absorb wave energy and reduce erosion

26
Q

ADV of rip rap

A
  • easy to maintain
  • cheap
  • easy to construct
27
Q

DIS of rip rap

A
  • can shift in storms
  • intrusive to environment
  • not local rocks
  • dangerous for tourists
28
Q

Revetements

A

sloping wooden/ rock/ concrete structures to reduce wave energy while allowing sediment through.

29
Q

ADV of revetements

A
  • reduce erosion
  • expensive to build but relatively cheap to maintain
  • implemented quickly
30
Q

DIS of revetements

A

intrusive
unnatural looking
create a strong backwash

31
Q

offshore breakwater

A

partly submerged rock barrier that breaks up waved further out at sea. wave energy and erosive power is reduced before the waves reach the shore.

32
Q

ADV of offshore breakwaters

A

effective permeable power

relocating a natural process

33
Q

DIS of offshore breakwaters

A

materials may be eroded quickly
contamination of local areas with eroded material (concrete)
navigation hazard
expensive

34
Q

what is soft engineering?

A

management techniques which work with natural processes to redirect them to the desired effect.
this requires long term intervention where the cost is shared over time.

35
Q

what are 6 soft engineering strategies?

A
beach nourishment
cliff regrading and drainage
dune stabilisation
marsh creation 
land use management
coastal realignment
36
Q

beach nourishment

A

addition of sand and pebbles to widen a beach

37
Q

ADV of beach nourishment

A

blends in

increases tourism

38
Q

DIS of beach nourishment

A

needs constant maintenance
dredging elsewhere effects habitats
expensive to maintain

39
Q

cliff regrading and drainage

A
  • reduces the angle of cliffs to stabilise it (less steep)

- remove water to reduce slumping and landslideds

40
Q

ADV of cliff regrading & drainage

A

effective on clay and loose rock
drainage = cost effective
stabilised cliff

41
Q

DIS of cliff regrading & drainage

A

cliff retreat
dries out and collapses
relatively low cost but ongoing maintenance
may be impractical if there are important land uses on the cliff top

42
Q

dune stabilisation

A

use plants to prevent LSD

43
Q

ADV of dune stabilisation

A

maintains the natural environment and is sustainable
relatively cheap
creates a wide beach, reducing erosion

44
Q

DIS of dune stabilisation

A

time consuming to plant

cut off area for tourists

45
Q

marsh creation

A

planting appropriate vegetation can stabilise sediment

= reducing the speed of waves = reduced erosive power and flooding.

46
Q

ADV of Marsh creation

A

natural buffer

habitat creation

47
Q

DIS of marsh creation

A

land loss

farm owners want compensation

48
Q

coastal realignment

A

managed retreat - allowing sea to breach defences and reach land behind. overtime marshland will develop

49
Q

land use management

A

wooden walk ways across dunes and fenced off areas protect regeneration of dunes and reducing vegetation loss.

50
Q

causes of increased flood frequency and severity

A
  • increased storm surges (warmer seas = low pressure systems)
  • increased sea level (CC)
  • estuarine flooding (river discharge)
51
Q

flood barrage

A

hard engineering construction across estuaries = allow tidal waters through but prevent unusually high tides, storm surges and flood tides when forecasted.

52
Q

is hard or soft engineering more sustainable?

A

soft engineering is usually cheaper
require less time and money to maintain
integrate with the natural environment
LOWER ECONOMIC cost and ENVIRONMENTAL impact/

53
Q

ICZM

A

integrated coastal zone management
considers all elements of a coastal system to form a management scheme which protects the environment while allowing people to use it.

54
Q

what are the 4 criteria for ICZM

A
  • ENVIRONMENT viewed as a whole
  • different LAND USE are considered - sustainably
  • LOCAL, REGIONAL, and NATIONAL levels of authority have an input in the plan
  • DYDNAMIC process where plans adapt to changing priorities and new information
55
Q

IPCC

A

Intergovernmental panel for Climate Change
climate experts from 130+ countries
there are no political or company ties.

56
Q

what are the aims of the IPCC

A

access the risks for human induced CC, its possible impacts and options for prevention.