Coasts EQ4 - Coastal management Flashcards

1
Q

What are the economic losses from coastal recession?

A
  • housing
  • businesses
  • agricultural land
  • infrastructure
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2
Q

What are the social losses from coastal recession?

A
  • relocation
  • loss of livelihood
  • amenity value
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3
Q

What are the environmental losses from coastal recession?

A
  • loss of coastal ecosystems and habitats
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4
Q

Why are economic losses from coastal recession often localised and small, and what is the cause when they are not?

A

Due to incremental nature of erosion, property at risk losing value before being destroyed, coastal defences
When losses are larger it is due to an unexpected erosion event (often mass movement related)

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5
Q

What was the cause of the 2013 North Sea storm surge?

A

Deep depression in the North Sea created a storm surge of 5.8m (recorded in Lincolnshire)

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6
Q

What were the social and economic costs of the 2013 North Sea Storm Surge?

A

SOCIAL - 15 deaths, 18000 evacuated, around 100,000 homes in Scotland lost power
ECONOMIC - cost to UK government £200 million

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7
Q

Why were the impacts of the 2013 North Sea storm surge not that damaging?

A

Due to 2800km of sea defences (UK) and forecastings and warnings saving 800,000 homes

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8
Q

What was the cause of the 2007 storm surge in Bangladesh?

A

Cyclone Sidr - 240km/h winds
Sent a 6m high storm surge to Bay of Bengal

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9
Q

What were the social and economic impacts of the 207 Bangladesh storm surge?

A

SOCIAL - 3000 deaths, drinking water contamination (salination), infrastructure destroyed
ECONOMIC - US$1.7 billion

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10
Q

Why were the impacts of the 2007 storm surge in Bangladesh so bad, and what will it be like in the future?

A

The surge breached coastal and river enbankments to leave a path of physical destruction.
Estuarine island subsidence, 71% of the mangrove forested coastline has retreated by 200m/year since Cyclone Sidr

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11
Q

Why has climate change created environmental refugees in Tuvalu?

A

Only 26 square kilometres of land, highest points less than 2m above sea level.
Could become uninhabitable in the next 50-100 years - this leads to the loss of language/culture/identity in the coming years. The rising ocean has already contaminated underground water supplies

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12
Q

What are the social, economic and environmental losses due to recession on the Holderness Coast?

A

SOCIAL - 30 villages lost since Roman times, many are reliant on tourism, potential loss of livelihood
ECONOMIC - visitor numbers dropping, 80,000 m2 of farmland is lost each year, it is predicted 200 homes and roads will fall into the sea by 2100
ENVIRONMENTAL - Spurn Head losing diversity due to sediment erosion, sites of specific scientific interest being destroyed

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13
Q

Why is erosion a problem for the Holderness coast?

A

Longshore drift - material moved through sediment cell
Geology - made of unconsolidated boulder clay which is easily eroded (glacial period deposits), little resistance
Fetch - 500 to 800km fetch means more destructive waves

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14
Q

What is hard engineering?

A

Building economically costly artificial structures which deliberately alter physical processes and systems

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15
Q

What are the different coastal hard engineering strategies?

A
  • groynes
  • sea walls
  • rip rap/rock armour
  • revetments
  • offshore breakwaters
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16
Q

What are the advantages and disadvantages of hard engineering?

A

ADVANTAGES - reassuring to at risk people, ‘one-off’ solution that can protect coast for decades
DISADVANTAGES - high initial and maintenance costs, can be prone to failure, visually unattractive, cause issues further down the coast

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17
Q

What is rock armour and what are it’s impacts?

A

Boulders placed to break up and dissipate wave energy
IMPACTS: Reduce wave energy, sediment deposition between rocks

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18
Q

What is an offshore breakwater and what are it’s impacts?

A

Offshore rock armour which causes waves to break before reaching shore, reducing wave energy and erosion
IMPACTS: deposition encouraged but interferes with longshore drift

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19
Q

What is a sea wall and what are it’s impacts?

A

Concrete physical barrier against erosion
IMPACTS: destruction of natural cliff face and foreshore, reflective ones can reduce beach volume

20
Q

What are revetments and what are their impacts?

A

Sloping permeable structures
IMPACTS: reduce wave power and may encourage deposition

21
Q

What are groynes and what are their impacts?

A

Vertical fences built at 90 degrees to the coast, spaced along the beach
IMPACTS: terminal groyne syndrome, deposition and beach accretion, sediment starvation downdrift

22
Q

What is soft engineering?

A

Approaches that attempt to work with physical processes and systems to protect coasts and manage changes in sea level

23
Q

What are the coastal soft engineering strategies?

A
  • beach nourishment
  • cliff stabilisation/regrading
  • dune stabilisation
24
Q

What are the advantages and disadvantages of soft engineering?

A

ADVANTAGES - less obvious, less intrusive at coast, may be cheaper in the long term
DISADVANTAGES - not suitable for all coasts

25
Q

What is beach nourishment and what are it’s impacts?

A

Artificially replenishing the sediment on a beach
IMPACTS: replaces sediment lost, enlarges beach to reduce wave energy and erosion, increases amenity value, outgoing costs high and sediment must be sustainable

26
Q

What is cliff stabilisation and what are it’s impacts?

A

Cliff slope angle reduced and revegetated to increase stability and reduce surface erosion
IMPACTS: reduces pore water pressure and mass movement risk

27
Q

What is dune stabilisation and what are it’s impacts?

A

Fences are used to reduce wind speeds across dunes, which are then replanted with marram and lyme grass to reduce erosion
IMPACTS: human recreation and tourism can trample and kill vegetation, erosion reduced by absorbed wave energy

28
Q

What is sustainable coastal management?

A

Managing the wider coastal zone in terms of people and their economic livelihoods, social and cultural wellbeing and safety from coastal hazards, as well as minimising environmental and ecological impacts

29
Q

What must be included within sustainable coastal management?

A
  • managing natural resources
  • managing flood and erosion risk
  • creating alternative livelihoods before existing ones are lost
  • adapting to sea level rise by relocation
  • educating communities
  • monitoring coastal change
30
Q

Why does sustainable coastal management often cause conflict?

A
  • people are forced to relocate
  • some erosion and flooding will always occur (unable to divert/protect)
  • future sea level rise is uncertain, so plans may be altered
31
Q

What is ICZM?

A

Integrated coastal zone management
Holistic approach that involves all stakeholders

32
Q

What are the 3 key characteristics of ICZM?

A
  • entire coastal zone managed - all ecosystems, resources and human activity
  • recognises importance of coastal zone to people’s livelihoods
  • management must be sustainable and ‘environmentally appropriate’
33
Q

What is a littoral cell?

A

All coastlines divide up into these ‘cells’ which contain sediment sources, transport paths and sinks. Each cell is managed as an integrated unit by a SMP

34
Q

What is a SMP?

A

Shoreline Management Plan

35
Q

What are the 4 policies available for coastal management in the UK?

A
  • No active intervention: land allowed to flood/eroded with no actions taken
  • Strategic (managed) realignment: coastline allowed to move naturally, but ‘directed’ in certain areas
  • Hold the line: build/maintain coastal defences
  • Advance the line: build new coastal defences seaward of existing coastline, often involves land reclamation
36
Q

What is cost-benefit analysis?

A

A process used to help decide if defending a coastline is economically justifiable

37
Q

What is an EIA?

A

Environmental Impact Asessment
A process that aims to identify short term impacts on environment from construction and the long term impacts of building new defences/changing policy

38
Q

Who are the winners and losers from coastal management?

A

WINNERS - people who have gained from decision, socially, economically or environmentally
LOSERS - those who lose property or are concerned about the impact on the environment

39
Q

Why is coastal erosion in developing countries rapid?

A
  • destruction of mangrove forests for shrimp farms
  • rapid coastal development, urbanisation
  • haphazard construction of defences with no overall plan
  • upstream dams on Asia’s major rivers disrupts sediment cells
40
Q

What SMP strategy is being used at Happisburg, and what are the impacts of this?

A

‘Do nothing’ approach
Cliffs eroding by a rate of 10-15m per year, and residents are extremely unhappy as 30 buildings have already been lost

41
Q

What SMP strategy is being used at Sea Palling, and what are the impacts of this?

A

Hold/advance the line
Offshore reefs built parallel to the coast, beach nourishment, 100,000 tonnes of boulders placed in front of sea wall.
As a result, beaches have been built up (Blue Flag status) and the Norfolk Broads have been protected - 6000 acres

42
Q

What strategies have been used to manage Chittagong from climate change causing sea level rise/storm surges?

A

Number of small schemes: raised embankments, sheds raised on platforms above expected sea level rise, constructing/improving 25 tropical cyclone shelters and training in climate resilience and adaptation measures

43
Q

What are the positives and negatives of Chittagong’s climate protection strategies?

A

POSITIVES - alleviation of poverty by 10%, generation of income opportunities, adaptation to climate change and reduction of disaster risk
NEGATIVES - disturbance of people and natural habitats, permanent removal of natural vegetation and relocation of some households (200 people) by road realignment.

44
Q

What strategies have been used in the Holderness Coast’s SMP?

A

Some areas are ‘hold the line’ but others are ‘do nothing’
£2 million groyne at Mappleton in 1992 - impacts on Great Cowden (do nothing)
Easington 1km long revetment
Hornsea 1.86km of concrete sea walls

45
Q

How effective is management on the Holderness Coast?

A

The artificially defended locations create non-eroding ‘hard points’ which interrupt natural processes (dynamic equilibrium of sediment cell)
This will create new bays and ‘headlands’ as beaches reorient themselves
Terminal groyne syndrome – starving one beach of sediment because of groynes