COASTS - EQ3

Question 1

Erosion - Holderness

Answer 1

• Europe’s fastest eroding coastline, avg rate of 2m/year
• Geology: Chalk, soft boulder clay (erodes rapidly, especially when saturated)
• LSD moving south AWAY
• Large fetch so powerful waves

Question 2

Climate Refugees - Kiribati

Answer 2

• 1.2cm/year sea level rise
• Peak height ASL ~ 2m
• Pop > 121,000 migrating to purchased land in Fiji
• Water insecurity b/c of saltwater infiltrating ground water supply
• Mangroves planted to limit erosion caused by high tides

Question 3

Subsidence - Jakarta, Indonesia

Answer 3

• ISOSTATIC - 32 million population city sinking 25cm/year
• EUSTATIC - Climate change
• Illegally draining aquifers b/c no access to clean water
• 32km sea wall has been built but standard is poor leading to undercutting

Question 4

Climate Change Developed Country - New York

Answer 4

• Melting glaciers is “halting” thermohaline circulation so pools in this area.
• Isostatic readjustments from ice sheet from 20,000 years ago
• Increased frequency and intensity of flooding

Question 5

Subsidence - Nile Delta

Answer 5

• Agricultural, urban and industrial sectors have been extracting groundwater at an exponential rate
• Aswan Dam (1960s) has reduced amount of sediment reaching delta by 98%
• 2nd largest supplier of natural gas in Africa
• 41% Egypts population at risk

Question 6

Coastal Flooding - Bangladesh

Answer 6

• 1.5m over past 50 years
• Deforestation to grow rice 3% a year
• 30 million live on unstable polders
• Polders prevent natural distribution of sediment
• 75% live below sea level
• Floodplain of 3 major rivers
• Himalayan snow melt and monsoon rain adds to flood risk

Question 7

Storm Surge - UK

Answer 7

• December 2013
• Storms brought by powerful jet streams across the Atlantic
• Storm funnelled into North Sea which gets shallower towards the South of the UK
• 18,000 evacuated
• 800,000 properties protected by Environment Agency flood defences
• London saw highest tide since Thames barrier built in 1984
• 2,800km of flood defences put to the test
• 64 severe flood warnings
• 720 properties flooded
• 1,700 hectares of farm land flooded
• Cost government £200 million
• £270 million invested in new defences

Question 8

Storm Surge - Hurricane Sandy

Answer 8

• October 2012
• 9ft flood in Manhattan
• > 100mph storms
• Coincided with highest tide of the month and densely populated New York
• 286 deaths
• > $60 billion in damaged (one of the most costliest)
• 346,000 homes damaged
• > 18,000 flights cancelled

Question 9

Soft Engineering - Bacton, Norfolk - Strategic Realignment

Answer 9

• 1.8 million cubic metres of sand pumped onto beach
• £20 million
• Protects gas terminal
• Still susceptible to damage, just delays it
• Takes time to see effects

Question 10

Hard Engineering - Rossall - Hold the line

Answer 10

• 320,000 tonnes of rock armour
• Protects 7,500 properties
• Schools and hospitals
• £64 million
• Eyesore
• Could be underwater in 100 years regardless

Question 11

Hard Engineering - Borth - Hold the line

Answer 11

• Offshore reef breakwater
• £12 million
• Surrendering Fairbourne (No active intervention)
• Protects tourism

Question 12

Soft Engineering - Steart Marshes - Strategic Realignment

Answer 12

• 400 hectares
• Realign coastline to allow new saltmarshes to form
• Protects from storm and tides
• £21 million
• Creates habitats, not an eyesore, better for environment
• Traps sediment that would otherwise build up further down the coast

Question 13

Coastal Management - Odisha, India

Answer 13

• Integrated Coastal Zone Management
• Stronger water quality laws
• 455km^2 mangrove replanted
• Coral reef regeneration
• Emergency cyclone shelters
• National parks

Question 14

Soft Engineering - Blackwater Estuary Essex - Advance the line