EQ3: How do coastal erosion and sea level change alter the physical characteristics of coastlines and increase risks?

Question 1

eustatic change

Answer 1

land ice melts and returns to the sea. works alongside thermal expansion (50% contributor to SLR). produces emergent coastlines (raised beaches and fossil cliffs). Scotland has 7 new raised beaches e.g Isle of Arran.

Question 2

isostatic change

Answer 2

downward movement of land causing localized SLR. creates submergent coastlines (rias, fjords and fjards). Plymouth Sound Ria, Milford Sound fjord.

Question 3

tectonic activity contribution to SL change

Answer 3

sea floor spreading creates larger platform for water to sit on. tectonic activity can change shape of basin- smaller basin= SLR

Question 4

coastal recession (Holderness Coast)

Answer 4

• erosion rate= 1.8m p annum
• rapid erosion bc soft rock lithology (chalk and boulder clay) and naturally narrow beaches (Cowden Farm)
• declining property prices, poor accessibility
• conflict between players

Question 5

coastal flooding (Kiribati)

Answer 5

• made of 33 atolls

- few cm rise will completely submerge it

Question 6

coastal flooding (Maldives)

Answer 6

• loss of tourism, beaches, soil and freshwater
• disrupting fishing industry
• damage to homes

Question 7

coastal flooding (the Philippines)

Answer 7

• highest damage cost bc of SLR ($6.5 bn/ annum)
• SLR approx. 5.8 mm p annum (higher than global avg) bc of Pacific ocean currents
• growing population e.g. Manila
• Manila bay: mangroves, corals, seagrass damaged bc of pollution, over- exploitation

Question 8

coastal flooding (San Fernando)

Answer 8

• by 2100 will lose 300 buildings; $2.5 mil property losses
• social amenity losses
• 130 fishermen earn $12 weekly: high unemployment so alt. jobs harder to find
• rip rap constructed to protect govt buildings e.g.$21,00 spent in San Augustin

Question 9

East Coast isostatic sinking case study

Answer 9

• more coastal flooding, erosion
• higher pop density so relocation in Happisburgh etc
• lots of power plants situated there (4 nuclear)
• low lying settlements e.g. Kings Lynn under threat bc valuable agricultural land loss
• National Park Norfolk Broads at risk (brings £5 mil into economy per annum)
• politically controversial bc some want managed retreat some want sea walls
• Thames Barrier protecting buildings £80+ bn but needs replacing (likely cost= £20 mil)

Question 10

storm surge (Chittagong, Bangladesh)

Answer 10

• most at risk from SLR (40% of all recorded SS happened there)]
• 60% of Bengali land is low lying
• SS have killed 1.3 mil since 1700
• SLR cause rivers to flow slower inc risk of river flooding
• wetter env breeds cholera and malaria outbreak
• main port of Chittagong out of action
• farmland loss bc of flooding, salinization causes dec GDP and food shortage e.g rice and veg
• coastal defence e.g. mangroves of the Sundarbans will be lost
• 2007: Cyclone Sidr caused $1.7 bn damage, 20 mil lost source of income (were already poor)

Question 11

storm surge (North Sea)

Answer 11

• 1953: 307 died in England. 2,100+ in Netherlands

- damage of £1.2 bn but even with improved warning system and forecasting cost was £1.7bn in 2013

Question 12

Nile Delta

Answer 12

• accounts for 2/3 of Egypt’s agricultural production, supports 40 mil ppl
• 2100 prediction of 28-29 cm rise would succumb 12.5% of cultivated areas and displace 10% of pop
• Aswan High Dam, sand replacing soil, urbanization and pop growth are anthropogenic causes
• agricultural area dec by 30% since 1990 replaced by fishing industries (built at expense of water bodies and sand dunes)
• 1990: 17% of area was water, 2014: 7%
• artificial ponds created e.g. at Lake Manzala for fish farms- leads to soil salination e.g. at Kafr al Sheikh
• urban land developed at expense of agricultural ( last 5 yrs road network inc by 35% better for farmers)
• overgrazing of date farms at Rosetta- dec agricultural productivity