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

Coastal Landscape and Change > EQ3: How do coastal erosion and sea level change alter the physical characteristics of coastlines and increase risks? > Flashcards

Flashcards in EQ3: How do coastal erosion and sea level change alter the physical characteristics of coastlines and increase risks? Deck (12):
1

eustatic change

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.

2

isostatic change

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

3

tectonic activity contribution to SL change

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

4

coastal recession (Holderness Coast)

- 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

5

coastal flooding (Kiribati)

- made of 33 atolls
- few cm rise will completely submerge it

6

coastal flooding (Maldives)

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

7

coastal flooding (the Philippines)

- 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

8

coastal flooding (San Fernando)

- 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

9

East Coast isostatic sinking case study

- 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)

10

storm surge (Chittagong, Bangladesh)

- 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)

11

storm surge (North Sea)

- 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

12

Nile Delta

- 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