Case studies Flashcards
(9 cards)
Guinea, West Africa
(coastal recession)
Capital: Conakry
-port city
-industry based on fishing, tourism, commerce
700m of erosion in 40 yrs
10cm SLR since 1980
Prediction of 1m by 2100
Dredging (removal of underwater soil) to deepen/clear shipping channels
Sand extraction from river for industry
Mangrove deforestation for fuel
Gravel extracted during diamond mining
Sea walls are expensive to maintain
Trinidad and Tobago
(coastal recession - loss)
SIDS
Mayaro is largest coastal devp
Low lying
SLR of 0.06m/yr
Winter storms have higher swell waves affecting N + E coasts
E coast subject to southerly LSD
Economic loss:
-dependant on petrochemical industry (40% GDP)
-all major gas pipeline come ashore at Guyaguayare which is site of greatest erosion
-low economies of scale so infrastructure loss more severe
-2014 Manzanillo beach flood destroyed 300m of major access road - up to £5mil
-Mayaro hosts luxury beach front homes
-Tourism
Social loss:
-Loss of watermelon and vegetable cash crops, loss of livelihood
-Manzanillo flood damaged transport/access, commuters can’t access oil + tourist industries
-Decreasing value of luxury coastal properties
-Break up of community
-Relocation costs for poorer
-Damage to tourism industry (aesthetics..)
-Social tensions by individual management attempts blocking LSD
Environmental loss:
-Nesting site for endangered Leatherback turtles (contribute to ecotourism)
-16,000 acre trinity hills wildlife sanctuary and reserve
HOWEVER - ecosystem could adapt to gradual changes
Slapton (as a sediment cell)
Sources -
1) Erosion of Start Point headland (Schist)
2) Cliff erosion and mass movement (Hallsands)
3) PAST - fluvial sediment (granite) from Dartmoor via river Dart
4) Marine transgression from offshore (flint)
Transport -
Waves refract around Start Bay
LSD South to North
Sink -
Slapton Sands
Management -
Material removed from Strete and returned to Beesands
New York
(Flood risk)
Hurricane Sandy, 2012
90mph winds
14ft high coastal flooding
53 killed
$32bn damage
Subway tunnels flooded, hospitals w/out power
Flood risk is problem for US East coast - 12% US lives there
Low lying
SLR worsened risk
Bangladesh
(Storm surges)
40% of all recorded storm surges have occurred within Bangladesh
Triangular shape of Bay of Bengal acts as funnel for tropical cyclones
Tropical cyclones cause intense rainfall and high wind speeds (inc wave height)
Coastline consists of unconsolidated delta sediment subject to erosion
Ganges + Brahmaputra river system has 3rd largest discharge in world
Deforestation of mangroves
Projected SLR of 55cm by 2100
Subsidence of delta by 8-18mm /yr due to isostatic adjustment caused by Himalayas uplifting
Environmental determinism - Study of how physical environment predisposes societies towards particular devp trajectories (nature controls human actions)
…
Management:
Chittagong + Dhaka each have population higher than 20 mil and are located near coast
Chittagong hosts main port, main source of GDP
Engineered coastal embankments
Emergency shelters + early warning system, 5000 volunteers
Inc pressure on coastal environment due to rapid coastal devp
Inc erosion rates
Lack of compensation for those who relocate/houses damaged
Fewer resources so less resistant structure
Funding based of loans and grants
(disproportionately affect poorer communities? - as they are forced to live in cheaper higher risk land)
Kiribati
Pacific small island developing states
100,00 people on 33 islands - mainly Tarawa atoll
Low lying atolls
Low pressure systems (storm surges, not trop storms)
Natural subsidence due to compaction of sediment under its on weight
Saltwater intrusion
Mangrove deforestation
Coral bleaching
Responses:
-mitigation: solar panels, local food
-adaption: sea walls, rainwater harvesting, buying new land
(environmental refugees)
‘protected culture’: pearl cultivation, coconut producers, fly fishing (tourism)
-young people leaving villages
-overfishing
Island initiative- devp sustainable economic activities to retain young people, funded by NZ businessmen, set up education managed marine area, changing flyfishing habits
Environmental refugees - move to NZ, will they be accepted?, dilution of culture
Netherlands
Rhine delta
Very low lying - 26% below SL
19cm SLR since 1900
Subsidence of 8mm/yr
Flood prone urban areas projected to inc from 30-125% by 2100
Great Flood in 1953 caused 5m storm surge
Management: ‘Room for the river’ plan
-involved all levels of stakeholders (govt thru to locals)
-considered, aided and compensated local farm owners when relocating
-protected areas with higher population density that is harder to move
-flood bypasses, deepening side channels, protecting flood plains
Portballintrae, Northern Ireland
Historic fishing village
-Leslie’s pier since 1760
-Damaged by storms, rebuilt and enlarged by 1970
Rapid growth since 1970s
-2nd homes
Huge amount of beach material removed
-Leslie’s pier diffracts incoming waves, causing waves to refocus at centre of bay
-LSD removes sediment East, away from centre
-Rip current removes sediment into deeper water
Attempted solutions
-Groynes built, sand nourishment, sea walls - no change
-Removed Leslie’s pier in 2022
-Need to remove sea wall as it causes scouring of beach material but controversial step for homeowners
-over £1.5 mil of engineering in past century
Slapton
