Physical Case Studies Flashcards
Fold Mountains: Livigno, Alps, Italy
Formation: geosynclines forced upwards on destructive collision margin
Problems: isolated, steep, thin soils, cold
Uses: transhumance, HEP, mining (adits horizontal mines), skiing (90% of local economy)
Adaptations: valley farming replaces transhumance, hairpins, snow sheds, avalanche gates, controlled avalanche expolosions
Volcanic Eruption: Mount St Helens, Cascade Ridge, Washington State, USA
18 May 1980
Formation: composite cone, destructive-subduction, andesitic lava, lateral blast
Effects: 27km wipeout zone, pyroclastic flow, 57 killed, ash brought NW US states to stand still (secondary - lahars)
Short-term Responses: USGS monitored eruption, 8km exclusion zone, emergency services and army mobilised, National Emergency declared, 2 million masks distributed, helicopters search and rescue
Long-term Responses: Spirit Lake and Toutle River cleared, USGS set up COSPEC, GPS, tiltmeters, seismographs
Positive Impacts: 2 million visitors a year, soil fertility increased
MEDC Earthquake: Kobe, Japan
17 January 1995 Nojima Fault under CBD 7.2 magnitude
Cause: destructive subduction, shallow focus
Effects: 5500 deaths, 30,000 injured, infrastructure collapsed in older suburbs, 2 tonne typhoon roofs pancaked, liquefaction in Osaka Bay, Hanshin Expressway collapsed, port out of action
Short-term Responses: rapid, emergency services and 3000 army troops sent to suburbs/Hanshin, sniffer dogs, thermal imaging equipment
Long-term Responses: retro-engineering (Osaka Bay Tower), 15m rods and shock absorbers on Hanshin, CBD rebuilt within year, 80% of port rebuilt in a year
LEDC Earthquake: Port au Prince, Haiti
13 January 2010, 7.0 magnitude direct hit on CBD
Cause: conservative, shallow focus, densely populated area, unprepared, building laws ignored
Effects: 250,000 dead, infrastructure collapsed, 1 in 3 buildings collapsed, jail broken open: 4000 escaped (secondary - cholera, typhoid)
Short-term Responses: uncoordinated, 1 ambulance, government collapsed, port inaccessible for 5 days, airport for 48 hours, hospitals overwhelmed
Long-term Responses: 1.5mil in temporary accommodation a year later, city not rebuilt
Tsunami: Japanese Tsunami, Sendai, Japan
11 March 2011
Cause: mega thrust 9.0 magnitude, destructive-subduction in Pacific Ocean, epicentre in Sendai, 10m high tsunami wave
Places affected: Minamisanriku (90% destroyed), Ofunato (10m sea wall overwhelmed because Japan sunk 1m), Fukishima Power Plant
Effects: Japan sank 1m, 15,000 deaths, yen fell sharply, stock exchange crashed, infrastructure destroyed, coastal towns wiped off map, Fukishima Power Plant meltdown
Short-term Responses: text and radio alerts released, army mobilised, international aid from charities (Oxfam, Red Cross), Fukishima 50 sent in (make power plant safe, severely reducing life expectancy)
Long-term Responses: Japan rebuilt coastal towns, shut down Fukishima forever, Sendai and Ofunato now rebuilt
Flooding in MEDC: Boscastle, Cornwall, UK
16 August 2004
Causes: flash flood: 15mm of rain in 15 mins, impermeable underlying rock reduced infiltration, steep v shaped valley increases surface run-off, confluence of 3 rivers increased discharge (Paradise, Jordan, Valency)
Effects: £15m on insurance claims, tourism reduced, homes devalued, infrastructure destroyed, no deaths
Responses (COORDINATED, RAPID): rapid evacuation, Coast Guard mobilised, RAF helicopters saved 150 people, motorised dinghies, temporary accommodation on football pitch
Flooding in LEDC: Indus River, Pakistan
July 2010
Causes: prolonged monsoon rains, run off from Himalayas, months of rainfall saturated ground, densely populated floodplain, Sukkur Barrage breached
Effects: Primary: Swat Valley cut off, 1600 deaths, thousands homeless, crops ruined Secondary: Cholera, typhoid
Responses (UNCOORDINATED, SLOW): heavy reliance on international aid, UN ambassador Angelina Jolie helped raise publicity, rural areas only accessible by donkey: slow, Taliban took advantage of slow response to supply aid and win over communities
Soft Engineering: Yellow River: China, River Rhine: Germany
Afforestation: Yellow River, China - Planting of trees to increase interception, 20% increase of trees in 2 years, doesn’t prevent flooding but increases lag time so lessens flood impacts
Floodplain Zoning: Rhine River, Germany - Floodplain divided into risk areas, water meadows next to river absorb water, trees and park act as buffer zone, hospitals and schools further away form river, land lost and not used economically
Dam/Reservoir in UK: Kielder Water, Northumberland, UK
Largest artificial lake in UK
Negatives: land lost, habitats and farmland lost, people relocated, high construction cost
Positives: North UK (surplus area) now supplies south (deficit area), flooded land was poor quality farmland and cheap land, reservoir manages flow of River Tyne, provides flood protection for Newcastle and Tyne Valley, provided HEP, free recreational and leisure activities for people to enjoy (picnic sites, nature trails and walks), provides water habitats and is a conservation area
Hard Engineering: : Yangtze River: China, Mississippi: USA
Three Gorges Dam: Yangtze River, China: - relocation of 1.4mil people, many settlements lost, no compensation for communities, dam prevents deposition of alluvium on farmland: less fertile farmland, most polluted reservoir on earth, + HEP produced for growing population, less flooding 1/100 to 1/1000 flood likelihood
Straightening: Mississippi, USA: + flows more quickly through big urban/industrial area: moves away from city quickly, - flooding further downstream
Cliff Collapse: Holderness Coast, North Yorkshire, UK
Rate of erosion: 2m a year (6m south of Mappleton due to terminal groyne syndrome)
Physical causes of erosion: strong destructive waves, strong winds, soft boulder clay easily eroded
Human causes of erosion: sea level rise (global warming), terminal groyne syndrome at Mappleton
Impacts: 4km land lost, gas station at Easington at risk, tourism threatened, infrastructure lost, habitats lost, trauma, compensation, fall in property price (houses valued at £1)
Coastal Flooding: Tuvalu, Polynesia
Facts: island is a coral atoll (porous), highest point on island: 4.5m
Economic impacts: infrastructure flooded, 90% GDP comes from tourism, fishing and farming hit, fall in property, airport flooded
Environmental impacts: salt water intrusion destroys habitats and crops (pulaka), coral reefs bleached by warm water, fish stocks decline
Social impacts: trauma, relocation of people to NZ, loss of culture and traditions
Political impacts: government campaigning to raise awareness, when to Copenhagen 2010 Climate Summit
Coastal Habitat: Keyhaven Marshes, Hampshire, UK
Formation: marshes formed behind Hurst Castle spit
Pioneer species: cordgrass
Habitats and species: low marsh: cordgrass and wold spider, high marsh: sea lavender, common blue, ringed plover, oyster catcher
Conservation: Hurst Castle spit protects marshes so spit it protected by groynes, 500m of rock armour, sea wall and nourishment, marshes grazed to keep cordgrass and other species healthy: controls weeds
Sustainable use: public use marshes sustainably: no entry at nesting times, footpaths clearly signed, dogs on leads, closed gates, no littering
Coastal Management: Lyme Regis, Dorset, UK
Method 1: beach front: groynes, extended Cobb, sea wall, rock armour, beach nourishment
Method 2: slopes: soil nailing/pilling to prevent landslides, landslide warning system
Benefits: 140 properties lost over next 50 years if no action taken, protection secures tourism (worth £994 million), safeguards beach, improves access to amenities BENEFITS OUTWEIGH COSTS 6:1
Costs: £21 million, terminal groyne syndrome further down the coast
