A-Level CIE Geography Physical

Subdecks (2)

Cards (62)

  • Great Barrier Reef
    600 years old
  • Great Barrier Reef
    • 2000km long
    • 2900 reefs
  • Great Barrier Reef generates $4bn of tourism per year
  • Great Barrier Reef
    • 1500 fish species
    • 400 coral species
  • Great Barrier Reef added to World Heritage list

    1981
  • Huge mines extract mineral wealth across the Great Barrier Reef, 5 times more than expected
  • Reefs make up less than 1% of oceans but support 25% of species
  • Threats to the Great Barrier Reef
    • Salinity changes
    • Pollution - nitrates (77k tonnes/year) from increased agriculture fertilisers
    • Crown of thorn starfish
    • Rising sea temperatures
    • Damage from tourism
  • Opportunities and management of the Great Barrier Reef
    • High value tourism
    • 2 million visitors per year
    • Whitsunday Islands - snorkelling
    • Fraser Island - 75 mile beach
    • Bioilluminescence
    • Turtles
    • Land-use Zoning— General use areas & preservation areas
  • Great Barrier Reef - Coal Industry
    • Aus shipped $30bn of coal in 2014
    • Employs 50k directly & 150k indirectly
    • Mines operate at a loss
    • Galilee basin - Queensland - coal deposits - would emit 700mol tonnes of CO2 for 50yrs
    • Dredging & dumping of coral reefs spoil
    • Destroy Manatee feeding ground
    HOWEVER:
    • Mining increases jobs by 15k & decreases energy prices
    • 2015 - reef 2050 - $80mil for reef protection - no climate change plans
  • Christchurch bay - Sediment Cells
    SEDIMENT SOURCES:
    • R.Avon, R.Stowe
    • Christchurch harbour, Christchurch ledge
    • Keyhaven & hurst beach (spit)
    • Rivers flow into sea at Barton & Becton
    • IOW, shingles bank & hurst castle
    SEDIMENT MOVEMENT PATTERN:
    • Moves through suspension - fine sediment
    • Sediment currents
    • Deposition on shingles bank as waves lose energy as they hit
    • long fetch = fast and high energy - less friction
  • Mangroves
    CONDITIONS:
    • 24*C+
    • Rainfall exceeds 1.25l
    • Equatorial coastlines
    • West = 8 species
    • East = 40 species
    • In lining of estuaries of rivers flowing into shallow seas
    • eg. Ganges & Brahmaputra
    • Low Oxygen & nutrients - high salinity & strong winds
    FEATURES:
    • Shallow root penetration - buttress roots
    • Extensive lateral spreading
    • Act as filters - removes soil & organic matter
    • Carbon sink in sediment - terrestrial & coastal
    THREATS:
    • Over - exploitation: fuels, dyes, poison, thatching
    • Challenging environment for life
  • Rias
    • Form when River Valleys are submerged
    • Eg. Dartmouth/Kingsbridge estuaries - South Devon
    • Unusually wide R.Valleys - deep sheltered waters
    • Poole Harbour - Brownsea Island used to be a hill
    • V. Shallow - 45cm+
    • Dalmatian Coastlines - rivers run parallel to the coast - leaves islands as they are submerged
    • Eg. Dalmatian coast - Croatia
  • Coastal Rebound
    • 2024 Isotatic rebound = coastal features raised
  • Submergent coastlines
    • North sea - off Essex coast
    • Submerge low-lying land masses
    • common in existing r. valleys
  • Coral reefs overtime
    • 1998 - Bleaching
    • 16% of world coral was damaged - particularly Puerto Rico - SW= 100% beached up to 40cm
    • 30*C waters
    • 2004 - Glbal assessment
    • 1/5 world reefs damaged beyond repair
    • 70% of reefs threatened
    • persian Gulf - 65% destroyed
    • % of recovering reefs has increased - 4% to 33%
    • 2010 - Initaive in climate change & coral reefs
    • 19% of world reefs lost - 35% threatened
    • 2011 - Assessment of reefs
    • 60% under local threats - 75% when including global threats - 90% by 2050
  • Coral & people
    • 500mil ppl depend on reefs for some aspect of life
    • 30mil depend on them for their entire livelihood - mostly in 80 LICs
    • 50% of world population lives on coastline - increased pressures
    • 2009 - world reefs = $100bn
    • Major bleaching in 1998, 2002 & 2006
  • Seafood
    • 1/4 of fish catch in LICs
    • Feeds 1m in Asia
  • 15 tonnes of fish/km^2 / year
  • Sell surplus
    • Coral triangle
    • Indonesia
  • New medicines
    • Chemicals produced for reef protection
    • Bone grafts
    • Leukaemia
  • Other products
    • Economic goods
    • Jewellery etc
  • Live fish & corals
    • In aquariums
  • Sand & limestone
    • In construction industry
  • Recreational value
    • Tourism
    • Snorkelling etc
  • Coastal Protection
    • Buffers adjacent shorelines through wave action & impact of storms
    • Maintains productive mangrove fisheries & wetlands around ports & harbours
  • Florida
    • $1.6bn revenue
  • Global value = $375bn
  • Framers Hill - Pahang - Malaysia
    BACKGROUND:
    • Western Malaysia - 100km from Kuala Lumpur
    • Rainfall = 20-140mm/month
    • Temp = 118-22*C
    • Humidity = 85-95%
    • Altitude = 1456m
    • Vegetation = Lower montane Forest
    VEGETATION OF SLOPES:
    • Brush bundles
    • Bamboo saplings
    • Coir rolls
    • Wooden stakes
    TEST RESULTS:
    • 1 yr = 75% of site 1 = covered by vegetation
    • 90% of site 2 = revegetated
    • control plot = 7 plant species present = weeds
    • No more landslides - control plot = undercutting & unstable soil
  • Frasers hill - Evaluation of Success
    • Geostructures - $3k to install - civil struuctures = $20k
    • Remote site - increased transport & labour costs
    • Geomaterials - abundantly available locally
    • Non - polluting - minimal maintenance & supports biodiversity
    • Used to make coir rolls 7 straw wattles - biodegrade after 1 yr = fertilisers
    • 18months later = restored cut slopes covered in vegetation & no more landslides
  • Puerto Rico mudslides - Oct 1985 - 129 dead
    • 70-805 step & hilly
    • 4 largest cities on coastal plain province
    • USGS landslide hazards project over 3.5yrs
  • Italian Mudlsides - 1951-98
    • 1 year of rain over 2 weeks - May 1998
    • Area has 2 active volcanoes
    • Overdevelopment of slopes
    • Developers set fire to vegetation - loosens soil & increases mudflows
    • Build on top of lava layers
  • The USA's Eastern Seaboard

    • Extensive coastal development
    • Tourism - Atlantic city - NJ
    • 75% Americans live 100kms from sea
    • Flat topography - NJ <3km above sea level
    • East coast sinking relative to sea levels
    • Barrier beaches being destroyed by storms
  • Methods of Management
    1. Hold the line - sea walls vs destructive waves
    2. Strategic retreat - Not possible in NYC, Miami or Boston
    3. New builds are away from the coastline
    4. Atlantic city & Miami Beach - pump in dredged sand to replenish beaches
    5. Hard Engineering - sea walls & groynes at sea right & Monmouth beach NJ
  • US Army = $64mil on replenishment - 30m washed off by sea
  • Hard Engineering - sea walls & groynes at sea right & Monmouth beach NJ failed in Texas due to poor maintenance & Construction
  • Land-use management
    1. Massachusets - can't build on coastal lands
    2. North Carolina - land left for erosion - size of 30x annual erosion - now 60x
  • USA - Eastern Seaboard - events
    • Planning for 1 in 100yr storm eg. Chatham - Massachusets (1987) smash barrier beach causing 20m of coastal erosion
    • Overcautious
    • Super Storm Sandy - October 2012
    • Hurricane force winds
    • High tides, Autumn (highest) tide - full moon
    • Storm Surge
  • New Zealand - Seasand mining at Mangawhai-Pakari
    • 2milm^3 mined of sand at 35-60m over 35yrs
    • Pre 1970 - Mined from Obama beach - sand spit changed shape and badly eroded
    • 1994 - 5 commercial extractors granted permits to dredge - up 10 165km^3 annually for 10 yrs only in water deeper than 25m
    • Groynes built - expensive
    • Working party to oversee actions & establish a sediment budget
    • Amount of sand is static - non-renewable
    • Aucklands shoreline variations can’t be proven to be due to mining
    • Sand dunes are sought after for tourists etc
  • Holderness Coastline - UK
    • Boulder clay - not much energy needed for erosion
    • longshore drift southwards = no beach to protect cliff
    • Ringborough farm = 145 acres (1939) now = 70 acres
    • businesses suffer - 215 caravans lost - 9 left
    • East riding - Hold the line
    • Withernsea - £7mil gabions protection - £250k/year
    • Kilnsea - No defences - can’t sell houses - flooding
    • Spurn point (spit) - 5km long - replenished by longshore drift - major in shipping into Humber estuary