A-Level CIE Geography Physical

• 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