A Level Geography - Physical Case Studies

• River Exe: Upper Catchment

  Area = 601 km^2, Max Height = 514 m
• River Exe: Land Use

  • 67% grassland
  • 15% woodland
  • 3% peat bog
• River Exe: Geology

  84.4% impermeable rocks, e.g. Devonian Sandstones
• River Exe: Water Balance

  65% surface runoff due to impermeable bedrock and drainage ditches
• River Exe: Consequences of Peat Usage

  • Decrease in water quality as more silt
  • Increase in speed of water flow
  • Increase in decomposition releasing carbon from this store
• River Exe: Wimbleball Reservoir

  Built in 1979

  Dammed River Haddeo

  Area: 150 hectares

  Supplies water to Exeter and East Devon

  Regulates water flow which prevents droughts and floods
• River Exe: Exmoor Mires Project

  1. Aims to block 100 km of ditches

  2. Aims to restore 2000 hectares of peatland

  3. This will increase water quality, carbon and water retention, biodiversity and thus educational opportunities and grazing and water for animals

  4. This will decrease the speed of surface runoff
• Amazon Rainforest: Water Cycles

  • 175,000 cumecs into Atlantic per day, which is 20% of total global discharge
  • Second largest river in the world by volume
  • At the river mouth, it is 14 km wide and 100 m deep
  • Average annual rainfall is 2300 mm but it can exceed 6000 mm
  • 33% of rainfall is discharged into the Atlantic with the remaining 67% either intercepted or evaporated
  • 50% of intercepted water evaporates
  • 70% of water remains in the Amazon water cycle once it enters
• Holderness Coast: Context

  • Located in East Yorkshire
  • Fastest eroding coastline in Europe at 1 m per year but erosion can exceed 10 m per year
  • Some stretches of coast have eroded 5 km since the Romans
  • Vulnerable due to narrow beach, lots of mass movement, powerful waves due to long fetch from the North Sea, weak till bedrock which was deposited 12,000 years ago by glaciers
  • Discordant coastline made up of chalk and boulder clay, the clay erodes fasted than the chalk
• Holderness Coast: Coastal Features

  • Flamborough Head is a chalk headland
  • Spurn Point is a very thin spit, it's a temporary store of sediment as it is frequently washed away
• Holderness Coast: Coastal Defences: Mappleton

  • Built in 1991
  • Cost £1.9 million
  • 60,000 tonnes of granite used to make 2 large rock groynes
  • These defences have increased erosion at Great Cowden where 100 holiday chalets and farmland have been lost
• Holderness Coast: Coastal defences pt2

  • Bridlington: 4.7 km sea wall
  • Spurn Point - groynes, rock armour, built by the army in 1849 but they left in the 1950s leaving the defences in disrepair
  • Kilnsea - no government built defences as the assests were not deemed valuable enough in a cost benefit analysis so locals have dug drainage ditches
  • Easington - rock armour and rip rap as there is a natural gas pipline here which accounts for 29% of the UK's supply
• Kiribati lies 2 m above sea level
• Kiribati was a colony of the UK, and its natural resources have been depleted
• Kiribati is a low income country
• The government of Kiribati relies on imports and foreign aid, as 33% of the government budget is aid from the EU and World Bank
• Badly positioned sea walls are increasing erosion and the volume of waste washed upon beaches in Kiribati
• Crops such as breadfruit and coconuts are failing in Kiribati, creating food insecurity
• The government of Kiribati has bought 5500 acres of land on Fiji in case the islands are submerged, but the locals are reluctant to leave as their traditions are reliant on the islands
• 50,000 trees have been planted in mangroves in Kiribati to reduce the impacts of storm surges and to prevent soil erosion
• Frequent flooding in Kiribati leads to soil infertility, which has increased the amount of unhealthy and imported food, leading to high rates of obesity and diabetes
• Locals in Kiribati have been teaching others traditional recipes using crops found on the islands
• There is a marine training centre in Kiribati where citizens can become sailors, and they can go on to work for the 6 German shipping companies who have offices on Kiribati and earn up to $700 per week
• School is compulsory in Kiribati from ages 6 to 14, where climate change is taught about
• Fishermen in Kiribati have abandoned traditional techniques and have now resorted to using neon lights to attract fish
• Marine biologists check the health of coral reefs more regularly in Kiribati due to the high levels of contamination due to waste from imported goods
• Mount Mayon 2018: Context

  • Most active volcano in the Philippines
  • Composite volcano
  • 250 km^2 area
  • Near the city of Legaspi
  • Monitored by the government agency PHIVOLCS
  • A result of the subduction of the Philippine Sea Plate under the Sunda Plate
• Mount Mayon 2018: Risk and Vulnerability

  • Ash settling can lead to building collapse
  • Lahars due to ash in gullies destroy farms in the short term but improve soil fertility in the long term
  • Nuees ardentes can flow down the gullies
  • Lava flows can destroy farming
  • 40 ravines surrounding the volcano prone to lava flows which make people vulnerable
• Mount Mayon 2018: Eruption pt1

  • Biggest eruption this century of Mayon
  • 13th January - phreatic eruption, ash launched 2.5 km into the air, ash fell in towns and there was a sulfur smell, the alert level was raised to a 2 and 40,000 people were evacuated from a 6 km radius
  • 14th January - 3 phreatic eruptions, 158 rockfalls, lava dome formed at the summit, alert level raised to a 3
  • 16th January - the lava reached the 6 km evacuation radius, the province of Albay declares a state of emergency
• Mount Mayon 2018: Eruption pt2

  • 22nd January - 3 km high ash column, hazards of lava fountains, pyroclastic flows, ash plumes, lava bombs and rock falls, alert level raised to a 4
  • 23rd January - 500 m high lava fountain, other hazards of ash plumes, rock falls and lava bombs, as a result schools were shut, the evacuation radius was expanded to 9 km with 74,000 more people evacuated, rain was forecast so there was potential for lahars, rock falls and land slides
  • February - eruption calms so schools reopen
  • March - eruption calms further so alert level falls to a 2
• Mount Mayon 2018: Impacts

  • 0 deaths due a good response
  • 86,000 affected with 65,000 people in 58 evacuation centres
  • $3.4 million in damage to farms
  • Roads were blocked and flights from Legaspi were suspended
• Mount Mayon 2018: Local and National Responses

  • The government set up a $1 million cash for work scheme
  • The government gives hygiene supplies to 50,000 families for 10 days after the eruption
  • The army was called in to prevent looting and help with the evacuation
  • The Red Cross was set in to help with first aid
  • The National Church helped 3400 families
• Mount Mayon 2018: International Responses

  • The US, UK and Canada recommended to their citizens not to visit Mayon
  • The US government supplied $100,000 in aid through USAID for hygiene supplies
• Tohoku: Spatial and Temporal Setting

  • 9.0 magnitude earthquake
  • Epicentre was 130 km east of the city of Sendai
  • A tsunami hit the coast
  • The earthquake lasted for 6 minutes
  • The earthquake was the fifth largest recorded since 1900
  • The earthquake had 10,000 times more energy than the Christchurch, New Zealand 17 days before
• Tohoku: Impacts

  • The people were prepared for the earthquake but not the tsunami
  • The tsunami hit 50 countries going as far as South America
  • Tokyo was damaged but most of the damage was felt in the North
  • The tsunami was 1 to 7 m high but it was 10 m high in Sendai
  • A 7.1 magnitude aftershock led to more building damage
  • 4 million homes were left without power
  • Japan's mountainous nature led to landslides and flooding as the earth works failed
  • Coastal areas suffered liquefaction which further impacted coastal areas alongside the tsunami
• Tohoku: Fukushima Nuclear Disaster

  • Most severe nuclear disaster since Chernobyl in 1986
  • Upon the earthquake the reactor automatically shut down but a 14 m high tsunami wave flooded the plant causing 3 nuclear meltdowns
  • Water in the Pacific Ocean was contaminated
  • The disaster caused no increase in birth problems
  • 80,000 people were evacuated from a 12 mile radius
  • Caesium 137, which has a half life of 30 years, contaminated the beef food chain
  • The government downplayed the impacts of the disaster to avoid limitations on nuclear power plants which led to public anger
• Tohoku: Short Term Local Responses

  • The tsunami warning was under 20 minutes which was not long enough
  • 340,000 people were displaced
  • The army led the response
  • The Japanese Red Cross received $1 billion in donations, the UK government sent search and rescue teams
  • 452,000 people were in evacuation shelters where the risk of pneumonia was high
  • 20,000 people died and 3000 people were left unaccounted for
• Tohoku: Long term local responses

  • There was a lack of disorder after the events due to the Japanese gaman mindset
  • 54 nuclear power plants were closed which led to 30% of Japan's energy capacity lost, resulting in fossil fuels imports from countries like Qatar
  • A better prediction model was created using gravity waves as they travel faster than seismic waves
  • The Japan Trench Fast Drilling Project was an expedition which aimed to investigate the properties and mechanisms of the fault which caused the earthquake by drilling 2 boreholes
• Tohoku: International Nuclear Responses

  • Germany passed legislation to close all nuclear power plants by 2022
  • Italy held a national referendum where 94% of people voted against nuclear power plants
  • China increased its number of nuclear power plants, aiming to have a capacity of 500 GW by 2050
• Hurricane Michael 2018: Context, Risk and Vulnerability

  • Strongest storm to make landfall in the US since Hurricane Andrew in 1992
  • Formed in the North Caribbean where it hit Cuba and Mexico
  • It was a Category 2 storm on 9th October but became a Category 5 storm on 10th October
  • It made landfall on Mexico Beach, Florida and it hit Florida, Georgia, North and South Carolina
  • Some areas of North and South Carolina were still recovering from the impacts from Hurricane Florence