Physcial geo case study

• Coasts: Mappleton
• Mappleton protection


  • Hard engineering
  • Positive
• Mappleton protection started


  1. 1991

  2. £3.5 million

  3. 400m of coastline
• North of the town was eroding quickly
• Mappleton defences


  • 2 granite groynes to prevent longshore drift
  • Rock armour to protect the clay cliffs
  • Landscaping to prevent slumping
  • Growth of grass species to prevent slumping (may cause biological weathering)
• Dorset Coast: Old Harry Rock
• Old Harry Rock


  • Stack and stump
  • Made from chalk, soft rock, don't erode away
  • Uses the 'do nothing' approach, used for tourism
• How Old Harry Rock is formed

  1. Starts with a crack in the cliff face, processes such as freeze-thaw and hydraulic action

  2. Turns into a cave, cave will get bigger and erode from both sides

  3. Arch is formed, gravity will cause the headland above (suspended) to collapse to form a stack

  4. Stack will collapse forming a stump
• Sundarbans, Bangladesh
• Sundarbans


  • Only 1m above sea level, leads to having a lot of fishing communities, relies heavily on fishing as an income
  • Very fragile environment, due to high tides/sea level rise, tropical storms, storm surges and flooding (60% of land)
  • Decomposition happens a lot which helps resist erosion, sand dunes can be seen
• Sundarbans natural damages


  • Coastal flooding
  • Cyclones
  • High level of salinity
  • Instability and remoteness, loss of species
• Sundarbans human damages


  • Over exploitation of resources
  • Conflict
  • Fishing techniques that destroy river/seabeds
  • Lack of awareness, humans eating tigers
• Uses of the Sundarbans mangrove

  • Goods: fuel, materials, food and drink, textiles, other
  • Services: protection, provision, value, maintenance
• Mitigation and resilience in the Sundarbans
• Amazon (both water and carbon)
• Amazon carbon


  • It's a carbon sink (one of the largest land ones), 1-3 gigatonnes per year, above ground 0.3-0.5% per year
  • 2015 the uptake of carbon was outweighed by carbon released by fossil fuels, 2010 was 10.8%
  • Due to change in climate and carbon input resulted in die young, grow quick, has spread across the Amazon
  • 1990s 2 billion tonnes of carbon to now 1 billion tonnes
• Effects of slash and burn in the Amazon

  1. Removes/reduces absorbency of humidity in soil up to 1m

  2. Facilitates sudden evaporation of water in forest canopy

  3. Increase in temperature and the albedo effect/reflection

  4. Reduces porosity of soil, more erosion
• Amazon water


  • 175,000 curies discharged per day (Negro River), 15% of all fresh water enters ocean
  • For the Rio Negro, 48% evaporated, 30% rain reaches ocean
  • Annual rainfall across whole basin is 2,300mm, in North West can be 6,000mm, half never reaches floor due to the vegetation cover
• Drivers of change in the Amazon

  • 2000-2007 deforestation rate was 19,400km², larger than Greece
  • Brazil is the 4th biggest climate polluter, 75% greenhouse gas due to deforestation and land use, 59% is lost by burning (slash and burn) and deforested (reduce humidity)
  • Destroy a carbon sink = a lot of CO2 released
  • Plants release salts which increase rainfall, reduction in rainfall due to deforestation
  • Soil porosity decrease, temperature increases, forest absorbs 11% of solar radiation
• River Nar, West Norfolk
• River Nar


  • The lower course is more artificial due to flood protections, e.g. river embankments
  • Areas around the river are 75% arable farmland, local plants such as sugar beets and barley
  • Cattle graze near Castle Acres (upper course), once was watercress fields now for cattle and sheep
  • Due to cattle the river banks have been destroyed, more susceptible to flooding and erosion
  • New less intensive cattle grazing techniques used to be more sustainable
  • Large industry removes gravel from lower course to be used in concrete and aggregate, created lakes and issues
  • In the lower course there is an artificial river that drains into chalk plateau, used as fresh water catchment
• Key features of the River Nar


  • It's in a valley
  • Norfolk River Trust in 2011 started protecting the forest and marsh, main aim was the chalk stream
  • Chalk streams have high biodiversity
  • Flooding isn't common as the mean flow is 1.16 cumecs, which is low
  • Has a small flood catchment, more susceptible to intense rainfall and change in topography
  • Many companies/sponsors help the SSSI, e.g. Coca Cola since 2013 helped prevent erosion, WWF try to return it to a more natural state
  • Try to recreate low-lying riverbanks to allow for vegetation growth, increases river flow rather than steep banks
  • Coca Cola has been receiving sugar beets from locals, gives jobs and social responsibility
• River Nar human impacts

  • Fish farms in the middle and lower course, employment and tourism but overfishing disrupts ecosystems, not sustainable
  • Pig farms have increased, causing algae blooms, poor water quality and death in ecosystem
  • Water is abstracted from the land for irrigation, excessive abstraction can change the rate of the river
  • Many land uses aren't sustainable, the SSSI aim to reduce the damage
• River Nar topography and climate

  • Mainly chalk, low precipitation in the area - 600mm per year, England average 855mm per year, 255mm difference
• River Nar management plans

  1. Middle and lower courses plan is to reduce flooding and erosion of river banks, built embankments along the river especially in front of historical landmarks

  2. The historical sites have ponds and channels which have natural miles, e.g. Pentney Abbey, Castle Acre Priory and old Millents

  3. Intensive pig farming have sustainable plans, more sheds, food and fields periodically, not to damage bank, soil and ecosystems, reduces the chances of infrequent volumes of slurry in the river
• Mount Mayon, Philippines, 2018 (volcano)
• Mount Mayon


  • In Asia in the Pacific ocean, on a peninsula of the main island in Albay Bay, LIC, 2462m above sea level, on the Ring of Fire
• Vulnerability of Mount Mayon

  • Population of 200,000, centre of tourism, education, wealth, services, commerce and transport
  • Due to being an LIC, heavily relies on agriculture
• Local and national response to the Mount Mayon eruption

  1. Army was ready to help, enforce evacuation if there was civil disturbance

  2. Red Cross set up first aid stations and welfare

  3. Council of churches in the Philippines relied 3,446 families

  4. Compiled $1 million for a cash for work program, also hygiene packages for 50,000 families for 100 days, provided food packs to evacuees for 100 days
• International response to the Mount Mayon eruption

  1. USA raised people to go

  2. UK and Canada advised people not to go to the volcano

  3. USA gave $100,000 which was distributed for families for hygiene and essentials, also latrines, bathing cubicles, hand washing stations, promoted safe water and hygiene practices
• comiled $1 milion fora case for work program
• also hygiene packages for 50 000 families for todays
• provided food pack to evacutese for 100 days
• USA rise people to go
• UK + Canada advise people not to go the volcanos
• USA gave $ 100 000 which distribute for families
• for hygine and essitals
• also laturives, bathing cubicles, hand washing station, promoted safe water and hygiene practices
• Timeline


  1. 13ᵗʰ: alerted and 40 ooo residents a 6km radious evacuated, phreatic eruption-ash plume of ~ 25000m in the air over a 1h 15m

  2. 14ᵗʰ: 3 more phreatic eruption, 15 8 rockfall events, lava flows and domes

  3. 16ᵗʰ: lava flow reaches the limited 6km evacuation zone, Albay declared state of calamity

  4. 27ᵗʰ: 3km tall ash colour, lava flows and pyroclastic flow, ash plume, lava bombs with rock fall

  5. 27ᵗʰ: 300-500m lava fountains, ash plumes, lava bombs, rockfall -danger extended 9 km-evacuation closed, more warming (of lahars)

  6. Next month: curption slowly subsided

  7. Another month: further fall in volcanic activity-dropped 2 levels by endof the month
• Mount On take in Japan

  • Groundwater super heated by magma expanding in the process causes sudden and violent explosion of rock, steam and ask from the sanity the mountain
  • Burning ash billowed down the mountainside
  • Eruption killed 57 people
  • Magma didn't roll down the slopes
  • Phreatic eruptions often have fewer warning signs
  • Researchers scrutinized the tilt prediction method gave a warning of 7 minutes
  • Was preceded by opening a vertical crack of 1100m deep
  • Change in tilt likely caused the widespread crack