Coasts

• What case study can be used for coastal management/ coastal erosion?


  Holderness Coastline
• What physical factors led to erosion at Holderness?

  - LONGSHORE DRIFT takes beach material southwards

  - TIDAL RANGE at Holderness is very high (up to 7m)

  - Two main rock types (GEOLOGY) are chalk + boulder clay -> both very easily erodable
• What human factors have led to erosion at Holderness?

  -PRESENCE OF PEOPLE - increasing population levels due to retirement + development of leisure + holiday parks

  - INTERFERING WITH NATURAL PROCESSES -downdrift impact of groynes at Hornsea means sediment is prevented from building beaches near Holderness -> sediment starvation may be a cause of such extreme erosion rates
• Social and economic impacts of erosion at Holderness?

  SOCIAL

  - property prices have fallen sharply

  - 30 villages have been lost since Roman times

  - People have lost their homes to erosion + farmland

  
  

  ECONOMIC

  - 80 000m2 of good quality farmland is lost each year -> impact of farmer's livelihood

  - vistor number have dramatically dropped -> tourism was a main source of income
• Who are the key players in managing the Holderness coastline?

  - Tourist industry wants more spending on coastal protection

  - Farmers want more protection for farmland

  - Residents want guarantee coastal protection for their homes + businesses

  - Insurance companies are increasingly refusing to insure vulnerable properties

  - RSPB want protection of Spurn Head - continuous longshore drift is needed
• What case study would you use for HUMAN ACTION ON EROSION?

  ASWAN DAM
• What is the Aswan damn?


  - an embankment dam built across the Nile

  - constructed to hold back water so it could be used to generate energy
• Benefits of Aswan dam?

  - controls annual flood water

  - provides 1/2 of Eygpts electricty

  - increases agricultural proudictivity -> irrigation

  - employment opportunities
• Negatives of the Aswan dam?

  - cost $1 billion to construct

  - flooded archelogical sites

  - changes to fishing patterns/ industry

  - nutrients are trapped in the dam -> less fertile soil

  - sediment is trapped in the dam -> coastline is eroding rapidly in the Med due to sediment starvation (Delta)
• What case study do you know about coastal flooding in the UK?

  STORM SURGE 2013

  CAUSES

  - intense low pressure system + spell of extreme weather alongside high seasonal tides

  IMPACTS

  - 2 deaths

  - 1400 homes flooded

  - £100 million in damages

  - sea wall destroyed

  - rail services majorly disrupted

  RESPONSES

  - hard engineering schemes

  - railway was rebuilt in 52 days

  
  

  Major impacts avoided as

  - thames barrier was raised to defend London + proetect from flooding
• What case study for coastal flooding internationally?

  Bangladesh flooding
• Backgorund information about Bangladesh?

  - world's most populated city

  - 169 million people

  - 46% of economy live less than 10m above sea level
• Human factors increasing flooding in Bangladesh?

  - REMOVAL OF VEGETATION - conversion of mangroves to shrimp farms led to 25% mangrove

  - BUILDING ON FLOODPLAINS - 46% of population live less than 10m above sea level

  DENSE POPULATION - high impacts if flooding occurs
• Physical factors increasing flooding in Bangladesh?

  HEIGHT ABOVE SEA LEVEL- country is already very low lying at at risk

  - FLOODPLAINS - lies on the floodplain for 3 major rivers

  - Isostatic adjustments

  - Every year the country struggles with flooding as snow melt adds to moonsoon rain fall and high tides in the Bay of Bengal
• Impacts of coastal flooding in Bangladesh?

  CYCLONE SIDR

  - cat 4 storm -> 6m storm surge

  - river embankments on one side of a village held firm against flood waters however the one on the otherside did not, as it had been lowered by authorities, allowing the storm surge to ruin the village

  - loss of life

  - damage to crops

  total cost of damage was $1.7bn
• What case study for sea level change?

  KIRIBATI
• How is Kiribati combating eustatic sea level change?

  KIRIBATI consists of 33 islands in the Pacific ocean all of which are very low lying

  - predicted that many of its islands will disapear in 50 years (sea levels are rising by 1.2cm a year)

  
  

  SHORT TERM IMPACTS

  - saltwater encroachment has contaminated freshwater supplies

  -crops are contaminated with sea water

  
  

  RESPONSE

  - President purchased land in Fiji so inhabitants now have a refuge somewhere else

  - land is also being used for agriculture + farm fishing projects to ensure the nations food security
• What impacts has coastal recession in the Phillipines had?

  SOCIAL

  - up to 2.3 million people affected

  - high unemployment due to loss of fishing industry

  - San Fernado expected to loss 300 buildings, schools

  
  

  ECONOMIC

  - losses of $6.5 billion a year

  - high levels of poverty makes country economically vulnerable

  
  

  ENVIRONMENTAL

  - Mangroves + coral reefs have been damaged by pollution and exploitation
• What impacts has coastal recession had in Australia?

  SOCIAL

  - Up to 250,000 homes at risk

  - tourism industry affected as major tourist hubs focus on coastline

  - people may have to relocate

  
  

  ECONOMIC

  - industrial, commercial, transport + housing infrastructure will be affected

  - In Queensland, a 0.2m rise will cause $1.4 billion in damages

  - $226 billion of infrastructure + homes at risk

  
  

  ENVIRONMENTAL

  - groundwater may be contaminated

  - 50% of coastline at risk

  - coral reef, mangrove forests + salt marshes at risk
• What is an example of sustainable coastal managment?

  ESSEX COASTAL REALIGNMENT

  - Essex wildlife trust bought 84 hectares of farmland + converted into saltmarshes + grassland

  -> old embankment will be breached

  - soil quality was low

  
  

  WINNERS

  - additional mudflats will absorb high tides + storm surges

  -> reduces water travelling up estuary

  
  

  LOSERS

  - RSPB concerned about impact on bird habitats with increased erosion

  - local fishermen concenered that sediment may kill or choke oysters
• Winners + losers -> HAPPISBURGH

  HAPPISBURGH

  - has a population of 1,400

  - on Norfolk coastline

  
  

  predicted that by 2100 coastline will receed by 200m

  - government annoced in 1996 - managed retreat in place

  - in 2004 this was moved to 'no active intervention'

  
  

  Happisburgh doesn't meet coast-benefit critea to build more sea defences due to high erosion rates (2m a year)

  
  

  WINNERS:

  - local government -> money can be spent elsewhere

  - local caravan parks -> have been given compensation + protection against erosion as they have economic value to government

  
  

  LOSERS

  - Tourists -> the destination may soon be destroyed

  - residents -> many aren't able to insure their homes + little compensation from government

  - environmental agency
• Winners + losers -> CHITTAGONG


  CHITTAGONG

  - located on south-east coast of Bangladesh

  
  

  Project

  - Coastal climate resiliant infrastructure project

  -> raising embankments by 60cm

  -> raising market areas above sea level

  
  

  WINNERS

  - improved road connections

  - more resistance to erosion

  Farmers -> infrastructure/materials improved

  LOSERS

  - 200 people displaced for new roads

  - ecosystem -> vegetation removed

  - high cost