Coasts case studies Flashcards
(19 cards)
Case study wave cut platform
Kimmeridge Bay, Dorset, UK
Case study cave arch stack stump
Old Harry Rocks, Swanage Bay
Durdle Door, Purbeck Isle
Case study ria
Plymouth sound
Case study fjord
Milford sound in New Zealand
Case study fjard
Gulf of Finland
Case study raised beach
North of Drumadoon on Isle of Arran is now about 5m above the current sea level
Case study fossil cliff
Sedbury Cliffs in Gloucestershire
Current rate of rise in sea level
2mm per year
Isostatic sea level change case study
2004 Indian ocean tsunami
- Coastline of Aceh dropped by 1m
- Some offshore islands raised out of sea by 2m
- Tectonic subsidence created rias
- Some coral reefs were raised up
The Nile delta case study
- Coastline experiencing retreat
- Coastal flooding will become more frequent due to climate change
- 3.3% of the delta land area will be lost
- 32.4% of the Nile delta is highly vulnerable
What did the IPCC 6th assessment report specify?
- Nearly 50% of all coastal wetlands have been lost over the last 100 years
- Current 1 in 100 year extreme sea level events are projected to occur at least annually
- Sea level will rise by about 0.55m by 2100
North Norfolk
- East Anglia is one of the UK’s most vulnerable regions to coastal erosion and sea level rise
- Boulder clay
- 2m a year retreating coastline
- Loss of homes due to retreat
- Sea levels are rising 4mm a year due to isostatic subsidence
- Salt marshes become waterlogged and so loss of habitat
- Over 30 homes lost in Happisburgh in 20 years
- Tourism threatened
- Saltwater intrusion
- Long fetch from Arctic and North Sea increases wave energy
- ‘Sacrificial zones’ are areas without protection
- 2013 North Sea storm surge flooded over 1400 homes across Norfolk, Suffolk and Lincolnshire
Bangladesh
- 70% of the land is less than 1m above sea level
- High exposure to coastal flooding
- Minor storm surges are catastrophic
- 3mm a year subsidence (land sinking)
- Extensive deforestation of mangrove forests due to agriculture as mangroves act as a natural buffer
- IPCC projects 1m rise by 2100
- Cyclone Sidr is a category 4 and had a storm surge of up to 6m
- Killed 3000 people
- Worsened by low elevation and deforestation of mangroves
Consequences of coastal flooding for Australia
- Half of coasts are vulnerable to erosion and retreat
- 80% of the coastline at risk in Victoria
- 1m rise will expose more than $162 billion of industrial, commercial, transport and housing infrastructure to coastal flooding and erosion
Consequences of coastal flooding for Philippines
- 5.8mm rise per year
- Losses of $6.5 billion a year
- High levels of poverty
- Welfare loss of $168,000 per year
Cost benefit analysis in Happisburgh
- No active intervention because defending village would impact wider coastal management plan
- Longer term managed realignment
- £160,000 available to Manor caravan park to relocate
- £2000 each to residents
- 35 houses saved by 2105
- Cost of coastal defences is £6,000,000
Coastal erosion in Suffolk and Norfolk
- Low lying
- Softer rock types
- 34 homes lost in Happisburgh
What 4 different SMP’s are there on the Holderness coast?
5,6,7,8
How is Happisburgh at risk?
- 1400 people in 600 houses
- Once some distance from the sea
- 250m lost between 1600 and 1850
