Coasts EQ4 - Coastal management Flashcards
What are the economic losses from coastal recession?
- housing
- businesses
- agricultural land
- infrastructure
What are the social losses from coastal recession?
- relocation
- loss of livelihood
- amenity value
What are the environmental losses from coastal recession?
- loss of coastal ecosystems and habitats
Why are economic losses from coastal recession often localised and small, and what is the cause when they are not?
Due to incremental nature of erosion, property at risk losing value before being destroyed, coastal defences
When losses are larger it is due to an unexpected erosion event (often mass movement related)
What was the cause of the 2013 North Sea storm surge?
Deep depression in the North Sea created a storm surge of 5.8m (recorded in Lincolnshire)
What were the social and economic costs of the 2013 North Sea Storm Surge?
SOCIAL - 15 deaths, 18000 evacuated, around 100,000 homes in Scotland lost power
ECONOMIC - cost to UK government £200 million
Why were the impacts of the 2013 North Sea storm surge not that damaging?
Due to 2800km of sea defences (UK) and forecastings and warnings saving 800,000 homes
What was the cause of the 2007 storm surge in Bangladesh?
Cyclone Sidr - 240km/h winds
Sent a 6m high storm surge to Bay of Bengal
What were the social and economic impacts of the 207 Bangladesh storm surge?
SOCIAL - 3000 deaths, drinking water contamination (salination), infrastructure destroyed
ECONOMIC - US$1.7 billion
Why were the impacts of the 2007 storm surge in Bangladesh so bad, and what will it be like in the future?
The surge breached coastal and river enbankments to leave a path of physical destruction.
Estuarine island subsidence, 71% of the mangrove forested coastline has retreated by 200m/year since Cyclone Sidr
Why has climate change created environmental refugees in Tuvalu?
Only 26 square kilometres of land, highest points less than 2m above sea level.
Could become uninhabitable in the next 50-100 years - this leads to the loss of language/culture/identity in the coming years. The rising ocean has already contaminated underground water supplies
What are the social, economic and environmental losses due to recession on the Holderness Coast?
SOCIAL - 30 villages lost since Roman times, many are reliant on tourism, potential loss of livelihood
ECONOMIC - visitor numbers dropping, 80,000 m2 of farmland is lost each year, it is predicted 200 homes and roads will fall into the sea by 2100
ENVIRONMENTAL - Spurn Head losing diversity due to sediment erosion, sites of specific scientific interest being destroyed
Why is erosion a problem for the Holderness coast?
Longshore drift - material moved through sediment cell
Geology - made of unconsolidated boulder clay which is easily eroded (glacial period deposits), little resistance
Fetch - 500 to 800km fetch means more destructive waves
What is hard engineering?
Building economically costly artificial structures which deliberately alter physical processes and systems
What are the different coastal hard engineering strategies?
- groynes
- sea walls
- rip rap/rock armour
- revetments
- offshore breakwaters
What are the advantages and disadvantages of hard engineering?
ADVANTAGES - reassuring to at risk people, ‘one-off’ solution that can protect coast for decades
DISADVANTAGES - high initial and maintenance costs, can be prone to failure, visually unattractive, cause issues further down the coast e.g terminal groyne syndrome
What is rock armour and what are it’s impacts?
Boulders placed to break up and dissipate wave energy
IMPACTS: Reduce wave energy, sediment deposition between rocks
What is an offshore breakwater and what are it’s impacts?
Offshore rock armour which causes waves to break before reaching shore, reducing wave energy and erosion
IMPACTS: deposition encouraged but interferes with longshore drift
