Coasts Flashcards
1
Q
Why is there an increase in coastal flooding in the Maldives?
(COASTAL FLOODING - DEVELOPING)
A
- The removal of Mangroves means there is a lack of roots in the soil.
- Several factors, such as waste disposal and logging have caused the soil to lack roots.
- The disturbance and removal of the mangroves is leading to an increased wave energy and height because the trees would normally act as a barrier to dissipate the waves energy before it reaches the land
2
Q
What is an example of a concordant coastline?
A
- Isle of Purbeck (Southern Coast) Dorset
- Lulworth cove formed by sea gradually eroding resistant Purbeck limestone at entrance of cove.
It then rapidly erodes the less resistant clays left behind, forming the cove/bay. - Kimmeridge bay formed of less resistant clays that have been eroded forming the cliffs.
3
Q
How is the Holderness coastline holistically managed?
COASTAL MANAGEMENT
A
- East riding of Yorkshire council has developed ICZM of a shoreline management plan incorporate different players to protect the coast
- Assess the potential erosion, flooding risk, sustainable coastal defence strategies and the needs of human/ natural environment
- 4 main players: national government agencies, local government, stakeholders in economy and environmental stakeholders.
- Uses a CBA and EIA to measure which areas need more protecting
4
Q
Who are the winners and losers of the holistic management plane of the Holderness coastline?
(COASTAL MANAGEMENT)
A
- Main winners:
- Hornsea + Withernsea more protected due to economic tourism
- Gas terminals and Easington are protected.
Main losers:
- Areas like Mapleton have little economic benefit so they aren’t protected as much
- Residents and landowners in areas around Flamborough where there is no active intervention.
5
Q
Where is Mapleton located?
COASTAL MANAGEMENT
A
- On the Holderness coast with a coastline consisting of boulder clay – susceptible to erosion
- High tidal range with rapid sea level rise expected
- Population of 350
- Located on main road connecting it to Hornsea and is used heavily by tourists/farmers
6
Q
How is Mapleton managed?
COASTAL MANAGEMENT
A
- During 1990 many hard engineering strategies were put in place
- £2m rock groynes have created large, sandy beaches so waves don’t reach cliffs reducing erosion
- Rock armour and vegetation has been effective and no evidence of mass movement from cliff stabilisation
- Large revetment has been built along shoreline
- No further properties have been lost and main road protected
7
Q
What are problems with the management of Mapleton?
COASTAL MANAGEMENT
A
- Area south of Mapleton now suffers greater erosion due to the groynes
- Groynes have starved beaches further down shore of sediment
- Cliffs are now exposed to erosion and slumping
- Many farms now been completely lost as well as farmland
8
Q
Human causes of coastal flooding in Bangladesh
COASTAL FLOODING MANAGEMENT
A
- 46% of population live less than 10m above sea level
- One of the world’s most populated countries
- Large amounts of sediment dumped in rivers
- Subsidence – some islands sunk by 1.5m due to deforestation and clearance of islands for crops.
- Coastal embankments are there to protect from tidal storms but also prevents natural sediment deposition
- 75% mangrove forests are retreating
9
Q
Physical causes of coastal flooding in Bangladesh
COASTAL FLOODING MANAGEMENT
A
- Located on floodplain where three large rivers converge
- Monsoonal rains and high tides common around Bay of Bengal
- Snowmelt from Himalayas adds to high tides
- Strong winds and storms are very common
10
Q
Coastal management in Bangladesh
COASTAL FLOODING MANAGEMENT
A
- Concrete embankments have stopped water flowing in to fields. However, they constrict and funnel tidal flows
- Mangrove forests to add cover and helps soak up flood water
11
Q
What are three examples of hard engineering used on the Holderness coastline and their impacts?
A
- Hornsea – sea walls, groynes + rock armour
impact : groynes starve beach further down the coastline - Mapleton – 2 rock groynes (1991) + rock armour
impact : cowden south of mapleton has increased erosion - Withernsea – curved sea wall (1990s) (cost £6m)
impact : waves noisier, views from hotels restricted and tourists find it unattractive
12
Q
What is an example of a discordant coastline?
A
- Isle of Purbeck (Eastern coast) Dorset
- Beds consist of unconsolidated clays/soils so are less resistant to erosion so a large bay has formed – Studland Bay
- Chalk at the Foreland is resistant so has formed cliffs and a headland – Old Harry
- Wealden beds are made from unconsolidated clays which formed Swanage Bay
- Purbeck + Portland beds consist mainly of limestone so they’re more resistant + so has created the headlands of Peveril Point and Durlston head
13
Q
What were the physical causes of Cyclone Sidr in Bangladesh?
A
- Tropical cyclone/ depression
- Strong winds of over 200km/hr
- Surge up to 6m in height
14
Q
What were the impacts of Cyclone Sidr in Bangladesh?
A
- 3363 deaths + over 55,000 injured
- Over 1.5 million homes damaged
- Breached coastal embankments causing heavy flooding + damaged sanitation and infrastructure increasing disease risk
- Electricity and communications knocked out
- Freshwater sources contaminated
- 700km electricity lines damaged
- Total cost $1.7bn
15
Q
What are the impacts of the North Sea storm surge (UK)?
COASTAL FLOODING - DEVELOPED
A
- Very strong winds over 200km/h across Scotland
- 1400 homes flooded and forced evacuation
- Cliff erosion lead to homes falling in the sea
- 2 people killed
- £100m cost in damage
