The Holderness Coast Case Study Flashcards
Which 4 factors suggest why coastal erosion such an issue on the Holderness coast
- geology
- fetch
- LSD
- subaerial processes
Influences on coastal erosion - geology
what are cliffs composed of
- shallow & sloping cliffs ranging between 5 & 20 metres high
- mainly consists of boulder clay made of glacial till
- which is structurally weak
- & provides little resistance to erosion
what is glacial till
- a mixture of fine clay, boulder clay & sands deposited by glaciers during the Devensian period
Influences on coastal erosion - geology
erosional features on cliffs
- the chalkband that surrounds the boulder clay creates a headland
- erosion along fault lines & bedding planes has created cliffs arches & stacks here
Influences on coastal erosion - fetch
The North sea
- The holderness is exposed to waves & winds from the North-East
- meaning it has a large fetch of 500-800 km, across the North Sea
Influences on coastal erosion - fetch
The Atlantic Ocean
- currents circulate around the Atlantic Ocean
- which has a fetch of 5000km or more,
- so currents add energy to destructive waves
Influences on coastal erosion - fetch
Sea level
-low pressure air systems –> raises sea level
Influences on coastal erosion - fetch
small seas
small almost enclosed seas generate huge waves during storms
Influences on coastal erosion - fetch
friction
- sea floor is deep so there is less friction
- meaning wave height and speed is not lowered
Influences on coastal erosion - LSD
transportation of material
- the boulder clay erodes to produce mainly clay particles
- which are transported out to sea in suspension,
- rather than accumulating onshore as beach sand
Influences on coastal erosion - LSD
narrow beaches
- beaches are narrow
- which is the result of an imbalance between the input of sand & removal of sand
- so these narrow beaches offer little friction to absorb wave energy
Influences on coastal erosion - LSD
tidal flows
- tides flow southwards,
- transporting sand by LSD
- leaving the cliffs at Holderness poorly protected against wave attack
Influences on coastal erosion - subaerial processes
chemical weathering
- chemical weathering is relatively ineffective at the Holderness coast
- except on chalk cliffs
Influences on coastal erosion - subaerial processes
mechanical weathering
- mechanical weathering involves freeze-thaw & the alternate wetting / drying of the boulder clay,
- making it crumbly in the dry period
Influences on coastal erosion - subaerial processes
mass movement
- slumping results from the alternate wetting & drying of the clays
- causing expansion & shrinkage
- leading to cracks during long dry periods
- subsequent rain enters & percolates into these cracks
- which weakens the cliffs
- causing slides down & is then removed by the sea
Where is the Holderness coast located
East coast of England, in Yorkshire
The holderness coast is the …………….. in Europe
fastest eroding coastline
The Holderness coast loses nearly ….of coastline annually
2m
Since the Roman times, the Holderness coasts has retreated by…..
4km
What are the key players objectives on the Holderness coast
Government
-the environmental agency is responsible for large scale coastal management alongside the local govt who manage the allocation of coastal defences in different coastal divisions
The govt budget for coastal management on the Holderness has been …. since 2010
cut
What are the key players objectives on the Holderness coast
Stakeholders in the local economy - tourism
-tourist industry has requested greater spending on coastal protection
What are the key players objectives on the Holderness coast
Stakeholders in the local economy - farmers
-farmers want money to protect their farmland
What are the key players objectives on the Holderness coast
Stakeholders in the local economy - residents
-residents want guaranteed coastal protection
What are the key players objectives on the Holderness coast
Stakeholders in the local economy - insurance
-insurance industries are increasingly refusing to insure vulnerable properties
What are the key players objectives on the Holderness coast
Environmental stakeholders
- English Nature & the RSPB want to protect
- Spurn head, one of the UK’s largest coastal spits,
- so a continual flow of sand southward by LSD is essential
- an important asset of this spit is its protection of the mudflats at Humber Bay estuary
Social Impacts of coastal erosion on Holderness
….homes will disappear by 2100
7000
Social Impacts of coastal erosion on Holderness
… villages have been lost since the Roman times
30
Social Impacts of coastal erosion on Holderness
Households are forced to…
relocate their homes & livelihoods which has severe mental health implications
Economic Impacts of coastal erosion on Holderness
Impacts on tourism
- Holiday parks have lost 100 chalets to the sea in the last 15 years,
- reduction in flow of tourists,
- less expenditure in the economy,
- leading to a fall in profits
Economic Impacts of coastal erosion on Holderness
……. hectares of farmland are lost each year
8000
Economic Impacts of coastal erosion on Holderness
………. is spent adapting to coastal recession not mitigating it
£1.2 million
Environmental Impacts of coastal erosion on Holderness
- the seawall & rock armour at Hornsea interrupts LSD
- meaning towns further North such as Mappleton are starved of sediment so its cliffs are further exposed to wave attack
- this is known as terminal groyne syndrome
Responses to erosion on the Holderness coast
seawall
First seawall was constructed in 1870 & has been extended 5 times since
Responses to erosion on the Holderness coast
rock armour
- In the southern end, the defences were reconfigured in 1977 to rock armour
- which allows sediment to accumulate and pass behind it
Responses to erosion on the Holderness coast
groynes
Groynes have been implemented in Hornsea which starve mappleton of sediment
What is the East Riding Coastal Fund
Offers limited assistance for those affected by coastal recession
What are the East Riding Coastal Fund’s two initiatives
-assistant grants
-adaptation package
What is the East Riding Coastal Fund’s Assistant Grants
-funds adaptations to properties who may be at risk in the future
What is the East Riding Coastal Fund’s Adaptation Package
- it can fund:
- an individual’s decision to replace a threatened coastal property with a new home inland
- where coastal defences aren’t viable, again only providing minor funds
