Holderness Flashcards
How long is the Holderness coast?
61km
Where is the Holderness coastline found?
From Flamborough Head to Spurn Head
What are most of the cliffs made from at Holderness?
Till (boulder clay)
What is the coastline often exposed to?
Powerful, destructive waves
What are the four coastal processes operating in the area?
Erosion, mass movement, transportation and deposition
What is the rate of erosion at Great Cowden?
Over 10m/year in recent years
Why are the cliffs prone to mass movement?
Water makes the clay heavier and acts as a lubricant between particles, which makes it unstable.
What does the ocean current created by winds create?
Transportation of movement south by longshore drift
Where is most material deposited?
Humber River
How have headlands and wave-cut platforms formed?
To the north of the area, the boulder clay overlies chalk. The chalk is harder and less easily eroded, so it has formed a headland (Flamborough Head) and wave-cut platforms, such as those near Sewerby.
Why are the cliffs tiered in some locations?
Slumps have occurred and have not yet been eroded.
How has a pebble and sand beach formed south of Flamborough Head?
The area is sheltered from wind and waves.
How and where have sand dunes formed?
Around Spurn Head, material transported by the wind is deposited.
Which processes have allowed has the spit (Spurn Head) to form at the mouth of the Humber Estuary?
Erosion and longshore drift
What has formed on the landward side of the spit (Spurn Head)?
Mudflats and saltmarshes
How far has the Holderness coastline retreated over the past 2000 years?
4km
How many villages have been lost to the sea?
30
Why is there the potential for the loss of settlements and livelihoods?
The village of Skipsea is at risk and 80 000 metres squared of good quality farmland is lost each year on the Holderness coast, affecting farmers’ livelihoods.
Why is there the potential for the loss of infrastructure?
The gas terminal at Easington is only 25m from the cliff edge.
How much of the coastline is protected by hardengineering strategies?
11.4km of 61km
How is Bridlington protected?
4.7km long sea wall and timber groynes
How is Hornsea protected?
Concrete sea wall, timber groynes and riprap
How is Mappleton protected?
Two rock groynes and 500m long revetment (built in 1991, cost £2 million)
How is Withernsea protected?
Groynes, sea wall and riprap (which was placed in front of the wall in 1992 following severe storms)
How is the Easington Gas Terminal protected?
By a revetment
How is the eastern side of Spurn Head protected?
By groynes and riprap
What is the advantage of groynes?
They trap sediment, increasing the width of the beach and protecting the local area from erosion.
What is the disadvantage of groynes?
Increases the erosion of the cliffs down-drift as the material eroded from the beaches there isn’t replenished.
What is the effect of trapped sediment on the Humber Estuary?
Sediment cannot reach the Humber Estuary and therefore the risk of flooding increases.
How does bay formation cause the cost of maintaining defences on headlands to become too high?
The pressure on the headlands increases.
What does the SMP for Holderness recommend for the next 50 years?
Hold the line (at Mappleton, Hornsea and Easington Gas Terminal, for example) and do nothing at less-populated stretches.
Why is managed retreat a more sustainable option?
It would allow the coast to erode as normal without endangering businesses (although relocation and compensation isn’t always possible)
What did Holderness Borough Council do in 1995 at Spurn Head?
Do nothing became the new strategy
What are the advantages of doing nothing at Spurn Head?
- saves money
- allows the spit to function naturally
What are the disadvantages of doing nothing at Spurn Head?
- over-washing may damage marsh environment
- coastguard station may be at risk
What does the SMP recommend in regard to the revetment protecting Easington Gas Terminal?
Maintain the defences for as long as the gas terminal is operating.
What are the disadvantages of maintaining the revetment defending Easington Gas Terminal?
- defences only span 1km so the village of Easington isn’t protected
- increased erosion rate at Sites of Special Scientific Interest (SSSIs) to the south
