Coastal Environment - Case Study Flashcards
How long is the Holderness coast
61km
It stretches from Flamborough Head to Spurn Head
What are the coastal processes acting at Holderness coast
Most of cliffs made of till, and the coast is exposed to powerful destructive waves from the North Sea during storms
Erosion - soft boulder clay (till) is easily eroded by wave action. In some places, rate of erosion has been over 10m/year in recent years.
Mass movement - boulder clay prone to slumping when wet. Water makes the clay heavier and acts as a lubricant between particles, which makes it unstable.
Transportation- longshore drift, transport material southwards.
Deposition - where the ocean current meets the outflow of the Humber River, the flow becomes turbulent and sediment is deposited.
Tell be about the general landscape at Holderness coast
In the north are steep chalk cliffs, wave cut platforms and sandy beaches. Further south there are less steep boulder clay cliffs, and around spurn head there are depositional features.
Tell me about headland and wave cut platforms in Holderness coast
To the north of the area, the boulder clay overlies the chalk. The chalk is less easily eroded, so it has formed a headland flamborough head, and wave cut platforms such as those near Sewerby. Flamborough head has features such as stacks, caves and arches.
Tell me about beaches in Holderness coast
The area to the south of Flamborough is sheltered from wind and waves, and wide sand and pebble beach has formed near Bridlington
Tell me about the slumping cliffs in Holderness coasts
Frequent slumps give the boulder clay cliffs a distinctive shape. In some locations several slumps have occurred and not yet been eroded, making the cliff tiered.
Tell be about the spit in Holderness coast
Erosion and longshore drift have created a spit with a recurved end across the mouth of the Humber Estuary - this is called Spurn Head. To the landward side of the spit, estuarine mudflats and saltmarshes have formed.
Why does the Holderness coastline need to be managed
The coastline has retreated by around 4km over the past 2000 years. Around 30 villages have lost.
Ongoing erosion could lead to
Loss of settlements and livelihoods, eg village of Skipsea is at risk and 80000m^2 of good quality farmland is lost each year.
Loss of infrastructure- the gas terminal at Easington is only 25 m from the cliff edge.
Loss of sites of special scientific interest (SSSIs) eg lagoons near easington provide habitats for birds.
Tell me about the hard engineering strategies along the Holderness coastline
A total of 11.4km of the 61km coastline is currently protected by hard engineering
Bridlington is protected by a 4.7km long sea wall as well as timber groynes
There’s a concrete sea wall, timber groynes and riprap at Hornsea that protect the village
Two rock groynes and a 500m long revetment were built at Mapleton in 1991. They cost £2 million and were built to protect the village and the coastal road nearby.
Easington gas terminal is protected by a revetment.
The eastern side of Spurn Head is protected by groynes and riprap.
Why are the existing hard engineering schemes not sustainable
Groynes trap sediment, increasing width of beaches, protects local area but increases erosion of the cliffs downdrift. Eg Mappleton groynes has increased erosion downdrift, cowden farm just south of mappleton is now at risk of falling into the sea.
The protection of local areas is leading to the formation of bays between those areas. As bays develop the wave pressure on headlands will increase and eventually the cost of maintaining the sea defences become too high.
What does the SMP for Holderness suggest
For the next 50 years it recommends, holding the line at some settlements and doing nothing along less populated stretches. However, this is unpopular with owners of land or property along the stretches where nothing is being done.
What is the Holderness coast
East Yorkshire
How has managed realignment been suggested
Eg. Relocating caravan parks further inland and allowing the land they are on to erode. This would be a more sustainable scheme as it would allow the coast to erode as normal without endangering businesses. However, there are issues surrounding how much compensation businesses will get for relocating. Also, relocation isn’t always possible, eg may be no land for sale to relocate buildings to.
