Holderness Coast Case Study Flashcards
Where is it located?
East coast of England, part of the East Riding of Yorkshire; a lowland agricultural region between the Chalk Hills and the North Sea
What is the average annual rate of erosion?
Two metres - some areas as high as 10.
What is the main reason for this coastal erosion?
Geological - the bedrock is made up of till which was deposited by glaciers over 12,000 years ago and is unconsolidated. Made up of clay and loose rocks, and this boulder sits on a layer of seaward sloping chalk.
What type of waves are present?
Destructive waves. The sea near the coast has a long fetch which is under the influence of north-easterly winds which creates large waves with a strong backwash.
Is sediment being removed faster than it can be replaced?
Double the amount of sediment is being removed by the backwash than transported along the beach through longshore drift, so beach material is not being built up.
What coastal defences are present at Mappleton?
The base of the cliff is protected with rock armour, and there are rocky groynes. This is done to protect Mappleton village and the important B road, but the north-east direction is being starved of sediment. The groynes and revetment cost £2 million to build (1991).
The tourist towns of Hornsea, Withernsea, and Bridlington experience outflanking. What is this?
Towns’ defences will create differentiated rates of erosion. Sections of coast directly north and south will erode faster. Over time the towns will project seawards like a headland. This in turn will create the need for further coastal defence on the sides
due to the process of wave refraction concentrating wave energy on the sides.
The village - Skipsea - experiences the highest rates of erosion in Europe. Why?
A combination of stormy weather, destructive waves, and rising sea levels caused more than 10m of cliff to disappear along a 2m stretch in just 9 months in 2020. They also do not have any coastal defences as more important areas are being protected (only have a certain amount they can pay towards defences - would rather protect industrial/agricultural/tourist areas.
Does this coastline experience any mass movement?
Boulder clay prone to slumping when wet. Makes it very unstable.
Loss of infrastructure at Easington.
Gas terminal only 25m from the cliffs edge - very vulnerable - protected by a revetment.
Sites of Special Scientific Interest - lagoons near Easington provide habitats for birds.
The Humber Estuary is nearby. Do the coastal defences affect it? Why/why not?
They do. Erosion of the Holderness Coast produces sediment that is usually washed into the Humber Estuary (forms tidal mudflats). Reduction of this sediment increases the flooding, and increases erosion along Lincolnshire’s coast.
What does the Shoreline Management Plan suggest for Holderness Coast?
‘Holding the Line’ in some areas - like Easington and Mappleton - and ‘Doing Nothing’ at less populated areas. People living at the DN or own areas located there are unhappy.
If land owners are forced to relocate, they may not be able to do so as not enough land is for sale for them to move to.
The revetments at the gas terminal are under HTL, but this is leaving Easington exposed and unprotected. The defences are also leaving the SSSIs to increased erosion south.
