2.4.2 The Holderness Coastline

Question 1

Fact about the holderness coastline and erosion

Answer 1

It is Europe’s fastest eroding coastline.

Question 2

What is the Holderness Coastlime?

Answer 2

It is 61km long and stretches from Flamborough Head to Spurn Head.

Question 3

Most of the cliffs are made from what type of rock?

Answer 3

Boulder clay.

Question 4

How does erosion operate on the Holderness Coastline?

Answer 4

The soft boulder clay is easily eroded by wave action.

The average rate of erosion is 1.8m per year.

In some places, e.g. Great Cowden, the rate of erosion is over 10m/year in recent years.

Question 5

How does mass movement operate on the Holderness Coastline?

Answer 5

Boulder clay is also prone to slumping when it’s wet. Water makes the clay heavier and acts as a lubricant between parties, which makes it unstable.

Question 6

How does transportation operate on the Holderness Coastline?

Answer 6

Prevailing winds from the northeast transport material southwards. These winds also create an ocean current, which transports material south by longshore drift. Rapid erosion means there is always plenty of sediment to be transported.

Question 7

How does deposition operate on the Holderness Coastline?

Answer 7

Where the ocean current meets the outflow of the Humber River, the flow becomes turbulent, and sediment is deposited.

Question 8

Coastal landscapes on the Holderness Coastline

Answer 8

• Headlands and wave-cut platforms
• Beaches
• Sand dunes
• Spit
• Slumping cliffs

Question 9

Headlands and wave-cut platforms on the Holderness Coastline

Answer 9

To the North of the Holderness, the boulder clay overlies chalk. The chalk is harder and less easily eroded, so it formed a headland (Flamborough Head) and wave-cut platforms, such as those near Sewerby, Flamborough Head has features such as stacks, caves and arches.

Question 10

Beaches on the Holderness Coastline

Answer 10

The area to the south of Flamborough Head is sheltered from wind and waves, and a wide sand and pebble beach has formed near Bridlington.

Question 11

Sand dunes on the Holderness Coastline

Answer 11

Around Spurn Head, material transported by the wind is deposited, forming sand dunes.

Question 12

Spits on the Holderness Coastline

Answer 12

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 has formed.

Question 13

Slumping cliffs on the Holderness Coastline

Answer 13

Frequent slumps give the boulder clay cliffs a distinctive shape.
In some locations, several slumps have occured and not yet been eroded, making the cliff tiered.

For example, slumps are common around Atwick Sands.

Question 14

How much has the Holderness coastline retreated by over the past 2000 years?

Answer 14

Around 4km.

Around 30 villages have been lost.

Question 15

What are some social, economic and environmental problems due to ongoing erosion in Holderness?

Answer 15

• Loss of settlements and livelihoods – e.g. the village of Skipsea is at risk and 80,000m2 of good quality farmland is lost each year on the Holderness coast, which has a huge effect on farmers’ livelihoods.
• Loss of infrastructure – the gas terminal at Easington is only 25m from the cliff edge.
• Loss of Sites of Special Scientific Interest (SSSIs) – e.g. the Lagoons near Easington provide habitats for birds.

Question 16

How much of the 61km coastline is protected by hard engineering?

Answer 16

11.4km

Question 17

Hard engineering on the Holderness Coastlines

Answer 17

• 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 Mappleton in 1991. They cost £2m and were built to protect the village and the B1242 coastal road.
• A landowner in Skipsea has used gabions to help protect his caravan park.
• They are groynes and a sea wall at Withernsea. Some riprap was also placed in front of the wall after it was damaged in severe storms in 1992.
• Easington Gas Terminal is protected by a revetment.
• The eastern side of Spurn Head is protected by groynes and riprap.

Question 18

Sustainability of existing schemes

Answer 18

[[Summarise]]

The groynes trap sediment, increasing the width of the beaches. This protects the local area but increases erosion of the cliffs down-drift (as the material eroded from the beaches there isn’t replenished). For example, the Mappleton scheme has caused increased erosion of the cliffs south of Mappleton. Cowden Farm, just south of Mappleton is not at risk of falling into the sea.

The sediment produced from the erosion of the Holderness coastline is normally washed into the Humber Estuary (where it helps to form tidal mudflats) and down the Lincolnshire coast. Reduction in this sediment increases the risk of flooding along the Humber Estuary and increases erosion along the Lincolnshire coast.
The protection of local areas is leading to the formation of bays between those areas. As bays develop the pressure on headlands will increase and eventually the cost of maintaining the sea defences may become too high.

All these problems make the existing scheme unsustainable.

Question 19

Why did the local council decide to stop trying to protect Spurn Head in 1991?

Answer 19

To save money and allow the spit to function naturally.

Question 20

How is Easington Gas Terminal protected?

Answer 20

It is currently protected by rock revetments, and the SMP recommends that these defences are maintained for as long as the gas terminal is operating.

However, the defences only span about 1 km in front of the gas terminal, meaning that the village of Easington (with a population of about 700 people) isn’t protected. The defences may also increase erosion at legally-protected Sites of Special Scientific Interest (SSSIs) to the south.

Question 21

How is managed realignment done in Holderness?

Answer 21

Managed realignment has been suggested for parts of the coastline, e.g. 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, e.g. there may be no land for sale to relocate buildings to.