Holderness coastline

Question 1

What is the geology like at the Holderness coastline?

Answer 1

has a HUGE impact on the coastline

• boulder clay deposited during the last glacial period - leads to extensive erosion and sediment transfer
• chalk containing vertical cracks and horizontal beds. Joints and faults are weaknesses which have been exploited by weathering and erosion eg. Selwick’s bay
• Rainwater enters clay causing mass movement eg. saturated clay slumps onto beaches, material slides seawards

Question 2

What is erosion like at the Holderness coastline?

Answer 2

One of the fastest eroding coastlines in Europe

• erosion rates in excess of 1m/year and up to 10m/year in places
• threat to the coastline - generates huge amounts of sediment which feed the sediment cell - builds up beaches and reduces erosion
• headland with steep cliffs (Flamborough head) - leads to wave refraction and erosion
• Bridlington bay has retreated 5km since Roman times

Question 3

What is Spurn Head?

Answer 3

• a spit which formed 8000 years ago in the south of the coastline
• a temporary sediment store formed by LSD - curved tip due to changes in wind direction
• nourished by sediment transfer and plays an important role in protecting towns and land bordering the river Humber from storm waves and flooding
• near the estuary mouth

Question 4

What are the waves like at the Holderness coastline?

Answer 4

• North East prevailing wind is the direction of the greatest fetch
• Atlantic fetch is over 5000km and the currents add energy to the waves in the North Sea, therefore waves are often powerful and destructive leading to extensive erosion

Question 5

What is the effect of rip currents along the Holderness coastline?

Answer 5

• excavate rods and deep hollows, which leads to catastrophic rates of cliff erosion.
• eg. Great Cowden and Easington - cliffs retreat locally at rates of 10m+/year

Question 6

What are the problems at Humber estuary?

Answer 6

• flooding
• predicted sea level rise threatens 500,000 people living less than 2m above the current sea level
• decreasing supplies of sediment from the Holderness cell are reducing the formation of new land

Question 7

What hard-engineering strategies are used at the Holderness coastline?

Answer 7

• wooden groynes at Hornsea - trap sediment carried by LSD, lead to Mappleton being starved of sediment, waves eroded cliffs so much that in the early 1990’s, nearly 4m/year was lost
• rock groynes at Mappleton - cost £2 million, caused Cowden to be starved of sediment leading to 3.7m/year erosion. Farms and 100 chalets at the holiday park destroyed
• revetments at Easington - built to protect Easington’s gas terminal. Large granite boulders which absorb wave energy
• 4.7km sea wall at Bridlington

Question 8

What soft-engineering strategies are used at the Holderness coastline?

Answer 8

dredging and pumping of sediment from offshore onto beach at Hornsea (beach nourishment) - creates a wider beach, replenished every 1-2 years due to strong storm surges

Question 9

What does the SMP at Holderness aim to achieve?

Answer 9

• allowing natural processes to continue from Flamborough head to Sewerby due to slow rates of erosion and no major properties at risk - may be negative impacts
• holding coastline from Sewerby to Kilnsea coast - hard-engineering strategies aim to protect the coastline from flooding. May be adverse effects at Mappleton. Approx 160 hectares will be lost by 2025
• limited intervention at Spurn Head - allowing to evolve naturally due to uncertainty around climate change. Potential for damage to historical attributes eg. Spurn head lighthouse

Question 10

What are the effects of storm surges on the Holderness coastline?

Answer 10

• low pressure weather from North Sea leads to powerful storm surges with destructive waves eg. 500+ killed by a storm surge in 1953