Holderness Case Study Flashcards
How far does the Holderness coast span? From where to where?
50km from Flamborough Head in the north to Spurn Point in the south.
What material is the cliffs made up of?
In the north, chalk, and to the south, soft boulder clays.
What are the natural beaches like? And why?
Narrow and unable to stop wave erosion. Lack of major rivers bringing in new sediment to the budget.
What are the beaches like in the summer/winter?
In the summer, they are built up enough for recreational use.
In the winter, they are just a small layer of sand covering the clay.
What was the avg prediction for sea level rise in Holderness for the next 50 years?
30cm, so 6mm/year.
What has been the previous sea level rise rate in the Holderness coast for the past 100 years?
1-2mm/year.
Why is the Holderness coasts sea level rising at a faster pace than previously?
Climate change and a north-easterly prevailing wind.
What do the beaches consist of on the Holderness coast?
Shingle and sand from the clay till.
How was Spurn Point formed?
Longshore drift transported material south, forming the spit at the mouth of the Humber estuary.
How many people did the 2001 and 2011 census’ indicate that Mappleton had?
2001: 249
2011:342
Where is Mappleton?
3 miles south of Hornsea, located on the B1242 road, which connects towns along the coastline.
What is the importance of the B1242 road?
Provides economic benefits to the locals, as it connects the towns with larger settlements such as Hornsea and Withernsea. It is used by holiday makers in the area and by local farmers for access to rich agricultural land.
In what year were sea defences built to save Mappleton from losing 30 homes and the B1242?
1991.
What was the rate of erosion at Holderness
before the sea defences were put in?
7-10 m per year on the boulder clay cliffs.
How much did the project cost?
£2 million.
What sea defences were put in?
Two rock groynes.
A revetment of large granite boulders.
Cliff stabilisation.
How did the rock groynes contribute to slowing erosion?
They trap materials carried by waves in lsd.
How did the revetment contribute to slowing erosion?
Placed like a wall in a 450m line of defence. Absorbs, doesn’t reflect wave energy using large air spaces between boulders and a broad surface area.
Where were the revetment boulders imported from?
Scandinavia and deposited by barge.
How did cliff stabilisation contribute to slowing erosion?
Vegetation planted on cliffs further stabilises them from mass movement and reduces the cliffs gradient to prevent undercutting.
What was the impact of cliff stabilisation on the erosion along the coast?
It has had a positive impact, managing mass movement as there has been no evidence of slumping over the past 25 years.
What was the impact of rock groynes on the erosion along the coast?
Lsd no longer operates along that section of the coast.
It has created a larger, sandier beach for Mappleton, meaning at high tide, waves don’t even reach the cliffs.
What was the impact of the revetment on erosion along the coast?
Successful in restricting waves from attacking the base of the cliffs.
What was the beneficial result of the scheme?
No properties have been lost to the sea and the B1242 remains safe.
