1. The Holderness Coastline –
The Management of Coastal Erosion
Holderness is a lowland region of England
that lies between the chalk hills of the
Wolds and the North Sea. It is part of the
East Riding of Yorkshire.
The Holderness Coast is one of Europe's
fastest eroding coastlines. The average
annual rate of erosion is around 2 metres
per year. The main reason for this is
because the bedrock is made up of till. This
material was deposited by glaciers around
12,000 years ago.
Information source: The University of Hull
2. The Holderness Coast is one of Europe's fastest eroding coastlines. The
average annual rate of erosion is around 2 metres per year. This is around 2
million tonnes of material every year. Under lying the Holderness Coast is
bedrock made up of Cretaceous Chalk. However, in most place this is covered
by glacial till deposited over 18,000 years ago. It is this soft boulder clay that is
being rapidly eroded.
The Holderness Coast is a great case study to use when examining coastal
processes and the features associated with them. The area contains 'text book'
examples of coastal erosion and deposition.
The exposed chalk of Flamborough provides examples of erosion, features
such as caves, arches and stacks. The soft boulder clay underlying Hornsea
provides clear evidence of the erosional power of the sea. Mappleton is an
excellent case study of an attempt at coastal management.
Spurn Point provides evidence of longshore drift on the Holderness Coast. It is
an excellent example of a spit. Around 3% of the material eroded from the
Holderness Coast is deposited here each year.
3. How might the geology of the area affect the shape of the
What processes are acting upon this coastline?
Geology Map of Holderness
Altitude Map of Holderness
4. What processes are acting upon this coastline?
The Holderness Coastline is made up of soft boulder clays (tills) left after the
retreat of the Devensian ice sheets about 12 000 years ago. They can be seen
on the coast, being rapidly eroded by the sea. To look at, they are a mass of
brown clay containing pieces of rock (erratics) brought here by the glaciers from
Scandinavia, Scotland, the Lake District and Northeast England. These soft,
recent deposits sit on a platform of chalk which slopes away gently to the east.
Erratics in till at Mappleton
5. What processes are acting upon this coastline?
Erosion of the Holderness cliffs is a cyclic, four stage process:
1. The soft Boulder Clay cliffs become saturated with rain water and lose their
2. The cliff is too steep and fails either as a block of material or as a slurry slide
3. Cliff failure reduces the angle and prevents further erosion but …
4. Large waves from the North East remove the debris in longshore drift to the
South and the cliff oversteepens, rain falls and the cycle begins again.
6. The order of this presentation…
1. Flamborough Head.
6. Spurn Head
7. 1. Flamborough Head
The chalk of Flamborough is a resistant rock that provides examples of erosion,
features such as caves, arches and stacks. The chalk has formed a headland.
8. 2. Mappleton
Situated approximately 3km south of Hornsea lies the village
of Mappleton. Supporting approximately 50 properties, the
village has been subject to intense erosion at a rate of 2.0m
per year, resulting in the access road being only 50m from
the cliff edge at its closest point.
Mappleton lies upon unconsolidated till (boulder clay). This material
was deposited by glaciers during the last ice age 12,000 years ago.
Mappleton lies upon unconsolidated till. This material was deposited by
glaciers during the last ice age 18,000 years ago.
The two rock groynes at Mappleton have helped develop wide and steep
In 1991 almost £2 million was spent on two rock groynes and a rock
revetment to protect Mappleton and the B1242 coastal road. Blocks of
granite were imported from Norway for the sea defences. The purpose of
the two rock groynes was to trap beach material. As the result of the
coastal management a substantial beach accumulated between the
groynes halting erosion.
Mappleton is an excellent case study of an attempt at coastal management. In 1991 two
rock groynes and a rock revetment made from huge blocks of Scandinavian rock were
As a consequence a substantial beach accumulated between the groynes halting erosion
(picture 1 below). However, further south the rate of erosion has increased significantly
(picture 2 below). This is because material which is being carried south is not being
replaced (it is trapped within the groynes). Therefore there is no beach to protect the cliffs.
Even during a neap tide ( a tide which is 30% less than the average tidal range) the sea
reaches the base of the soft cliffs and erosion occurs.
1 Cliffs to the north. Sea defences mean
that the beach has grown and the cliffs are
stable (look at the grass growing!)
2 Cliffs to the south. The sea defences
don’t protect this area and the land is
Defences = Beach build up
No defences = Beach erosion
12. 3. Aldbrough
Aldbrough is a small settlement to the south of Mappleton.
Where Mappleton had substantial sea defences built,
Aldbrough has none. The cliffs here are rapidly eroding.
Some residents think that the sea defences at Mappleton has
made things worse. Why would they think this?
14. 4. Withernsea
This settlement attracts tourists, so substantial sea
defences have been constructed to maintain the beach.
How many sea defences can you see in this picture?
15. Withernsea – how does it all work?
16. 5. Kilnsea
The old settlement of Kilnsea has now been completely
lost. Sea defences were built here in the early 1900s to
protect the Godwin Battery - a defensive gun emplacement
and the rail-head for a light railway to further military
installations on Spurn point. The sea defences are now
crumbling and erosion is progressing rapidly.
Old map of Kilnsea Current aerial photo of Kilnsea
18. 6. Spurn Head
The area known as Spurn forms the southern extremity of the Holderness coast and includes
the unique feature of Spurn Head, a sand and shingle spit 5.5km long, reaching across the
mouth of the Humber. Spurn is made up of the material which has been transported along
the Holderness Coast. This includes sand, sediment and shingle.
Spurn Point provides evidence of
longshore drift on the Holderness
Coast. It is an excellent example of a
How would sea defences along
the coastline affect Spurn?
19. Spurn Head
1. The material eroded from the Holderness cliffs is swept southwards.
2. North easterly waves move the coarser sands and gravel down towards the mouth of the
3. The finer sands and clays are swept offshore and continue southwards towards the Wash.
4. Spurn Head ‘hangs like a rudder’ for six kilometres off the end of Holderness, built by the
sands and gravels eroded from the cliffs and transported south by longshore drift
5. In the past Spurn Head
seems to have grown and
been washed away in a
regular cycle, slowly moving
towards the east to keep
pace with the erosion of the
6. For over 100 years the
position of Spurn has been
fixed by artificial sea
defences. These defences
are now falling into disrepair
and the sea is starting to
erode parts of the peninsula
20. Spurn Head
Spurn Head changes position. Most of the spit has
flexible road surfaces, which are like mats that can be
picked up and moved following major storms.
There is plenty of evidence of this
movement. Former railway tracks that
were built to move building materials
along Spurn (for the building of Bull
Fort in the Humber Estuary) now
appear to lead into the sea.
21. Spurn Head
Is Spurn eroding?
The end of Spurn is fairly stable. This is due to
it’s size and the presence of deep rooted plants.
The rest of Spurn erodes and moves constantly.
There are some groynes to protect it, but these
are very old now.
22. Spurn Head
Is it important to protect access to Spurn Point?
Full time lifeboat men live here with their
The Humber estuary is very busy with
large ships. It is one of the most
dangerous estuaries in Europe, so pilots
guide boats in and out. Their base is on
Spurn for quick access to sea. The pilots
do not live on Spurn.
Spurn is also important for birds and wildlife.
23. Locational Context
What is a sediment cell?
Today coastlines are
managed as complete
systems, as Sediment
cells, within which is a self-
contained cycle of erosion,
transport and deposition of
24. What is the aim of a SMP?
• To provide the basis for sustainable coastal
defence policies within a sediment cell and to set
objectives for the future management of the
• SMP’s set out a strategy for coastal defence for
specified lengths of coast identified as sediment
cells. They are funded mostly by DeFRA, the
Environment Agency and local councils.
25. Strategic Coastal Defence Options in
• Largely piecemeal
• Local defence schemes
• Only protect areas immediately threatened
• Serious knock on effects downshore
e.g. groynes or revetments starve beaches downshore
of sediment and actually accelerate erosion in
these areas. Building sea walls may also reduce
sediment inputs, degrading beaches and mudflats
and threatening increased erosion and coastal
26. Strategic Coastal Defence Options
Coastal defence schemes today are not
haphazard! A great deal of care and scientific
research goes into planning their type and
location. The 4 options are:-
1) Do nothing
2) Hold the existing defence line by maintaining or
improving the standard of protection
3) Advance the existing defence line
4) Retreat the existing defence line
30. Broader Implications 1
• 23% total land area lies within 10km of the coast
• 16.9 million people live within the coastal zone
• Land use:
- 33% pasture
- 25% arable
- 7% woodland
- 2% heathland
- 3% cliffs, beaches and mudflats
- 30% buildings, roads, recreation facilities
• 40% UK manufacturing industry lies close to the coast
31. Broader Implications 2
• Sea defences around the UK coast cost £300 million to
• There have been a number of spectacular cliff falls in
recent years e.g. Holbeck Hall Hotel in Scarborough (see
• On the Holderness coast erosion rates have reached 11m
per year. In Suffolk 8.5 metres per year
• Estimates suggest that by 2027 an area the size of Jersey
will have been lost on the east coast of the UK alone!
32. Holbeck Hall Hotel landslide,
Scarborough. June 3rd
33. Holbeck Hall Hotel, Scarborough
34. Holbeck Hall Hotel, Scarborough
35. Holbeck Hall Hotel, Scarborough
36. Holbeck Hall Hotel, Scarborough
37. Images of Scarborough prior to
Defence Work starting April 2002
38. Overtopping caused Marine Drive to
be closed 35 times per year!
39. The pier is a listed structure first
built in 1732. Seaward wall in
extremely poor condition
40. Marine drive sea wall in a very poor
41. Marine drive sea wall in a very poor
42. Accropode armoured revetment to
seriously reduce risk of overtopping
43. Scarborough today after £33million spent
on coastal defence 2002  2007
44. Scarborough today after £33million spent
on coastal defence 2002  2007
45. Scarborough today after £33million spent
on coastal defence 2002  2007
46. Scarborough today after £33million spent
on coastal defence 2002  2007
47. The future?
Many key industries, farms and homes lie within 50 meters of the
1. Should they
2. What effects
areas of the
3. Who should