COASTS - HOLDERNESS COAST CASE STUDY Flashcards
Where is it located in the UK?
Eastern England
How large is the sediment cell and what two points is it between?
50km
Flamborough Head (chalk) to Bridlington Bay to Spurn Point
How far has it retreated since Roman times?
6km
How much have global temperatures risen by? (+ since when) and how much has sea level risen by (+ since when)?
1 degree Celsius since AD1500
Global sea level rise by between 10 and 25cm since 1900
What is the geology of the area?
chalk (Flamborough Head) and clay
What is the weather in the area?
winter storms > storm surges (stronger waves and higher sea levels)
Storm rain intensifies sub aerial processes > saturated clay cliffs resulting in increased runoff and slumping
What is the prevailing wind and what does this cause?
From the NE > longshore drift > low energy environment of the Humber Estuary > formation of spits, mudflats and sand dunes
Give some information about Flamborough Head
- chalk (resistant rock) headland
- horizontal bedding planes
- erosion > hydraulic action, wave quarrying, abrasion, undercutting of the cliff = wave-cut platforms, wave refraction e.g. Selwicks Bay
Give some information about Spurn Head
- 6km compound spit
- growing at 10cm/year
- winter storms periodically threaten to breach the narrow neck and cut it off from the mainland
- 1800s groynes and revetments (1950s protected by Royal Engineers, now Yorkshire Naturalists’ Trust
What has occurred within the management of the coastline?
- Hold the line (protection of key settlements) e.g. Bridlington, Hornsea, Withernsea, and protect coastal road (Mappleton - gas processing facility)
- No active intervention (essential material for Spurn Point - 20% of UK imports from Humber)
- Little need to protect northern part of the sediment cell
What has occurred at Hornsea and what are the advantages and disadvantages?
Holiday resort with promenade and hotel frontage (multiplier effect) so tourism is important
- maintaining sea wall, groynes (£5.2million), steel doors at beach entrance, sea wall slightly raised, sand dunes planted with trees
ADVANTAGES
- groynes effective locally with low cost and acceptable visually
DISADVANTAGES
- trapping sand scours Mappleton
- Groynes rarely work on their own
- continuous maintenance (expensive overtime)
- groynes dont hold mud
What has occurred at Withersea and what are the advantages and disadvantages?
Resort (sea wall and groynes), wave return wall, rip rap, beach nourishment (£6.3 million total) > emphasis on comprehensive approach
ADVANTAGES
- holds the line
- calms concerns of local residents and hoteliers
- saves seasonal jobs in resort
DISADVANTAGES
- costs limited length of sea wall
- rocks reduces access to the beach
- limited views
- problem of wave noise
What has occurred at Easington?
Resentment protects gas terminal (£4.5mn) which handles 25% of North Sea production but fails to protect village - conflict with environmental groups
What has occurred at Spurn Head and what are the advantages and disadvantages?
Protection abandoned in 1995
ADVANTAGES
- growing annual costs have been saved
- may repair itself
- environmental groups wanted the spit to become an island
DISADVANTAGES
- community of lifeboat men and families have to relocate
- loss of ‘heritage coast’ site
- loss/risk of important bird habitat
- problem of flooding (1/2 million <2m above sea level)
- decr sediment supply (Humber Catchment) reducing formation of new land
What has occurred Mappleton?
1991 £2.1 million supported by EU funding
- 1988 (retreated close to 3.5kms)
- houses at risk of falling in
IMPLEMENTED
- 2 rock grounds
- rock revetment
- regarded cliffs
- beach nourishment
- new access road, car park and toilet
2002
- re-guarded cliff showing signs slumping
- beyond groynes being undermined
- cliff face below car park being eroded
