Coasts - North Yorkshire, Holderness Coast CS - HE Flashcards
Where do the predominant winds come from?
The North East
How much material is deposited at spurn point?
3%
Where does the eroded material travel?
Southwards
Why is coastal management needed?
- Protect economic assets -> tourism/gas terminal/port
- Protect residential areas
- To appease citizens campaigns
- To address previous management issues
- To manage retreat the line
- To protect SSSI
What type of geology is at the Holderness coastline?
- Boulder clay + glacial till
- Limited sediment replacement
What type of fetch and waves occur here?
- Long fetch
- Strong destructive waves
What are the beaches like on the Holderness coastline?
Small + narrow
By how much is the Holderness eroding?
2 m/yr
How many shoreline management plans are there in the UK?
22
What protection is put in place in Scarborough?
- Protecting £300 million assets from £25.7 million coastal defence schemes
What are the key places along the Holderness coastline receiving management?
- Bridlington
- Skipsea
- Hornsea
- Mappleton
- Withernsea
- Easington
What management at Bridlington?
Groynes
What management at Skipsea?
- Limited defences protect residential properties
- No groynes, limited beach material arrives
What management is implemented at Hornsea?
- Sea wall protecting holiday resort with a promenade and hotel frontage
- Wooden Groynes repaired and built at a cost of £5.2 million
Why is it important to protect Mappleton?
- Protection of the B1242 road - tourism
- High rates of erosion at Mappleton >2m a year
- Cowden Farm and Grange Farm at risk
- 30 homes need protecting
What management has been developed at Mappleton?
- Hold the line
- L shaped revetments (£2 million)
- Rock groynes (scandinavian granite) and a 450m line of rock revetments
- Cliffs at Mappleton regraded and planted to a reduced angle and therefore more stable.
What are the unintended consequences of management at Mappleton?
- Farmers have lost land eg Cowden Farm and Grange Farm Terminal groyne syndrome prevalent .
- Huge crenulated bays carved out immediately after hard engineering at Mappleton
- Reduced amount of sediment transported south to Spurn Point Spit and Humber estuary
What are the intended consequences of management at Mappleton?
- Kinetic and potential erosional energy of the waves NO longer an issue
- High tide no longer reaches the cliff line
- Large sandy beach retained.
- Erosion is NO longer a threat
What management has been developed at Withernsea?
- Advance the line 9 times
- Sea wall, rip rap in front of it, and rip rap extended to halt TGS
- Defences cost £6.2 million -> good value save seasonal jobs
Why did Easington gas terminal need protecting?
- Protecting economic and strategic assets
- Provides UK 25% of energy
- Protect SSSIs, lagoons and bird sanctuary
- Increased rates of erosion
What management has been developed at Easington?
- £4.5 million defences
- 1991 1 Km revetment using 130,000 tons of rock was placed against the current cliff line.
What is Spurn Point spit protecting?
- Humber estuary -> shipping lanes in Humber port
- Hull offshore wind farm industry
How much land has been lost since roman times?
- 3 miles
What are the three main changes to the coastline?
- Coastline retreat
- Spurn point has become more recurved with a salt marsh behind it -> more deposits