4. UK Evolving Physical Landscape: Coastal Landscape, Flooding, Management Flashcards
Which Coast has one of the highest rates of Coastal Erosion?
Holderness Coast - East coast of England
61km long
Flamborough Head to Spurn Head (spit)
What happens at Holderness Coast?
Erosion - cliffs collapse - 1.8m of land lost / yr
Great Cowden - 10m / yr
Cliff - Boulder Clay - easily eroded - slumps when wet
Narrow beaches - less protection from sea erosion
Prevailing winds from North East - increase wave power over long distance - Highly erosive
Eroded material moved south - longshore drift - exposing new area of cliff to waves
What has been put in place to protect Holderness Coast?
Over 11km protected by hard engineering strategies to protec:
- Towns and Villages eg Hornsea
- Infrastructure like important link B roads
- Gas terminal at Easington
Coastal defences called GROYNES at Mappleton
Groynes and sea wall at Hornsea and Withersea
What has been the impact of the protection put in place for Holderness Coast?
Problems further down coast - Groynes cause narrow beaches further down coast
Great Cowden - farms, caravan parks - danger of falling into sea
Material from Holderness transported south to Humber Estuary and Lincolshire cost
Risk of flood in Humber Estuary as less material to slow water down
Increased Coastal retreat on Lincolshire coast
Spurn Head spit - danger of eroding away as less material added to it
Bays forming between protected areas - becoming headlands - eroded more heavily
Maintaining defences becoming more expensive
What is increasing the risk of Coastal Flooding?
Climate change
Rising Sea Levels - threat to low lying land - Higher tides - more floods - remove more material from beaches - become narrower - more erosion of cliffs
Storm Frequency - waves more erosional power - sort rock erodes more easily - strong waves move more material further - leaving areas vulnerable to erosion and flooding
What is the threat to People at the Coast?
Lowland - permanently flooded and inhabitable
Coastal industries may be closed due to damage - fishing boats
Damage to roads and rail - railway line Dawlish Devon runs along sea
Can affect tourism
What is the threat to the Environment at the Coast?
Ecosystems affected - organisms damaged / killed by salty sea water
Agriculture - soil fertility impacted
Floodwater force - uproot trees - drown vegetation
Conservation areas threatened by coast erosion - Holderness lagoons protected - separated from sea by BAR - if eroded will lose lagoon
What are the types of Coastal Defenses?
Hard and Soft Engineering
What is Hard Engineering?
Man-made structure - control flow of sea - reduce flooding and erosion
Sea Wall - hard material - prevents erosion - very expensive
Groynes - wooden or stone fences - right angle to coast - trap material transported via longshore drift - create wider beaches - more protection - impact is they starve beaches further down coast making narrower
What is Soft Engineering?
Scheme set up using knowledge of sea and processes to reduce effects of flooding and erosion
Beach replenishment - Bring in sand and shingle to upper part of beach - wider beaches - taking material from seabed can kill organisms e.g sponges / coral - expensive as has to be repeated
Slope Stabilisation - reinforce slopes concrete nails and metal netting - prevents mass movement - very expensive and difficult to install
Strategic Realignment - Remove existing defence and allow land behind to flood - becomes marshland creating new habitats - controversial to flood farmland
How are Management Strategies sustained?
Need to ensure dont cause problems further down coast where people live and work
Need to be cost effective also
Integrated Coastal Zone Management (ICZM) - protects and takes everyone’s interest into account - easier to find solutions people will agree with - long term approach that can be adapted to meet future needs
