Coasts case studies Flashcards
Holderness background
- Yorkshire
- losing 2m of coast per year
- lost 4km since Roman times
- 29 villages lost to the sea
- 80000m2 of farmland lost per year
Why is there so much erosion at Holderness?
- Geology: weak boulder clay
- waves: powerful and destructive (5000km atlantic fetch)
- narrow beaches
What’s happening at Mappleton?
- population 250
- road 34m from the sea, cheaper to defend than move
- community built their own revetment and groynes
- terminal scour
What’s happening at Kilnsea?
- most southerly village on Holderness
- lost 300m of land in 150 years
- population 90
- vulnerable to floods
Why is the coast of west africa eroding so quickly?
- 1-2m retreat per year
- rising sea levels
- lack of defences
- dams trap sediment which can’t be deposited at coast
- destruction of mangroves
What is the Deltawerken (Netherlands)?
- hard engineering megaproject
- dams and gates constructed to control flow of water between the eastern islands
What is happening at Kiribati?
- roads eroded
- food insecurity
- homes submerged/destroyed
Where is eustacy affecting?
- Kiribati
- Flooding rias eg Kingsbridge
where is isostacy affecting?
ice melting in scotland
- scotland rising by 1.5mm p/year
- south uk sinking by 1mm p/year eg essex
what is happening in the isle of arran, scotland?
relict cliffs eg kings cave
isle of arran - raised beach 5m above sea level
due to isostatic uplift
why is bangladesh vulnerable to floods?
monsoons, himalayan snowmelt
- 2004 floods covered half of country, killed 600
Ria
Kingsbridge, south devon
fjord
Sognefjord, norway
- 205km long
- 1.3km deep
- 4.5km wide
Fjard
Kanholmsfjarden, Sweden
Dalmatian coast
croatia
- 1240 islands parallel to coast
maldives
The Maldives have an average height of 1.5 m above sea level, but its population of 400,000 is too large to be easily accommodated elsewhere. It’s highest point is 2.3 m above sea level, and a 50 cm rise would flood 77% of it.
hallsands
sediment cell disruption
shingle dredged offshore to provide material for construction of dockyard in plymouth, so shingle from the beach slipped into holes left. As sea levels fell, deep fast-flowing channels which stopped material being deposited at Hallsands developed