Coasts Flashcards
What are the 4 weathering processes
Onion skin
Freeze thaw
Biological
Chemical
What are the 4 erosional processes
Hydraulic action
Attrition
Abrasion
Solution
How is material transported
Traction
Saltation
Suspension
Solution
Describe a constructive wave
Strong swash
Short fetch so less energy
Low frequent
DEPOSIT
Describe a destructive wave
Strong backwash
Long fetch so a lot of energy
High frequency
ERODE
What is weathering
Doesn’t remove material and happens on land
Cause by animals, plants and the weather
What is erosion
It is caused by the waves and removes material from cliffs
How do stumps form
At a headland
Crack cave arch stack stump
What is the difference between a bar and a spit
A bar is attached at 2 ends- joins two headland together
A spit is only attached at 1 end, and forms by a river mouth where the constant water flow stops it reaching the next headland
What waves form a: Spit and bar Headland Bay Wave cut notch and platform
Spit and bar= constructive (long shore drift)
Headland= destructive, waves erode softer rock faster then the harder rock
Bay= constructive, material is dumped between two headlands to make a beach
Wave cut notch and platform= destructive, hydraulic action makes an undercut so the cliff becomes unstable and topples, and the material is taken away to make the platform
Why is the sea level rising
Thermal expansion- as the water temp rises, the water expands
Ice caps melting- more water is added to the sea
What are the problems and impacts of sea levels rising
Maldives- no higher than 2m so islands will be flooded and disappear Drinking water will be polluted from contamination with sea water Islands will become overcrowded Islands shrink Uninhabited island destroyed by humans No tourism Increased risk from storms Soil and land eroded by waves
What is being done in the Maldives
Very expensive circular sea wall around islands to stop floods
New island are being built
Islands are being raised higher by added material by dredging the sea
New houses built which are better equipped to deal with floods
What is happening at Christchurch bay
Cliff retreat and cliff collapses because of geology (permeable sands above impermeable clay= slumping)
Waves are destructive and have a 3000mile fetch so are very powerful
Human activity is weakening the cliff from tourism and building
What are the impacts of cliff collapse
Homes lost and the value of homes decreases
There is less land to build on, so natural areas are being destroyed to allow for new buildings
Roads and railways are threatened
Fewer tourists from danger and smaller beaches and beach huts destroyed
Less income for businesses
What is being done to reduce impacts of cliff collapse and retreat
Some areas have been left to retreat (naish farm= sssi)
Sea walls have been built
Groynes to reduce lsd
Rock armour
Beach replenishment
People prevented from walking in weak areas to reduce biological weathering and some development have been stopped
What are hard engineering strategies
Things that work against nature, are long lasting but expensive
Rock armour
Sea walls
Groynes
What is soft engineering
Strategies that work with nature, can be cheap and have little effect on the environment, but are not as reliable Dune regeneration Beach nourishment Marsh creation Managed retreat
What is the problem at studland bay
Big conflict between tourists and consevationist
Habitat is rich is rare wildlife, with rare ecosystems. The marram grass stabilises the dunes and allows for other plant so grow which attracted other wildlife like the dart ford warble, nightjar, all the species of reptiles in the uk, sand lizard, and the spiny seahorse
However tourists bring litter, start fires, are destructive, erode the dunes, boast destroy the marine habitats, want facilities and destroy plant life
How is studland bay managed
Boardwalks restrict movement and stop erosion of the dunes Information boards Boats can't anchor Facilities are in one place Bins Fire education and prevention equipment Car park restrictions
