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Geography - Coastal Managment - Coggle Diagram
Geography - Coastal Managment
Why?
maintain balance between forces of nature and demands of people
people at the coast need to be protected
erosion
flooding
sea levels expected to rise
coastal defences will become more expensive
Hard Engineering
using man-made structures to control power of sea
reduce flooding and erosion
Sea Walls
Explanation
concrete walls placed at foot of a cliff to prevent erosion
curved to reflect the energy back into sea
Costs
unnatural
waves still powerful and can erode wall
Expensive
5000-10000
Benefits
effective
creates walkway
Groynes
Explanation
wooden or rock structures built at right angles to beach
Costs
short lifespan
replaced every 10-15 yrs
unnattractive
by trapping sediment, increases erosion elsewhere
Benefits
builds a beach
tourism
reduce longshore drift by trapping material
Rock Armour
Explanation
large boulders placed at foot of cliff
break waves and absorb energy
Costs
looks different to local geology (imported rocks)
rocks are expensive to transport
Benefits
relatively cheap
easy to maintain
used for fishing
Gabions
Explanation
rocks held in mesh wired cages
placed in areas affected by erosion
Costs
cages rust
not very strong
unnatural
Benefits
cheap to produce
eventually merge into landscape
Soft Engineering
more environmentally friendly methods that work with natural processes to protect the coast
Managed Retreat
Explantion
let the sea flood low-lying land
allows salt marshes to develop
humans control how far coastline moves back
Costs
very expensive to set up
loss of land and amenities
cost of relocating infrastructure
conflict with land owners
Benefits
creates intertidal salt marsh
natural barrier against storm waves
reduce flood rise
new habitat encourages wildlife
nature reserves
environmental and social opportunities
Beach Nourishment and Reprofiling
Explanation
sand and shingle pumped onto existing beach to build it up
Costs
material dredged elsewhere
constantly replaced
Benefits
blends in with existing beach
bigger beach
tourism
Dune Regeneration
Explanation
marram grass planted on sand to stabilise dunes and help them develop
Costs
damaged by storms
Time consuming
Benefits
maintains natural environment
good for wildlife
relatively cheap