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Managing coastal erosion - Coggle Diagram
Managing coastal erosion
Why?
lots of people live and work along coastlines
coastlines can be valuable areas economically
sometimes in coastal areas one can find fragile ecosystems
How?
Hard engineering techniques
Expensive
Negative impact on landscape and natural environment
Unsustainable
Examples
Sea walls
: built along the base of cliffs to prevent erosion and flooding.
Their structure can cause the erosion of the beach at the base of the sea wall
Expensive
Visually intrusive
High cost of maintenance
Groynes
: barriers built at right angles to the beach to trap sediment
Unattractive to tourists
Expensive to build and maintain
Rock armour
: large boulder placed along the base of a cliff to absorb energy from waves
Boulders are expensive to obtain and transport
Revetments
: barriers placed at the top of beaches to protect the base of cliffs
Not suitable when wave energy is high
Cheap(er)
Less visual impact
Gabions
: metal cages which encloses boulders to absorb the energy from waves
Cheap(er)
Less visual impact
Short(er) lifespan
Offshore breakwaters
: large concrete blocks located offshore to reduce the power of the waves or change their direction to reduce longshore drifts
Unattractive
Expensive
Beach and cliffs retain their natural appearance
Soft engineering techniques
Examples
Beach nourishment
: replace beach material that has been removed and create higher and wider beaches by transporting sand and shingle
Preserve natural appearance of the beach
Dredging of sand and shingle increases erosion in other areas
Cheap
Managed retreat
: areas of coast are allowed to erode and flood (where the land is of low value)
Encourages development of beaches and saltmarshes
Preserve natural environment
Farmers lose their land
Less expensive
More sustainable and long term
Less impact on the natural environment
