Coastal defences Flashcards
Hard engineering
Physical structure
Woods/concrete
More effective
Expensive + ugly
Examples of hard engineering
Rip-rap Gryones Revetments Sea wall Breakwater
Rip-rap
Large boulders placed at bottom of cliffs
Absorb wave energy
Effective
ugly
reduce access to beach
expensive
Gabion
Large boulders in cages
Effective
Quickly to be installed
Ugly
Reduces access to beach
Expensive
Groynes
Stop longshore drift washing away beach material
Effective
Needs replacing regularly
Ugly
Cause problems down the coast, not receive beach material
Sea walls
Concrete
Absorbs wave material
Recurved –> direct wave energy to sea
Effective
Expensive
Ugly
Reduce access
Breakwater
Built out to the sea
Waves break on breakwater instead of coast
Near river mouths or ports
Expensive
Disrupt shipping + marine animals
Revetment
Similar to sea walls but wooden
bottom of cliff
absorbs energy
needs replacement
cannot protect against bit storms
Soft engineering
Look more natural
Cheaper
Cannot withstand strong storms
Dune stabilisation
planting vegetation on berms
more stable
reduce moisture uptake
Cliff regrading
make cliffs less steep
less undercutting
less risk of collapsing
Beach nourishment
Adding more sand to beach
Beach drainage
Removing excess water from beach/coast
Managed retreat
Low value land chosen to be flooded by sea
Changing ecosystem of land by adding salt water
