Hard engineering Flashcards
What is hard engineering? (Hard coasts)
It involves the use of structures made of solid materials to stop coastal erosion
What are the 6 hard engineering strategies? (Hard coasts)
Sea walls Groynes Riprap Gabion Revetments Off-shore water breaks
How do sea walls work? (Hard coasts)
A long concrete barrier along the coast that absorbs the energy of the waves
How do sea groynes work? (Hard coasts)
Wooden fences made from piles of rock built out into the sea
How do riprap work? (Hard coasts)
They are placed at the bottom of a cliff to absorb the wave energy but allowing the water to drain
How do gabions work? (Hard coasts)
Wide cages filled with boulders, placed at the rear of the beach for protection from waves and encourages sand dunes to form
How do revetments work? (Hard coasts)
Sloping concrete wooden defence facing the sea, that absorb wave energy
How do off shore water breaks work? (Hard coasts)
Built parallel to the coast from rock. Waves are forced to break before they reach the shore
How effective are sea walls? (Hard coasts)
+ effective
+ last around 100 years
- expensive
- visually unappealing
How effective are groynes? (Hard coasts)
+ reduces rate of LSD
+ cheap to build and maintain
- lasts around 30 years
- trapping sane in one area makes another area deprived
How effective are riprap? (Hard coasts)
+ cheap
+ last around 120 years
- erosion can still take place
- can be moved easily
How effective are gabions? (Hard coasts)
+ very cheap
- short term, 5-10 years
- cages are prone to rusting
How effective are revetments? (Hard coasts)
+ cheap
- less durable than sea walls
- do not provide total protection
How effective are off shore water breaks? (Hard coasts)
+ effective
+ do not spoil the beach
- highly expensive
- hard to maintain
