Coastal Management 46 Flashcards
hard engineering examples
sea walls- have a curved surface to reflect waves back into sea
groynes- trap sediment that’s being moved by long shore drift
rock armour- rocks force waves to break and absorb their energy
gabions- placed at the back of sandy beaches
soft engineering examples
beach nourishment-
dune regeneration-
beach reprofilling
what’s the difference between hard and soft engineering
soft engineering approaches works with natural processes wheres hard involves building structures
name 2 examples of coastal defences
hard engineering
soft engineering
what is hard engineering
man-made structures built to control the flow of the sea and reduce flooding and erosion
what is soft engineering
schemes set up using knowledge of the sea and its processes to reduce the effects of flooding and erosion
Name 4 hard engineering defence systems
-sea wall
-gabions
-rock armour
-groynes
Name 3 soft engineering defence systems
-beach nourishment
-beach reprofiling
-dune regeneration
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What is a sea wall
a wall made out of a hard material (concrete) that reflects waves back to the sea
What is a gabion
a wall made of wire cages filled with rocks
-built on the foot of cliffs
What is a rock armour
-boulders that are piled up along the coast
-also called a rip-rap
What is a groyne
wooden/stone fences built at right angles to coasts
-trap material transported by longshore drift
state the advantages and disadvantages for sea walls
adv
-prevents erosion of the coast
-acts as a barrier to prevent flooding
disadv
-very expensive
-looks unnatural
state the advantages and disadvantages for gabions
adv
-absorb wave energy, reducing erosion
-cheap and easy to build
disadv
-ugly
-wire cages corrode overtime
state the advantages and disadvantages for rock armour
adv
-absorbs wave energy
-cheap defence
disadv
-need to be replaced often
state the advantages and disadvantages for groynes
adv
-create wider beaches which slows waves, protection from flooding
-cheap defence
disadv
-narrow beaches
-greater erosion due to narrow beaches
state the advantages and disadvantages for beach nourishment and reprofiling
adv
-creates wider beaches, slowing waves
disadv
-taking material from seabed kills organisms
-very expensive
-has to be repeated
state the advantages and disadvantages for dune regeneration
adv
-maintains a natural coastal environment
disadv
-protection is limited
-nourishment is very expensive
what is beach nourishment and reprofiling
sand and shingle from elsewhere thats added to the upper part of beaches
what is dune regeneration
-creating or restoring sand dunes by nourishment or by planting vegetation to stabilise sand
state what managed retreat is
allows the sea to flood or erode an area of relatively low value
