Coastal management Flashcards
what are the different types of coastal management?
-hard engineering
-soft engineering
what are the different types of hard engineering?
-sea walls
-groynes
-rock armour
-gabions
describe sea walls
a wall made out of a hard material like concrete that reflects waves back to the sea, placed at the top of the beach or the foot of the cliffs
describe groynes
timber or rock structures built out to sea from the coast (at right angles), they trap sediment being moved along by longshore drift
describe rock armour
pieces of large boulders dumped at the foot of the cliff, rocks force waves to break, absorbing their energy and protecting the cliffs
describe gabions
wire cages filled with rocks that can be built up to support a cliff or provide a buffer against the sea
what are the benefits of sea walls?
-effective against erosion
-gives a sense of security against flooding
-often has walkway or promenade for people to walk along
what are the benefits of groynes?
-creates a wider beach which slows the waves, giving more protection which is beneficial for the tourists
-not too expensive
-useful structures for fishing
what are the benefits of rock armour?
-cheap and easy to maintain
-quick to build
-absorb wave energy so reduces erosion and flooding
-versatile
what are the benefits of gabions?
-cheap to produce
-flexible to design
-can improve drainage of cliffs
-will eventually merge into landscape
what are the costs of sea walls?
-looks unnatural
-very expensive and high maintenance
-can impede access to the coast
-can create a strong backwash which erodes under the wall
what are the costs of groynes?
-interruption of longshore drift, causes erosion elsewhere
-look unattractive
-stops people walking on the beach
what are the costs of rock armour?
-can be expensive to transport
-doesn’t fit with local geology
-obtrusive
-access to the beach can be difficult
-can be moved by strong waves
what are the costs of gabions?
-unattractive
-only lasts 5-10 years
-can only be used on sandy beaches as shingle will damage them
what are the types of soft engineering?
-beach nourishment
-beach re-profiling
-sand dune regeneration
-managed retreat / coastal realignment
describe beach nourishment
-adding sand or shingle to an existing beach to make it higher or wider
-sediment usually obtained locally
what’s beach recharge?
material from the seabed
what’s beach recycling?
material moved from down a drift area and returning it up drift
describe beach re-profiling
-artificial reshaping of the beach using existing beach material
-in winter beach is lowered by destructive waves, so bulldozers move material back up the beach after winter storms
describe sand dune regeneration
-artificial creation of new sand dunes or the restoration of existing dunes
-sand dunes are buffers to the sea but are easily damaged and destroyed by trampling
-marram grass is planted to stabilise dunes and fences are used to keep people of newly planted areas
what are the benefits of beach nourishment?
-fewer waves reach the back of beach, reducing erosion
-cheap and easy to maintain
-blends in with beach
-increases tourist potential by creating a bigger beach
what are the benefits of beach re-profiling?
-creates larger beach to be a buffer between land and sea
-beach looks natural
what are the benefits of sand dune regeneration?
-sand dunes provide a barrier between land and sea
-maintains a natural coastline environment, popular with people and wildlife
-cheap and usually volunteer labour
what are the costs of beach nourishment?
-needs constant maintenance
-taking material from the seabed can kill organisms
