Coastal management Flashcards
How much of the worlds population live near the coast?
. Half of the worlds population live within 60km of the coast
How many of the total of large cities are at the coast?
3/4
Why do we manage coastal areas?
. tourism
. industries
. coastal protection
. fisheries
. transport
What is hard engineering?
artificial structures using various materials to reduce the impact of coastal processes.
What are groynes?
timber or rock structures built at right angles to the coast. They trap sediment being moved by longshore drift.
What are the advantages of groynes?
. builds up the beach and increases tourist opportunities
. protects the land behind it
What are the disadvantages of groynes?
. beach further up the coast maybe starved of sediment
How much do groynes cost?
£5,000 to £10,000 each
What are sea walls?
stone or concrete walls at the foot of a cliff which are usually curved to reflect the waves energy back out to sea
What are the advantages of sea walls?
.very effective against erosion
. often make a promenade for people to walk along them
What are the disadvantages of sea walls?
. very unnatural looking
. need a high level of maintenance
How much do sea walls cost?
£6000 per m
What are rip raps?
large rocks placed at the base of a cliff. It breaks up the energy of the waves while allowing water to pass through.
What are the advantages of rip raps?
. cheap and easy to construct and maintain
What are the disadvantages of rip raps?
. the rocks are usually not local so look out of place
. can be dangerous if people climb on them
How much do rip raps cost?
£1000 to £3000 per metre
What are offshore breakwaters?
a partly submerged barrier designed to break up the waves before they reach the coast.
What are the advantages of offshore breakwaters?
an effective barrier that does not obstruct the beach in any way
What are the disadvantages of offshore breakwaters?
. visually unappealing
. a potential navigation hazard
How much do offshore breakwaters cost?
£1000 to £3000 per metre
What are revetments?
sloping wooden or concrete structures placed at the foot of a cliff and they break up the waves energy.
What are the advantages of reventments?
relatively cheap to build
What are the disadvantages of reventments?
. they can cause erosion further out to sea
. usually very unattractive
. expensive to maintain
How much do reventments cost?
up to £4500 per metre
What is soft engineering?
where the natural environment is used to help reduce coastal erosion and river flooding
What is beach nourishment?
the process where sand is dredged from the seabed and placed on the beach
What is the advantages of beach nourishment?
. relativly cheap and easy to maintain
. looks natural
. increase tourist potential
What are the disadvantages of beach nourishment?
it needs constant maintainance because of natural processes of erosion and longshore drift
What is the cost of beach nourishment?
£3000 per metre
What is cliff regrading and drainage?
.reducing the steepness of the cliff to help stabilize it
. drainage removes the water to prevent landslides and slumping
What are the advantages of cliff regrading and drainage?
. can be effective on clay or soft rock
.drainage is cost effective
What are the disadvantages of cliff regrading and drainage
. regrading effectively causes the cliff to retreat
. drained cliffs can dry out and lead to collapse
How much does cliff regrading and drainage cost?
cost is variable
What is dune stabilisation?
. marram grass can be planted to stabilize dunes
. areas can be fenced off to keep people off
What are the advantages of dune stabilisation?
. maintains a natural environment
. provides important wildlife environments
. relatively cheap
