EQ4 Coasts Flashcards
what are the economic costs of coastal recession?
loss of property, homes, businesses and farmland
easy to quantify
what are the social costs of coastal recession
relocation, loss of jobs- quantifiable
impact on health - mental stress and worry
- much harder to quantify
what are the environmental costs of coastal recession
loss of coastal ecosystems and habitats
likely to be small as ecosystems largely adapted to coastal system
why are economic losses dur to coastal recessino usually small
erosion incremental- small numbers of properties impacted over a long period
properties lose value long before destroyed by erosion so lack of a market
areas of high popn density usually protected by defences so at lower risk
why can economic costs rom coastal recession begin to creep up?
costs very specific to locations
in some places residential land values are high- as coasts are desirable locations
locations of known risk will have lower values
when are the largest economic losses from coastal recession?
unexpected events
why is there a total loss in value of properties at risk of erosion?
property insurance doesn’t cover coastal erosion
do not compensate individuals if homes lost
so leads to inability to sell property
what are the 4 coastal management strategies
hold the line
advance the line
managed retreat
no active intervention ‘do nothing’
describe hold the line management approach
build or maintain coastal defences so that the position of the shoreline remains the same over time
describe managed retreat
allow coastline to move naturally by manage the process to direct it in certain areas
describe advance the line management approach
build new coastal defences on the seaward side of existing coastline
involves land reclamation
describe no active intervention coastal management approach
no investment in defending against flooding or erosion
whether or not defences have existed previously
what is taken into account when managing a coastline
engineering feasibility
environmental sensitivity
land use value
impacts on coastal processes
political, social and economic impacts
pressure from communities
cultural and ecological value of land
what is cost benefit analysis
a tool used to help decide whether defending a coastline is ‘worth it’
considers tangible and intangible factors
what is hard engineering in coastal management
building artificial structures which try to control or stop natural processes
economically costly
directly alter processes
what is soft engineering in coastal management
attempt to work with physical systems and processes to protect coasts
examples of hard engineering in coastal management
groynes
sea walls
rip rap
revetments
offshore breakwaters
examples of soft engineering at coasts
beach nourishment
cliff regrading and drainage
dune stabilisation
what are the relative costs of some examples of hard engineering (£)
groynes - 150-2500
revetments - 500-3000
rock breakwater - 1750-4300
rip rap - 1350-6000
what are groynes
timber or rock structures built at right angles to the coast
trap sediment moved along the coast by longshore drift, building up the beach
advantages of groynes
- built up beach increases tourist potential and protects land behind it
- work with natural processes to build up the beach
- not too expensive
disadvantages of groynes
- starve beaches further along the coast of fresh sediment as LDS is interrupted
- leads to increased erosion elsewhere
- can be very unattractive
what are sea walls
made of stone or concrete at the foot of a cliff or at the top of a beach
usually have a curved face to reflect waves back into the sea
advantage of sea walls
effective in preventing erosion
often have a promenade for people to walk along
disadvantages of sea walls
- reflect wave energy rather than absorbing it
- can be intrusive and unnatural looking
- very expensive to build and maintain
what is rip rap
rock armour
large rocks placed at foot of a cliff or top of a beach
forms a permeable barrier to the sea, breaking up waves but allowing some water to pass through
advantages of riprap
relatively cheap and easy to construct and maintain
often used for fishing from, or sunbathing by tourists
disadvantages of riprap
rocks used often taken from elsewhere so don’t fit in with local geology - can look out of place
can be very intrusive
rocks can be dangerous for those clambering over them
what are revetments?
sloping wooden, concrete or rock structures
placed at foot of cliff or top of beach
break up wave energy
advantages of revetments
relatively inexpensive to build
disadvantages of revetments
intrusive and very unnatural looking
can need high levels of maintenance
what is offshore breakwater
a partially submerged barrier designed to break up waves before they reach the coast
advantages of offshore breakwater
effective permeable barrier
disadvantages of offshore breakwater
visually unappealing
potential navigation hazard
what is beach nourishment
addition of sand or pebbles to an existing beach to make it higher or wider
sediment usually dredged from nearby seabed
advantages of beach nourishment
relatively cheap and easy to maintain
looks natural and blends with existing beach
increases tourist potential through creating bigger beach
disadvantages of beach nourishment
needs constant maintenance due to constant erosion and LSD
what is cliff regrading and drainage
reduces angle of cliff to help stabilise it
drainage removes water to prevent landslides and slumping
advantages of cliff regrading and drainage
regrading can work on clay or loose rock where other methods don’t work
drainage is cost effective
disadvantages of cliff regrading and drainage
regrading causes cliff to retreat
drained cliffs can dry out and lead to collapse- rockfall
what is dune stabilisation
marram grass can be planted to stabilise dunes
areas can be fenced to keep people off newly planted dunes
advantages of dune stabilisation
maintains natural coastal environment
provides important wildlife habitats
relatively cheap and sustainable
disadvantages of dune stabilisation
time consuming to plant marram grass
people may respond negatively to being kept off certain areas
what is marsh creation
a form of managed retreat
allows low lying coastal areas to be flooded by the sea
land then becomes a salt marsh
advantages of marsh creation
- relatively cheap as often involves land reverting to original state before being managed for agriculture
- creates new natural defence
- creates important habitat
disadvantages of marsh creation
agricultural land lost
farmers or land owners need to be compensated
what s a SMP
shoreline management plan
a strategy for coastal defence for a specified length of coast taking into account of natural coastal processes and other environmental influences and needs
what is an EIA
environmental impact assessment
what is an ICZM
integrated coastal zone management
what is a heritage coast
stretches of beautiful, undeveloped coastline which are managed to conserve their natural beauty and improve accessibility for visitors
what is an ICZM
- entire coastline managed - not just zone where breaking waves cause erosion. could mean management across political boundaries
- recognises importance of coastal zone to people’s livelihoods
- recognises that management should be sustainable
who are the winners and losers in coastal management
winners: people who have gained from the decision economically (property is safe) or environmentally (habitat conserved) or socially (communities remain in place)
losers: people likely to lose property or see coastline concreted over (environmental negative)
