EQ4 Coasts Flashcards
(56 cards)
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
