Studied by 4 people
why is flood risk increasing in the UK?
increasing population so more housing being built on floodplains
changes to land use e.g more impermeable surfaces so greater surface run-off
changes to weather patterns due to climate change e.g storms, drought
dams and reservoirs - hard or soft?
hard engineering
river straightening and dredging - hard or soft?
hard engineering
embankments (levees) - hard or soft?
hard engineering
flood relief channels - hard or soft?
soft engineering
demountable flood banters - hard or soft?
soft engineering
flood barriers/storm surge barriers - hard or soft?
hard engineering
flood warnings and preparation - hard or soft?
soft engineering
floodplain zoning - hard or soft?
soft engineering
river restoration - hard or soft?
soft engineering
positives of dams and reservoirs
can attract tourists
can be used to produce electricity by passing water through a turbine within the dam
negatives of dams and reservoirs
dams trap sediment - reservoirs can hold less water
habitats are flooded so leads to rotting vegetation
cost of dams and reservoirs
very expensive
positives of river straightening and dredging
more water can be held in the channel
can be used to reduce flood risk in built-up areas
negatives of river straightening and dredging
dredging needs to be done frequently
speeding up the river increases the flood risk downstream
cost of river straightening and dredging
expensive
positives of embankments (levees)
cheap with a one-off cost
allows flood water to be contained within the river
negatives of embankments (levees)
looks unnatural
water speeds up and can increase flood risk downstream
cost of embankments (levees)
cheap
positives of flood relief channels
removes excess water from the river channel to reduce flooding
negatives of flood relief channels
expensive to build
if water levels continue to rise, the relief channel may also flood
cost of flood relief channels
expensive
positives of demountable flood barriers
good for places where a permanent sea wall would look ugly
more cost efficient than permanent barriers
negatives of demountable flood barriers
need 24 hours warning to set the barriers up so risk that not installed in time
can only be used in that specific location
cost of demountable flood barriers
cheap
positives of flood barriers/storm surge barriers
can protect large areas from storm surges
the gates can be closed when a high tide is forecast
negatives of flood barriers/storm surge barriers
construction costs high
regular maintenance needed
cost of flood barriers/storm surge barriers
very expensive
positives of flood warnings and preparation
people have time to protect their properties
many posessions can be saved, resulting in fewer insurance claims
negatives of flood warnings and preparation
some people may not be able to access the warnings
flash floods may happen too quickly for a warning to be effective
cost of flood warnings and preparation
fairly cheap
positives of floodplain zoning
more expensive buildings and land uses are further away from the river, so have a reduced flood risk
less damage is caused
negatives of floodplain zoning
not always possible to change existing land uses
planners have to decide what type of flood to plan for
cost of floodplain zoning
cheap
positives of river restoration
restoring meanders help to slow down the rivers
natural rivers are more attractive and better for wildlife
negatives of river restoration
flooding is still likely
flood banks will still be needed
may result in change of land use
cost of river restoration
cheap at first, but gets really expensive
