Zusammenfassung der Ressource
Hard Engineering
- Dams
- A barrier to obstruct the flow of water
- +Highly effective
- + Supply HEP
- -Silt collects behind dams
- +Create jobs
- - Could force people out of homes
- - Unnatural
- -Expensive
- -Flood areas upstream
- CASE STUDY Three
gorges dam
- Removal of settlements
- -Expensive/Complicated
- + 100% flood risk reduction
- Flood interception Schemes
- building a bypass channel,using a new
channel to store excess water, using
embanments
- -Expensive
- +reduces flood risk in towns/cities
- Flood storage resevoirs
- store excess water in
upper reaches of
catchment
- +Natural looking
- + Can provide water elsewhere
- -Requires a lot of land
- -Expensive due to buying
land
- Unless built on cheap
high land (little of this
in the U.k)
- Relief channels
- redirect water around a
settlement to re-enter the
main channel later
- +can be used to supply water as well
- +Natural looking
- -Expensive so can only be used where it
is impossible to alter existing channel
- Channel improvements
- Smoother(with
concrete), dredging,
channel straightening
- +Move water out of area quicker
- +Increases channel capacity
- +Accomodates larger discharge
- -can increase risk of flooding
downstream
- -requires maintenence
- -Short term benefits
- -More erosion downstream
- -Enlarged channels often arent used and fill
with weeds
- Flood walls, levees and
embankments
- Walls and levees add height to channel
- +Embankments(if set back from channel) can
provide storage for excess flood waters while
inhabited areas remain unaffected
- -Expensive
- - Eye sore
- -Could speed up water
downstream and flood
somewhere else