Flood Management - It Reduces The Risk Of Flooding Flashcards
HE - Dams and Resevoirs
• used to regulate the river flow and reduce the risk of flooding.
- multipurpose - several functions
- very effective in regulating water flow
- construction of dams can be very controversial
- costs huge amounts of money
- can cause more flooding downstream away from the dams
HE - Channel Straightening
River straightening involves curring through meanders ro create a straight river channel. Faster velocity less discharge
• protects v location from flooding
- may increase the flood risk further downstream.
- can cause the channel to silt up + very unattractive and unnatural river embankments + can damage habitats
HE - Embankments
It is a raised riverbank. Raising level of riverbank allows river channel to hold more water before flooding occurs.
- Cheaper and more sustainable
- protects valuable property
- mud looks more natural
• concrete looks unnatural
HE - Flood relief channels
It is a man made river channel constructed to go around an urban area
• During times of high flow, Sluice gates can be opened to allow excess water to flow away into the food river channel and reduce the threat of flooding.
- Construction takes time
- Expensive
- Takes up land
SE- Wetlands and Flood Storage Area
Wetland environments on river floodplains are very efficient in storing water. Wetlands are deliberately allowed to form flood storage areas - water can be stored to reduce risk of flooding further downstream.
- Fits w/ natural environment
- Stores water away - reduces risk of flooding further downstream
• Can still flood
SE- Floodplain zoning
Restricts different land uses to certan location on the floodplain. Areas close to the river and at risk from flooding can be kept clear of high value land. (LOW VALUE LAND NEAR RIVER)
- floodplain zoning can reduce overall losses caused by flood damage.
- protects high value land
- difficult to implement on floodplains that have already been developed and can cause land prices to fall.
- only used on new cities
SE- River Restoration
When the river course of a river has been changed artificially, river restoration can return it to its original course.
- Reduces the likelihood of a major flood downstream
- Good for wildlife/ the environment
- Can still flood
- Time consuming
Flood warning - how are rivers monitored?
using satalites and computer technology
+ imnstruments that measure the river leevl
+ computer to predict floods using data
Flood warning - how deos the environment agency warn people about floods?
warnibngs are sent tot the emergency services and teh public using social media, text, email
3 levels:
1) flood watch - expected, people shoudl be prepared
2) flood warning - when actyual threat - move all valuable itemns upstairs
3) severe flood warnings - danger to life - evict
Flood warning - why do the environmental agency make floodd maps?
to identify areas at risk from flooding. Ppl living in these areas arfe encouraghed to move. Plan, give flood warnings out, use flood gates and sandbags
Flood warning - why do the property values of places classed as at risk of flooding still fall?
insurance increases so ppl don’t wanna live there
bank may not give mortgages
York flood amangement scheme social impact cost
buses in, out and around York are diverted along a designated route wheneever a flood ahppens which means longer journeys to work
York flood amangement scheme social impact benefit
reduced level of anxiety and depression through fear of flooding
York flood amangement scheme enviornmental impact ENVIRONMENTAL IMPACT costs
earth embankments, along teh River Ouse, have been constructed using soil and excavated alluvium
York flood amangement scheme environmental impact enviropnmental impact benefirts
washlands srorage schmee developed in 1983. this stores 2.3 mill cubic metres of wateer and is able to lower the flood level. This provides a habitat for birds
