1.9 Flood Management Flashcards
What is channel management?
Changes to the river channel such as increasing the height or straightening
What is basin management?
Schemes that aim to reduce the amount and velocity of water flowing towards a river.
Such as a reservoir
What is hard engineering?
Intervening directly with a river’s natural processes such as building a concrete embankment along a river channel
What is soft engineering?
Aiming to work with the river’s natural processes that has less impact than hard engineering
Eg creating wetlands on the floodplain to store water
What is warning and forecasting?
Monitoring precipitation and river levels to issue warnings
Making flood defence decisions
Sustainability, social, economic, environmental impacts
Hard engineering option: dams and reservoirs
Regulate river flow, multi purpose, prevent floods, water supply, hydroelectric power, recreation (fishing)
Effective, store water and released slowly during low flow conditions.
Very controversial. Costly!
River straightening
Increase in gradient, velocity, moving the problem downstream :(
Levees and embankments
Raising the level increases the capacity, hold more water.
Easily, cheaply, sustainable, minimal environmental impact.
Concrete walls- expensive, more effective
Diversion spillways
Divert water away from built up areas. High flow, gates opened
Expensive, can be positive to environment
Soft engineering- planting trees
Afforestation, in upland areas increase interception and slows water transfer.
Soft engineering- wetlands
Efficient at storing water
Habitats, breeding grounds
Soft engineering- riverbank conservation
Planting vegetation like bushes and trees along banks to stabilise it
Soft engineering- Land use management and floodplain zoning
Not allowed for housing, used for parks and recreation grounds
River restoration
Returning a artificially altered river back to it’s natural state. Eg meanders and wetlands
