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Flood Warning Systems - This enables people time to remove possessions and evacuate areas.
Sandbagging - This attempts to flood proof homes and buildings as a last resort.
Insurance - This spreads the cost of the flood damage.
Flood Plain Zoning - This tries to organise the flood defences in such a way that land that is near the river and often floods is not built on. This could be used for farming. The areas that rarely get flooded therefore would be used for houses, transport and industry .
Occurs where the flood risk across different parts of the floodplain is assessed and resulting land use takes this into account. Areas that are at risk of flooding have low value land uses.
Copy the diagram textbook page 119
Land use management = flood plain zoning It restricts development – a problem when there is a shortage of housing It can’t be used in areas that are already urbanised There are no new buildings or roads on the flood plain to be damaged so the impact of any flooding is reduced It provides recreational opportunities Planning restrictions prevent buildings or roads being constructed on the flood plain. Use of the floodplain is restricted to things like playing fields, allotments or parks. More water can infiltrate grassy surfaces so there is less surface run off which reduces discharge and flooding Disadvantages Extra benefits How it works
Wetland and river bank conservation Less land is available for farming Vegetation protects against soil erosion Vegetation creates wildlife habitats Wetlands store flood water and also slow it down. This reduces flooding downstream. Conserving or re-establishing wetlands gives natural protection from flooding. Planting trees and shrubs along the river bank increases interception and lag time and reduces discharge. This also decreases flooding (= riparian buffers) Disadvantages Extra benefits How it works
River restoration Local flood risk can increase especially if nothing is done to prevent major flooding Little maintenance is needed as the river is left in its natural state The river provides a better habitat for wildlife Making the river more natural – e.g. by removing man made levees and allowing the river to flood naturally. As the water spreads out over the floodplain, the river’s discharge is reduced which reduces the flooding risk downstream Disadvantages Extra benefits How it works
Flood protection *Dams *reservoirs *straighten channels *Dredging *levees and embankments *land use zoning *afforestation plenary The challenge: to talk for sixty seconds on one of the flood control measures without any hesitation, repetition or deviation.
Where the economic social and political need is high and the flood risk is great hard engineering structures must be used. An example of this in the UK is the Thames Barrier. Here the potentially lethal combination of
River flooding risk from inland
Tidal flooding dangers from the sea
The largest concentrations of people and commercial activities in the UK
meant that London had to be protected whatever the economic and environmental costs of barrier construction.