(1.3.3) Flood management + Conflict

What are the aims of flood management?

• Reduce the amount of water reaching river

• Educate people on what they should do before, during and after floods

• Divert the flood water away from populated areas

• Slow the rate of water into rivers

Define hard enginering.

A method of river flood management that involves major construction work to change/alter the river.

Define soft engineering.

A method of river flood management that works/attempts to work with natural river processes. Rarely involves major construction work.

What does forecasting and education as management strategies entail?

Work to make people less vulnerable and more aware of how to respond.

What does planning as a management strategy entail?

Reduced impact through flood proof buildings and careful design to minimise damage and loss.

Classify as hard/soft engineering and define: Embankments

• Hard engineering

• Consists of using levees to raise river banks to increase capacity

Pros and Cons of embankments:

Pro →

• cost effective

• makes people feel secure

Con →

• can increase flooding downstream

• if it breaks, the surge of water would be catastrophic

Classify as hard/soft engineering and define: Channelisation

• Hard engineering

  Consists of :

• straightening the channel- speeding up water flow

• dredging- deepens river to hold more water

Pros and Cons of channelisation:

Pros

• dredging increases capacity

• straightening- quick flow past urban area

Cons

• dredging damages ecosystems and is expensive

• straightening- downstream flood risk increased

Classify as hard/soft engineering and define: Spillways

• Hard engineering

• Consists of forming two paths for the water to go and meet later on

Pros and Cons of spillways:

Pros

• Divert excess water away, reducing flooding

• Can create ecosystems

Cons

• if water levels rise, both may flood

• Costly to build

Classify as hard/soft engineering and define: Dams

• Hard engineering

• Trap water and controlled release

Pros and Cons of dams:

Pros

• Controlled flow → electricity and power

Cons

• holding back sediment → faster flow of water → downstream flooding risk

• disrupt habitats and communities

Classify as hard/soft engineering and define: Floodplain

• Soft engineering

• Consists of empty land that water can flow into

Pros and Cons of floodplains:

Pros

• reduces discharge downstream

Cons

• reduces land for agriculture and development

• expensive

Classify as hard/soft engineering and define: Land Use Zoning

• Soft engineering

• Only certain land uses permitted on floodplain areas, reducing risk to important areas

Pros and Cons of land use zoning:

Pros

• less overall damage if important areas are not at direct risk

Cons

• difficult to modify pre-existing areas

• reduces available land for development and agriculture

Classify as hard/soft engineering and define: Afforestation

• Soft engineering

• Consists of reducing discharge by increasing infiltration and interception by planting trees

Pros and Cons of afforestation:

Pros

• Reduces flood risk through increasing time taken for water to reach rainfall

Cons

• Not feasible in all areas

Why might different groups support different approaches to managing flooding?

People will prioritise their own beliefs and some strategies are more beneficial to them than others.

Which management technique might wildlife groups be in support of?

Those with conservation at the forefront will probably support soft engineering to minimise the effect on nature and habitats.

Which management technique might residents be in favour of?

Those living in at risk areas would likely support hard engineering to keep themselves and their homes safe.

Which management technique might business owners be in support of?

Probably hard engineering to ensure that their properties and investments near flood prone areas remain safe and undamaged.

List some factors that could cause alternative geographical futures:

• Reduction of impermeable surfaces when building

• Floodproofing houses

• Restrictions on building on floodplains

• Encourage use of brownfield sites for housing development

How would the reduction of impermeable surfaces change the future of the UK?

Increase in permeability → increased infiltration → slower rate of discharge rise

How would the floodproofing of houses change the future of the UK?

Floodproof houses→ safer from flooding → less damage and destruction