MANAGEMENT

• dams and reservoirs - how it works

  a large concrete barrier built across a river to slow its flow, this causes the valley behind the dam to flood, forming an artificial lake known as a resevoir.water is released in a controlled way to reduces the risk of flooding
• are dams and resevoirs hard or soft engineering?

  hard engineerng
• disadvantages of dams and reservoirs

  • restrics supply of water
  • displaces farmers from their homes
  • breaks up exensive communities
  • expensive
  • soil can become less fertile
  • disrupts migrating fish
• advantages of dams and resevoirs

  • no risk of flooding downstream
  • create new habitats
  • provide hydroelectricity and clean drinking water
• channel straightening - how it works

  when a meandering section of a river is engineered to create a widened, straightened snd deepened course. this reduces the flood risk by moving water out of the area more quickly
• is channel straightening hard or soft engineering?

  Hard engineering
• disadvantages of channel straightening

  • causes more erosion
  • greater sediment buildup - the river then meanders again
  • can damage wildlife
  • channel needs to be lined with concrete
• advantages of channel straightening

  • moves water and sediment out of the area quickly
  • easier for boats to travel
  • less flood risk
• embankments - how it works

  an artificially raised river bank, this means that more water can be held in the channel. the river banks are then reinforced with gabions or lined with concrete
• are embankments hard or soft engineering?

  Hard engineering
• disadvantages of embankments

  • if the water rises above the embankments it can cause severe flooding
  • gabions and concrete lining damage habitats and look bad
  • they require maintenance
  • can errode quicker if made from earth
  • prevents access
• advantages of embankments

  • reduces flooding by increasing rivers capacity
  • provide habitats for wildlife
  • cheap
  • can be used as a walkway
• flood relief channels - how it works

  a man made channel that runs parallel to the main river and in times of high river discharge the relief channel takes the excess water
• are flood relief channels hard or soft engineering?

  Hard engineering
• disadvantages of flood relief channels

  • can cause destruction to wildlife and habitats
  • settlements downstream can have increased flooding
  • epensive
  • takes a long time to set up
• advantages of flood relief channels

  • diverts water away from built up areas
  • can be used for nature reserves
  • reduces insurance costs
  • secures the environment
• flood plain zoning - how it works

  building is restricted on parts of the floodplain that are likely to be affected by flooding
• is flood plain zoning hard or soft engineering

  soft engineering
• disadvantages of floodplain zoning

  • doens't protect urban areas that have already been built on floodplains
  • limits the buildings of homes to meet the housing shortage in the UK
• advantages of floodlain zoning

  • reduces risk to life and cost of damage
  • less impermeable surfaces near the river bank
  • creates space for cattle and green space for cities
• flood warnings and preparation - how it works

  the environment agancy issue warnings through TV, radio the internet and messages. the level of precipitation and discharge of rivers are monitored to provide up-to-date flood information
• are flood warnings and preparation had or soft engineering?

  Soft engineering
• disadvantages of flood warnings and preparation

  • not everyone has the correct technology
  • flashfloods could happen to quickly
  • doesn't prevent the flooding - only reduces the impact
• advantages of flood warnings and preparation

  • emergancy services and forces are on standby
  • people can prepare and protect
  • media publicises information
  • cheap
• planting trees - how it works

  planting trees across slopes and on flood plains reduces the risk of flooding as the trees intercept water by their leaves and take up water through their roots
• is planting trees hard or soft engineering?

  Soft engineering
• disadvantages of planting trees

  • takes years for trees to grow
  • reduces amount of land available for farming
  • changes appearances of landscapes
• advantages of planting trees

  • increases interception
  • less soil erosion
  • increases biodiversity
  • helps to reduce climate change
• river restoration - how it works

  when a river channel that has been previously hard engineered is restored to its natural channel e.g removing embankments
• is river restoration hard or soft engineering?

  Soft engineering
• disadvantages of river restoration

  • can cut through farmland
  • crops can flood
  • expensive
• advantages of river restoration

  • creates better habitats and biodiversity
  • makes the area more attractive
  • less risk of flooding
  • little maintenance