mississippi

• Mississippi River


  • Largest drainage basin in USA and parts of Canada
  • Located in SE of USA
• Uses of the Mississippi River

  • Shipping channel
  • Recreation
  • Hydroelectric power
  • Drinking water
• The Mississippi River is hard to engineer
• Levee engineering


  1. Raised 15m

  2. Strengthened to enclose channel for 3,000km
• Levees failing


  Riverbed silting up
• Hard engineering is more effective in the short term but less sustainable
• New floodplain ends below risen river bed in New Orleans, which is 4.3m
• Less alluvium deposited


  Soil less fertile, artificial fertilisers needed
• Dams on main tributaries

  1. 100 dams controlling tributaries

  2. Expensive to construct and maintain

  3. Unsustainable
• River straightening


  1. Meanders cut through stretch of 1,750km

  2. Creates fast flowing channel

  3. May cause floods downstream
• Soft engineering: Afforestation


  • Trees planted in upper course to intercept (Tennessee)
  • Not applied over wide enough area
  • Trees haven't grown large enough to be effective
• Soft engineering: Safe flood zones


  • Housing bought by country and demolished to allow flooding
  • Some states still developing housing on floodplains e.g. St Louis
• Soft engineering: Washlands


  1. Morganza spillway opened in 2011 to flood 12,000 km² of farmland

  2. 2011 flood showed lack of washland
• US conservation spent £25 million buying farmland
• hard engineering methods

  • levees

  • dams

  • river straightening
• soft engineering methods

  • afforestation

  • safe flood zones

  • washlands
• river outside british isles : mississippi