002 - Floodplain management

Syllabus Point

Explain (AO2) the stream channel processes (erosion, transport, deposition) and explain the resultant landforms found on floodplains.
Examine (AO2) the human modifications of a floodplain and their effect on the size and probability of floods.
Evaluate (A03) the costs and benefits of alternative stream management strategies.

Key Terminology

  • Examine
  • Explain
  • Evaluate
  • Deposition
  • Erosion
  • Attrition
  • Hydraulic Action
  • Corrasion
  • Corrosion
  • Transportation - solution, suspension, saltation, traction
  • Floodplain
  • Meander
  • Ox-bow lake
  • Levee
  • Pool
  • Riffle
  • Delta
  • V and U shaped Valley
  • Afforestation
Define the terms below using your 'IB Geography. Course Book' by Cooke and Nagle, the command term posters in the classroom and the links below.




Activity One - Watch and record

  • You will be developing a landforms guide, so as you watch the YouTube clip below make notes on how the different landforms are created and which processes are associated with them.

Taken From: https://www.youtube.com/watch?v=JqFhmZc5Wis




Activity Two - Guide


You will developing a guide to the different landforms that can be created on a flood plain. When devising the guide you will need to include the following points:
          • Description of what the landform looks like.
          • Image of the landform (you could be asked to draw or identify one in the exam)
          • Explanation of how the landform is created.
          • No more than two A4 sides in length.

Resources

    • Use the information in the previous activities.
    • The text book 'Geography. Course Companion' by Cooke and Nagle

    • The text book 'Geography. An Integrated Approach' by David Waugh

Example

River Landforms





Activity Three - Comprehension

Human modifications on flood plains occur for a variety of reason but primarily for the building of houses, infrastructure and flood control. Reading pages 123-124 in your 'Geography Course Companion' text book, explain how the following factors impact the flow of water in a drainage basin:
        1. Encroachment on the river channel
        2. Replacement of vegetation by impermeable surfaces
        3. Building activities
        4. Dams
        5. Water resource problems
        6. Flood control problems



Activity Four - Magnitude and Frequency

  • Using the graph below, explain the relationship between magnitude and frequency.
Taken from: http://d32ogoqmya1dw8.cloudfront.net/images/quantskills/methods/quantlit/redriverrec.gif


  • How could the human modifications on a flood plain influence the graphs results?



Activity Five - Stream Management

As humans are increasingly building on flood plains due to the desirability of the flat fertile land, there is an increased potential for flooding. To try and prevent flooding humans have developed alternatives to stream management. 
  1. With the aid of diagrams, describe what the following alternative management strategies are and explain how they impact the flow of water. 
  2. Complete a cost-benefit analysis for each form of alternative stream management.
          • channelisation
          • diversion channels
          • levees/flood embankments
          • channel enlargement
          • intercepting channels
          • removal of settlements
          • land-use management
          • straightening of channels
          • afforestation

Resources

  1. 'Geography Course Companion' by Nagle and Cooke pages 125-126
  2. Greenfield Geography
  3. The British Geographer