1 / 29

The middle course of the river

The middle course of the river. Learning objective To be able to explain the characteristics of the middle course of the river To be able to able landforms created in the middle course. The BIG Question Why does the middle course have meanders?.

jenn
Télécharger la présentation

The middle course of the river

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. The middle course of the river Learning objectiveTo be able to explain the characteristics of the middle course of the river To be able to able landforms created in the middle course

  2. The BIG QuestionWhy does the middle course have meanders? C-D Must be able to describe the process that leads to the formation of meanders. A*-B Must be able to explain the process that leads to the formation of river meanders.

  3. What is the middle course like? http://www.youtube.com/watch?v=_jOFjaLO98I • What are the characteristics? • What landforms are created?

  4. Traction Saltation Suspension Solution How is material transported downstream? Boulders and pebbles are rolled along the river bed at times of high discharge. Sand sized particles are bounced along the river bed by the flow of water. Fine clay and sand particles are carried along within the water even at low discharges. Some minerals dissolve in water such as calcium carbonate. This requires very little energy.

  5. How is material transported downstream?

  6. Deposition The River Conwy has deposited material in this section of its course. Suggest reasons why this has happened.

  7. Water in a meander bend Water in a meander does not all travel at the same speed. The fastest and most powerful water travels around the outside of the bend. Think about being in the back or a car when going round the corner… Or being on a rollercoaster and being thrown to one side of the carriage.

  8. When this happens in a river it starts to develop this bending pattern.The key players in this pattern developing are e______, t_________ and deposition.

  9. Meander = a bend in a river

  10. Meanders As the course of a river approaches its middle stages it flows over flatter land. Lateral erosion dominates as the river swings in large bends known as meanders. Meanders constantly change their shape and position. Water is pushed to the outer bend . This reduces friction with the bed and banks. So the river has more energy for transporting material which can erode the outside bank via abrasion.

  11. TASK 1: Draw a river. Make sure it has bends it in like this one: TASK 2: Using a different colour mark on your river the route of the fastest water.

  12. Where the red line hits the banks – it erodes material. In the areas of the river the water is travelling slower, the water has less energy and so deposits the erodedmaterial.

  13. Erosion Deposition

  14. TASK 2: Add to your diagram where deposition and erosion are taking place Deposition Erosion = Erosion = Deposition

  15. A cross section through a meander

  16. Cross section of a meander

  17. A cross section through a meander Meander bend on the River Conwy A B Explain why there is more deposition at ‘A’ rather than at ‘B’ (3)

More Related