1. River Processes
Lesson 3 – page 3

2. Lesson Aims To learn what is erosion: To learn what is transportation:
Abrasion
Hydraulic action
Attrition
Solution
To learn what is transportation:
Traction
Saltation
Suspension
To learn what is deposition.
Key Skill = Communication

3. Erosion
Erosion is the wearing away of land and then the transportation of the worn away material.

4. Erosion
Abrasion: When material carried by the river rubs against its banks and bed.
Attrition: Rocks transported by the river collide, break up into smaller pieces and become smoother and more rounded.
Hydraulic action: The force of moving water.
Solution: When chemicals in water dissolves the rock.

5. Activity What is erosion?
What are the 4 processes that make up river erosion?

6. Transportation
Is the movement of the material that has been eroded. This material is called the load.

7. Transportation
Bedload (along the streambed – sometimes called traction)
Saltation (by a series of hopping movements along the bed)
Suspended load (above the bed)
Solution (dissolved in the water).

8. Activity What is transportation?
What are the 4 processes that make up river transportation?

9. Deposition
As the river loses energy it can no longer carry its load. The load settles to the river bed. The larger load settles first.

10. Activity
Explain why deposition happens in rivers.

11. Extension Activity
Try to devise a sketch or sketches to help illustrate the processes of erosion and transportation.