2Lesson Aims To learn what is erosion: To learn what is transportation: AbrasionHydraulic actionAttritionSolutionTo learn what is transportation:TractionSaltationSuspensionTo learn what is deposition.Key Skill = Communication
3ErosionErosion is the wearing away of land and then the transportation of the worn away material.
4ErosionAbrasion: 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.
5Activity What is erosion? What are the 4 processes that make up river erosion?
6TransportationIs the movement of the material that has been eroded. This material is called the load.
7TransportationBedload (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).
8Activity What is transportation? What are the 4 processes that make up river transportation?
9DepositionAs the river loses energy it can no longer carry its load. The load settles to the river bed. The larger load settles first.
10ActivityExplain why deposition happens in rivers.
11Extension ActivityTry to devise a sketch or sketches to help illustrate the processes of erosion and transportation.