River erosion occurs through processes like abrasion and hydraulic action that wear away rock in the river bed and banks. This shapes the landscape, creating narrow V-shaped valleys through vertical erosion and lengthening rivers upstream through headward erosion. Lateral erosion widens the river channel and forms U-shaped valleys. River transportation involves moving eroded material downstream via traction, saltation, suspension, or solution based on the size and weight of the load.

1. Works of river

2. Previous lessonRiver erosion

4. River erosionThe process of wearing away of the rocks on the bed and banks of the river by the energy of the river flow.

5. River erosion also happens by the load carries on the river channel itself.

6. The erosion rate varies with different volume and velocity.Processes involved in river erosion.Corrasion (abrasion)AttritionSolution (corrosion)Hydraulic action

7. Types of river erosionVertical erosionHeadward erosionLateral erosion

8. Vertical erosionRiver removes material from river bedBy corrosion/abrasion processResult:Deepen a river channel and create narrow V-shaped valley.

9. Headward erosionRiver cut its sourceResults: lengthening of the river in the upstream direction

10. Lateral erosionThe wearing away of river bankBy corrosion and solution process.Result: widen the river and form a U shaped valley.

11. River transportation

12. Objectives:Understand river transportation

13. Understand processes of river transportation (suspension, saltation, traction and solution)

14. River transportationWhen a river transport its load downstream.The loads are the eroded materialsThe volume and velocity of the river affects the river transportation rate

15. 4 ways of river transportationTractionSaltationSuspension

16. TractionMaterial: Big rocksHow? Rolling and Dragged on the river bedWhy? They are heavy

17. saltationMaterial: small stonesHow? Hopping and Bouncing on the river bedWhy? Caused by swirling water

18. suspensionMaterial: fine (very small) rocks.How? Carried along the river surfaceWhy? They are very light

19. SolutionMaterial: dissolved materialsHow? Carried along the waterCant see by naked eyes

20. Mnemonics:Teacher (Traction)SAya (SAltation)SUka (SUspension)SOtong (SOlution)

21. Summary:RivertrasportationDefinition:4 ways of river transportation: