Fluvial processes part two
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Rivers undergo three main processes: erosion, transportation, and deposition. They erode most in their upper reaches where the channel is narrow and flow is fast. In their middle reaches, transportation dominates as the channel widens and sediment of varying sizes is moved downstream. Deposition occurs most in lower reaches where the channel is wide and flow slows, causing sediment to drop out of the river system. These fluvial processes shape the landforms left behind, such as deltas, valleys, and floodplains.
Fluvial processes part two
- 1. Fluvial Processes II A revision of Fluvial Processes, Landforms and Characteristics
- 2. Fluvial Processes • Rivers are driven by Gravity and the water cycle • They have elements, processes and create landforms as outputs.
- 3. Fluvial Processes • Rivers Erode • Rivers Transport • Rivers Deposit
- 4. The Elements of the Process • The Elements of fluvial Processes are • Gravity • Water • Sediment • Topography
- 5. The Outputs of the Process • The outputs of the processes are landforms such as deltas, V-shaped valleys, islands and oxbow lakes.
- 6. How Rivers erode • When a river is flowing fast it has a lot of energy to erode the bed and banks of its channel. • This occurs in the upper portions of the river.
- 7. How Rivers transport • Rivers transport larger material where they have the most energy. • Large sediment (rocks) require a lot of energy to be moved. Small sediment (ash) requires little energy to be moved.
- 8. How Rivers Transport • Sediment is moved… • In Suspension (dissolved) • By Saltating (bouncing) • By Traction (rolling)
- 9. How Rivers Transport • Rivers mainly transport in the mid section of the river
- 10. At the base the river is wide and slow
- 11. How Rivers Deposit • Rivers deposit their load (sediment) when they lose energy. • Where rivers flow slowly they drop their sediment.
- 12. Where Rivers Deposit • Rivers flow slowly at their mouth in the lower section of the river. • Rivers flow slowly on the inside of bends.
- 13. Characteristics of the River • Text Upper course Narrow channel, fast flowing Mid Course Medium channel, medium speed Lower Course Wide Channel, Slow Velocity
- 14. Processes on the River • Text Erosion Dominates Transport Dominates Deposition Dominates
- 15. Erosion and Deposition Fast = Erosion Slow = Deposition
- 16. Why the Channel Moves • Text Channel moves this way Outside of Bend = Fast flow Inside of Bend and Erosion = Slow Flow And Deposition
- 17. Rivers at the mouth are wide • Text
- 18. Rivers at the source are narrow and fast
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