What is the river course
The path of the river as it flows downhill
Where is the upper course
Closest to the source of the river
Where is the lower course
Closest to the mouth of the river
How do rivers form channels and valleys
Upper course properties
Middle course properties
Lower course properties
Vertical erosion
Lateral erosion
- Dominant in the MIDDLE and LOWER courses
Name the four process of erosion
Hydraulic action
The force of water breaks rock particles away from the river channel
Abrasion
Eroded rocks picked up by the river SCRAPE and RUB against the channel, wearing away.
Most erosion happens by abrasion
Attrition
Eroded rocks picked up by the river SMASH into each other breaking into smaller fragments.
The edges are rounded off as they rub together
Solution
River water DISSOLVES some type of rocks e.g. chalk and limestone
Name the four processes of transportation
Traction
Large particles (like boulders) are PUSHED along the river bed by the water FORCE
Saltation
PEBBLE sized particles are BOUNCED along the river bed by the water FORCE
Suspension
SOLUBLE materials DISSOLVE in the water and are CARRIED along
Solution
River water DISSOLVES some type of rocks e.g. chalk and limestone
When does deposition happen and why
- Happens when a river slows down (loses velocity)
Why do rivers slow down and deposit material
What happens when a river is eroding and depositing material
Meanders and ox-bow lakes
Where are meanders found
In the middle and lower courses
Formation of a meander