Geography Paper 1 - Rivers Flashcards
What does Fluvial mean?
It means rivers
What are Fluvial processes?
- Erosion - they pick up or erode weathered material
- Transport - they carry or transport the material somewhere else
- Deposition - they drop the material / deposit it
What are the types of river erosion?
- Hydraulic Action
- Abrasion
- Attrition
- Solution
What is Hydraulic Action?
The force of the river against the banks can cause air to be trapped in cracks and crevices. The pressure weakens the banks and gradually wears it away.
What is Abrasion?
Rocks carried along by the river wear wear down the river bed and banks.
What is Attrition?
Rocks being carried by the river smash together and break into smaller, smoother and rounder particles.
What is solution?
Soluble particles are dissolved into the river.
What are the shapes Fluvial processes create called?
Landforms
What are two ways Fluvial processes create landforms?
Create some landforms by eroding material and others by depositing material.
What are the two directions rivers erode?
- Lateral Erosion
- Vertical Erosion
What is the effect of the valley in vertical erosion and where does it happen?
- Deepens the valley
- At the start of the river - Higher Course.
What are types of transportation of materials?
- Suspension
- Traction
- Solution
- Saltation
What is suspension?
Fine light material is carried along in the water
What is solution?
Minerals are dissolved in water and carried along in solution
What is Saltation?
Small pebbles and stones are bounced along the river bed
What is traction?
Large boulders and rocks are rolled along the river bed
Define the load of the river
The load of the river is the material carrier by the river.
What is deposition?
This is when a river drops the eroded material (load) it has been carrying.
When does deposition occur?
When a river slows down or loses velocity
What are ways river loses velocity?
- River bursts it’s banks during a flood
- The amount of water (or volume of water) in the river decreases
- The water becomes shallower (e.g on the inside of a bend of a river)
- The river meets the sea at its mouth
What are characteristics of the upper course of a river?
- V-Shaped valley
- Narrow and shallow channel
- Steep Valley sides
- Steep Gradient
- Lateral Erosion (straight river)
What are characteristics of the middle course of a river?
- More gentle sloping valley sides than upper course but more than lower course.
What are characteristics of the lower course of a river?
- Wider and deeper channel
- Gentle gradient
- Wide and flat valley
- Lateral Erosion (bends in the river)
What are rivers that connect to a bigger one leading to a sea/ocean called?
Tributary
