- Define and explain A River's Journey in your own words
- Use key terms such as meander accurately
- Apply what you have learned to new examples and questions
- Avoid the common mistakes learners make with this topic
This lesson focuses on A River's Journey: follow a river from its source to its mouth through the upper, middle and lower courses.
Follow a river from its source to its mouth through the upper, middle and lower courses.
Key ideas
A river changes along its course
In the upper course, steep slopes give the river energy to erode downwards, cutting V-shaped valleys and waterfalls. In the middle course the valley widens and the river begins to meander. In the lower course the gentle slope means deposition dominates, building floodplains and deltas at the mouth.
Four processes of erosion
Hydraulic action is the force of the water itself; abrasion is material scraping against rock like sandpaper; attrition is pebbles knocking together and becoming smaller and rounder; solution is minerals dissolving in slightly acidic water. All four act together in rivers and at the coast.
Key term — meander: A bend in a river, formed where faster water on the outside of the bend erodes and slower water on the inside deposits.
In which course of a river would you find a waterfall?
The upper course.
Answer: The upper course.
- Thinking deposition only happens at the mouth Deposition happens wherever a river loses energy — on the inside of bends, behind obstacles, and across floodplains in floods, not just at the mouth.
- Confusing erosion with weathering Weathering breaks rock in place; erosion moves it. Freeze-thaw is weathering, but a river carrying pebbles away is erosion.
Practice
Hydraulic action, abrasion, attrition and solution.
Water flows fastest on the outside of the bend, giving it more energy to erode the outer bank.
Sand and shingle are deposited, building a gently sloping slip-off slope (point bar).
Weathering breaks rock down in place; erosion wears it away and transports it.
Quick check
Which of these best defines "meander"?
A cliff is being undercut by waves at its base. Which process is at work, and what might happen next?
- A River's Journey: follow a river from its source to its mouth through the upper, middle and lower courses.
- A river changes along its course: In the upper course, steep slopes give the river energy to erode downwards, cutting V-shaped valleys and waterfalls.
- hydraulic action: Erosion caused by the sheer force of water — waves or river currents compress air into cracks, widening them.
- Watch out for: thinking deposition only happens at the mouth