River Processes Lab
The work a river does: the four types of erosion, the four ways it carries its load, and how it drops that load as it slows, changing all the way down the long profile from source to mouth.
Use it, the way the marks are given
Free interactive practice at using the material, which is what the marks are for.
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The work a river does
A river is always at work: tearing at its bed and banks, carrying the pieces downstream, and dropping them when it runs out of energy. Exam questions rarely ask you to list the processes; they describe one and ask which it is. This module works through the four kinds of erosion, the four ways a river carries its load, and where it lets that load go.
River words to know
Learn these before you name a process.
Abrasion against attrition
The commonest mix-up: ask what is being worn away.
Ask what is worn, and by what
In the exam, do not just list the processes; say which one a description shows. Ask two questions: what is being worn away, and what is doing the wearing. Water pushing into cracks by its own force is one process; the load grinding against the channel is another; the load battering itself into smaller, rounder pieces is a third; and rock quietly dissolving in the flow is the fourth. The same load then travels rolled, bounced, floating or dissolved, and settles wherever the river loses energy.
Match the erosion
- hydraulic action
- abrasion
- attrition
- solution
- the force of the water breaking rock away
- the load scraping the bed and banks
- the load knocking together and wearing smaller
- the water dissolving soluble rock
Match the transport
- traction
- saltation
- suspension
- deposition
- large rocks rolled along the bed
- small stones bounced along the bed
- fine material carried within the water
- the load dropped when the river slows
Which process is this?
Rocks carried by a river knock together and are worn smaller and rounder. Which process is this?
- Attrition
- Abrasion
- Hydraulic action
- Deposition
True about river processes
Select the TWO true statements about river processes.
- Hydraulic action is the force of the water alone
- A river drops its load when it slows down
- Abrasion is rocks wearing each other smaller
- Suspension means large boulders rolled along the bed
Measure the middle course
A river is 60 km long from source to mouth, and its middle course makes up one third of that length. Divide 60 by 3 to find the length of the middle course in km. What is the answer?
Order the long profile
Put the stages of a river from source to mouth in order, earliest first.
- Near the source the river is steep and narrow
- In the middle course it widens and speeds up
- In the lower course it is wide and slow
- At the mouth it drops its load
Complete the rules
The wearing away of the bed and banks is _____. The force of the water alone is _____ action. The load scraping the channel is _____. The load knocking together and wearing smaller is _____.
Spot the transport methods
Tap the TWO ways a river transports its load.
- rolling large rocks along the bed
- carrying fine material within the water
- dissolving the banks with acid rain
- freezing the water into solid ice
Name the process
Read each real river clue and name the process.
- The river water alone forces into cracks in the bank and breaks pieces off. Which process is this?
- Stones carried by the river bounce along the bed in a series of small hops. Which transport method is this?
- The river reaches flat land, slows right down and lets go of the material it was carrying. What is this?
Explain river processes
Explain how a river erodes, transports and deposits material.
- Name and explain the four erosion processes
- Explain the ways a river transports its load
- Explain when and why a river deposits its load