River Processes Flashcards
What is traction?
Traction is rolling stones along the river bend, this needs the most energy, it occurs between the top and middle of the river and happens to boulders.
What is corrosion?
Corrosion is the chemical reaction (and an erosion process) which takes place between specific types of rocks and river water.
What is Abrasion?
When the load is carried along the river and thrown up the river banks with considerable force. Corrosion then follows.
The
What is Erosion?
Erosion processes consist of; hydraulic action, Mass movement, Chemical weathering and Freeze-thaw weathering and biological weathering.
What is hydraulic action?
When the pressure of the water being pushed against the banks and beds. It also includes the compression of air in cracks. This pressure causes the rocks to fall off.
What is chemical weathering?
Rainwater that contains weak acid that can react with certain types of rocks. The carbonates in limestone are dissolved by these weak acids, this causes the rocks to break up and disintegrate.
☔️Rainwater that contains
What is soil creep?
Soil that moves slowly down a hill
What is slumping?
a fast moving landslide (consisting of soil) which leaves a curved surface.
What is Freeze-thaw weathering?
When the temperature falls below freezing water, it turns to ice. The ice expands and this puts pressure on the rock (causing fragments to break off)
What is biological weathering?
When a seed falls into a crack, when the moisture comes it grows into a plant, the cracks then expand.
What is suspension?
Suspension is when clay and silt sized particles are transported down the river
What is saltation?
Saltation is when sand sized particles bounce along the bed of the river resembling a leap from. The particles get bigger as they move along the river bed.
What is Attrition?
Attrition is when rocks come from the source of the river. These rocks bang into each other and chip away, creating sand and small pebbles.
