River Processes Flashcards
What is erosion
The key concept of the upper course
‘ the wearing away of the land’
What are the 4 main types of erosion
Abrasion
Attrition
Solution
Hydraulic action
Whats abrasion
Sand and stones on the river bed and banks and wear them away
What’s attrition
Rocks and stones knock together and wear each other away. The stones become smoother and more rounded.
What is Hydraulic action
In a fast flowing river the water is forced into the cracks in the banks. Over time it breaks up the bank.
What are the two types of erosion which are most active when making a waterfall
Hydraulic action and abrasion
What is Deposition
Is the dropping off of material as the river slows down.
It does not have enough energy to carry the material, this causes deposition.
What are the 4 processes or transportation
Traction
Saltation
Suspension
Solution
Traction definition
Boulders and pebbles are rolled along the river bed at times of high discharge.
Saltation definition
Sand sized particles are bounced along the bed by the flow of the water
Suspension definition
Fine clay and particles are carried along with the water even at low discharges
Solution definition
Some minerals dissolve in water such as calcium carbonate, this requires very little energy
