Erosion, Transportation And Deposition Flashcards
What is erosion
Erosion is the wearing away of the bed and banks of the channel. It involves picking up and removal of material. It occurs when the river has high energy available
Describe characteristic of high energy river
Large fast flowing rivers transport more sediment and carry out more erosion than small low energy rivers
Describe the characteristic of a low energy river
Reduced energy and discharge means that less sediment is transported downstream, deposition occurs
What is hydraulic action
The force of the river against the banks causes air to become trapped in the cracks in the rock and causes the rock to break apart
What is abrasion
Scraping, scoring and rubbing action of materials carried along by the river, which wears down the bed and banks. Very effective during turbulence and floods
What is attrition
Rocks carried by the river SMASH TOGETHER and against the river bed and break into smaller, smoother and more rounded particles. Larger material upstream and smaller material downstream
What is solution/corrosion
Dissolving of chemicals/minerals in the rock by weak acids in the river
What is transportation
Rivers pick up the load and carry it downstream
What is traction
ROLLS the heaviest stones and boulders along the river bed by water moving downstream
What is saltation
Medium sized rocks BOUNCE along the river bead
What is suspension
The smallest particles are CARRIED ALONG in the river
What is solution
Some chemicals dissolve in the water
What is deposition and why does it happen
When the river drops the loads it has been carrying. This happens when the velocity/discharge of the river is reduced and its energy is reduced so it is not able to erode or transport material so the load is dropped, starting with the largest first
When does deposition take place
MDF
