fluvial processes Flashcards
(19 cards)
What is erosion?
wearing away of the bed and banks or a river channel by moving water
What is transportation?
when material (sediment) is carried by a river
What is deposition?
when sediment is dropped off by the river because it doesn’t have enough energy
What are the four erosional processes?
abrasion, hydraulic action, attrition, and solution
What is abrasion?
rocks and stones carried by the river wear away the bed and banks by scraping them
What is hydraulic action?
the power of the water forces air into cracks in the banks and weakens them so they eventually collapse
What is attrition?
the particles carried by the river are bashed against each other, making them smaller and rounder
What is solution?
the water dissolves soluble materials from the bed and banks which helps them to break up
What are the four processes of transportation?
traction, saltation, suspension, and solution
What is traction?
rolling large stones along the bed of the river
What is saltation?
bouncing smaller particles along the bed
What is suspension?
sediment that floats within the river flow
What is solution?
minerals dissolved in the water
What is velocity?
speed of the flow of the water - it increases from source to mouth
What could cause an increase in velocity?
waterfalls and the outside of a river bend
What could cause a decrease in velocity?
the inside of a river bend
What is discharge?
volume of water in a river passing a given point at a given time - it increases from source to mouth
What could cause an increase in discharge?
high rainfall, tributaries
What could cause a decrease in discharge?
drought
