River Processes Flashcards
what is erosion?
the wearing away of rock by the natural processes of rivers
what are the different types of erosion?
•attrition
•hydraulic action
•abrasion
•solution
what is attrition?
rocks being carried by the river smash together and break into smaller, smoother particles
where is attrition most likely to happen?
the middle and lower course
what is hydraulic action?
the force of the rivers against the banks can cause air to get trapped in gaps. The force of the water weakens the banks and wears it away
where is hydraulic action most likely to occur?
the middle and upper course
what is abrasion?
rocks carried along by he river scrape along the river bed
where is abrasion most likely to occur?
the upper course
what is solution in terms of erosion?
soluble particles being dissolved in water
where is solution most likely to occur?
the lower course
what is transportation?
the ways in which the river transports it’s loads
what is solution in terms of transportation?
minerals being dissolved in water. This is a chemical change
where is solution most likely to occur?
the lower course
what is suspension?
fine, light material being carried along by the river
where would suspension most likely occur?
middle and lower course
what is saltation?
small pebbles and stones bouncing along the river bed
where is saltation most likely to happen?
the middle and upper course
what is traction?
large boulders and rocks being rolled around the river bed
where is traction most likely occur?
the upper course
what does the size of the load the river carries depend on?
the energy the river has- the more energy the bigger the load
what is deposition?
when a river loses energy so drops whatever load it is carrying
what is sediment?
deposited load
why do rivers deposit load?
•drier weather so less energy
•river slows in speed so less energy e.g. inside bend of river
•river floods
