River processes flashcards AS level

Question	Answer
Bedload	Large particles that cannot be picked up by the current. Saltation: pebbles/sand/gravel temporarily lifted and bounced along the riverbed. Traction: largest particles rolled along the riverbed.
Suspended load	Fine particles of clay and silt are dislodged and carried by current turbulence.
Solution / dissolved load	Soluble rock held in solution. Chalk/limestone.
Corrasion	River picks up material and erodes the banks/bed by abrasion. Most effective during flooding. Erodes horizontally and vertically.
Attrition	Bedload collides with other rocks which break into smaller pieces over time. Smooths angular rocks.
Hydraulic action	Force of water breaks into cracks in river bank. Compressed air in cracks increases pressure and the bank breaks apart. Cavitation: collapsing bubbles of air weaken banks.
Solution / Corrosion	Occurs continuously. Independent of velocity or discharge. Chemical composition of water (concentration of acid).

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	Created by Tamara Herrington over 10 years ago