Erosion, Transportation and Deposition

Question 0

Describe the four processes of erosion taking place in the River Dance.

Answer 0

Abrasion - eroded rocks picked up by the river scrape and rub against the channel, wearing it away.
Attrition - eroded rocks picked up by the river smash into each other and break into smaller, more rounded fragments.
Hydraulic action - the force of the water breaks rock particles away from the river channel.
Solution - river water dissolves some types of rock, e.g. chalk and limestone.

Question 1

Name and describe two processes by which material is transported in rivers.

Answer 1

Traction
is when large particles are pushed along the river bed by the force of the water.
Suspension
is when small particles are carried along by the water.
Solution
is when solvable materials are dissolved in the water and carried along.

Question 2

Deposition occurs when rivers slow down. Describe four reasons why rivers slow down.

Answer 2

Rivers slow down when the volume of water in the river falls.
They also slow down when the amount of eroded material in the water increases,
when the water is shallower, e.g. on the inside of a bend,
and when they reach their mouth.