River Processes

Question 1

What are the 3 main river processes?

Answer 1

Erosion, transportation and deposition

Question 1

What is erosion?

Answer 1

The process that wears down river beds

Question 2

What is transportation?

Answer 2

Rivers moving material

Question 3

What is deposition?

Answer 3

When rivers drop the material they’ve been carrying

Question 4

What are the 4 subsections in erosion?

Answer 4

Hydraulic action, abrasion, attrition and solution

Question 5

What is hydraulic action?

Answer 5

Where fast flowing water is forced into cracks and breaks up the river bank over time

Question 6

What is abrasion?

Answer 6

Where sand and pebbles get dragged along the river bed (or knock into it) by saltation, wearing away the river bed

Question 7

What is attrition?

Answer 7

When rocks knock together and wear each other away

Question 8

What is solution?

Answer 8

When alkaline rocks get dissolved by acidic rain water

Question 9

What are the 4 subsections of transportation?

Answer 9

Traction, saltation, suspension and solution

Question 10

What is traction?

Answer 10

When large stones get dragged along the river bed

Question 11

What is saltation?

Answer 11

When smaller stones are picked up, then dropped, giving them a bouncing motion

Question 12

What is suspension?

Answer 12

When tiny particles are carried in the rivers current

Question 13

What is solution in transportation?

Answer 13

When dissolved chemicals are carried along the river

Question 14

When does erosion occur?

Answer 14

If a river has a lot of energy left over after overcoming friction (a fast flowing, efficient channel)

Question 15

When does deposition occur?

Answer 15

If a river does not have enough energy to carry a load

Question 16

What are the 3 types of weathering that happen in a river valley?

Answer 16

Physical, chemical and biological

Question 17

What is physical weathering?

Answer 17

When physical force breaks rocks into pieces, e.g freeze-thaw weathering

Question 18

What is chemical weathering?

Answer 18

Any chemical change/ decay of a rock, e.g acid rain on limestone

Question 19

What is biological weathering?

Answer 19

Where small cracks in rocks allow plant roots to penetrate, forcing the cracks apart as the plant grows

Question 20

What are the two types of mass movement?

Answer 20

Soil creep (slow)
Slumping (rapid)

Question 21

What is soil creep?

Answer 21

When rain dislodges tiny soil particles at a rate of around 2m per year

Question 22

What is slumping?

Answer 22

Where a large segment of a cliff moves down a slope