FLUVIAL PROCESSES

Question 1

Weathering

Answer 1

Breakdown + decay of rock by natural processes without any moving force (no movement)

Question 2

Erosion

Answer 2

Wear away and moving (transport) of material by a moving force

Question 3

Mass movement

Answer 3

Movement of material (weathered) downslope due to gravity

Question 4

Deposition

Answer 4

Disposal of material carried by a moving force (e.g. river)

Question 5

Load

Answer 5

All material being transported by the river

Question 6

Bed load

Answer 6

All material transported on the river bed

Question 7

4 types of erosion

Answer 7

• hydraulic action
• Abrasion
• Attrition
• Solution

Question 8

Hydraulic action

Answer 8

Water enter cracks in rocks in the river bank and bed, breaking it apart and carrying it away

Question 9

Abrasion

Answer 9

Scraping of rocks against the river bed

Question 10

Attrition

Answer 10

Particles in the river collide with each other, making them rounded and smaller

Question 11

Solution

Answer 11

Soluble minerals in rocks are dissolved and carried away by the river

Question 12

4 methods of transport

Answer 12

• Traction
• Saltation
• Suspension
• Solution

Question 13

Traction

Answer 13

Large rocks rolling along the river bed

Question 14

Saltation

Answer 14

Smaller rocks bouncing along the river bed

Question 15

Suspension

Answer 15

Light material carried along by river flow, not heavy enough to sink

Question 16

Physical/mechanical weathering

Answer 16

• Thermal expansion: rock expand by sun and contracts at night. Breaks rock over time
• Freeze-thaw weathering: Water in cracks freezes and expands. Breaks/fractures rock

Question 17

Chemical weathering

Answer 17

Breakdown of rocks due to acid rain

Question 18

Biological weathering

Answer 18

roots of plant enter cracks of rocks and gradually split the rock

Question 19

2 types of mass movement

Answer 19

• Slumping: bottom of valley is cut away by river. Slope becomes unstable and weathered material slumps down
• Soil creep: gradual movement of weathered material down slope due to gravity, collects at bottom of valley

weathered material

Question 20

Deposition

Answer 20

When river has less energy, lower discharge. Happens near sea/lake, and inner bends of meanders

Question 21

Vertical and lateral erosion

Answer 21

Vertical erosion : deepening of river bed

- Lateral erosion: widening of a river channel