Rivers: VOF/SOF

Question 1

State the factors affecting the volume of river?

Answer 1

1. Size of drainage basin
2. Presence of vegetation
3. Permeability of rocks/ground type
4. Climate (amount of precipitation)

Question 2

How does size of drainage basin affect volume of river?

Answer 2

Larger drainage basin-> more tributaries-> greater VOF/discharge

Vice versa

Question 3

How does the presence of vegetation affect volume of river?

Answer 3

Abundant vegetation-> more rain intercepted by plants-> more infiltration-> lower surface runoff-> lower VOF/discharge

Vice versa (Sparse vegetation)

Question 4

How does permeability of rocks/ground type affect volume of river?

Answer 4

More permeable rocks/ground-> more water passes through/higher infiltration-> lower surface runoff-> lower VOF/discharge

Vice versa

Question 5

How does climate affect volume of river?

Answer 5

Dry season-> lower amount of rainfall-> smaller VOF/discharge

Vice versa

Question 6

State the factors affecting speed of flow of river

Answer 6

1. Gradient of channel
2. Roughness of channel
3. Wetted perimeter
4. Depth of channel

Question 7

How does gradient of channel affect speed of flow of river?

Answer 7

Steep slope-> more energy-> greater SOF

Vice versa

Question 8

How does roughness of channel affect speed of flow of river?

Answer 8

Smoother channel-> lesser friction with obstacles-> faster SOF

Vice versa

Check notes for drawing

Question 9

What is wetted perimeter and how does it affect speed of flow of river?

Answer 9

1. Wetted perimeter refers to the length and breadth of the channel in contact with the river’s water
2. Greater wetted perimeter-> more friction-> lower SOF

Vice versa

Check notes for drawing

Question 10

How does depth of channel affect the speed of flow of river?

Answer 10

Greater depth-> lesser friction-> higher SOF

Vice versa