REVISION AS CAMBRIDGE GEOGRAPHY: RIVERS - STREAM AND RIVER VELOCITY.

1. AS GEOGRAPHY
HYDROLOGY
4 QUESTIONS
REVISION
STREAM/RIVER
VELOCITY

2. DEFINITION
The stream or river velocity is the speed of water flow, such as the
distance travelled per unit of time.

3. QUESTION 1
Which three factors control velocity?

4. ANSWER
Gradient channel, efficiency channel roughness.

5. QUESTION 2
Why does velocity normally increase downstream even though
gradient usually decreases?

6. ANSWER
Because the other factors are more important.

7. QUESTION 3
How and why does velocity vary across a channel?

8. ANSWER
The lowest velocity occurs nearest the bed and banks, with the highest
velocity towards the centre off the channel.
This is due to friction between the moving water and the bed/bank
material.

9. QUESTION 4
What is a thalweg of a river?

10. ANSWER
The downstream line of maximum velocity.