Name: Period:
Stream Discharge
The water velocity needed to carry sediment depends on the size of the sediment. A larger rock requires a lot more stream velocity then a smaller rock.
Let’s look at the Relationship of Transported Particle Size to Water Velocity chart on page 6 of your reference table.
Notice that a boulder needs about a minimum velocity of about 350 cm/sec, where a pebble only needs a minimum velocity of 75 cm/sec to transport it.
1. What is the minimum velocity needed to transport a cobble? ______
Lets look at the chart again.
If water slows down it will deposit any size sediment that is too large to carry.
2. If a river is carrying a load of sediment and it is moving at a speed of 700 cm/sec, but slows to 200 cm/sec, what two types of sediments will it deposit? ______and ______
3. If it had only slowed down to a velocity of 300 cm/sec, what is the only sized particle that would have deposited. ______
Stream velocity can increase or decrease as a result of several things.
4. If a stream enters a still body of water will its velocity increase or decrease? ______
5. If a stream’s slope increases would its velocity increase or decrease? ______
6. What if its slope decreased? ______
7. If a stream’s discharge (amount of water flowing in the stream) increases would its velocity change? ______
8. With that said would rivers have greater velocity in the spring or summer? ______
10. Why? ______
______
A Review on Meanders
a
b
c d
11. Which has faster moving water a or b? ______
12. Where is deposition occurring a or b? ______
13. Where is the river cut bank steeper c or d______
1 2
3
Which of the numbers above most likely represents letter d on the last page? ______(We are looking at the steepness of the channel!)