How Does Stream Flow Change over Time? (ES1301)
Background
You will view images that suggest the key controls of stream flow. You will view examples illustrating situations where rainfall, snowmelt, and water release from dams caused stream flow to change. You will examine graphs of stream discharge coupled with graphs of rainfall, snow depth, and temperature to analyze how these factors affect stream flow. Finally, you will interpret a set of graphs to make inferences about the factors controlling observed discharge.
Stream discharge is the volume of water that flows past a point over a specific period of time. Factors that affect stream discharge include rainfall, snowmelt, and releasing water from dams. When discharge increases, velocity is likely to increase. As velocity increases, the eroding ability of the stream also increases.
Conclusions
1. Describe three (3) factors that control how much water is flowing in a river.
2. This question refers back to slide 11 on the PowerPoint from today. What were the factors that caused the increase in discharge (different flow conditions) of the three rivers on page 3 of the investigation?
3. What do the spikes in the graph indicate?
4. List the date and amount of discharge for the two highest peaks on the graph.
5. What do the spikes in the graph indicate?
6. List the date and amount of precipitation for the two highest peaks on the graph.
7. Record the amount and dates of the five (5) discharge spikes and amount and dates of the seven (7) precipitation spikes.
Discharge Spike # / Amount / Date1
2
3
4
5
Precipitation Spike # / Amount / Date
1
2
3
4
5
6
7
What do you notice about the timing of the peaks of discharge and rainfall?
8. What do you conclude from the timing and relationship between peaks of discharge and temperature starting in March? What other data might you need to confirm your hypothesis?
9. What do you notice about the timing of the peaks of discharge and rainfall? What do you conclude from this relationship?
10. What relationship exists between temperature and discharge? What do you conclude from this relationship?
11. What do you think is responsible for the regular shape of the discharge peaks? Speculate on the cause of the major discharge peak at the end of March.
12. THIS QUESTION IS THE MOST IMPORTANT QUESTION OF THE ENTIRE INVESTIGATION!!! HERE IS WHERE I WANT YOU TO WRITE CRITICALLY ABOUT THE ENTIRE INVESTIGATION. I WILL BE LOOKING AT YOUR RESPONSES TO THIS QUESTION VERY CAREFULLY!!
Write a summary describing the factors that affected the discharge of Hubbard Brook in February, 2000. Be sure to refer to specific peaks on the graphs, and be sure to connect events and peaks to each other, if applicable.
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