ISP 217L Lab 6 Assignment Water and the Environment Laboratory ISP 217 Lab Write-Up Assignment Help
Lab 6
How are flow, turbidity, and precipitation related for the Red Cedar River?
50 points; NOTE: Required for all students
Due May 2nd by 5pm in Room 14 Natural Resources in my Mailbox (Katelyn King)
A. Graphs, Tables, and Calculations
Before beginning, download the 5 weeks of USGS discharge and MSU precipitation data from their
respective websites (see the Lab Manual for instructions). Use March 19th, 2018 as the start date and
April 20th, 2018 as the end date for download. You may elect to download all the data at once on April
21st, or download portions in advance to allow you to begin working on components of the assignment.
Be sure you convert USGS discharge data to cms (m3/s), or you won’t be able to make meaningful
comparisons to your data!
1. Hydrograph (a graph showing discharge and precipitation through time): make a hydrograph for the
Red Cedar River using a secondary y-axis line graph (see Excel Manual Tutorial 7).
a. Plot precipitation on one y-axis, USGS discharge on the other y-axis, and date on the x-axis.
Use the full 5-weeks of data you downloaded; you do not need your own measurements
here. Be sure the variables are paired up by sample date! [5 pts]
2. Scatter plot: Your team’s six discharge measurements vs. USGS discharge during the same 6 days. Be
sure the two datasets are paired-up by sample date first, then plot one discharge vs. the other
discharge. (Note: Dates will not be on an axis).
a. Include a trend line, its equation, and R2 on the graph. [5 pts]
3. Correlation analysis: calculate the correlation coefficient (r) for the relationship you graphed in part
(2) above [2 pts]
4. Scatter plot: Your six turbidity estimates vs. USGS discharge, recorded on the same days. Be sure the
two datasets are paired-up by sample date before plotting (Dates will not be on an axis)!
a. Include a trend line, its equation, and R2 on the graph. [5 pts]
5. Scatter plot: Your six load estimates vs. USGS discharge, recorded on the same days. Be sure the two
datasets are paired-up by sample date first (Dates will not be on an axis)!
a. Include a trend line, its equation, and R2 on the graph. [5 pts]
ISP 217L Lab 6 Assignment Page 2
B. Questions
1. State all four of your hypotheses. Do the data support or reject your hypotheses? [4 pts]
2. How do your measurements of discharge compare to those of the USGS (graph 2)? [4 pts]
a. Interpret the correlation coefficient you computed in #3 above.
b. If the two data sets are equivalent or strongly correlated, what would you expect to see in
your scatter plot?
3. How long does it take for discharge to change in response to rain? What might account for the lag
time? Is there a relationship between discharge and river depth? How might this sort of
information about rivers generally be useful to society? [3 pts]
4. Some people may hypothesize that turbidity should increase as river discharge increases, whereas
others could convincingly argue that it should decrease. Explain why both might be reasonable
expectations, even though they are mutually exclusive. Do your data actually support one of these
hypotheses over the other? Explain. [4 pts]
5. Why might people that live on Lake Michigan near the mouth at Grand Haven, over 200 km (124
miles) down river (via the Grand River) be intensely interested in the status of the Red Cedar
River? What are some things you can do (or be more aware of), as someone living in the Red
Cedar’s watershed, to help improve the river’s reputation? [3 pts]
C. Style, Clarity, and Mechanics
1. Complete heading provided [1 pt]
2. Length is appropriate; questions are answered concisely [3 pts]
3. No distracting punctuation, spelling errors, grammar, or mechanics (assignment reads clearly and
smoothly) [6 pts]
4. Graphs/tables are legible and thoughtfully displayed, with descriptive titles and proper labels
with units [subtract 1 point for every oversight]
Late, hand-written, electronically-submitted, and unstapled assignments will not be accepted.
Useful Excel Manual tutorials for this lab exercise:
Tutorial 2. Excel Basics II: Performing Calculations and Building Functions
Tutorial 3. Excel Basics III: Importing Downloaded Data into Excel
Tutorial 7. Secondary y-axis Line Graphs
Tutorial 8. Scatter Plots and Correlation
