# How are flow, turbidity, and precipitation related for the Red Cedar River

How are flow, turbidity, and precipitation related for the Red Cedar River?
Due May 4th, 2015 by 5:00 PM, 161 Natural Resources; required for all students 50 points
A. Graphs, Tables, and Calculations
?Download the 5 weeks of USGS discharge and MSU precipitation data from their respective websites (see the Lab Manual for instructions). Use March 23rd, 2015 as the start date and April 28th, 2015 as the end date for download. You may elect to download it all at once on April 29th, or download portions in advance to allow you to begin working on components of the assignment. Convert USGS discharge data to m3/s, or you woni??t be able to make meaningful comparisons to your data!
?i. Produce one scatter plot of the relationship between your teami??s 8 discharge measurements and
?2
those recorded by the USGS on the same 8 days. Include a trend line, its equation, and R on the
graph. [4 pts]
ii. Create a hydrograph (a graph showing discharge and precipitation through time) for the Red Cedar River using a secondary y-axis line graph (see Excel Manual Tutorial 7). Plot precipitation on one yaxis and USGS discharge on the other. 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 first! [4 pts]
i. Produce one scatter plot of the relationship between your 8 depth estimates and USGS discharge, recorded on the same 8 days. Include a trend line, its equation, and R2 on the graph. [4 pts]
ii. Produce one scatter plot of the relationship between your 8 turbidity estimates and USGS discharge, recorded on the same 8 days. Include a trend line, its equation, and R2 on the graph. [4 pts]
iii. Produce one scatter plot of the relationship between your 8 load estimates and USGS discharge, recorded on the same 8 days. Include a trend line, its equation, and R2 on the graph. [4 pts]
B. Questions
1. State your hypothesis(es). Do the data support or reject your hypothesis(es)? [2 pts]
?2. How do your measurements of discharge compare to those of the USGS? Calculate, provide, and interpret the correlation coefficient (r): what is it telling you exactly? If the two data sets are equivalent or strongly correlated, what would you expect to see in your scatter plot? [4 pts]
??ISP 217L Lab 6 Assignment Spring 2015 Page 1
3. List some specific sources of potential measurement error to account for any deviations between your measurements of discharge and those reported by the USGS. How might these sources of error (variation) be minimizedi??how could we improve our accuracy)? [4 pts]
4. How long does it take for discharge to change in response to rain? What might account for the lag time? Is there much predictive power of discharge for river depth (provide and interpret R2)? How might all of this information be useful to society in general? [3 pts]
?5. Some people may predict that turbidity and load should increase as river discharge increases, whereas others could convincingly argue that they should decrease. Explain why both might be reasonable expectations, even though they are mutually exclusive. Do your data actually support one of these predictions over the other? Explain, and discuss the predictive power (R2). [4 pts]
6. The Red Cedar has a reputation as a polluted and unhealthy river, due to too many nutrients, high bacteria loads, and declining fisheries (symptoms of intense urbanization and agriculture), though its condition has been improving. 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 acutely interested in the status of the Red Cedar? What are some things you can do (or be more aware of), as someone living in the Red Cedari??s watershed, to help improve the riveri??s condition? [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.