Department of Earth Science | Northeastern Illinois University

Earth Science 121

Watersheds and Streams: Finding and Analyzing Patterns
(Due at the beginning of class, Thursday, December 7, 2006)

Where to Begin

In class, you collected data on stream hydrographs (graphs of discharge vs. time) and some information on watersheds. 

Please note!  Some changes occurred during class time as people added or changed their study areas.  Please check your list for these changes:
    * There are only two entries for Addison Creek at Bellwood, so cross one off your original sheet. 
    * There are three entires for the Des Plaines River--one at Gurnee, and two at Riverside (a Riverside entry was added during class.  Please make sure you added it to your data sheet!)
    * There should be an entry for the Little Calumet River.  Please make sure you added it to your data sheet.

          Click here if you want a clean copy of the data collection sheet, with the corrections added (Excel worksheet).

What to Do with the Data

Once you have a complete data set, do the following:

1) Analyze the data, looking for patterns in the relationships between variables.  Look for trends: for example, you might find that whenever variable X increases, so does variable Y.  Or, when watersheds are located in, say, urban areas, their hydrographs seem to exhibit a certain characteristic, something that doesn't occur when they are in rural areas.  Or maybe you'll find that when the storms occur in a certain season, or in a certain type of terrain, the hydrographs look a certain way.  List as many patterns as you can find!  The person who lists the most patterns will get a (small) prize.

2) Choose two of the patterns you listed in Step 1, and for each of the two patterns, do the following:
       A) Propose a hypothesis to explain the pattern.  (E.g., why does variable Y seem to increase every time variable X increases?  Explain.)

B) Note any exceptions to the pattern, and explain them.  (Why do these streams/hydrographs not fit the pattern?  What's different about them?)

       C) Suggest a way you could further explore your hypothesis, or a way to test it to see if it holds true.

What to Hand In

* Your data collection worksheet (see the link above if you want a clean copy with the corrections added)

* Your typed answers to Questions 1 and 2, above.  Remember to answer Question 2 for two of the patterns you discovered!

Department of Earth Science | Northeastern Illinois University

© 2006 Laura L. Sanders.  Last updated November 30, 2006.