Watersheds and
Hydrographs: Finding and Analyzing Patterns
(Due
at the beginning of
class, Wednesday, April 25, 2007)
Where
to Begin
In class,
you collected data on stream
hydrographs
(graphs of discharge vs. time) and some information
on watersheds, and we recorded it all on a worksheet.
Click
here if you want a clean copy of the legal-sized data collection sheet
we used in class
(Excel worksheet).
If you need to
look at the hydrographs again, they're hanging in the classroom, along
with the Illinois maps.
Now, your job is
to analyze the data to find patterns. Because the data we are
working with are "live" and have never before been collected in the
same place at the same time, you could discover something entirely
new! So look hard.
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. For something to be a
pattern,
it has to show the same relationship repeatedly.
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 one of the two
patterns,
do the following:
A) Propose a hypothesis to explain the
pattern. (For example, 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
© 2007 Laura L. Sanders. Last updated
April 18, 2007.
Department
of Earth Science | 
Northeastern
Illinois University