Objectives 1

Department of Earth Science |Northeastern Illinois University

PRINCIPLES OF HYDROGEOLOGY
ESCI 337
Spring, 2009

Daily Objectives #2 (January 15, 2009)                                        Dr. Sanders

By the end of today's class, you should be able to do the following:

v From last time: Describe the purpose and function of a rain barrel, and make quantitative calculations to estimate how a rain barrel is involved in the water budget of a residential property in Chicago.

v New this time: Use concepts of length, area, volume, and flow rate to quantify hydrologic variables.

v Solve a hydrologic problem in a sequence of logical steps, using reasonable units, significant figures, and dimensional analysis.

Our agenda today:

    Teams get together to go over their calculations

    Compare answers between teams:
          How big is the property? How does the area compare to an acre?
          Describe how big an acre is in non-technical terms.
          How much of the property is in garden plots?
          What is the area of the roof?

    If there are differences between answers, what accounts for them?

          What is a typical rainfall in Chicago? (cite your sources)
          What depth annual precipitation do we get in Chicago?
          What volume annual precipitation do we get in Chicago?

    Problem-solving: See "Hints for Solving Quantitative Problems".

    Dimensional analysis: using units of measurement to help solve problems.

    Significant figures: what is the appropriate number to report?

    Now let's move on to the rest of the questions. Answer them using dimensional analysis and paying attention to significant figures:

          How much rain will the roof collect in a typical rainfall?
          Are two barrels enough to store water from a typical rainfall?
          Are two barrels enough for me to store water to irrigate my entire garden?
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Groups that finish early should consider these questions:

If the rain falls at a rate of 1 inch per hour, how long would it take to fill a rain barrel?
How heavy would a full rain barrel be?

How big are the differences between answers? How much difference indicates "the same amount", and how much difference indicates a "real" difference?

Homework: For Tuesday, as a group (one set of answers for the whole group), complete Homework #1.

Department of Earth Science | Northeastern Illinois University