Department of Earth Science |Northeastern Illinois University
Daily Objectives #12 (October 12, 2005)                                        Dr. Sanders

Homework #3 (on siphons) is due today!  Each individual student must hand in a homework paper.
Homework #4 (on lab tests of hydraulic properties) is due at the beginning of class Monday, Oct. 17.  One per group!

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

v  Describe the relationships between and among the following properties of porous materials:

p  porosity and effective porosity;
p  specific retention and specific yield;
p  specific yield and effective porosity; and
p  specific yield, specific retention, and porosity.

v
Explain the meaning of the terms hydraulic conductivity and permeability (also called intrinsic permeability), and explain the difference between the two.

v  Give typical ranges of the value of hydraulic conductivity and permeability of different types of porous materials, using the correct units of measurement.

v  Sketch the Darcy tube apparatus and describe how it works.

v  List the kinds of rocks and sediments that are generally considered aquifers, and those that are generally considered aquitards.

v  Sketch a cross section illustrating the generalized hydrostratigraphy of northeastern Illinois.

v  Use your knowledge of hydraulic properties to solve three practical problems:

 q  We will need to add water to saturate the sediments in the Darcy tube.  When we're done with the experiments, we will need to drain it before putting it away.  Estimate how much water will be needed to fill the Darcy tube.  Then, estimate how much water will drain out. q  Figure out how much water was lost from an aquifer during a drought (Chapter 3, Problem #9, on p. 111). q  Look at the map in the Willman (1971) ISGS circular ("Summary of the Geology of the Chicago Area").  Based on the information in the map/document, decide where in the Chicago area people could find abundant ground water that they could tap with shallow wells.  Then, combining this information with the information on the map of the bedrock geology of Illinois, identify areas that are likely to have abundant ground water that can be tapped with deeper wells--wells that extend into the bedrock.  q  On the NEIU campus, to find abundant ground water, would we need to drill shallow wells?  Or deep wells?

Department of Earth Science | Northeastern Illinois University

© 2005 Laura L. Sanders.  Last updated October 12, 2005.