Review for Exam #2

Department of Earth Science |Northeastern Illinois University

PRINCIPLES OF HYDROGEOLOGY
ESCI 337
Spring, 2004

Review for Exam #2 (March 11, 2004) Dr. Sanders

On Exam #2, you should be able to do the following:

v Use simple lab apparati to investigate the movement of water through open conduits and through porous media: Bucket-to-Bucket Transfer, Capillary Action, Darcy Discovery, Draining Work, Holey Water Bottle, and Infiltration Observation.

v Define each of the following hydraulic properties of porous materials:

porosity effective porosity specific yield specific retention

v Evaluate whether or not the a given value for those quantities is reasonable.

v Give the typical range of values of porosity, specific yield, and specific retention of different types of porous materials, using the correct units of measurement.

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 Using constant head and falling head permeameters, measure the hydraulic conductivity of sediment samples.

v Explain the meaning of the terms hydraulic conductivity (K) and intrinsic permeability (K_i), , 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 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 Sketch the Darcy tube apparatus and describe how it works.

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. (On the NEIU campus, to find abundant ground water, would we need to drill shallow wells? Or deep wells?)

v Explain the meaning of each of these terms. Use diagrams if they help!

    1) aquifer
    2) confined aquifer
    3) unconfined aquifer
    4) perched aquifer

    5) aquitard (or confining layer)
    6) water table
    7) potentiometric surface
    8) capillary fringe (or capillary zone, or tension-saturated zone)

o Explain the differences in flow of three different fluids (soybean oil, Log Cabin syrup, and water) through a porous medium.

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 Find the answer to problem 5 at the end of Chapter 3 (p. 110), in which you calculate the K of sediment given its intrinsic permeability.

v Convert latitude and longitude measurements from units of decimal degrees to units of degrees, minutes, and seconds.

                             Lambert Coordinates
Well ID          X                         Y                    Longitude        Latitude         Community

00405         3318497.750         3170116.250          -88.32792       41.73634      MONTGOMERY
00406         3317428.000         3170504.250          -88.33183       41.73744      MONTGOMERY
00628         3313073.250         3168831.250          -88.34794       41.73298      MONTGOMERY
00629         3320884.750         3152309.250      -88.31998       41.68717      MONTGOMERY

v Draw a contour map of ground water elevation for the shallow aquifer (glacial sediments) based on the values given on the map on p. 110 (see instructions on p. 109).

z Explain the meaning of hydraulic head and hydraulic gradient.

z State Darcy's Law and explain each of the variables in the equation.

Department of Earth Science | Northeastern Illinois University