Department
of Earth Science |
Northeastern
Illinois University
PRINCIPLES
OF HYDROGEOLOGY
ESCI
337
Spring,
2004
Daily Objectives #19 (March
30, 2004)
Dr. Sanders
By
the end of today's class, you should be able to do the
following:
v Quickly sketch flow nets
for a variety of flow situations, given partial information about the
system.
v Using someone else's sketch of
water levels in piezometers (I will assign this part), draw a
quantitatively accurate flow net, including flow lines, equipotential
lines (labeled with their hydraulic head value), and water table.
v
Dam Flow Net:
n
Draw a quantitatively accurate
flow net for flow beneath the dam on the handout provided. Be
sure to label equipotential lines with their value. For
simplicity's sake, let's all use the same datum: the flat bottom
of the main portion of the dam.
n
Answer the following questions
about the dam flow net:
o If the sediments have a hydraulic
conductivity of 0.28 m/day, and the dam is 200 m long going back into
the page, calculate the flow rate of water under the dam. (Give
your answer in units of cubic meters/day.)
o At Point A, what is the total
hydraulic
head? Elevation head? Pressure head?
v FLOWNET
Software: Using the FLOWNET software included with your
textbook, complete the exercises on the handout provided.
v Ground
Water Flow Model: Measure the elevations of water levels in the
piezometers in the "sand tank" ground water flow model. Use the
bottom of the model as a datum, and measure in centimeters.
Record the value for each piezometer on the handout provided.
Then, use the data to construct a flow net for the model. (Hint:
you already know what the flow lines
should look like, based on the dye tracks on the other side of the
model. You also know what all the boundaries are. Use that
information to help you draw your equipotential lines.)
© 2004 Laura L.
Sanders.
Last updated March 30, 2004.