Department of Earth Science |Northeastern Illinois University

ESCI 337
Fall, 2005

Daily Objectives #19 (November 9, 2005)                                        Dr. Sanders

Confined and unconfined aquifers; combining geology with flow nets/water level maps

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

v  Draw a quantitatively accurate flow net for flow beneath a dam, and use it to make calculations of discharge below the dam.  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  Evaluate other flow nets drawn by your colleagues, pointing out specific good points and flaws.

v  Describe the difference between unconfined and confined aquifers, and given subsurface data, identify them.

v  Describe how geologic conditions relate to hydrogeologic conditions.  For example, what geologic conditions consitute a no-flow boundary?  constant head boundary?  aquifer?  aquitard?

  Use published maps to investigate geologic conditions in this area:
        Well #10: Twp 38N, Range 8E, Section 33, Plot 4h.  (This well is 82 ft deep.)
        Well #11: Twp 38N, Range 8E, Section 33, Plot 5h.  (This well is 59 ft deep.) 

Department of Earth Science | Northeastern Illinois University

© 2005 Laura L. Sanders.  Last updated November 9, 2005.