Department of Earth Science |Northeastern Illinois University
Daily Objectives #14 (October 16, 2007)                                        Dr. Sanders

 By the end of today's class, you should be able to do the following: v Hydrostratigraphy Distinguish between confined aquifers and unconfined aquifers. Recognize and delineate hydrostratigraphic units. Explain the difference between lithostratigraphic units and hydrostratigraphic units. v Flow Nets Identify boundaries to a flow system, and for the first three listed below, tell the relationship between the boundary and flow lines, and the boundary and equipotential lines: no-flow (impermeable) boundaries: hydrostratigraphic hydrodynamic water table boundary constant head boundaries constant flow boundaries (rarely used in modeling natural systems). v Hydrogeologic Maps and Cross Sections Use water levels in wells and/or piezometers, and flow system boundaries, as the basis for drawing water level maps and flow nets. Use Darcy's Law to calculate flow through an area illustrated on a flow net. Find borehole data for Illinois, and use it to delineate hydrostratigraphic units and construct hydrogeologic cross sections.

Today's Agenda:

v Darcy Tube: Debrief the Darcy tube exercise.

v
Hydrostratigraphy
• Recognize and delineate hydrostratigraphic units.  (How are they different from lithostratigraphic units?)
• Distinguish between confined aquifers and unconfined aquifers.
v Hydrogeologic Maps and Cross Sections
• Construct a map-view flow net on Figure 3.32 from your textbook, and identify any boundaries that appear on it.  Use it to solve "Analysis b" on p. 109 of your textbook.
v Flow Nets
• Identify boundaries on each of the flow nets we have constructed thus far.   Look for examples of each of these:
• no-flow (impermeable) boundary:
•  hydrostratigraphic
•  hydrodynamic  (Hint: Explain why sometimes it is okay to call a "no-flow" boundary an "impermeable" boundary--but other times, that term doesn't really apply.)
• water table boundary