Jodi Ryder

Central Michigan University

This is an activity for an elective undergraduate hydrogeology course with about 40% each geology and environmental science majors and 20% earth science education students.

Students coming in have completed a 100 level geology lab course so they should know how to use the US Public Land Survey System and topographic maps. At this point in the course we have already discussed the hydrologic cycle, soil and subsurface properties including the arrangement of strata into aquifers and aquitards, and Darcy flow.

This is a weekly lab/homework activity. About 3 hours of class time are used to introduce the activity and allow work in small groups. Students may spend an additional 2 hours refining their maps and preparing the lab to submit for grading.

1. To interpret spatially discrete data representing a third dimension through the use of contours.
2. To apply flow calculations to systems represented by contoured data.

This activity helps students develop their spatial reasoning skills both in the development and interpretation of the maps and also in the application of the 1-d form of Darcy's law to a 3-D space.

Students must apply trigonometry to complete the activity.

Students first study the movement of water in aquifers through a lecture on Darcy's flow experiment. Then they practice applying the concepts of hydraulic conductivity and head differentials to 1 dimensional column examples. Next they use flow simulators to view flow through a cross section of an aquifer model. This activity is the final piece in the development of the idea of head driven flow. Students are given data about the thickness and head values of an aquifer member. They plot the aquifer thickness and potentiometric surface then determine the flow direction and estimate the groundwater flow velocity.

The students submit a table of isopach thicknesses, two contour maps, and their calculations of flow direction and velocity. I grade each of these items (allowing some room for inexperience on the map drawings).

An example within the activity is reproduced from:

http://www3.interscience.wiley.com:8100/legacy/college/levin/0470000201/chap_tutorial/ch09/chapter09-6.html which is an online section from: The Earth Through Time, 9th Edition
Harold L. Levin, Washington University, St. Louis (Professor Emeritus) ISBN: 978-0-470-38774-0 ©2010 624 pages