Head and Pieziometric Surfaces #2
Summary
This activity steps students through the process of mapping and interpreting contours. It includes examples and follow up practice activities.
Context
Audience
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.
Skills and concepts that students must have mastered
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.
How the activity is situated in the course
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.
Goals
Content/concepts goals for this activity
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.
2. To apply flow calculations to systems represented by contoured data.
Higher order thinking skills goals for this activity
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.
Other skills goals for this activity
Students must apply trigonometry to complete the activity.
Description of the activity/assignment
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.
Determining whether students have met the goals
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).
More information about assessment tools and techniques.Teaching materials and tips
- Activity Description/Assignment:Head and Potentiometric Surface Activity (Acrobat (PDF) 848kB May25 10)
- Instructors Notes:
- Solution Set:
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Other Materials
Supporting references/URLs
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
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