Integrated Critical Zone project

class='author'>Nick Bader, Whitman College

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Initial Publication Date: June 6, 2013


This project is a way to assemble information about geology, hydrogeology, and soils into a coherent whole in a way that may otherwise not happen in any one class. The "critical zone" concept ties the pieces together. This project is not tied to a course but I have used it as a component of a senior assessment for geology students.

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This could be effective as a stand-alone project in an upper-level integrative course on soils and hydrology/hydrogeology or an upper level environmental geology course.

Skills and concepts that students must have mastered

This exercise that students know or can figure out:
1. Basic concepts of soils and soil horizons
2. Basic concepts from hydrogeology: the likely shape of the water table near a perennial stream, the vadose and phreatic zones, etc.
3. How to use library and web resources to locate soils and geologic data for their location

How the activity is situated in the course

I have used this as part of a senior assessment.


Content/concepts goals for this activity

Soil horizons, the shape of the water table, depth to bedrock, the components of the unconfined aquifer, etc.

Higher order thinking skills goals for this activity

The higher order goal is to understand how the soil type, geologic units, and hydrogeology fit together in a particular place.

Other skills goals for this activity

Finding information from the soil survey, USGS and state surveys, etc.

Description and Teaching Materials

The attached file contains the handout for students. In this case the assignment is written as an open-book exam, but it could also be a homework project.

Student handout for Critical Zone project (Acrobat (PDF) 32kB Apr15 13)

Teaching Notes and Tips

Provide two sheets of 11x17 paper for this assignment, one for a working sketch and one to turn in.

You will almost certainly want to provide a different area of the world for your project. It is useful to choose an area near a body of perennial surface water to pin down the location of the potentiometric surface, and an area for which a geologic map with cross sections is available.

Depending on the students' background, they may not know how to search for soil survey information. I have directed them to the old print copies of the soil survey in the past (available at the library) because they contain maps and are easily understandable. Alternatively you could direct students to the web soil survey at


To assess this project, check two things: (1) are the soil and geologic unit descriptions accurate for this area? and (2) does the water table and saturated-unsaturated zone description pass a plausibility check? Make sure that the soil information is correct for this site and is not merely a description of soils in general.

References and Resources