Physical Hydrogeology

From GeoClasses

Jump to: navigation, search

ESCI 4211/6211: Physical Hydrogeololgy

  • Time - Fall 2007:
    • "Lecture": 2:40 pm - 4:05 pm Tues/Thurs
    • "Lab": 4:20 - 6:00 Thurs
  • Prerequisites: at least 1 year of geology and 1 semester of calculus.
  • Text: Applied Hydrogeology by C.W. Fetter.
    • Supplemental:
      • Groundwater Mechanics by Otto Strack
      • Environmental Isotopes in Hydrogeology by Clark and Fritz
      • Groundwater in Geologic Processes by Ingebritsen and Sanford
  • Room: 216 Johnson Hall


Instructor: Lensyl Urbano, Ph.D. Email: lurbano
Office: 204 Johnson Hall Office Phone: (901) 678-4543
Office Hours: MWF 10:00AM to 12:00AM or by Appointment
web page: http://lurbano-5.memphis.edu/Classes/index.php/Phys_Hydro

Contents


Course goals

This class will enable students to

  • explain the physics of flow through porous media at both the micro and macro scales using both conceptual and mathematical models.
  • measure hydrogeologic parameters using laboratory and field techniques.
  • monitor and model groundwater chemical transport for conservative and non-conservative tracers under uniform and variable density conditions.
  • Students will be able to produce numerical models (using GMS with MODFLOW) of hydrogeologic situations.

Academic conduct

Expectations for academic integrity and student conduct are described in detail on the website of the Office of Student Judicial and Ethical Affairs (http://saweb.memphis.edu/judicialaffairs). Please take a look, in particular, at the sections about “Academic Dishonesty,” “Student Code of Conduct and Responsibilities,” and “Disruptive Behaviors.” I will expect students to be aware of these guidelines and to conduct themselves accordingly.

Grading

Undergraduates: Your grades will be determined from

  • Midterm exam - 25%
  • Final exam - 25%
  • Lab reports - 25%
  • Term project (including peer review) - 25%

Graduate students

  • Midterm exam - 25%
  • Final exam - 25%
  • Lab reports - 25%
  • Term project (including peer review) - 20%
  • Project presentation - 5%

Seminars

  • NGWA 2007 Darcy lecturer Jim Butler at the University of Memphis on September 17, at 1 pm in the Engineering Auditorium, Herff College of Engineering.
    • Jim is a highly accomplished hydrogeologist, especially in field-related studies of porosity and permeability. Jim will give a lecture on “Getting the Information Ground Water Modelers Need: A Report from the Field.”

Class outline and notes

Week 1: Hydrology and mass balance

Introduction to hydrology

Lab 1

  • Create a lumped parameter model for a watershed with variable sized lake using MS Excel.
    • Create a concept sketch first.
    • Main principles
      • Conservation of mass
      • Open water evaporation vs evapotranspiration
      • Potential versus actual evapotranspiration

What do hydrogeologists do?

  • Reading: Fetter Ch. 1
  • Classroom discussion:
    • Identify practical issues that hydrogeologists address.
    • What capabilities do hydrogeologists need to have to be able to perform these jobs?
    • What are the ethical issues involved given the relationships between environmental firms and their clients?

Week 2: Darcy's Law and Properties of Porous Media

Properties of porous media

  • Reading: Fetter Ch 3
  • Classroom discussion
    • What properties of geologic material determine the hydraulic conductivity?
    • What is an aquifer, and what properties of geologic material determine if it is an aquifer or not?
  • Media:Phys Hydro Lect 003.ppt
  • Construct flow nets for simple and complex hydrogeologic situations including:
    • confined, unconfined and mixed flow.
    • river and lake interactions.

Lab 2: Potentiometric maps and flow nets

  • Model flow through a darcy tube in Excel
    • Show the derivation of the equation for head.
    • Show graphs of hydraulic head where;
      • a1. K is uniform
      • a2. the first half (50cm) of the tube has 5x the conductivity of the second half.
      • b1. the cross-sectional area is equal to the head (with uniform K).
      • b2. the cross-sectional area is equal to the head and the first half (50cm) of the tube has 5x the conductivity of the second half.
    • How does lowering the hydraulic conductivity affect the shape of the water table.
    • Present the spreadsheet with the model.
  • Media:Phys Hydro Lect 002.ppt

Week 3: Confined flow

Lecture notes and models

Draw flow nets,

  • Put in a zone of low conductivity in the middle of the model. How does it affect flow.
  • Put in a zone of high conductivity in the middle of the model. How does it affect flow.

Groundwater flow equations

  • Apply Darcy's law to create a numerical model of fluid flow through the Darcy tube (using Excel).
    • Assume steady-state flow. (Laplace equation)
  • Classroom discussion
    • What is hydraulic head? (elevation and pressure head)
    • Under what conditions does Darcy's law apply? (Reynolds number)
    • Derive the groundwater flow equation of confined flow. (Fetter Ch. 4.7)

Lab 3: Porosity, specific yield and specific retention

  • Design an experiment to determine the porosity (Φ), specific yield (Sy) and specific retention (Sr) of the samples provided.
    • Write detailed instructions about how to perform this experiment. (so that someone who has not tried it could do it)
    • Be sure to note and propagate the experimental error associated with your method.

Week 6: Groundwater flow to wells

Assignment

  • Glossary Peer Review:
    • Beth --> KC, Lydia
    • KC --> Beth, Mary
    • Matt --> KC, Mary
    • Mary --> Lydia, Matt
    • Lydia --> Matt, Beth
  • Peer review criteria:
    • Accuracy
    • Easy to understand
  • Hand in:
    • Corrected version for each item not accurate or could be better explained.
    • 1 paragraph summary of accuracy and readability of the assignment.

Lab 4:

Prepare a report describing the what was shown during the field trip to Neilans' reach on the Loosahatchie river.

Field Trip notes

Trip to see the rotary drilling rig and geophysical logging of MLGW well.

Assignment

  1. Determine the hydraulic conductivity, transmissivity and specific storage coefficient using the following pump test models.
  2. Run models until steady state then determine the same values using the Thiem equation.

Lab 5: Grain size analysis for hydraulic conductivity

Determine the hydraulic conductivity of Memphis sand and Loosahatchie River samples from grain-size analysis.

Leaky aquifers

Reading: Fetter - section 5.4.2 and pg 177-188.

  • Hantush assumptions and the Hantush-Jacob formula
  • Time/drawdown graphs for leaky aquifers.
  • Non-equilibrium flow in a Leaky, Confined aquifer with no storage in the aquitard.
    • Walton type curves:
    • Hantush inflection point method:

Lab 5a: Hydrogeologic properties from pump and slug tests

Solute Transport

Flow Nets Lab

Groundwater contamination

Remediation

Water rights


Groundwater modeling

Based on the assignment at: http://serc.carleton.edu/files/NAGTWorkshops/hydrogeo/activities/Callahan-MODFLOW.doc

You have already calculated the maximum and minimum recharge.

Use the 2d Excel groundwater model for unconfined flow to model the system.

  • 2d-gw model
  • This Excel model has NO FLOW boundaries by default, so you'll need to change the appropriate boundaries to constant head.
  • You'll also need to change the dx and dy values in the right worksheets. While it is possible to make the cells square, it's easier just to adjust the dx and dy values and use 25 cells in each direction.
  • Finally, you'll need to input the recharge values and hydraulic conductivities.
  • Bonus: You may also put in the well from the assignment.


Final


.

Labs

Lab 2: Potentiometric maps and flow nets

  • Model flow through a darcy tube in Excel
    • Show the derivation of the equation for head.
    • Show graphs of hydraulic head where;
      • a1. K is uniform
      • a2. the first half (50cm) of the tube has 5x the conductivity of the second half.
      • b1. the cross-sectional area is equal to the head (with uniform K).
      • b2. the cross-sectional area is equal to the head and the first half (50cm) of the tube has 5x the conductivity of the second half.
    • How does lowering the hydraulic conductivity affect the shape of the water table.
    • Present the spreadsheet with the model.
  • Media:Phys Hydro Lect 002.ppt

Lab 3: Porosity, specific yield and specific retention

  • Design an experiment to determine the porosity (Φ), specific yield (Sy) and specific retention (Sr) of the samples provided.
    • Write detailed instructions about how to perform this experiment. (so that someone who has not tried it could do it)
    • Be sure to note and propagate the experimental error associated with your method.

Lab 4: Darcy's Experiment

  • Reading: Fetter Ch 3.4
  • Using Darcy tubes to determine permeability/hydraulic conductivity of sediments.

Lab 5: Computer models of groundwater flow


Notes

Personal tools