GEGN 681 Vadose Zone Hydrology 

Course Syllabus Fall 1999

 

24 August, 1999

 

Prof. John McCray

Office:  BH 305 D

Contact Info:  303-384-2181,  jmccray@mines.edu

Office Hours (preliminary):  Monday 4 pm-5pm, Wednesday, 9:15-10:15

 

Course web site:  http://www.mines.edu/Academic/courses/geology/gegn681/

 

Text:  Tindall, J.A., Kunkel, J.R., 1999.  Unsaturated zone hydrology, Prentice Hall Inc.

 

Topics to be covered in the course:

 

This is the first time this course material has been offered.  Thus, it is difficult to say how fast we will cover the material.  I prefer for everyone to have ample opportunity to discuss and thoroughly understand the topics we cover, as opposed to simply pushing through a particular agenda.  Please consider the below syllabus to be a flexible document.   The predicted number of class periods currently prepared for each topic is given in parenthesis.

 

Introduction/Administration/Motivation (1 lecture)

Basic Soil Physics (2)

Soil-Water Energy (1)

Capillary Pressure and hysteresis (2)

Vadose-zone parameter measurement labs (1-2)

Theory of Soil Water Movement, Unsaturated K, Diffusivity (2)

Richards’ equation and applications (2)

Capillary-pressure and unsaturated hydraulic-K: estimation (RETC) & scaling (1)

Richard’s Equation:  Hydrus 2D numerical modeling of water flow (3-4)

Selected soil chemistry (1.5-2)

Contaminant transport in the vadose zone (3-4)

Contaminant transport modeling using Hydrus 2-D (2)

Impact of soil layers on unsaturated flow and transport (1)

Preferential flow in the vadose zone (1)

Vapor transport in the vadose zone (1-1.5)

Three-phase flow in the vadose zone (2)

GSA conference – no class (1), but an out-of-class lab will make up for it.

 

Grading

 

Two Exams                  25% each

Literature Review 25%

Homework                   20%*

Participation                   5%*               * these percentages may change somewhat.

 

Class Schedule

Lecture 1.  Administration, introduction to the vadose zone, computer model simulations. (1.1)

Lecture 2.  Description of a multiphase system, basics structure of soils (2.1-2.6).

Lecture 3.   Density-Volume relationships, nterfacial energy, wettability, and capillary pressure (2.7, 4.2., 4.3).

Lecture 4.   Energy status of soil water, functional relationships associated with capillary pressure (4.4 - 4.6).

Lecture 5.   Hysteresis of capillary pressure, question and answer session (4.7).

Lecture 6.   Measurement in the vadose zone,  sample variability and sampling philosophy. 

Lecture 7.   Review of saturated water flow, derivation of Pouiselle’s Equation.  Assumptions associated with Darciy’s Law,  unsaturated hydraulic conductivity 7.1-7.7, 7.10, 8.1, 8.2).

Lecture 8.   Unsaturated Flow of immiscible fluids, soil-water diffusivity and specific water capacity, capillary tube model, Mualem’s relationship and others (8.2- 8.4) 

Lecture 9.      Use of RETC computer program. 

Lecture 10.  Soil physics laboratory exercise:  moisture content, bulk density.

Lecture 11.  Richards’ Equation: derivation, various forms, source terms, boundary terms (8.3).

Lecture 12.  One-dimensional capillary-driven flow (absorption): linearized Richards’ equation,  Boltzman transformation of nonlinear Richards’ equation (8.5).

Lecture 13.  Advantageous uses of the similarity transform, experimental measurement of soil-water diffusivity.   One-dimensional infiltration (capillarity and gravity), general principles.   (11.1)

Lecture 14.  Infiltration Theories:  Green-Ampt equation, Solution to linearized Richards’ equation, and Philip’s quasi-analytical solution (11.1, 11.2).

Lecture 15.  Review basic principles (rainfall rates vs. infiltration, soil surface effects).   Numerical solutions to   1-D Richards’ equation.  Steady flow near a water table, plant-root uptake, basic evaporation from a water table, various other one-dimensional models for infiltration, infiltration vs. runoff, (11.1, 11.2). 

End Material for Midterm #1

 

Lecture 16.  Dual-porosity model of unsaturated flow, preferential flow, unsaturated flow in layered soils, unsaturated flow in crusted soils, runoff (11.3 -11.6)

Lecture 17.  Evaporation, transfer of heat at the soil surface, energy budget, impact of evapotranspiration and vegetation on soil moisture (9.1-9.6).

Lecture 18.  Multidimensional flow in soils Field-scale applications to vadose zone hydrology, water and energy budgets (11.6, 11.7, 11.8, 12.1-12.3,13.2).

Lecture 19.  Contaminant transport: Inter-phase equilibrium partitioning (air-water, water-NAPL, sorption), non-equilibrium mass transfer, and advection-dispersion equation for saturated & unsaturated water flow (10.1-10.3).  

Lecture 20.  Contaminant transport: retardation due to sorption, chemical reactions, decay, general transport and retardation due to contaminant distribution and partitioning in multiphase media  (10.3-10.11).

Lecture 21.  Contaminant transport: Dual-domain models for mobile-immobile regions, two site mass transfer, and transport in fractured media.  Transport in layered media, preferential flow of solutes.  (10.12, 10-13).

Lecture 22.  Special vadose-zone contaminant-transport topics important in Colorado: pesticides and nitrates.

Lecture 23.  Gas flow and transport in the vadose zone, Klinkenberg and Knudsen phenomena, flow of contaminant vapors in the vadose zone, density-driven vapor flow, gas-phase pump tests, vadose-zone partitioning tracer tests. (9.7- 9.9)

Lecture 24.  HYDRUS 2-D (unsaturated water flow – basic infiltration)

Lecture 25.  HYDRUS 2-D (unsaturated water flow –crusted and/or layered soils)

Lecture 26.  HYDRUS 2-D  (unsaturated water flow – special topics)

Lecture 27.  HYDRUS 2-D  (contaminant transport in unsaturated systems - basic)

Lecture 28.  HYDRUS 2-D  (contaminant transport in unsaturated systems - pesticides)

Lecture 29.  HYDRUS 2-D  (contaminant transport in unsaturated systems – special topics)