Draft Tutorials in Soil Physics

by D.L. Baker  home

Reconstructed 26 June 2004

   In order to reduce the size of these tutorials on this site by tens of megabytes, the HTML pages are no longer here. They are replaced by the original MS PowerPoint 97 and associated files in zip form (ZipMagic 4.0). Unlike previous versions of PPT files on this site, these should have all the images in them. Follow the links and click on the appropriate download file, *.zip. Your browser may do the rest, if you have a zip program installed. WinZIP should also open the files. This and the finite differences tutorial section have been the most popular sections on this site. If there is anyone who wishes to obtain a copy of these sections in zipped PowerPoint or HTML, or any others of interest, for the purpose of putting up a mirror site, please contact me.

   These tutorials were written in support of the subcontract of Dr. H. Don Scott at the University of Arkansas, Fayetteville, to a USDA grant to Dr. David Nofziger, Oklahoma State University. The grant supports the development of Internet-based tutorials in undergraduate Agronomy, especially Soil Physics. This work is a mostly-organized set of about 585 MS PowerPoint slides that have been partially converted here to html. Please be aware that there may be some bad links. Please be aware that these slides are mostly as written for Dr. Scott. The first section, basica0, borrows heavily from his textbook, as noted in the first slide. Other sections borrow occasionally from other sources, as implied in the references.

   Copyright rules: This is a shareware style web site. These slides shall not be downloaded and used for commercial gain of any kind; they are free to download and use for private or educational purposes only, with attribution. Please be aware that most of the rest of the www.aquarien.com site is protected by registered copyright. The principles of fair use for private and educational purposes apply to the entire site. As long as you do not charge for the use of this material, do not make malicious or misleading changes, and do not use this material without proper attribution and citation, both to this author and site and to the references cited herein, you may copy and use this material for any legitimate educational purpose. For example, even a consultant may use the material to educate the consultant's client, but shall not charge them for the copying or use of it, not even T-shirts.

   These tutorials range in difficulty from sophomore to the senior/graduate/postdoctoral level. They begin with the basics and extend to a new exact solution to Richards' equation for unsaturated horizontal and vertical flow, which reduces it to a numerical solution of an ordinary differential equation under given conditions. The following links are roughly organized according to difficulty and the necessary sequence for understanding. Concepts not presented here may be reserved to other subcontracts on Dr. Nofziger's grant.

05/25/2002 - Someone correctly pointed out that the PowerPoint sources in the Soil Physics Tutorials will not download with all the images. This may not be fixed for some time. (Now fixed, I hope.)

6/27/2004 - As noted above, the site has been reconstructed to remove the HTML pages and replace them with zipped files of the original PowerPoint presentations.


Mathematical and Physical Basics

basic-a  What is soil? Soil physical quantities.

basic-b  Particle size, porosity, energy and work, water in soil pores, head concepts.

basic-c  Water flow in pores, rules of differentiation.

deriv-a  Darcy's law for horizontal and vertical flow in saturated soil, conductivity means in saturated soil, horizontal flow in layered soil.

deriv-b  Unsaturated pore space and water content, the pressure-saturation relation.

deriv-c  Unsaturated conductivity, mean conductivities for horizontal and vertical steady-state unsaturated flow, min-max and mean value properties in steady unsaturated flow, unsaturated conductivity distributions in space.

deriv-d  Testing conductivity means for mathematical validity, visualizing unsaturated conductivity means.

More Advanced Mathematical Concepts

pde-a  Unsaturated flow and Darcy's law, Richards' equation by mass conservation, anisotropy, Richards' equation in three dimensions.

pde-b  Classical Green-Ampt infiltration in horizontal and vertical flow in to homogeneous porous media, modern Green-Ampt infiltration. (Note: "Put links here" in the last slide refers to the gsreq links below)

findif-a  Using finite difference methods in soil physics, infiltration and redistribution example, Richards' equation, contaminant transport in steady flow, flow of water from a table to surface evaporation, the concentration of salt due to surface evaporation.

findif-b  Stability analysis for finite difference numerical methods.

findif-c  Newton's method and finite difference Richards' equation.

gsreqhcp  A exact numerical solution for Richards' equation for horizontal flow and a constant pressure boundary condition, with comparisons to finite difference models. (Note: If any titles in this set still say "general solution", this is not strictly correct; this approach is limited to inflows that produce monotonically decreasing wetting fronts. It may also work with drainage, but this has not been done yet. The utility of this approach is that it transforms Richards' equation to an ordinary differential equation, which can be addressed by students before taking a course in partial differential equations.)

gsreqvcp  An exact numerical solution for Richards' equation for vertical flow and a constant pressure boundary condition, with comparisons to finite difference models.

gsreqhcf  An exact numerical solution for Richards' equation for horizontal flow and a constant flow boundary condition, with comparisons to finite difference models.

gsreqvcf  An exact numerical solution for Richards' equation for horizontal flow and a constant flow boundary condition, with comparisons to finite difference models.

gsreqvvf  An exact numerical solution for Richards' equation for vertical flow and a variable flow boundary condition, with comparisons to finite difference models, known limitations for the approach.

Field Concepts

field-a  NRCS runoff calculations, with flow chart.

field-b  Evapotranspiration, including a Basic program for the Penman equation.

field-c  Root extraction, distribution and stress.

field-d  Empirical infiltration equations.

field-e  Models of infiltration into sand-loam layers from constant head.

Statistical Concepts

geostat-a  Basic statistical concepts for soil physics.

geostat-b  Statistical analysis of some field data for saturated conductivity, bulk density and worm holes.

geostat-c  Statistical analysis and color contours of a synthetic data set of saturated conductivity and porosity, including some variograms.

geostat-d  A time-series field data set, soil temperature at 10.2 and 30.5 cm.

geostat-e  Variograms of some weather data.

Problem Sets

problem set a  These problem sets include mathematical problems for the basic-a, basic-b, basic-c, deriv-a, deriv-b, deriv-c, deriv-d, pde-a and pde-b slide sets.

problem set b  These problem sets includ mathematical problems for the field concepts slide sets.

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