HYDRUS Textbook

Soil Physics with HYDRUS

Published: May 26 2010

Table of Contents

• Book Description
• #k2 Book Errata
• #k3 Software simulations described in the text
• #k4 MS Excel files for examples described in the text
• #k5 MS Excel files for problems described in the text
• #k6 Book Reference
• #k7 HYDRUS book PowerPoint slides for teaching
• #k8 Teaching videos for simple laboratory experiments
• #k9 Answers to Selected Chapter Problems
• #k10 Where to buy

Book Description

Numerical models have become much more efficient, making their application to problems increasingly widespread. User-friendly interfaces make the setup of a model much easier and more intuitive while increased computer speed can solve difficult problems in a matter of minutes. Co-authored by the software’s creator, Jirka Šimůnek, Soil Physics with HYDRUS: Modeling and Applications demonstrates one- and two-dimensional simulations and computer animations of numerical models using the HYDRUS software.

Classroom-tested at the University of Georgia by Dr. David Radcliffe, this volume includes numerous examples and homework problems. It provides students with access to the HYDRUS-1D program as well as the Rosetta Module, which contains large volumes of information on the hydraulic properties of soils. The authors use HYDRUS-1D for problems that demonstrate infiltration, evaporation, and percolation of water through soils of different textures and layered soils. They also use it to show heat flow and solute transport in these systems, including the effect of physical and chemical nonequilibrium conditions. The book includes examples of two-dimensional flow in fields, hillslopes, boreholes, and capillary fringes using HYDRUS (2D/3D). It demonstrates the use of two other software packages, RETC and STANMOD, that complement the HYDRUS series.

Hands-on use of the windows-based codes has proven extremely effective when learning the principles of water and solute movement, even for users with very little direct knowledge of soil physics and related disciplines and with limited mathematical expertise. Suitable for teaching an undergraduate or lower level graduate course in soil physics or vadose zone hydrology, the text can also be used for self-study on how to use the HYDRUS models. Using the information in this book, users can run models for different scenarios and with different parameters, thus gaining a better understanding of the physics of water flow and contaminant transport.

Preface

In 1985, Gaylon Campbell published a slim volume entitled Soil Physics with Basic (Campbell, 1985). This textbook was one of the first and best publications to show the potential for numerical computer models to solve applied problems in the field of soil physics. Since that time, numerical models and computers have come a long way. Numerical models have become much more efficient and can now be applied to two- and three-dimensional problems of saturated and unsaturated water flow, heat flow, and solute transport. User-friendly interfaces have been developed that make the setup of the model much easier and more intuitive. The interfaces are especially helpful in displaying the model output of two- and three-dimensional simulations in a way that is immediately intelligible to students, including the use of computer animation. Computer speed has increased to the point that very difficult problems can be solved within a matter of hours, including powerful inverse methods that could only be applied to analytical solutions in the past.

One of the most advanced and popular numerical computer models for the field of soil physics is the HYDRUS series: HYDRUS-1D and HYDRUS (2D/3D). In our conversations with soil physicists teaching undergraduate and graduate courses in soil physics and vadose zone hydrology across the US, Europe, Australia, and Asia we have found that many are using HYDRUS models in some portion of their course. We developed this textbook to use the HYDRUS models to teach the principles and applications of soil physics. The HYDRUS models include the Rosseta-based pedotransfer functions, which we use to illustrate soil water characteristic curve relationships and unsaturated hydraulic conductivity functions. HYDRUS-1D is used for hands-on problems that demonstrate infiltration, evaporation, and percolation of water through soils of different textures and layered soils. It is also used to show heat flow and solute transport in these systems, including the effect of physical and chemical nonequilibrium conditions. Examples of two-dimensional flow in fields, hillslopes, boreholes, and capillary fringes are included using HYDRUS (2D/3D). Use of two other software packages that complement the HYDRUS series is shown. One of these is the Code for Quantifying the Hydraulic Functions of Unsaturated Soils (RETC; van Genuchten et al., 1991), used to fit soil water retention curves. The other is the Studio of Analytical Models for Solving the Convection-Dispersion Equation (STANMOD; Toride et al., 1999) which uses analytical solutions to solve solute transport problems. The HYDRUS models, RETC, and STANMOD can be downloaded here.

There are many excellent packages such as Mathcad (Parametric Technology Corporation) and Matlab (The Mathworks, Inc.) that can be used in conjunction with a soil physics textbook. However, as discussed by Wraith and Or (1998), the learning curve for using these packages is steep and the packages can be expensive. On the other hand, most students are familiar with Microsoft Excel and have it on their computers. Our experience has been that students are very receptive to learning “new tricks” with Excel. With a little work, Excel can be used to accomplish many of the tasks that the math software packages would be used for in a soil physics course (including matrix computations) and we use it throughout this textbook.

Our textbook should be suitable for teaching an undergraduate or a lower level graduate course in soil physics or vadose zone hydrology. It assumes that students are familiar with differential and integral calculus. However, a course could be taught to students with only differential calculus since derivations involving integral calculus appear at the end of each chapter and could be optional for students. The textbook should also be suitable for an individual who wants to teach herself/himself about the field of soil physics and how to use the HYDRUS models.

Comparing our textbook to the other excellent soil physics textbooks available, our book is not as quantitative as the books by Warrick (2003) or Tindall and Kunkel (1999). It is comparable to the books by Hillel (2004) and Jury and Horton (2004). Little detail on measurement methods is included as these methods change rapidly and there are excellent references (e.g., Dane and Topp, 2002). Gas flow is not treated in this book (except for the volatilization of solutes). This is because the HYDRUS models do not simulate gas flow, other than carbon dioxide transport in the specialized UNSATCHEM module. In our opinion, the primary contribution of this textbook is in the extensive use of the HYDRUS and related models to teach soil physics.

• Errata
  
• Answers to Selected Chapter Problems
   

Discussion Forum

We are initiating a Discussion Forum on the book “Soil Physics with HYDRUS” published in 2010. The purpose of the forum is to answer questions or receive comments about the book. We would like to focus on using the HYDRUS family of models to teach soil physics, but more general topics related to the book are also welcome.

Software simulations described in the text

Download all HYDRUS-1D examples (zip, 1.1 Mb).
Download all HYDRUS (2D/3D) examples (zip, 21 Mb).

MS Excel files for examples described in the text

Download all Excel Examples (zip).

=== MS Excel files for problems described in the text ====

Download all Excel Problems (zip).

Reference

Radcliffe, D., and J. Šimůnek, Soil Physics with HYDRUS: Modeling and Applications, CRC Press, Taylor & Francis Group, ISBN-10: 142007380X, ISBN-13: 9781420073805, pp. 373, 2010.

Additional HYDRUS Tutorials, Examples, and Test Problems

Check out additional HYDRUS tutorials, examples, and test problems:
HYDRUS-1D examples
HYDRUS-1D tutorials
HYDRUS (2D/3D) examples
HYDRUS (2D/3D) tutorials

HYDRUS Book PowerPoint Slides for Teaching

PowerPoint files with all equations, tables, and figures:
Chapter 1: Soil Solid Phase
Chapter 2: Soil Water Content and Potential
Chapter 3: Steady Water Flow in Soils
Chapter 4: Heat Flow in Soils
Chapter 5: Transient Water Flow in Soils
Chapter 6a: Solute Transport in Soils
Chapter 6b: Solute Transport in Soils

YouTube Videos Showing Basic Laboratory Experiments

Soil sampling, bulk density, and water content
Soil water curve
Permanent wilting point
Particle size distribution
TDR
Tensiometers
Temperature

Where to buy

The book is not distributed by PC Progress. It is distributed by the publisher CRC Press and other distributors, such as Amazon, CRC Press, and Taylor & Francis.