Lesson 1 - Course Introduction

Nothing you will learn in the course of your studies will be of the slightest possible use to you, save only this, that if you work hard and intelligently, you should be able to detect when a man is talking rot, and that, in my view, is the main, if not the sole, purpose of education.

John Alexander Smith

This self-paced Course is intended to provide you with an introduction to the GoldSim Contaminant Transport Module.

The GoldSim Contaminant Transport Module is a program extension to GoldSim that allows you to simulate the release, transport and fate of mass (e.g., contaminants) within complex engineered and/or natural environmental systems. Unlike the basic GoldSim framework itself, which is quite generic and can therefore be applied to a very wide variety of problems, the Contaminant Transport Module was specifically designed to a be applied to a particular class of problems: those associated with modeling the transport (movement) of mass (typically dissolved contaminants in water) through an environmental system (e.g., soils, surface water bodies, groundwater).

This Course assumes that you are already familiar with the basic GoldSim framework. As a result, no effort is spent at all in explaining the fundamentals of GoldSim or how to interact with the user interface. If you are not familiar with the basic GoldSim framework, you must first take the Basic GoldSim Course, and then return to this Course.

So what is required to take this course?

• As pointed out above, you must be familiar with the basics of using GoldSim.
• A solid quantitative background is assumed, but no specific mathematical skills are required beyond a very basic understanding of calculus. Of course, the stronger your analytical and quantitative background, the easier you are likely to find the Course.
• A basic understanding of fundamental contaminant transport concepts (e.g., advection, dispersion, diffusion, sorption) is also assumed. Although they will be reviewed, it is assumed that you already have some understanding of these fundamental concepts. In fact, such an understanding is required to build a contaminant transport model using any kind of software. An excellent introductory textbook on this topic is Chemical Fate and Transport in the Environment by Hemond and Fechner.
• Solving the equations associated with realistic contaminant transport problems (using any tool) generally requires use of numerical methods (as opposed to analytical solutions), and this is certainly the case for GoldSim. However, this Course does not require a detailed understanding of numerical methods. Having said that, this Course does discuss (in general terms) how GoldSim goes about solving the equations that represent the systems you are modeling. This is important, because as a general rule, you should not use “black boxes” to build models. If you don’t understand how a tool works, you should not use it. Hence, the general concepts necessary to understand how GoldSim solves the equations numerically are provided in such a way that they can be understood by anyone with a solid quantitative background. Details of how GoldSim solves the equations can be found in the Appendices to the Contaminant Transport Module User’s Guide.

If you work straight through (which is not necessarily recommended), the Course will likely take no less than 40 hours to complete (and if you tend be very methodical and spend time exploring the Help system as you take the Course, it could take much longer). The Course is organized into Units and Lessons so you can easily take it at your own pace (and the site will remember where you last left off). The ideal approach is probably to spend perhaps just a couple hours per day with the Course and spread it out over several weeks or a month. This then provides you with an opportunity to give some considered thought to the information that was presented, and prevent “information overload”. On the other hand, if you are already very familiar with contaminant transport modeling (and/or have a strong quantitative background), you may want to approach the Course in a more intensive manner and cover the material more rapidly.

This is a “hands-on” Course. That is, while you are taking it, you are expected to simultaneously use the software. As a result, if possible, it is recommended that you use a large (or high resolution) screen with this Course on one side of the screen and GoldSim on the other, an extended desktop (e.g., using two monitors) or perhaps two computers (a computer for the software and a tablet for the Course). Throughout the Course, we use a number of simple Exercises and Examples to help you learn how to use the software. In order for this Course to be effective at all, it is critical that you work through these Exercises and Examples.

Finally, it is important to understand that this Course teaches you how to use the Contaminant Transport Module, but this is simply one step toward building complex contaminant transport models. Building realistic and useful models requires four things:

1. An understanding of fundamental contaminant transport concepts (e.g., advection, dispersion, diffusion, sorption);
2. An understanding of the use of one or more tools (e.g., GoldSim) that you can use to build a model;
3. A conceptual and quantitative understanding of the specific system you are trying to model; and
4. The ability to evaluate a system, conceptualize it in a generalized (and often abstract) way, and subsequently represent the features, processes and events defining the system quantitatively at an appropriate level of detail.

This Course focuses primarily on the second item. As noted above, although basic contaminant transport concepts are reviewed, it is assumed that you already have an understanding of these. Furthermore, if you want to model a particular system, it is assumed that you have a conceptual and quantitative understanding of that system, so the third item will not be discussed at all. The fourth item (which is arguably the most difficult skill to acquire) is not specific to the Contaminant Transport Module. This ability is required to use GoldSim (or any simulation tool) for any kind of application. As such, it was discussed in some detail in Unit 17, Lesson 4 of the Basic GoldSim Course.