MODFLOW 2001 and Other Modeling Odysseys Proceedings, 2001, International Ground Water Modeling Center, Colorado School of Mines, Golden, CO, p. 815-822 The Power of Spreadsheet Models

Prior to using MODFLOW, students need experience with simpler codes that provide “hands-on” experience setting up boundary and initial conditions, coding simple solution algorithms, and handling numerical errors. The best way to do this is using spreadsheet models; faculty no longer can expect students to know a common computer language, but students are familiar with spreadsheets. Many aspects of flow and transport modeling may be taught using spreadsheets. Students can quickly set up a spreadsheet model of a simple problem (e.g, the two-dimensional Toth regional flow system problem), watch the iterative solution on-screen, and view the final distributions of heads or concentrations. The same problem may be solved later using MODFLOW. Spreadsheets can be set up to calculate water balances, compute and graph calibration statistics, and perform sensitivity analyses. With the basic principles of modeling in hand, students are introduced to more complex concepts used in MODFLOW such as conductances and head dependent fluxes. Spreadsheets can be designed to mimic packages in MODFLOW such as Zonebudget, River, Well, and Recharge. Thus, spreadsheets provide an easy way to teach finite-difference theory and modeling concepts, as well as their implementation in MODFLOW.