FLOTRAN, a three-dimensional ground water model, with comparisons to analytical solutions and other models

FLOTRAN is a ground water flow and transport model developed in the past fe w years which takes advantage of recent advances in numerical methodology. FLOTRAN solves the governing equations for flow and contaminant transport u sing Godunov-mixed methods. in which a higher-order Godunov method is used to approximate the advective flux, and a mixed finite element method is use d for the dispersive transport. A mixed finite element method is also used to solve the flow equation. As part of the development of this new model, w e have tested it against known analytical and numerical solutions to the eq uations approximated by the model. In this work, we have tested FLOTRAN aga inst 1-D and 2-D analytical solutions, Galya's 3-D horizontal plane source solution, two radial semi-analytical solutions, and two numerical models, B IOPLUME II and MT3D. We have also tested FLOTRAN on a hypothetical partiall y saturated flow problem. FLOTRAN performed well on these tests, generally matching analytical solutions to within a few percent, and matching as well as or better than the other numerical models in most cases. (C) 2000 Elsev ier Science Ltd. All rights reserved.