SUMATRA-1 is a one-dimensional Hermitian finite element (HFE) model for simulation of simultaneous movement of water and a solute in a heterogeneous soil profile. The transport equation includes the effects of linear adsorption and zero- and first-order decay. The HFE scheme generates the most accurate solutions of both the moisture and solute fronts, although at the expense of computational time. However, for extreme dry soils a regular finite difference or a linear finite element method with mass-lumping should be used. The model can handle both saturated and moderately unsaturated soil conditions. Both fairly abrupt layering and smoothly changing soil profiles can be handled.

SUMATRA-1 runs in batch mode only. Input data files are created using a text editor. The program is distributed on DOS-formatted diskettes containing source code, executable image, and an example data set. Documentation includes user's instructions, theory, and example problems.

SYSTEM REQUIREMENTS

• Intel 80i86 based computer
• 640 Kb conventional RAM
• DOS 3.0 or higher
• hard drive with about 3 Mb free disk space
• math coprocessor

Author: M.Th. van Genuchten (Princeton University)