GGSD Program Details for MT3DMS

MT3DMS

Category	Contaminant transport (3D)
Platform	DOS
Status	Freeware
Description	MT3DMS is a modular three-dimensional transport model based on MT3D as originally developed by Zheng (1990) at S. S. Papadopulos & Associates, Inc., and subsequently documented for the Robert S. Kerr Environmental Research Laboratory of the United States Environmental Protection Agency. This version of the program has the following expanded capabilities 1) a third-order total-variation-diminishing (TVD) scheme for solving the advection term that is mass conservative but does not introduce excessive numerical dispersion and artificial oscillation; 2) an iterative solver based on generalized conjugate gradient methods to remove stability constraints on the transport time stepsize; 3) options for accommodating nonequilibrium sorption and dual-domain advection-diffusion mass transport; and 4) a multi-component program structure that can accommodate add-on reaction packages for modeling general biological and geochemical reactions. It includes three major classes of transport solution techniques in a single code, i.e., the standard finite difference method; the particle-tracking-based Eulerian-Lagrangian methods; and the higher-order finite-volume TVD method. It is implemented with an optional, dual-domain formulation for modeling mass transport. With this formulation, the porous medium is regarded as consisting of two distinct domains, a mobile domain where transport is predominately by advection and an immobile domain where transport is predominately by molecular diffusion. Instead of a single "effective" porosity for each model cell, two porosities, one for the mobile domain and the other for the immobile domain, are used to characterize the porous medium. The exchange between the mobile and immobile domains is specified by a mass transfer coefficient. The dual-domain advective-diffusive model may be more appropriate for modeling transport in fractured media or extremely heterogeneous porous media than the single porosity advective-dispersive model, provided that the porosities and mass transfer coefficients can be properly characterized. The modular structure of the transport model makes it possible to simulate advection, dispersion/diffusion, source/sink mixing, and chemical reactions separately without reserving computer memory space for unused options; furthermore new packages involving other transport processes and reactions can be added to the model readily without having to modify the existing code.
Cost	Free on www
Data formats supported	None stated
Supplier in United States of America	International Ground Water Modeling Center