MT3D/MT3DMS

SOFTWARE REVIEW by Henning Prommer, Ph.D.,

Utrecht University (Netherlands)

 

MT3DMS is a public domain solute transport model for saturated porous media. In its current version it handles three-dimensional advective-dispersive transport of multiple chemical species and a range of simple chemical reactions. Moreover it serves also as the "engine" to compute advective-dispersive transport in other models that have more advanced reaction capabilities and for the variable density simulator SEAWAT. Notable features of MT3DMS that distingish it from many other solute transport models include the availability of several different numerical solution techniques for advective transport and the variety of boundary conditions and features that are needed to build realistic models. In particular the particle-tracking based solution schemes can produce results that are essentially free of numerical dispersion in the absence of excessive grid refinement - a common problem among many other models.

Since its initial release as the single species simulator in 1990 MT3D, it has undoubtedly become the workhorse of computational contaminant hydrology. Of course, the most obvious reason for this is its full compatibilty with MODFLOW. Other important reasons for its popularity, among practitioners and researchers, are its robustness, which allows new users to quickly come up with accurate results, and its very good documentation which includes the availabilty of its source code. The source code of MT3DMS is written in Fortran using a MODFLOW-type easy to follow modular structure.

With MT3DMS, the transport of multiple species can be carried out simultaneously, whereby each species can be subject to sorption, either using linear, Freundlich or Langmuir isotherms, and/or first-order degradation reactions. This limits the reaction capabilities to cases where the reaction rates of each species can be assumed not to depend significantly on concentrations of other chemical species. That feature can be used, for example, to calibrate a (nonreactive) transport model (see Figures) by simultaneously carrying out simulations for several nonreactive species (or species that can in a particular case study be considered as being inert). MT3DMS capabilities also include a dual domain transport formulation that might be used for simulations of fractured or highly heterogeneous aquifers. MT3DMS, like MODFLOW, does not come with its own graphical user interface and thus its ease of use ultimately depends on the GUI selected for processing data input/output. However, as MT3DMS is supported by essentially all commonly used MODFLOW GUIs, users have a good choice among several products. MT3DMS can be downloaded for free from http://hydro.geo.ua.edu/mt3d/index.htm. The page contains also links to several GUI suppliers.

Rating System
5=Excellent, 4=Very Good, 3=Good, 2=Satisfactory, 1=Poor

Ease of Use
4
GUI
na
Application
5
Output/Plotting
n/a
Documentation
5
Best Feature
Choice of Different Solvers for Advective Transport
Speed
4
Worst Feature
Transient simulations of thin layers in combination with drying/(re)wetting conditions
Overall Rating
5