MT3D
Criterion | Explanation |
General Description | Subsurface simulation of saturated zone solute transport. Uses output from MODFLOW to solve convective-dispersion equation. |
Model Domain | Subsurface saturated zone |
Developer | U.S. Geological Survey (USGS) |
Hardware computing requirements | Used on personal computers running various versions of the Microsoft Windows operating system. It is recommended to have 2 GB of RAM available to hold all required data. If there is insufficient RAM to run the model, then MT3D-USGS will not initiate the beginning of the simulation. |
Code language | FORTRAN 90 |
Original application | MT3D-USGS is an updated release of the groundwater solute transport code MT3DMS. The code now simulates unsaturated-zone transport and transport within streams and lakes, including solute exchange with connected groundwater. Other capabilities include:
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Public/proprietary and cost | Public; No cost |
Physically or empirically based | Physically based |
Mathematical methods used | MT3D-USGS solves an advection-dispersion-reaction in a groundwater flow system under generalized hydrogeologic conditions. The code implements a corrected formulation of the transient storage term. New improvements in the code include:
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Input data requirements | MT3D-USGS will not work if a flow-transport link file has not first been generated by MODFLOW-2005 (Harbaugh, 2005) or MODFLOW-NWT. The data arrays in MT3D-USGS are dynamically allocated, so models are not limited by hard-coded array limits. The NAME file contains the names of most input and output files used in a model simulation and controls the parts of the model program that are active. This contains variables including the many budget, transport, and reaction packages. Files such as those used for input of concentrations saved in a previous simulation as the initial condition for a continuation run are read in as binary (unformatted) files. Files such as those used to save formatted concentrations at observation points and mass budget summaries, or for input data from files that are separate from the primary package input files, are input as text files. |
Outputs | An output listing file is required for every simulation. Output can be saved for the (binary) concentration file, the formatted concentration observation file, the formatted mass budget summary file, and the model configuration file. Optional CTO file (ASCII) contains a well-by-well printout of the mass balance related to the CTS mass budget package. |
Pre-processing and post-processing tools | Visual MODFLOW (Waterloo Hydrogeologic), Groundwater Vistas (Rockware), USGS Model Muse and Model Viewer |
Representation of uncertainty | The model does not have built-in uncertainty representation. This can be assessed for each specific case using sensitivity analysis. |
Prevalence | Several scientific publications have described the use of MT3D. In the Delta, Deverel et al. (2017) used MT3D coupled with MODFLOW to simulate DOC transport on Twitchell Island. |
Ease of use for public entities | There are no restrictions for use. Model files can be accessed at: |
Ease of obtaining information and availability of technical support | User guides and example problems available. There is limited support for correcting bugs and clarification of how MT3D-USGS is intended to work. |
Source code availability | Source code available via https://water.usgs.gov/ogw/mt3d-usgs/ |
Status of model development | Developed and available for use. |
Challenges for Integration | For integration with surface water modeling, temporal and spatial scales and calculations associated with MODFLOW modeling are different that those used for surface water models. See challenges associated with MODFLOW. MT3D used for simulation of DOC transport and loads on Delta islands. |
References
Bedekar, V., Morway, E.D., Langevin, C.D., and Tonkin, M., 2016, MT3D-USGS version 1: A U.S. Geological Survey release of MT3DMS updated with new and expanded transport capabilities for use with MODFLOW: U.S. Geological Survey Techniques and Methods 6-A53, 69 p., http://dx.doi.org/10.3133/tm6A53.
Deverel, S. J, Leighton, D. A, Lucero, C., & Ingrum, T., 2017, Simulation of Subsidence Mitigation Effects on Island Drain Flow, Seepage, and Organic Carbon Loads on Subsided Islands Sacramento–San Joaquin Delta. San Francisco Estuary and Watershed Science, 15(4), https://escholarship.org/uc/item/4q340190.
Harbaugh, A.W., 2005, MODFLOW-2005: The U.S. Geological Survey Modular Ground-water Model–the Ground-water Flow Process: U.S. Geological Survey Techniques and Methods 6-A16, p. 253. Available online at http://water.usgs.gov/ogw/modflow/MODFLOW.html.
See https://water.usgs.gov/ogw/mt3d-usgs/ for an overview of MT3D-USGS, as well as various downloads.