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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| MODFLOW | 3/4 | https://en.wikipedia.org/wiki/MODFLOW | reference | science, encyclopedia | 2026-05-05T10:12:39.169012+00:00 | kb-cron |
MF2K-GWM or GWM-2000 (version 1.1.4, May 31, 2011, branched from mf2k 1.17.2), with groundwater management capability using optimization MF2K-FMP (version 1.00, May 19, 2006, based on mf2k 1.15.03), with Farm Process MF2K-GWT (version 1.9.8, October 28, 2008, based on MF2K 1.17.02), groundwater flow and solute-transport model SEAWAT (version 4.00.05, October 19, 2012), variable-density flow and transport processes VSF (version 1.01, July 5, 2006), variably saturated flow
=== MODFLOW-2005 === MODFLOW-2005 differs from MODFLOW-2000 in that the sensitivity analysis, parameter estimation, and uncertainty evaluation capabilities are removed. Thus, the support for these capabilities now falls to "clip on" codes that are supported externally to the MODFLOW support effort. In addition, the code was reorganized to support multiple models within one MODFLOW run, as needed for the LGR (Local Grid Refinement) capability. MODFLOW-2005 is written primarily in Fortran 90 and C, with C being used for one solver. The current version of MODFLOW-2005 is version 1.12.00, released on February 3, 2017. Related or branched codes include:
MODFLOW-CFP (version 1.8.00, February 23, 2011), conduit flow process to simulate turbulent or laminar groundwater flow conditions MODFLOW-LGR (version 2.0, September 19, 2013), local grid refinement GWM-2005 (version 1.4.2, March 25, 2013), groundwater management capability using optimization MF2005-FMP2 (version 1.0.00, October 28, 2009), estimate dynamically integrated supply-and-demand components of irrigated agriculture as part of the simulation of surface-water and ground-water flow MODFLOW-NWT(version 1.1.3, August 1, 2017), Newton formulation for solving problems involving drying and rewetting nonlinearities of the unconfined groundwater-flow equation. MODFLOW-OWHMv1 (version 1.00.12, October 1, 2016), The One-Water Hydrologic Flow Model (MF-OWHM1), developed cooperatively between the USGS and the U.S. Bureau of Reclamation, is a fusion of multiple versions of MODFLOW-2005 (NWT, LGR, FMP, SWR, SWI) into ONE version, contains upgrades and new features and allows the simulation of head-dependent flows, flow-dependent flows, and deformation dependent flows that collectively affect conjunctive use of water resources. MODFLOW-USG. All version of MODFLOW listed above are constructed on what is called a structured grid. That is, the grid is composed of rectilinear blocks. The only exception is the LGR capability, which allows locally refined grids to be inserted into the structure of a "parent" grid. The local area is again composed of rectilinear blocks, but the blocks are smaller. Experimentation with a much more flexible grid structure resulted in the release of MODFLOW-USG (version 1.3.00, December 1, 2015), designed to be adapted to a wide range of grid variations using unstructured grids. MODFLOW-USG has similar capabilities as MODFLOW 6, which provides grid capabilities with and intermediate level of flexibility. MODFLOW-USG Transport. An update of MODFLOW USG including multiple solute species transport, density dependent flow and transport, use of the Richard's equation for flow and transport in the unsaturated zone and air-water interface sorption. Some of the updates to the model have also been made to accommodate for transport of PFAS.
=== MODFLOW 6 === MODFLOW 6 (MF6), first released in 2017, is the sixth core version of MODFLOW to be released by the USGS. This release is a rewrite of MODFLOW following an object-oriented programming paradigm in Fortran, and provides a platform that includes the capabilities from several previous MODFLOW-2005 versions, including MODFLOW-NWT, MODFLOW-USG, and MODFLOW-LGR. MODFLOW 6 supports structured or unstructured grids, has full support for the Newton-Raphson formulation, and has a unique Water Mover Package that allows flows to be routed between the advanced packages, including the Streamflow Routing, Lake, Multi-Aquifer Well, and Unsaturated Zone Flow Packages. MODFLOW 6 also contains a Groundwater Transport (GWT) model that simulates transient three-dimensional solute transport on structured or unstructured grids and through the advanced flow and mover packages. An Application Programming Interface (API) is also available for MODFLOW 6, which allows the program to be coupled with other models or controlled with popular scripting languages, such as Python. While there are a few features lacking in the current release that are supported in MODFLOW-2005, most of the popular capabilities in previous MODFLOW versions are available in MODFLOW 6. The current version is 6.2.2, released July 30, 2021.
=== MODFLOW-OWHM Version 2 === The MODFLOW One-Water Hydrologic Flow Model version 2 (MF-OWHM) is a major rewrite of MF-OWHM1 released in 2020. MF-OWHM is a MODFLOW-2005 based integrated hydrologic model designed for the analysis of conjunctive-use management. The term “integrated” refers to the tight coupling of groundwater flow, surface-water flow, landscape processes, aquifer compaction and subsidence, reservoir operations, and conduit (karst) flow. This fusion results in a simulation software capable of addressing water-use and sustainability problems, including conjunctive-use, water-management, water-food-security, and climate-crop-water scenarios. As a second core version of MODFLOW-2005, MF-OWHM maintains backward compatibility with existing MODFLOW-2005 versions. Existing models developed using MODFLOW-2005, MODFLOW-NWT, MODFLOW-SWI, MODFLOW-SWR, MODFLOW-LGR, and MODFLOW-CFP can also be simulated using MF-OWHM. The Farm Process (FMP) is part of MF-OWHM but is the only component that does not maintain input backward compatibility with past releases (see the FMP_Template for new input structure). MF-OWHM also includes a Surface Water Operations Module (SWO) with a Fortran-like scripting language, Slang, that can specify dynamic reservoir and stream operations. A current major application of MF-OWHM, developed by the USGS, is the California Central Valley (CVHM2). The current USGS Approved Software version is 2.3.0 released on January 15, 2024, and current preliminary-beta release of 2.3.1b-4 released on February 27, 2025.
== Packages == The names in this table are the labels used to turn MODFLOW capabilities on and off via a key input file. Most capabilities have many alternatives or can be omitted, but the ones related to the BASIC Package are always required. Many of the capabilities introduced are supported in later versions, though the grid change enabled with MODFLOW-USG and MODFLOW 6 meant that such backward compatibility was rather selective.
== Graphical user interfaces == There are several graphical interfaces to MODFLOW, which often include the compiled MODFLOW code with modifications. These programs aid the input of data for creating MODFLOW models.