Modflow usg

MODFLOW-USG

Application:Groundwater Flow Modeling
Method:Finite Volume
Model Type:3D
Developer:U.S. Geological Survey

Why MODFLOW-USG with GMS?
GMS provides a custom interface to the MODFLOW-USG model offering a simple way to set model parameters and a graphical user interface to run the model and visualize the results. Gather background data from a variety of sources from GIS to CAD and access online data from numerous databases of maps, images, and elevation data. GMS allows you to interact with models in true 3D taking advantage of optimized OpenGL graphics and to create photo-realistic renderings and animations for PowerPoint, print, and web presentations. GMS is the only MODFLOW-USG interface that supports any unstructured grid type including nested grids and grids based on triangles, rectangles, hexagons, and other cell shapes.

Try GMS Free for 14 Days >Purchase GMS with MODFLOW-USG >

MODFLOW-USG Description:
MODFLOW-USG offers the ability to create unstructured grids in order to increase model resolution around features such as rivers and wells. By varying the resolution in a groundwater model, more detailed information may be represented in areas that matter most resulting in more accurate models with quicker runtimes.

Unstructured grid types include quadtree (nested grids), voronoi (variably sized polygon), and tri-quad (triangle and quadrilateral) grids.

MODFLOW-USG Package	Description
GNC	Ghost Node Correction
CLN Process	Connected Linear Network
BCT	Block Centered Transport
DDF	Density Dependent Flow
DPT	Dual Porosity Transport
PCB	Prescribed Concentration Boundary
TVM	Time-variant Materials (MODFLOW-USG Transport)

Sours: https://www.aquaveo.com/software/gms-modflow-usg

Overview of MODFLOW-USG

A plot of head errors from an example MODFLOW-USG simulation.

Errors in simulated heads from the a MODFLOW-USG simulation with ghost node correction.

A version of MODFLOW, called MODFLOW-USG (for UnStructured Grid), was developed to support a wide variety of structured and unstructured grid types, including nested grids and grids based on prismatic triangles, rectangles, hexagons, and other cell shapes. Flexibility in grid design can be used to focus resolution along rivers and around wells, for example, or to subdiscretize individual layers to better represent hydrostratigraphic units.

MODFLOW-USG is based on an underlying control volume finite difference (CVFD) formulation in which a cell can be connected to an arbitrary number of adjacent cells. To improve accuracy of the CVFD formulation for irregular grid-cell geometries or nested grids, a generalized Ghost Node Correction (GNC) Package was developed, which uses interpolated heads in the flow calculation between adjacent connected cells.

MODFLOW-USG includes a Groundwater Flow (GWF) Process, based on the GWF Process in MODFLOW-2005, as well as a new Connected Linear Network (CLN) Process to simulate the effects of multi-node wells, karst conduits, and tile drains, for example. The CLN Process is tightly coupled with the GWF Process in that the equations from both processes are formulated into one matrix equation and solved simultaneously. This robustness results from using an unstructured grid with unstructured matrix storage and solution schemes.

MODFLOW-USG also contains an optional Newton-Raphson formulation, based on the formulation in MODFLOW-NWT, for improving solution convergence and avoiding problems with the drying and rewetting of cells. Because the existing MODFLOW solvers were developed for structured and symmetric matrices, they were replaced with a new Sparse Matrix Solver (SMS) Package developed specifically for MODFLOW-USG. The SMS Package provides several methods for resolving nonlinearities and multiple symmetric and asymmetric linear solution schemes to solve the matrix arising from the flow equations and the Newton-Raphson formulation, respectively.

Download Current Version of MODFLOW-USG

Documentation for MODFLOW-USG

Panday, Sorab, Langevin, C.D., Niswonger, R.G., Ibaraki, Motomu, and Hughes, J.D., 2013, MODFLOW-USG version 1: An unstructured grid version of MODFLOW for simulating groundwater flow and tightly coupled processes using a control volume finite-difference formulation: U.S. Geological Survey Techniques and Methods, book 6, chap. A45, 66 p., https://doi.org/10.3133/tm6A45

Programs Related to MODFLOW-USG

GRIDGEN, a utility for creating layered quadtree grids for use with MODFLOW-USG.

Superseded MODFLOW-USG Versions

The following software is not actively supported by the USGS. The software has been superseded by the latest MODFLOW-USGS release above. The software versions below are provided online for historical reference only, and the files may contain outdated information or broken links.

Find MODFLOW-Related Software

Visit the MODFLOW and Related Programs page for a list of MODFLOW-related software.

How to Cite MODFLOW-USG

Panday, Sorab, Langevin, C.D., Niswonger, R.G., Ibaraki, Motomu, and Hughes, J.D., 2017, MODFLOW-USG version 1.4.00: An unstructured grid version of MODFLOW for simulating groundwater flow and tightly coupled processes using a control volume finite-difference formulation: U.S. Geological Survey Software Release, 27 October 2017, https://dx.doi.org/10.5066/F7R20ZFJ

Software License and Purchase Information

This software is a product of the U.S. Geological Survey, which is part of the U.S. Government.

Cost

This software is freely distributed. There is no fee to download and (or) use this software.

License

Users do not need a license or permission from the USGS to use this software. Users can download and install as many copies of the software as they need.

Public Domain

As a work of the United States Government, this USGS product is in the public domain within the United States. You can copy, modify, distribute, and perform the work, even for commercial purposes, all without asking permission. Additionally, USGS waives copyright and related rights in the work worldwide through CC0 1.0 Universal Public Domain Dedication (https://creativecommons.org/publicdomain/zero/1.0/ ).

Sours: https://www.usgs.gov/software/modflow-usg-unstructured-grid-version-modflow-simulating-groundwater-flow-and-tightly

GMS:MODFLOW-USG

MODFLOW
Pre-processing
MODFLOW Commands
Building a MODFLOW Model
Map to MODFLOW
Calibration
Packages Supported in GMS
Saving a MODFLOW Simulation
Importing MODFLOW Files
Unsupported MODFLOW Features
Post-processing
MODFLOW Display Options
MODFLOW Post-Processing Viewing Options
Reading a MODFLOW Simulation
Tutorials
MODFLOW Tutorials
Packages
Flow:	BCF6, HUF, LPF, UPW
Solvers:	DE4, GMG, NWT, PCG, PCGN, LMG, SIP, SOR, SMS
Other:	BAS6, BFH, CHD1, CLN, DRN1, DRT1, EVT1, ETS1, GAGE, GHB1, GNC, HFB1, HUF, LAK3, MNW1, MNW2, OUT1, RCH1, RIV1, SFR2, STR1, SUB1, SWI2, WEL1, UZF1
v • e

Starting at GMS version 10.0, GMS supports MODFLOW-USG. MODFLOW-USG is a version of MODFLOW based on finite volume calculations, thus allowing for many different types of grid cells. This allows the model grid to more accurately match the model domain and be more efficiently refined in areas where more accuracy is desired.

MODFLOW-USG models are built using unstructured grids, or UGrids, which are a new (as of GMS 10.0) type of geometric object that can handle the wide variety of cell types supported by MODFLOW-USG.

The MODFLOW-USG model is included with all paid editions of GMS.

Choosing MODFLOW Version

Only MODFLOW-USG is supported when using unstructured grids. MODFLOW-USG can also be used for a model using a 3D grid. Choosing to use MODFLOW-USG is done in the MODFLOW Global/Basic Package dialog. With a 3D grid at any time the user can switch from one MODFLOW version to another.

MODFLOW Global/Basic Packagedialog

Unsupported Features

Previous to GMS 10.1 there was no support for the following MODFLOW-USG features, though the CLN and GNC packages and the import feature are now supported in current versions of GMS.

Packages/processes
Older versions of GMS cannot read MODFLOW-USG files written by any non-GMS software. This is because there was no standard way to define the unstructured grid geometry. GMS writes a *.VTU (Visualization Toolkit unstructured grid) file with the MODFLOW files to define the grid geometry. In GMS 10.1 and later versions a model that was created outside of GMS can be imported as long as there is either a *.vtu file (VTK unstructured grid file) or a *.gsf file (Grid Specification File) present to define the grid geometry because the MODFLOW-USG native input files do not include locations of the grid nodes (unfortunately).

Additionally, PEST-ASP is currently unsupported in MODFLOW-USG

MODFLOW-USG Files

Here are tables of some of the available input and output files for MODFLOW-USG.

For more information on these files see the manual

Name	Description
MFN	MODFLOW Name File
GLO	Global Listing File
DIS	Discretization File
OC	Process Output Control Option File
BA6	Basic Package Global Options File

Name	Description
SMS	Sparse Matrix Solver

Name	Description
BCF	Block-Centered Flow
LPF	Layer Property Flow

Name	Description
CHD	Time-Variant Specified-Head
DRN	Drain
EVT	Evapotranspiration
GAG	Gage
GHB	General Head Boundary
GNC	Ghost Node Correction
HFB	Horizontal Flow Barrier
LAK	Lake
RCH	Recharge
RIV	River
SFR	Streamflow-Routing
STR	Stream-Routing
SUB	Subsidence
WEL	Process Well

Name	Description
OBS	Main Observation Process Input
DROB	Drain Observation
CHOB	Constant-Head Flow Observation Input

Name	Description
MFS	MODFLOW Super File
MFW	GMS MODFLOW World File
MFR	GMS MODFLOW Result Index File
PRJ	Projection
CSV	Cell Summary Comma Separated Value Excel
HFF	Head and Flow File Link to MT3DMS
H5	Hierarchal Data Format (HDF5) Array & List Data
M2P	MODFLOW Pest
PARAM	Parameter Information

Name	Description
CCF	Cell-to-Cell Aquifer Flow
CCF2	Cell-to-Cell Stream Reach Outflow
DRW	Drawdown
GLO	Global Listing
HED	Head Output
OUT	Output
VTU	Visualization Toolkit Unstructured Grid

Name	Description
_W	Weighted Residuals
_WW	Weighted Equivalents & Weighted Observation
_WS	Weighted Residuals and Simulated Equivalents
_R	Unweighted Residuals
_OS	Observed Values and Simulated Equivalents
_B	Data Exchange File
_NM	Weighted Residuals and Probability Plotting

Practical Notes

When using MODFLOW-USG to re-wet cells:

In the MODFLOW SMS Solver dialog, the Nonlinear solution method should be set to one of the two Newton methods.
In the LPF Package dialog, each layer should be set to Convertible Upstream (this is essentially a Newton layer).

External Files

MODFLOW

MODFLOW is the U.S. Geological Survey modular finite-difference flow model, which is a computer code that solves the groundwater flow equation. The program is used by hydrogeologists to simulate the flow of groundwater through aquifers. The source code is freepublic domain software,^[1] written primarily in Fortran, and can compile and run on Microsoft Windows or Unix-like operating systems.

Since its original development in the early 1980s,^[2] the USGS has made four major releases, and is now considered to be the de facto standard code for aquifer simulation. There are several actively developed commercial and non-commercial graphical user interfaces for MODFLOW.

MODFLOW was constructed in what was in 1980's called a modular design. This means it has many of the attributes of what came to be called object-oriented programming. For example, capabilities (called "packages") that simulate subsidence or lakes or streams, can easily be turned on and off and the execution time and storage requirements of those packages go away entirely. If a programmer wants to change something in MODFLOW, the clean organization makes it easy. Indeed, this kind of innovation is exactly what was anticipated when MODFLOW was designed.

Importantly, the modularity of MODFLOW makes it possible for different Packages to be written that are intended to address the same simulation goal in different ways. This allows differences of opinion about how system processes function to be tested. Such testing is an important part of multi-modeling, or alternative hypothesis testing. Models like MODFLOW and SUMMA, a program from NCAR that simulates surface processes like rainfall-runoff and gully erosion, make this kind of testing more definitive and controlled. This results because other aspects of the program remain the same. Tests become more definitive because they become less prone to being influenced unknowingly by other numerical and programming differences.

Groundwater flow equation[edit]

The governing partial differential equation for a confined aquifer used in MODFLOW is:

${\frac {\partial }{\partial x}}\left[K_{{xx}}{\frac {\partial h}{\partial x}}\right]+{\frac {\partial }{\partial y}}\left[K_{{yy}}{\frac {\partial h}{\partial y}}\right]+{\frac {\partial }{\partial z}}\left[K_{{zz}}{\frac {\partial h}{\partial z}}\right]+W=S_{{S}}{\frac {\partial h}{\partial t}}$

where

Finite difference[edit]

The finite difference form of the partial differential in a discretized aquifer domain (represented using rows, columns and layers) is:

${\begin{aligned}&{\mathit {CR}}_{{i,j-{\tfrac {1}{2}},k}}\left(h_{{i,j-1,k}}^{m}-h_{{i,j,k}}^{m}\right)+{\mathit {CR}}_{{i,j+{\tfrac {1}{2}},k}}\left(h_{{i,j+1,k}}^{m}-h_{{i,j,k}}^{m}\right)+\\&{\mathit {CC}}_{{i-{\tfrac {1}{2}},j,k}}\left(h_{{i-1,j,k}}^{m}-h_{{i,j,k}}^{m}\right)+{\mathit {CC}}_{{i+{\tfrac {1}{2}},j,k}}\left(h_{{i+1,j,k}}^{m}-h_{{i,j,k}}^{m}\right)+\\&{\mathit {CV}}_{{i,j,k-{\tfrac {1}{2}}}}\left(h_{{i,j,k-1}}^{m}-h_{{i,j,k}}^{m}\right)+{\mathit {CV}}_{{i,j,k+{\tfrac {1}{2}}}}\left(h_{{i,j,k+1}}^{m}-h_{{i,j,k}}^{m}\right)+\\&P_{{i,j,k}}\,h_{{i,j,k}}^{m}+Q_{{i,j,k}}={\mathit {SS}}_{{i,j,k}}\left(\Delta r_{j}\Delta c_{i}\Delta v_{k}\right){\frac {h_{{i,j,k}}^{m}-h_{{i,j,k}}^{{m-1}}}{t^{m}-t^{{m-1}}}}\end{aligned}}$

where

$h_{{i,j,k}}^{m}\,$ is the hydraulic head at cell i,j,k at time step m

CV, CR and CC are the hydraulic conductances, or branch conductances between node i,j,k and a neighboring node

$P_{{i,j,k}}\,$ is the sum of coefficients of head from source and sink terms

$Q_{{i,j,k}}\,$ is the sum of constants from source and sink terms, where $Q_{{i,j,k}}<0.0\,$ is flow out of the groundwater system (such as pumping) and $Q_{{i,j,k}}>0.0\,$ is flow in (such as injection)

${\mathit {SS}}_{{i,j,k}}\,$ is the specific storage

$\Delta r_{j}\Delta c_{i}\Delta v_{k}\,$ are the dimensions of cell i,j,k, which, when multiplied, represent the volume of the cell; and

$t^{m}\,$ is the time at time step m

This equation is formulated into a system of equations to be solved as:

${\begin{aligned}&{\mathit {CV}}_{{i,j,k-{\tfrac {1}{2}}}}h_{{i,j,k-1}}^{m}+{\mathit {CC}}_{{i-{\tfrac {1}{2}},j,k}}h_{{i-1,j,k}}^{m}+{\mathit {CR}}_{{i,j-{\tfrac {1}{2}},k}}h_{{i,j-1,k}}^{m}\\&+\left(-{\mathit {CV}}_{{i,j,k-{\tfrac {1}{2}}}}-{\mathit {CC}}_{{i-{\tfrac {1}{2}},j,k}}-{\mathit {CR}}_{{i,j-{\tfrac {1}{2}},k}}-{\mathit {CR}}_{{i,j+{\tfrac {1}{2}},k}}-{\mathit {CC}}_{{i+{\tfrac {1}{2}},j,k}}-{\mathit {CV}}_{{i,j,k+{\tfrac {1}{2}}}}+{\mathit {HCOF}}_{{i,j,k}}\right)h_{{i,j,k}}^{m}\\&+{\mathit {CR}}_{{i,j+{\tfrac {1}{2}},k}}h_{{i,j+1,k}}^{m}+{\mathit {CC}}_{{i+{\tfrac {1}{2}},j,k}}h_{{i+1,j,k}}^{m}+{\mathit {CV}}_{{i,j,k+{\tfrac {1}{2}}}}h_{{i,j,k+1}}^{m}={\mathit {RHS}}_{{i,j,k}}\end{aligned}}$

where

${\begin{aligned}{\mathit {HCOF}}_{{i,j,k}}&=P_{{i,j,k}}-{\frac {{\mathit {SS}}_{{i,j,k}}\Delta r_{j}\Delta c_{i}\Delta _{k}}{t^{m}-t^{{m-1}}}}\\{\mathit {RHS}}_{{i,j,k}}&=-Q_{{i,j,k}}-{\mathit {SS}}_{{i,j,k}}\Delta r_{j}\Delta c_{i}\Delta v_{k}{\frac {h_{{i,j,k}}^{{m-1}}}{t^{m}-t^{{m-1}}}}\end{aligned}}$

or in matrix form as:

$A\mathbf {h} =\mathbf {q}$

where

A is a matrix of the coefficients of head for all active nodes in the grid

${\mathbf {h}}$ is a vector of head values at the end of time step m for all nodes in the grid; and

$\mathbf {q}$ is a vector of the constant terms, RHS, for all nodes of the grid.

Limitations[edit]

The water must have a constant density, dynamic viscosity (and consequently temperature) throughout the modelling domain (SEAWAT is a modified version of MODFLOW which is designed for density-dependent groundwater flow and transport)

${\mathbf {K}}={\begin{bmatrix}K_{{xx}}&0&0\\0&K_{{yy}}&0\\0&0&K_{{zz}}\end{bmatrix}}\$

Versions[edit]

Cover image from McDonald & Harbaugh (1983),^[3]which illustrates a computer surrounded by modules and arraysused by MODFLOW. This was said at the time to resemble a "component stereo system".

"Modular Model"[edit]

The USGS throughout the 1970s had developed several hundred models, written in different dialects of FORTRAN. At the time, it was common practice to rewrite a new model to fit the need of a new groundwater scenario. The concept for MODFLOW was originally designed in 1981 to provide a common modular groundwater model, which could be compiled on multiple platforms without major (or any) modification, and can read and write common formats. Different aspects of the groundwater system would be handled using the modules, similar to the idea of a "component stereo system". The original name of the code was "The USGS Modular Three-Dimensional Finite-Difference Ground-Water Flow Model", or informally as "The Modular Model." The name MODFLOW was coined several years after the initial code development, which started in 1981.^[2]

The first version of MODFLOW^[3] was published on December 28, 1983, and was coded entirely in FORTRAN 66. The source code for this version is listed in USGS Open File Report 83-875 referred to above.

MODFLOW-88[edit]

This version of MODFLOW^[4] was rewritten in FORTRAN 77, and was originally released on July 24, 1987. The current version of MODFLOW-88 is 2.6, released on September 20, 1996.

MODPATH, was initially developed in 1989 to post-process the steady-state MODFLOW-88 data to determine three-dimensional pathlines of particles. This innovation has been indispensable for the fields of contaminanthydrogeology. It is still used as a post-processor in recent versions of MODFLOW.

A separate program, MODFLOWP, was developed in 1992 to estimate various parameters used in MODFLOW. This program was eventually built into MODFLOW-2000.

MODFLOW-96[edit]

MODFLOW-96 (version 3.0) was originally released on December 3, 1996, and is a cleaned-up and revised continuation of MODFLOW-88.^[5]^[6] There are three final releases of MODFLOW-96:

MODFLOW-96 (version 3.3, May 2, 2000)
MODFLOW-96h (version 3.3h, July 10, 2000), with HYDMOD package
MODFLOWP (version 3.2, Oct 9, 1997), MODFLOW-96 with parameter-estimation

Several graphical interfaces were first developed using the MODFLOW-96 code.

MODFLOW-2000[edit]

MODFLOW-2000 (version 1.0; version numbering was reset) was released on July 20, 2000, which merged MODFLOWP and HYDMOD codes into the main program and has integrated observation, sensitivity analysis, parameter estimation, and uncertainty evaluation capabilities.^[7] Many new packages and enhancements were also included, including new solvers, stream and saturated flow packages. The internal design concepts also changed from previous versions, such that packages, processes and modules are distinct. This version was coded in a mixture of FORTRAN 77, Fortran 90, and one solver was programmed in C. MODFLOW-2000 can also be compiled for parallel computing, which can allow multiple processors to be used to increase model complexity and/or reduce simulation time. The parallelization capability is designed to support the sensitivity analysis, parameter estimation, and uncertainty analysis capabilities of MODFLOW-2000.

The final version of MODFLOW-2000 (or MF2K) is version 1.19.01, released on March 25, 2010. There are four related or branched codes based on MODFLOW-2000:

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[edit]

MODFLOW-2005 ^[8] 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.^[9] 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.^[10]

MODFLOW-OWHM[edit]

MODFLOW-OWHM^[11] (version 1.00.12, October 1, 2016), The One-Water Hydrologic Flow Model (MODFLOW-OWHM, MF-OWHM or One-Water^[12]), 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.

Being based on the MODFLOW-2005 source code, MODFLOW-OWHM is the second core release of MODFLOW-2005. MODFLOW-OWHM provides the ability to simulated demand-driven, supply-limited hydrologic systems, as commonly occur in arid agricultural areas in which the demand for water exceeds supply. When the added capabilities are not used, MODFLOW-OWHM performs exactly like MODFLOW-2005, or MODFLOW-NWT, or MODFLOW-LGR (depending on the features used).

There is an online input guide that explains the input for the packages that MODFLOW-OWHM supports and formal documentation is at the USGS Publications Warehouse.

MODFLOW-USG[edit]

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^[13] (version 1.3.00, December 1, 2015), designed to be adapted to a wide range of grid variations using unstructured grids. MODFLOW-USG was replaced with MODFLOW 6, which provided grid capabilities with and intermediate level of flexibility.

MODFLOW 6[edit]

MODFLOW 6 (MF6), released in 2017, is the sixth core version of MODFLOW to be released by the USGS.^[14] This release is a rewrite of MODFLOW-USG 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. There are still features lacking in the current release that are supported in MODFLOW-2005, such as subsidence, and stream flow routing (SFR) only supports rectangular wetted perimeters.^[15] The current version is 6.2.1, released February 19, 2021.^[16]

Packages[edit]

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.

Name	Long name	Version introduced
Basic Package and its Components
BAS	Basic Package	original
OC	Output Control	original
DIS	Discretization	MODFLOW-2000 (1.0)
DISU	Unstructured Discretization	MODFLOW-USG (1.0)
DISV	Discretization by Vertices	MODFLOW 6 (1.00)
IC	Initial Conditions	MODFLOW 6 (1.00)
Groundwater flow packages
BCF	Block-Centered Flow Package	original
CLN	Connected Linear Network Process	MODFLOW-USG (1.0)
GNC	Ghost Node Correction Package	MODFLOW-USG (1.0)
HFB	Horizontal Flow Barrier Package	MODFLOW-88
HUF	Hydrogeologic Unit Flow Package	MODFLOW-2000 (1.1)
LPF	Layer-Property Flow Package	MODFLOW-2000 (1.0)
NPF	Node Property Flow	MODFLOW 6 (1.00)
SWI2	Seawater Intrusion Package	MODFLOW-2005 (1.11)
UPW	Upstream Weighting Package	MODFLOW-NWT (1.0)
UZF	Unsaturated-Zone Flow Package	MODFLOW-2005 (1.2)
Conjunctive Use and Land Use Simulation
FMP	Farm Process	MODFLOW-FMP
SWO	Surface Water Operations	MODFLOW-OWHM (2.0)
Specified Head boundary packages
CHD	Constant-Head Boundary / Time-Variant Specified-Head	MODFLOW-88
FHB	Flow and Head Boundary Package	MODFLOW-96 (3.2)
Specified flux boundary packages
FHB	Flow and Head Boundary Package	MODFLOW-96 (3.2)
RCH	Recharge Package	original
WEL	Well Package	original
Head-dependent flux boundary packages
DAF	DAFLOW	MODFLOW-96
DRN	Drain Package	original
DRT	Drain Return Package	MODFLOW-2000 (1.1)
ETS	Evapotranspiration Segments Package	MODFLOW-2000 (1.1)
EVT	Evapotranspiration Package	original
GHB	General-Head Boundary Package	original
LAK	Lake Package	MODFLOW-2000 (1.1)
MAW	Multi-Aquifer Well	MODFLOW 6 (1.00)
MNW	Multi-Node, Drawdown-Limited Well Package	MODFLOW-2000 (1.11)
RES	Reservoir Package	MODFLOW-88 (2.6)
RIP	Riparian Evapotranspiration Package	MODFLOW-OWHM (1.0)
RIV	River Package	original
SFR	Streamflow-Routing Package	MODFLOW-2000 (1.14.00)
STR	Stream Package	MODFLOW-88
SWR	Surface-Water Routing Process	MODFLOW-NWT 1.08
UZF	Unsaturated-Zone Flow Package	MODFLOW-2005 (1.2)
Solvers
DE4	Direct Solver Package	MODFLOW-88 (2.5)
GMG	Geometric Multigrid Solver	MODFLOW-2000 (1.15.00)
LMG	Link-AMG Package	MODFLOW-2000 (1.4) ^{[Note 1]}
NWT	Newton-Raphson	MODFLOW-NWT (1.0)
PCG	Preconditioned Conjugate-Gradient Package	MODFLOW-88
PCGN	Preconditioned Conjugate Gradient Solver with Improved Nonlinear Control	MODFLOW-2005 (1.9.0)
SIP	Strongly Implicit Procedure Package	original
SMS	Sparse Matrix Solver	MODFLOW-USG (1.0)
SOR	Slice Successive Over-Relaxation Package	original
Miscellaneous packages
GAG	Gage	MODFLOW-2000
HYD	HYDMOD	MODFLOW-2000 (1.1)
IBS	Interbed-Storage	MODFLOW-88
KDEP	Hydraulic-Conductivity Depth-Dependence Capability	MODFLOW-2000 (1.12)
LMT	Link-MT3DMS	MODFLOW-2000 (1.5)
LVDA	Model-Layer Variable-Direction Horizontal Anisotropy Capability	MODFLOW-2000 (1.12)
MVR	Water Mover	MODFLOW 6 (1.00)
STO	Storage	MODFLOW 6 (1.00)
SUB	Subsidence and Aquifer-System Compaction	MODFLOW-2000 (1.12)
SWT	Subsidence and Aquifer-System Compaction Package for Water-Table Aquifers	MODFLOW-2000 (1.18)
UTL	Utility	original
Observation process input files
OBS	Input File For All Observations	MODFLOW-2000
HOB	Head-Observation	MODFLOW-2000
DROB	Drain Observation	MODFLOW-2000
DTOB	Drain Return Observation	MODFLOW-2000
RVOB	River Observation	MODFLOW-2000
GBOB	General-Head-Boundary Observation	MODFLOW-2000
CHOB	Constant-Head Flow Observation	MODFLOW-2000
ADV	Advective-Transport Observation	MODFLOW-2000 (1.0)
STOB	Stream Observation	MODFLOW-2000
Obsolete packages
GFD	General Finite-Difference	MODFLOW-88 to 96
TLK	Transient Leakage	MODFLOW-88 to 96

^Due to licensing restrictions, the USGS is no longer able to publicly distribute the Algebraic Multi-Grid

Graphical user interfaces[edit]

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.

Non-commercial interfaces[edit]

Non-commercial MODFLOW versions are free, however, their licensing usually limit the use to non-profit educational or research purposes.

ModelMuse is a grid-independent graphical user interface from the USGS for MODFLOW 6, MODPATH, SUTRA, and PHAST version 1.51. There are no license restrictions. The source code is included.
MODFLOW-GUI – Made by the USGS: it is updated often to match the current USGS MODFLOW development. It supports MODFLOW-96, MODFLOW-2000, MODFLOW-2005, MODPATH, ZONEBUDGET, GWT, MT3DMS, SEAWAT, and GWM. Source code for MODFLOW-GUI is included. It depends on Argus ONE: a commercial interface for constructing generic models. There are no license restrictions beyond those of Argus ONE.
PMWIN – "Processing MODFLOW" (for Windows) – powerful freeware for MODFLOW processing and visualization, provided alongside an instructional book;^[17] also available in Traditional Chinese. The license for this version is limited to non-commercial use.
mflab - mflab is a MATLAB interface to MODFLOW. The user builds and analyzes models by writing a set of MATLAB scripts. This results in flexible and efficient workflows, allowing a great deal of automation.
iMOD - Free and open source interface developed by Deltares. iMOD contains an accelerated version of MODFLOW with fast, flexible and consistent sub-domain modeling techniques. Facilitating large, high resolution MODFLOW modeling and geo-editing of the subsurface
FREEWAT is a free and open source, QGIS-integrated modelling platform integrating MODFLOW (MODFLOW versions integrated are MODFLOW-2005 and MODFLOW-OWHM) and the following MODFLOW-related simulation codes: MT3DMS, MT3D-USGS, SEAWAT, ZONE BUDGET, MODPATH, UCODE-2014. FREEWAT has been developed in the framework of the H2020 FREEWAT project (FREE and open source software tools for WATer resource management), financed by the EU Commission under the call WATER INNOVATION: BOOSTING ITS VALUE FOR EUROPE. The source code is released under a GNU GENERAL PUBLIC LICENSE, Version 2, June 1991, along with a complete set of User Manuals and tutorials.

Commercial programs[edit]

Commercial MODFLOW programs are typically used by governments and consultants for practical applications of MODFLOW to real-world groundwater problems. Professional versions of MODFLOW are generally priced at a minimum of around $1000 and typically range upward to US$7000. This is a list of commercial programs for MODFLOW:

All current versions of these programs run only on Microsoft Windows, however previous versions of GMS (up to Version 3.1) were compiled for several Unix platforms.

Former graphical interfaces[edit]

Graphic Groundwater – Windows-based interface
ModelCad – A Windows-based interface, developed by Geraghty and Miller, Inc.
ModIME – A DOS-based interface by S.S. Papadopulos & Associates, Inc.

References[edit]

^Water Webserver Team (March 5, 2014). "Software User Rights Notice". Water Resources of the United States. U.S. Department of the Interior, U.S. Geological Survey. Retrieved 2014-05-27.
^ ^a^bMcDonald M.G. & Harbaugh, A.W. (2003). "The History of MODFLOW". Ground Water. 41 (2): 280–283. doi:10.1111/j.1745-6584.2003.tb02591.x. PMID 12656294.
^ ^a^b^cMcDonald, M.G. & Harbaugh, A.W. (December 28, 1983). A modular three-dimensional finite-difference ground-water flow model. Open-File Report 83-875. U.S. Geological Survey.
^McDonald, M.G. & Harbaugh, A.W. (1988). A modular three-dimensional finite-difference ground-water flow model(PDF). Techniques of Water-Resources Investigations, Book 6. U.S. Geological Survey.
^Harbaugh, A.W. & McDonald, M.G. (1996a). User's documentation for MODFLOW-96, an update to the U.S. Geological Survey modular finite-difference ground-water flow model(PDF). Open-File Report 96-485. U.S. Geological Survey.
^Harbaugh, A.W. & McDonald, M.G. (1996). Programmer's documentation for MODFLOW-96, an update to the U.S. Geological Survey modular finite-difference ground-water flow model(PDF). Open-File Report 96-486. U.S. Geological Survey.
^Harbaugh, A.W., Banta, E.R., Hill, M.C., and McDonald, M.G. (2000). MODFLOW-2000, the U.S. Geological Survey modular ground-water model — User guide to modularization concepts and the Ground-Water Flow Process(PDF). Open-File Report 00-92. U.S. Geological Survey.CS1 maint: multiple names: authors list (link)
^Harbaugh, Arlen W. (2005). MODFLOW-2005, The U.S. Geological Survey Modular Ground-Water Model—the Ground-Water Flow Process. Techniques and Methods 6–A16. U.S. Geological Survey.
^Mehl, Steffen (2005). MODFLOW-2005, The U.S. Geological Survey Modular Ground-Water Model—Documentation of Shared Node Local Grid Refinement (LGR) and the Boundary Flow and Head (BFH) Package. Techniques and Methods 6–A12. U.S. Geological Survey.
^Niswonger, Richard G.; Panday, Sorab; Ibaraki, Motomu (2011), MODFLOW-NWT, A Newton Formulation for MODFLOW-2005, Techniques and Methods 6-A37, Reston, VA: U.S. Geological Survey
^Hanson, Randall T.; Boyce, Scott E.; Schmid, Wolfgang; Hughes, Joseph D.; Mehl, Steffen W.; Leake, Stanley A.; Maddock, Thomas, III; Niswonger, Richard G. (2014), One-Water Hydrologic Flow Model (MODFLOW-OWHM), Techniques and Methods 6-A51, Reston, VA: U.S. Geological Survey, p. 134CS1 maint: multiple names: authors list (link)
^"Mf-Owhm | Modflow Owhm".
^Panday, Sorab; Langevin, Christian D.; Niswonger, Richard G.; Ibaraki, Motomu; Hughes, Joseph D. (2013), MODFLOW–USG Version 1: An Unstructured Grid Version of MODFLOW for Simulating Groundwater Flow and Tightly Coupled Processes Using a Control Volume Finite-Difference Formulation, Techniques and Methods 6-A45, Reston, VA: U.S. Geological Survey
^Hughes, Joseph D.; Langevin, Christian D.; Banta, Edward R. (2017). "Documentation for the MODFLOW 6 framework". Techniques and Methods. Techniques and Methods 6-A57. p. 40. doi:10.3133/tm6A57.
^Langevin, Christian D.; Hughes, Joseph D.; Banta, Edward R.; Niswonger, Richard G.; Panday, Sorab; Provost, Alden M. (2017). "Documentation for the MODFLOW 6 Groundwater Flow Model". Techniques and Methods. Techniques and Methods 6-A55. doi:10.3133/tm6A55.
^"MODFLOW 6: USGS Modular Hydrologic Model".
^Wen-Hsing Chiang (2005). 3D-Groundwater Modeling with PMWIN (Second ed.). Springer. doi:10.1007/3-540-27592-4. ISBN .

External links[edit]

Sours: https://en.wikipedia.org/wiki/MODFLOW

Usg modflow

Abstract

A new version of MODFLOW, called MODFLOW–USG (for UnStructured Grid), was developed to support a wide variety of structured and unstructured grid types, including nested grids and grids based on prismatic triangles, rectangles, hexagons, and other cell shapes. Flexibility in grid design can be used to focus resolution along rivers and around wells, for example, or to subdiscretize individual layers to better represent hydrostratigraphic units. MODFLOW–USG is based on an underlying control volume finite difference (CVFD) formulation in which a cell can be connected to an arbitrary number of adjacent cells. To improve accuracy of the CVFD formulation for irregular grid-cell geometries or nested grids, a generalized Ghost Node Correction (GNC) Package was developed, which uses interpolated heads in the flow calculation between adjacent connected cells. MODFLOW–USG includes a Groundwater Flow (GWF) Process, based on the GWF Process in MODFLOW–2005, as well as a new Connected Linear Network (CLN) Process to simulate the effects of multi-node wells, karst conduits, and tile drains, for example. The CLN Process is tightly coupled with the GWF Process in that the equations from both processes are formulated into one matrix equation and solved simultaneously. This robustness results from using an unstructured grid with unstructured matrix storage and solution schemes. MODFLOW–USG also contains an optional Newton-Raphson formulation, based on the formulation in MODFLOW–NWT, for improving solution convergence and avoiding problems with the drying and rewetting of cells. Because the existing MODFLOW solvers were developed for structured and symmetric matrices, they were replaced with a new Sparse Matrix Solver (SMS) Package developed specifically for MODFLOW–USG. The SMS Package provides several methods for resolving nonlinearities and multiple symmetric and asymmetric linear solution schemes to solve the matrix arising from the flow equations and the Newton-Raphson formulation, respectively.

Publication type	Report
Publication Subtype	USGS Numbered Series
Title	MODFLOW–USG version 1: An unstructured grid version of MODFLOW for simulating groundwater flow and tightly coupled processes using a control volume finite-difference formulation
Series title	Techniques and Methods
Series number	6-A45
DOI	10.3133/tm6A45
Year Published	2013
Language	English
Publisher	U.S. Geological Survey
Publisher location	Reston, VA
Contributing office(s)	Office of Groundwater
Description	Report: vii, 68 p.; Available Software
Larger Work Type	Report
Larger Work Subtype	USGS Numbered Series
Larger Work Title	Section A: Ground Water in Book 6 Modeling Techniques
Country	United States
Online Only (Y/N)	Y
Additional Online Files (Y/N)	Y
Google Analytic Metrics	Metrics page

Sours: https://pubs.er.usgs.gov/publication/tm6A45

GMS: Converting a MODFLOW model to MODFLOW-USG

What am I. You are a free bird. See how many women love you. I love them and that's why I taught them to love themselves. Which they are now doing with pleasure, but already without me.

You will also like:

Both from Irka's words, and from the view that opened up to him. Turning back to chat with her friend, Sveta unfolded coming from a young man. The young man, perhaps not realizing it, also felt her energy. The main in the relationship, the hidden contact took place.

modflow+usg

1252 1253 1254 1255 1256

Modflow usg

MODFLOW-USG

Overview of MODFLOW-USG

Download Current Version of MODFLOW-USG

Documentation for MODFLOW-USG

Programs Related to MODFLOW-USG

Superseded MODFLOW-USG Versions

Find MODFLOW-Related Software

How to Cite MODFLOW-USG

Software License and Purchase Information

GMS:MODFLOW-USG

Choosing MODFLOW Version

Unsupported Features

MODFLOW-USG Files

Practical Notes

External Files

See also

MODFLOW

Groundwater flow equation[edit]

Finite difference[edit]

Limitations[edit]

Versions[edit]

"Modular Model"[edit]

MODFLOW-88[edit]

MODFLOW-96[edit]

MODFLOW-2000[edit]

MODFLOW-2005[edit]

MODFLOW-OWHM[edit]

MODFLOW-USG[edit]

MODFLOW 6[edit]

Packages[edit]

Graphical user interfaces[edit]

Non-commercial interfaces[edit]

Commercial programs[edit]

Former graphical interfaces[edit]

See also[edit]

References[edit]

External links[edit]

Usg modflow

Links

Abstract

You will also like: