COMPUTATIONAL ENGINES                                          MODELING SYSTEMS                                          

SLWL                                                                                        WhAEM2000
CZAEM                                                                                      GFLOW
ModAEM                                                                                    Visual AEM
GFLOW-EPA                                                                              ArcAEM
3DFlow                                                                                       Winflow
PhreFlow                                                                                    AnAqSim
Split                                                                                           SLAEM, MLAEM/2, MLAEM
TimML                                                                                        GMS
Bluebird/Cardinal

SLWL
Web: strackconsulting.com/home (comes with book Groundwater Mechanics)
License: Free
Version: 1.1 (1989)
“SLWL is a Fortran code for flow in single layer homogenous aquifers including functions for wells, line sinks, ponds, uniform flow, and rainfall recharge functions.”

Otto Strack
Strack Consulting, Inc.
North Oaks, MN
strackinc@comcast.net
Return to top.

CZAEM
Web: www.epa.gov/ada/csmos/models/czaem.html
License: Free
Version: 1.1 (1996)
“The Capture Zone Analytic Element Model (CZAEM-DOS by Otto Strack and others) is a single layer model for simulating steady flow in homogeneous aquifers using the analytic element model.  This Fortran code serves as a tool in the wellhead protection decision-making process by delineating capture zones and isochrones of residence times.  The command line package includes analytic elements for wells, rivers, and recharge.  The sophisticated capture zone maps are generated by determining all stagnation points and dividing streamlines in the regional flow domain.”

Stephen Kraemer
USEPA, Center for Subsurface Modeling Support (CSMoS)
Ada, OK
kraemer.stephen@epa.gov
Return to top.

ModAEM
Web: modaem.sourceforge.net
License: Open source GPL
Version: 1.4-alpha 1 (2001)
“A high performance, open source, analytic element code, written in object-based Fortran, designed for interfacing with other models or GUIs.  ModAEM is highly modular in design, parallelizable, and a production code. ModAEM was the solution engine for the EPA modeling system WhAEM2000 version 1, and is currently used in GMS.

Vic Kelson
W.H.P.A. Inc.
Bloomington, IN
vic@wittmanhydro.com
Return to top.

GFLOW-EPA
Web download: ftp://ftp.epa.gov/sandyrun/WhAEM_Development/Solver/
License: Open source, artistic license (contact Kraemer for details).
Version: (2004)
“An open source version of the single layer GFLOW1 solution engine by Henk Haitjema that is part of the EPA modeling system WhAEM2000 version 2.”

Stephen Kraemer
USEPA, Center for Exposure Assessment Modeling (CEAM)
Athens, GA
kraemer.stephen@epa.gov
Return to top.

3DFlow
Web download: groundwater.ce.ksu.edu/
License: Free
Version: 2x3 (2001)
“3DFlow is a public domain, interactive computer tool that models and visualizes 3D groundwater flow. This tool simulates steady flow to horizontal wells, partially penetrating wells, and fully penetrating wells in a regional field of uniform flow. Aquifer features may be located in a horizontal aquifer bounded by two planes, in a semi-infinite aquifer bounded by one horizontal plane, or in an aquifer that is infinite in extent. 3DFlow provides an interactive learning environment with pull-down menus and projection of a 3D view region on the screen.”

David Steward
Civil Engineering
Kansas State University
Manhattan, KS
steward@ksu.edu
Return to top.

Split
Web download: www.groundwater.buffalo.edu/software/software.html
License: Free
Version: 3.0 (2005)
“Split is a Fortan program for analytic modeling of single-layer groundwater flow in heterogeneous aquifers. Split includes particle tracking, capture-zone delineation, and parameter estimation. Split supports modeling of inhomogeneities bounded by polygons, spatially variable recharge, rivers and lakes with bed resistance, discharge- and head- specified boundaries, and many other features. The only input is hydrogeologic features. The user is not required to make decisions that affect the numerics of the underlying computational engine.” SPLIT is the solver implemented in Visual Bluebird and ArcAEM

Igor Jankovic
Civil Engineering
SUNY, University at Buffalo
Buffalo, NY
ijankovi@eng.buffalo.edu
Return to top.

PhreFlow
Web download: www.groundwater.buffalo.edu/software/software.html
License: Free
Version: 1.1 (2001)
“PhreFlow models 3D transient flow and advective transport in a domain bounded by an impermeable base, a phreatic surface with recharge, and head specified lateral boundaries. The domain may contain an arbitrary number of wells of any orientation and inhomogeneities shaped as rotational ellipsoids of arbitrary conductivity. The well discharges and recharge can vary with time. PhreFlow uses a combination of the analytic element method to account for spatial distribution of heads and discharges and a finite difference method to account for transient conditions. PhreFlow outputs include heads, particle pathlines and capture zones. The programs Split and PhreFlow have also been used to investigate macroscopic dispersion. Research versions of these programs allow for implementation of as many as 100,000 circular inhomogeneities in 2D (Split) and 10,000 inhomogeneities shaped as rotational ellipsoids in 3D (PhreFlow) with analytic accuracy. The programs, including examples, manuals, references and movies depicting the dispersion process, may be downloaded from the web site above.”

Randal Barnes
Civil Engineering
University of Minnesota
Minneapolis, MN
barne003@maroon.tc.umn.edu
Igor Jankovic
Civil Engineering
SUNY
Buffalo, NY
ijankovi@eng.buffalo.edu
Return to top.

TimML
Web: http://bakkerhydro.org
License: Open Source GPL
Version: TimML 3.0 (Feb 2007)

"TimML is a computer program for the modeling of steady-state multiaquifer flow with analytic elements and consists of a library of Python scripts and FORTRAN extensions. TimML may be applied to an arbitrary number of aquifers and leaky layers. The head, flow, and leakage between aquifers may be computed analytically at any point in the aquifer system. The design of TimML is object-oriented and has been kept simple and flexible. New analytic elements may be added to the code without making any changes in the existing part of the code. TimML is coded in Python, a free, open-source, powerful programming language; occasional use is made of FORTRAN extensions to improve performance. TimML is free and open-source software and is released under the GNU Lesser General Public License. "

Mark Bakker
Delft University of Technology
The Netherlands
markbak@gmail.com
Return to top.

Return to top.

WhAEM2000
Web download: http://www.epa.gov/athens/software/whaem/index.html
License: Open source artistic license
Version: 3.2 (June 2005)
The U.S. EPA's Wellhead Analytic Element Model, WhAEM2000 for Windows (98/NT/XP), is a ground water geohydrology computer program. WhAEM2000 is a public domain, ground-water flow modeling system designed to facilitate capture zone delineation and protection area mapping in support of the State's Wellhead Protection Programs (WHPP) and Source Water Assessment Planning (SWAP) for public water supply wells in the United States. WhAEM2000 provides an interactive computer environment for design of protection areas based on radius methods, well in uniform flow solutions, and geohydrologic modeling methods. Protection areas are designed and overlaid upon US Geological Survey Digital Line Graph (DLG) or other electronic base maps. Base maps for a project can be selected from a graphical index map for the State. Geohydrologic modeling for steady pumping wells, including the influence of hydrological boundaries, such as rivers, recharge, and no-flow contacts, is accomplished using the analytic element method.

Stephen Kraemer
USEPA, Center for Exposure Assessment Modeling (CEAM)
Athens, GA
kraemer.stephen@epa.gov
Return to top.

GFLOW
Web download: www.haitjema.com
License: Proprietary
Version: 2.1.0 (June 2005)
“GFLOW is a highly efficient stepwise groundwater flow modeling system developed by Haitjema Software, a subdivision of Haitjema Consulting, Inc. GFLOW is a Windows 98/NT/XP program based on the analytic element method. It models steady state flow in a single heterogeneous aquifer using the Dupuit-Forchheimer assumption. While GFLOW supports some local transient and three-dimensional flow modeling, it is particularly suitable for modeling regional horizontal flow. To facilitate detailed local flow modeling, GFLOW supports a MODFLOW extract option to automatically generate MODFLOW files in a user defined area with aquifer properties and boundary conditions provided by the GFLOW analytic element model. GFLOW also supports conjunctive surface water and groundwater modeling using stream networks with calculated baseflow.”

“For more information on using the analytic element method for groundwater flow modeling see the textbook "Analytic Element Modeling of Groundwater Flow" by Henk Haitjema, Academic Press, 1995. See also Amazon.com.”

Henk Haitjema
Haitjema Software, LLC
Bloomington, IN
support@haitjema.com
Return to top.

Visual AEM
Web download: http://www.civil.uwaterloo.ca/jrcraig/VisualAEM/Main.html
License: Free, requires Surfer ®.
Version: 1.0 (2008)
“Visual AEM is a graphical user interface for single and multi-layer analytic element modeling of (mostly) steady-state groundwater flow and numerical/analytical modeling of vertically-averaged contaminant transport. Visual AEM is designed for simplicity of use, but includes many robust tools and methods for development of regional scale groundwater flow and transport models or local scale models nested in larger hydrogeologic domains.  Included in this current release:  Support for multi-layer modeling with the TimML numerical engine;  Limited support for transient flow (Theis pumping wells); Multi-species numerical contaminant transport using analytic (AEM) flow fields; More advanced analytical transport solutions (including parent-daughter decay/biodegradation); Improved support for basemaps (vector or raster) and digital elevation models (DEMs); A geological media database for importing common soil types and properties; Element geometric simplification routines; Extended support of contour labeling and visualization, with contour masking; Extended mesh and grid editing capabilities;  Improved object manager features; More robust model checking; An updated version of the numerical engine Bluebird/Cardinal (version 3.5); Many minor revisions, including bug removal."

Return to top.

ArcAEM
Web download: http://www.groundwater.buffalo.edu/software/ArcAEM/ArcAEMMain.html
License: Open Source
Version: 2.2 beta (2006)
“ArcAEM is an extension to ESRI ArcGIS™ 8.x/9.x that enables the development, analysis, and calibration of analytic element models from within ArcMap™. ArcAEM provides an easy-to-use interface for configuring the input files for the groundwater flow model SPLIT, which solves the two-dimensional steady-state saturated flow equation using the analytic element method (AEM). ArcAEM also provides a variety of tools for automated configuration, checking, and simplification of applications containing thousands of elements.”

Alan Rabideau
University of Buffalo
Buffalo, NY
rabideau@eng.buffalo.edu
Return to top.

WINFLOW
Web download: www.groundwatermodels.com/software/software.asp
License: Proprietary
“WinFlow is a powerful yet easy-to-use groundwater flow model. WinFlow is similar to Geraghty & Miller's popular QuickFlow model which was developed by one of the authors of QuickFlow. The most notable improvement over QuickFlow is compatibility with Microsoft Windows V3.1/95/NT. WinFlow is a true Windows program incorporating a multiple document interface (MDI). WinFlow is an interactive analytical model that simulates two-dimensional steadystate and transient groundwater flow. The steady-state module in WinFlow simulates groundwater flow in a horizontal plane using analytical functions developed by Strack (1989). The transient module uses equations developed by Theis (1935) and by Hantush and Jacob (1955) for confined and leaky aquifers, respectively. Each module uses the principle of superposition to evaluate the effects from multiple analytical functions (wells, etc.) in a uniform regional flow field.”

Jim Rumbaugh
ESI
Herndon, VA
salesus-esi@groundwatermodels.com
Return to top.

AnAqSim
Web download: www.fittsgeosolutions.com
License: Proprietary
Version: 1.0 (2011)
“AnAqSim (Analytic Aquifer Simulator) is groundwater flow modeling software based on an analytic element  approach that  divides the modeled region into subdomains. This approach makes AnAqSim much more capable and versatile than earlier analytic element programs like TWODAN (earlier Fitts Geosolutions software).
The key new capabilities built into AnAqSim are:

• Fully transient capabilities using finite-difference time steps
• Isotropic or anisotropic subdomains, with variable direction and ratio of anisotropy
• Multiple layers with spatially-variable vertical leakage between layers (3-D)
• Ability to transition from multi-layer modeling in the area of interest to fewer layers or a single layer in the far-field”
  

Charlie Fitts
Fitts Geosolutions
Scarborough, ME
info@fittsgeosolutions.com
Return to top.

SLAEM, MLAEM/2, MLAEM
Web download: strackconsulting.com/home
License: Proprietary
Version: 5.02 (1997)
“The AEM family of computer programs, presently SLAEM, MLAEM/2, and MLAEM, are based on the Analytic Element Method, developed by Dr. O.D.L Strack. For a description of the Analytic Element Method, see Groundwater Mechanics by O.D.L Strack (Prentice-Hall, 1989). The computer programs are intended for modeling regional groundwater flow in systems of confined, unconfined, and leaky aquifers. SLAEM (Single Layer Analytic Element Model) is the single-layer version of the program, MLAEM/2 (Mulit Layer Analytic Element Model) can access 2 layers, while the number of layers supported by MLAEM is limited only by hardware. All programs run under UNIX (on Sun computers) and under Microsoft Windows® 95 and NT®. The programs are native windows applications and are accessed via a modern and flexible Graphical User Interface (GUI), as well as via a command-line interface. The latter capability makes it easy to drive the program from other programs like ArcView, ArcInfo, and PEST. The programs create files from data entered graphically via the GUI; these files can be read in later. The programs read DXFfiles and produce BNA files that may be read by other programs, such as SURFER.”

Otto Strack
Strack Consulting, Inc.
North Oaks, MN
strackinc@comcast.net
Return to top.

GMS
Web download: http://chl.erdc.usace.army.mil/CHL.aspx?p=s&a=Software;1
License: Proprietary (free to EPA)
Version: 7 (2011)
“The Groundwater Modeling System (GMS) provides an integrated and comprehensive computational environment for simulating subsurface flow, contaminant fate/transport, and the efficacy and design of remediation systems.”
“GMS integrates and simplifies the process of groundwater flow and transport modeling by bringing together all of the tools needed to complete a successful study. GMS provides a comprehensive graphical environment for numerical modeling, tools for site characterization, model conceptualization, mesh and grid generation, geostatistics, and sophisticated tools for graphical visualization.”
“Several types of models are supported by GMS. The current version of GMS provides a complete interface for the codes MODAEM, FEMWATER, MODFLOW2000, MODPATH, MT3D, RT3D, ART3D, SEAM 3D, NUFT, UTCHEM, FACT and SEEP2D. The parameter estimation codes PEST and UCODE are also supported. Additional tools and interfaces for models are being designed in an on-going development process so stay tuned for more features.”

Coastal and Hydraulics Laboratory
Vicksburg, MS
gms@erdc.usace.army.mil
Return to top.