Search         Language
Schlumberger Water Services Schlumberger Shopping CartShopping Cart (Empty)
Schlumberger Water Services
 
 
Spotlight
Visual MODFLOW
Advanced contaminant transport & groundwater modeling software.
Learn More...

 
You are here: SEAWAT
URL: http://www.swstechnology.com//seawat.php
Print this page

Go to the Visual MODFLOW Premium page. Text on SEAWAT v.4.extracted from the USGS website

Introduction to Visual MODFLOW
What's New in Visual MODFLOW 2009.1
SEAWAT Version 4

Introduction to Visual MODFLOW

Visual MODFLOW is the most complete and easy-to-use modeling environment for practical applications in three-dimensional groundwater flow and contaminant transport simulations. This fully-integrated package combines MODFLOW, MODPATH, ZoneBudget, MT3Dxx/RT3D, and WinPEST with the most intuitive and powerful graphical interface available. The logical menu structure and easy-to-use graphical tools allow you to:

  • easily dimension the model domain and select units,
  • conveniently assign model properties and boundary conditions,
  • run the model simulations (MODFLOW, MODPATH, ZoneBudget, MT3D/RT3D, and WinPEST are seamless integrated),
  • calibrate the model using manual or automated techniques, and
  • visualize the results using 2D or 3D graphics

The model input parameters and results can be visualized in 2D (cross-section and plan view) or 3D at any time during the development of the model or the displaying of the results. For complete three-dimensional groundwater flow and contaminant transport modeling, Visual MODFLOW is the only software package you will need.

When you purchase Visual MODFLOW, or any Schlumberger Water Services software product, you not only get the best software in the industry, you also gain the reputation of the company behind the product, and professional technical support for the software from our team of qualified groundwater modeling professionals. Schlumberger Water Services has been developing groundwater software since 1989 and our software is recognized, accepted and used by groundwater professionals in over 90 different countries around the world. This type of recognition is invaluable in establishing the credibility of your modeling software to clients and regulatory agencies.

(top)

What's New in Visual MODFLOW 2009.1

The main interface for Visual MODFLOW 2009.1 has much of the same user-friendly look and feel as previous versions of Visual MODFLOW, but what’s “under the hood” has been dramatically improved to give you more powerful tools for entering, modifying, analyzing, and presenting your groundwater modeling data. Some of the more significant upgrade features in the latest version of Visual MODFLOW are described below.

The following new features are available in Visual MODFLOW 2009.1:

Support for SEAWAT v.4

Visual MODFLOW supports the following new features available in SEAWAT Version 4:

  • A temperature species can now be added when defining a new transport variant, allowing you to simulate heat and solute transport simultaneously.
  • Simulate the effect that fluid viscosity variations have on resistance to ground-water flow using the Viscosity (VSC) Package.
  • Simulate fluid density as a function of temperature and one or more MT3DMS species and, optionally, a pressure term. You can also specify one of several non-linear equations to represent the dependence of viscosity on temperature.
  • A new option in the simulation settings for the VDF package allows for solving the Variable Density Flow (VDF) equation to update the flow field only if fluid densities have changed by a user-defined value. This option can potentially reduce runtimes for simulations in which a new flow solution is not required for each transport time step.
  • For the Time-Variant Constant-Head (CHD) package, auxiliary variables can now be used to designate the fluid density value associated with the prescribed head. You can now determine the reference head values at constant-head boundaries using one of the following options:
    • Use Simulated Density: The input head is converted to the reference head using calculated fluid density value at the cell.
    • Use Specified Density: The input head is converted to the reference head using a user-defined density value.
    • Use Average Density: The input head is converted to the reference head using the average of the calculated fluid density values of the overlying active cells.

(top)

SEAWAT: A Computer Program for Simulation of Three-Dimensional Variable-Density Ground-Water Flow and Transport

SEAWAT Version 4 Overview

SEAWAT is a generic MODFLOW/MT3DMS-based computer program designed to simulate three-dimensional variable-density ground-water flow coupled with multi-species solute and heat transport. The program has been used for a wide variety of ground-water studies including those focused on brine migration in continental aquifers as well as those focused on saltwater intrusion in coastal aquifers. SEAWAT uses the familiar structure of MODFLOW and MT3DMS. Thus, most of the commonly used pre and post-processors can be used to create SEAWAT datasets and visualize results. The MODFLOW concepts of "packages" and "processes" are retained in SEAWAT, which allows the program to work with many of the MODFLOW-related software programs, such as MODPATH, ZONEBUDGET, and parameter estimation programs. SEAWAT is a public domain computer program. The source code and software are distributed free of charge by the U.S. Geological Survey.

SEAWAT Version 4 is a replacement for SEAWAT-2000. SEAWAT-2000 users are encouraged to use this new version, even if the new features are not required for a particular application. SEAWAT Version 4 is backward compatible with datasets created for SEAWAT-2000 and, therefore, SEAWAT-2000 is no longer supported or maintained.

What's New in Version 4

SEAWAT Version 4 is the most recent SEAWAT release, and like SEAWAT-2000, Version 4 is based on MODFLOW-2000 and MT3DMS. SEAWAT Version 4 retains all of the functionality of SEAWAT-2000 and is backward compatible with SEAWAT-2000 datasets. SEAWAT Version 4 includes the following new features:

  • Effects of viscosity variations on ground-water flow can be represented with the Viscosity (VSC) Package.
  • Unique diffusion coefficients can be entered for each MT3DMS component. This allows thermal diffusivity to be used for the temperature component, and molecular diffusion coefficients to be used for solute species.
  • Fluid density and viscosity can be calculated as a function of one or more MT3DMS species.
  • Additional options are available for specifying the density value associated with constant-head (CHD) boundaries.
  • New options and program redesign allow for faster execution times.

Previous SEAWAT versions are also available for download from this site; however, these versions are no longer maintained, updated, or supported. Users are encouraged to use the most recent version of SEAWAT as it may contain fixes and improvements that are not included in older versions.

Information and Downloads

(top)

__________________________

 

SEAWAT Version 4: A computer program for simulation of multi-species solute and heat transport

By Christian D. Langevin (U.S. Geological Survey, Fort Lauderdale, Florida),
Daniel T. Thorne, Jr. (Georgetown College, Georgetown, Kentucky),
Alyssa M. Dausman (U.S. Geological Survey, Fort Lauderdale, Florida),
Michael C. Sukop (Florida International University, Miami, Florida), and
Weixing Guo (Schlumberger Water Services, Fort Myers, Florida)

(top)

Summary of SEAWAT Version 4

Abstract

The SEAWAT program is a coupled version of MODFLOW and MT3DMS designed to simulate three dimensional, variable-density, saturated ground-water flow. Flexible equations were added to the program to allow fluid density to be calculated as a function of one or more MT3DMS species. Fluid density may also be calculated as a function of fluid pressure. The effect of fluid viscosity variations on ground-water flow was included as an option. Fluid viscosity can be calculated as a function of one or more MT3DMS species, and the program includes additional functions for representing the dependence on temperature. Although MT3DMS and SEAWAT are not explicitly designed to simulate heat transport, temperature can be simulated as one of the species by entering appropriate transport coefficients. For example, the process of heat conduction is mathematically analogous to Fickian diffusion. Heat conduction can be represented in SEAWAT by assigning a thermal diffusivity for the temperature species (instead of a molecular diffusion coefficient for a solute species). Heat exchange with the solid matrix can be treated in a similar manner by using the mathematically equivalent process of solute sorption. By combining flexible equations for fluid density and viscosity with multi-species transport, SEAWAT Version 4 represents variable-density ground-water flow coupled with multi-species solute and heat transport. SEAWAT Version 4 is based on MODFLOW-2000 and MT3DMS and retains all of the functionality of SEAWAT-2000.

SEAWAT Version 4 also supports new simulation options for coupling flow and transport, and for representing constant-head boundaries. In previous versions of SEAWAT, the flow equation was solved for every transport timestep, regardless of whether or not there was a large change in fluid density. A new option was implemented in SEAWAT Version 4 that allows users to control how often the flow field is updated. New options were also implemented for representing constant-head boundaries with the Time-Variant Constant-Head (CHD) Package. These options allow for increased flexibility when using CHD flow boundaries with the zero-dispersive flux solute boundaries implemented by MT3DMS at constant-head cells.

The report contains revised input instructions for the MT3DMS Dispersion (DSP) Package, Variable-Density Flow (VDF) Package, Viscosity (VSC) Package, and CHD Package. The report concludes with seven cases of an example problem designed to highlight many of the new features.

(top)

Method

The variable-density ground-water flow equation is solved using a finite- difference approximation similar to the one solved by MODFLOW-2000. The solute- transport equation is solved using one of the approaches available with MT3DMS.

(top)

History

SEAWAT Version 4.00.02 2008/04/29 - This version of SEAWAT contains fixes for two memory conflicts. The first was with the MNW Package. The second was between the OBS Process and the Integrated MT3DMS Process.

SEAWAT Version 4.00.01 2008/04/29 - This version of SEAWAT contains a fix for a minor programming error that may have caused the dcdt term of the flow equation to be too large.

SEAWAT Version 4.00.00 2008/03/28 - First release of SEAWAT Version 4. SEAWAT now contains capability to simulate simultaneous solute and heat transport. This SEAWAT version contains MODFLOW Version 1.18.00 and MT3DMS Version 5.2. This SEAWAT version also contains fixes for several bugs found in previous SEAWAT versions: (1) groundwater fluxes for perched water table conditions with strong density variations were not calculated properly; (2) in the budget calculations, there was an error in the flux calculated for the front face of constant head cells; (3) for mixed steady state and transient simulations, if the first stress period was specified as steady state, all remaining stress periods were simulated as steady state.

SEAWAT-2000 Version 3.13.00 2006/04/21 - This version of SEAWAT was updated with MODFLOW Version 1.16.00. Additionally, ETS and DRT are now compatible with the VDF proces

SEAWAT-2000 Version 3.12.00 2006/03/14 - This version of SEAWAT was updated with MT3DMS Version 5.10, which includes a new zero-order growth/decay option within the reactions package. This option may be useful for simulating groundwater age as a separate species.

SEAWAT-2000 Version 3.11.02 2005/09/23 - This version of SEAWAT contains a fix for a minor bug that may have caused some transport timesteps to be too short.

SEAWAT-2000 Version 3.11.01 2005/07/25 - This version of SEAWAT contains a bug fix for head-dependent flux calculations for some boundary types.

SEAWAT-2000 Version 3.11.00 2005/04/29 - Added MODFLOW-2000 Version 1.15.00 and MT3DMS Version 5.00. Also added compatability between MNW wells and the VDF Process for freshwater parts of a model domain.

SEAWAT-2000 Version 3.10.01 2004/03/30 - This version of SEAWAT contains bug fixes for three coding errors: (1) In the previous version, the value for HDRY was not always written to the output head file if a cell went dry during the simulation. (2) A runtime error was encountered in certain instances when the IMT Process was used with the GWF Process (instead of the VDF Process). (3) If MODFLOW timesteps were shorter than the calculated transport timestep, the density array was not updated properly.

SEAWAT-2000 Version 3.10 2004/02/13 - This version of SEAWAT contains substantial improvements over previous releases. The program is now based on MODFLOW-2000 (Version 1.12.01) and MT3DMS (Version 4.500), and uses the concept of a process. Details of SEAWAT-2000 are described in U.S. Geological Survey Open-File Report 03-426.

SEAWAT Version 2.12 2002/09/13 - Fixed problem with calculation of EVT fluid density. Thanks to Adam Taylor and Barclay Shoemaker. Also fixed bug in calculation of default riverbed thickness. Thanks to Lou Motz and Nebiyu Tiruneh from the University of Florida for locating this problem.

SEAWAT Version 2.11 2002/08/09 - Fixed bug that caused program to bomb for certain problems involving wetting and drying. Thanks to Trayle Kulshan and Steve Gorelick from Stanford University for help in locating this problem.

SEAWAT Version 2.10 2002/02/07 - Code consists of MODFLOW-88 and MT3DMS Version 3.50.A. Upgraded the CFACE subroutine with the improved CFACE subroutine from MT3DMS Version 4.00. Reformulated flow equation to conserve fluid mass. Redesigned boundary conditions to represent variable-density flow. Added an iterative method for coupling flow and transport. Program redesigned as double precision.

SEAWAT Version 1.1 1998/05/01 - Initially released by Weixing Guo (Missimer International, Inc.) and Gordon D. Bennett (S.S. Papadopulos & Associates, Inc.)

(top)

Data Requirements

In order to use SEAWAT, initial conditions, hydraulic properties, and stresses must be specified for every model cell in the finite-difference grid.

(top)

Output Options

Primary output is head and concentration, which can be written to the listing file or to separate binary files. Other output includes the complete listing of all input data, drawdown, flow budget, and transport budget data. Flow budget data are printed as a summary in the listing file, and detailed budget data for all model cells can be written into a separate file. All binary output is written to files that are opened with the FORM='BINARY' option. This means that some pre- and post-processors may not be able to read the output unless the open statements are modified, the program is recompiled, and the model is rerun.

(top)

System Requirements

SEAWAT is written in Fortran 77 with the following extensions: use of variable names longer than 6 characters, Fortran 90 statements for dynamic memory allocation, a call to SUBROUTINE GETARG to retrieve command-line arguments, and two calls to DATE_AND_TIME, which is a Fortran 90 intrinsic subroutine. Generally, the program is easily installed on most computer systems. The code has been used on DOS-based 386 or greater computers having a math coprocessor and 4 mb of memory.

(top)

Processes

GLO1 -- Global Process
GWF1 -- Ground-Water Flow Process
VDF1 -- Variable-Density Flow Process
OBS1 -- Observation Process
SEN1 -- Sensitivity Process
PES1 -- Parameter-Estimation Process
IMT1 -- Integrated MT3DMS Process

Process compatibility issues are described in the user's manual. In general, the VDF and IMT Processes are not compatible with SEN and PES, and are only slightly compatible with OBS. VDF is an alternative to GWF, and thus the two cannot be used concurrently in a simulation.

(top)

Packages Compatible with the Variable-Density Flow (VDF) Process

BAS6 -- Basic
BCF6 -- Block-Centered Flow
LPF -- Layer Property Flow
HUF2 -- Hydrogeologic Unit Flow. Note that VDF is not yet compatible with the Layer Variable-Direction Horizontal Anisotropy (LVDA) capability. The LVDA capability should not be used with the VDF process. The VDF process is compatible with the three features described in Open-File Report 03-347.
HFB6 -- Hydraulic Flow Barrier
DRN -- Drain
RIV -- River
GHB -- General-Head Boundary
EVT -- Evapotranspiration
WEL -- Well
RCH -- Recharge
CHD -- Time-Variant Constant Head
FHB -- Flow and Head Boundary
MNW -- Multi-Node Well
DRT -- Drains with Return Flow
ETS -- Evapotranspiration with a Segmented Function
SIP -- Strongly Implicit Procedure
SOR -- Slice-Successive Overrelaxation
PCG -- Preconditioned Conjugate Gradient Solver (also called PCG2)
DE4 -- Direct Solver
GMG -- Geometric Multi-Grid Solver
OC -- Output Control Option
LMT6 -- Linkage with MT3DMS
BTN -- Basic Transport
ADV -- Advection
DSP -- Dispersion
SSM -- Source/Sink Mixing
RCT -- Reaction
GCG -- Generalized Conjugate Gradient Solver
TOB -- Transport Observations
OBS -- Observation
HOB -- Hydraulic-Head Observation
GHOB -- General-Head Boundary Observation
DROB -- Drain Observation
DTOB -- Drain with Return Flow Observation
RVOB -- River Observation
CHOB -- Constant-Head Flow Observation

Other packages (distributed with MODFLOW-2000) are included in SEAWAT, however, these additional packages may not be compatible with the VDF Process.

(top)

Documentation

The basic documentation is contained in the following three reports:

Langevin, C.D., Thorne, D.T., Jr., Dausman, A.M., Sukop, M.C., and Guo, W., 2007, SEAWAT Version 4: A Computer Program for Simulation of Multi-Species Solute and Heat Transport: U.S. Geological Survey Techniques and Methods. Book 6, Chapter A22, 39 p.

Langevin, C.D., Shoemaker, W.B., and Guo, W., 2003, MODFLOW-2000, the U.S. Geological Survey Modular Ground-Water Model--Documentation of the SEAWAT-2000 Version with the Variable-Density Flow Process (VDF) and the Integrated MT3DMS Transport Process (IMT): U.S. Geological Survey Open-File Report 03-426, 43 p.

Guo, W., and Langevin, C.D., User's guide to SEAWAT: A computer program for simulation of three-dimensional variable-density ground-water flow: Techniques of Water-Resources Investigations of the U.S. Geological Survey, Book 6, Chapter A7, 77 p.

Users will also need documentation for MODFLOW-2000 and MT3DMS, and possibly the references cited in those reports.

(top)

Disclaimer

This program is public domain and is released on the condition that neither the U.S Geological Survey nor the United States Government may be held liable for any damages resulting from their authorized or unauthorized use. See also User Rights.

(top)

Extracted from the USGS website

 

 
Schlumberger Water Services provides innovative groundwater monitoring and sampling instruments, field data acquisition accessories, and software for environmental data management, analysis, visualization, conceptual modeling and simulations, with a complete range of training and support services for environmental consultants, government agencies, industry, and educational/research institutions.
Visit our website in Spanish | Dutch | French | Portuguese | German
© Schlumberger. Privacy Statement | Terms of Services | About SWS | Groundwater Links | Site Map
© Schlumberger. all rights reserved. Printed on Saturday, February 04, 2012 at 05:45:56 AM