Water Resources Applications Software

Geochemical || Ground Water || Surface Water || Water Quality || General

Summary of SUTRA

       sutra - Saturated and (or) unsaturated, constant or variable-density
               fluid flow, and solute or energy transport (2-dimensional
               finite-element code)

       SUTRA is a finite-element simulation model for saturated-
       unsaturated, fluid-density-dependent ground-water flow with energy
       transport or chemically-reactive single-species solute transport.
       SUTRA may be employed for areal and cross-sectional modeling of
       saturated ground-water flow systems, and for cross-sectional
       modeling of unsaturated zone flow.  Solute transport simulation
       using SUTRA may be employed to model natural or man-induced chemical
       species transport including processes of solute sorption, production
       and decay, and may be applied to analyze ground-water contaminant
       transport problems and aquifer restoration designs.  In addition,
       solute transport simulation with SUTRA may be used for modeling of
       variable density leachate movement, and for cross-sectional modeling
       of saltwater intrusion in aquifers in near-well or regional scales,
       with either dispersed or relatively sharp transition zones between
       freshwater and saltwater.  SUTRA energy transport simulation may be
       employed to model thermal regimes in aquifers, subsurface heat
       conduction, aquifer thermal energy storage systems, geothermal
       reservoirs, thermal pollution of aquifers, and natural hydrogeologic
       convection systems.

       The model employs a two-dimensional hybrid finite-element and
       integrated-finite-difference method to approximate the governing
       equations that describe the two interdependent processes that are
       simulated:  (1) fluid density-dependent saturated or unsaturated
       ground-water flow, and either (2a) transport of a solute in the
       ground water, in which the solute may be subject to equilibrium
       adsorption on the porous matrix, and both first-order and zero-order
       production or decay, or (2b) transport of thermal energy in the
       ground water and solid matrix of the aquifer.

       Version V09972D - Second revision in 1997.  Addition of option to
          use Fortran 90 dynamic array dimensioning.  Addition of two
          output files containing simulation results in simple column
          format.  No changes to input data format, except that the two new
          files and their unit numbers must be specified in the "SUTRA.FIL"
          Name File.

       Version V06902D - First revision in 1990.  Note that input and
          output files from the version V12842D are NOT compatible with
          version V06902D.  Minor modifications in old data files are
          necessary as described in the change notes and the revised pages
          of the documentation.

       Version V12842D - Original version distributed in 1984.
       Two SUTRA data files are required: (1) SUTRA input data and (2)
       initial conditions of pressure and concentration or temperature for
       the simulation.  See documentation for detailed coding instructions
       and description of input parameters.  Reprogramming of subroutines
       BCTIME and UNSAT is required to implement time-dependent boundary
       conditions and unsaturated flow functions, respectively.

       A graphical postprocessor, SUTRA-PLOT, developed by Souza (1987) is
       available for use with SUTRA.  This postprocessor facilitates
       interpretation of the simulation results.

       SUTRA is written in Fortran 77 including optional Fortran 90
       statements allowing dynamic array allocation.  SUTRA requires that
       files needed for the simulation be defined prior to execution.  A
       Name File (SUTRA.FIL) is used for this purpose.  For each file (up
       to six), the unit number is specified on one record followed by a
       record specifying the file name.  The format of the Name File is
       described in the documentation.  Generally, the program is easily
       installed on most computer systems.  The code has been used on a
       wide variety of computers, ranging from UNIX-based computers to DOS-
       based 386 computers with as little as 640K of RAM.

       Souza, W.R., 1987, Documentation of a graphical display program for
          the saturated-unsaturated transport (SUTRA) finite-element
          simulation model: U.S. Geological Survey Water-Resources
          Investigations Report 87-4245, 122 p.

       Voss, C.I., 1984, A finite-element simulation model for saturated-
          unsaturated, fluid-density-dependent ground-water flow with
          energy transport or chemically-reactive single-species solute
          transport: U.S. Geological Survey Water-Resources Investigations
          Report 84-4369, 409 p.

          U.S. Geological Survey
          Office of Hydrologic Research
          Clifford I. Voss
          431 National Center
          Reston, VA  20192

          U.S. Geological Survey
          Hydrologic Analysis Software Support Program
          437 National Center
          Reston, VA 20192

       Official versions of U.S. Geological Survey water-resources analysis
       software are available for electronic retrieval via the World Wide
       Web (WWW) at:


       and via anonymous File Transfer Protocol (FTP) from:

         (path: /pub/software).

       The WWW page and anonymous FTP directory from which the SUTRA
       software can be retrieved are, respectively:


       See for
       information on ordering printed copies of USGS publications.

       mgenrad(1) - SUTRA utility program to generate a simple mesh
       mgenrec(1) - SUTRA utility program to generate a simple mesh
       pbcgen(1) - SUTRA utility program to generate hydrostatic
       sutraplt(1) - Graphics postprocessor program for SUTRA

       Related models:
       moc(1) - Two-dimensional method-of-characteristics
                ground-water flow and transport model
       modfe(1) - Modular finite-element model for areal and
                  axisymmetric ground-water flow problems
       modflow(1) - Modular three-dimensional ground-water flow
       Modflowp(1) - Parameter-estimation version of the modular model
       vs2di(1) - A graphical software package for simulating fluid flow
                  and solute or energy transport in variably saturated
                  porous media

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