datididatticamisure in tempo realemodellinotizie   Home
 

Scheda modello

MODFLOW: A Modular Three Dimensional Finite-Difference Ground Water Flow Model

MODFLOW is a 3D, cell-centered, finite difference, saturated flow model developed by the United States Geological Survey. It can perform both steady state and transient analyses and has a wide variety of boundary conditions and input options.
MODFLOW is divided into a series of components called "packages." Each package performs a specific task. Some of the packages are always required for a simulation and some are optional. The input for each package is contained in a separate text file.
The block centered flow package performs the cell by cell flow calculations withthe capability to rewet dry cells. The river package is used to simulate river type boundary conditions. The recharge package simulates recharge to the groundwater from precipitation. The well package is used to simulate well type boundary conditions, the drain package to simulate drain type boundary conditions, the evapotranspiration package to simulate the effect of evapotranspiration in the vadose zone. The general head boundary package is used to simulate head type boundary conditions where the value of the boundary condition depends on the head in the cell and it is commonly used to simulate lakes.
The packages used for the computation are: the Strongly Implicit Procedure Package package, which is an iterative solver based on the strongly implicit procedure, the Pre-conditioned Conjugate Gradient Package package, an iterative solver based on the preconditioned conjugate gradient technique, and the Slice Successive Over-relaxation Package package, another iterative solver based on the slice successive overrelaxation technique.

KEYWORDS

area: ground water
objectives: simulation
description: water flow, three-dimensional domain, finite difference, saturated media, stationary conditions, transient conditions

SOFTWARE AVAILABILITY

The program is available at:

IGWMC Europe
TNO Institute of Applied Geoscience
P.O. Box 012
2600 JA Delft, The Netherlands
Phone: +31.15.697215
FAX: +31.15.564800
Order Nø FOS 08 PC

or

Scientific Software Group
P.O. Box 23041
Washington D.C.
20026-3041
Phone: 703-620.9214
Fax: 703-620.6793

AUTHORS

M.G. Mc Donald and A.W. Harbaugh
U.S. Geological Survey

REFERENCES

  • Michael G. McDonald and Arlen W. Harbaugh, A MODULAR THREE DIMENSIONAL FINITE-DIFFERENCE GROUND-WATER FLOW MODEL, Book 6 Chapter A1 of "Techniques of Water Resources" investigation of the united States Geological Survey, U.S. Government Printing Office, 1988.
  • McDonald, M.G. and Harbaugh, A.W., 1988, A modular three-dimensional finite-difference ground-water flow model: U.S. Geological Survey Techniques of Water-Resources Investigations Book 6,Chapter A1, 586 p.
  • Hill, M.C., 1990, Preconditioned conjugate-gradient 2 (PCG2), a computer program for solving ground-water flow equations: U.S. Geological Survey Water-Resources Investigations Report 90-4048, 43 p.
  • Prudic, D.E., 1989, Documentation of a computer program to simulate stream-aquifer relations using a modular, finite-difference, ground-water flow model: U.S. Geological Survey Open-File Report 88-729, 113 p.
  • Leake, S.A. and Prudic, D.E., 1988 Documentation of a computer program to simulate aquifer-system compaction using the modular finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 88-482, 80 p.
  • Harbaugh, A.W., 1992, A generalized finite-difference formulation for the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 91-494, 60 p.
  • McDonald, M.G., Harbaugh, A.W., Orr, B.R., and Ackerman, D.J., 1992, A method of converting no-flow cells to variable-head cells for the U.S. Geological Survey modular finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 91-536, 99 p.
  • Goode, D.J. and Appel, C.A., 1992, Finite-difference interblock transmissivity for unconfined aquifers and for aquifers having smoothly varying transmissivity: U.S. Geological Survey Water Resources Investigations Report 92-4124, 79 p.
  • Hsieh, P.A. and Freckleton, J.R., 1993, Documentation of a computer program to simulate horizontal-flow barriers using the U.S. Geological Survey modular three-dimensional finite-difference ground-water flow model: U.S. Geological Survey Open-File Report 92-477, 32 p.
  • Leake, S.A., Leahy, P. Patrick, and Navoy, Anthony, S., 1994, Documentation of a computer program to simulate transient leakage from confining units using the modular finite-difference ground-water flow model: U.S.Geological Survey Open-File Report 94-59, 70 p.

 

 

Estratto dalla banca modelli del progetto CEE GAIA INCO - www.ess.co.at/GAIA