1. General Model Information

Name: MODFLOW with parameter estimation

Acronym: MODFLOWP


Main medium: terrestrial
Main subject: hydrology
Organization level:
Type of model: partial differential equations (finite differences,3D), static-algebraic equations
Main application: research
Keywords: groundwater, saturated flow, water flow, finite difference, 3-dimensional, parameter estimation, Gauss-Newton method, conjugate-direction

Contact:

Mary C. Hill
USGS-WRD
P.O. Box 25046, M.S. 413
Lakewood, CO 80225
Phone:
Fax : (303)236-5034
email: mchill@brrcrmail.cr.usgs.gov

R. Steven Regan
U.S. Geological Survey USGS-WRD
Hydrologic Analysis Software Support Tea
437 National Center
Reston, VA 20192
Phone:
Fax :
email: h2osoft@usgs.gov

Author(s):

Abstract:

This program is a new version of the U.S. Geological Survey modular, three-dimensional, finite-difference, ground-water flow model ( MODFLOW ), which, with the new Parameter-Estimation Package, can be used to estimate parameters by nonlinear regression. Parameters used to compute the following MODFLOW model inputs can be estimated: layer transmissivity, storage, coefficient of storage, hydraulic conductivity, and specific yield; vertical leakance; horizontal and vertical anisotropy; hydraulic conductance of the River, Streamflow- Routing, General-Head Boundary, and Drain Packages; areal recharge; maximum evapotranspiration; pumpage; and the hydraulic head at constant-head boundaries. Nearly any spatial variation in parameters can be defined by the user. Data used to estimate parameters can include existing independent estimates of parameter values, observed hydraulic heads or temporal changes in hydraulic heads, and observed gains and losses along head-dependent boundaries (such as streams). Model output includes statistics for analyzing the parameter estimates and the model; these statistics can be used to quantify the reliability of the resulting model, to suggest changes in model construction, and to compare results of models constructed in different ways.

METHOD: Parameters are estimated by minimizing a weighted least-squares objective function by the modified Gauss-Newton method or by a conjugate-direction method.


II. Technical Information

II.1 Executables:

Operating System(s): DOS and UNIX (The code has been used on UNIX-based computers and DOS-based 386 or greater computers having a math coprocessor and 4 mb of memory.)

II.2 Source-code:

Programming Language(s): Fortran 77 (extensions: use of variable names longer than 6 characters and greater than 19 continuation lines.) directory with all files modflowp.tar.Z Europe: modflowp.tar.Z

II.3 Manuals:



II.4 Data:



III. Mathematical Information


III.1 Mathematics


III.2 Quantities


III.2.1 Input

III.2.2 Output


IV. References

Bentley, L.R., 1994, Solving and calibrating groundwater flow systemswith thepenalty method: in Hipel, K. W., ed., Stochastic and statistical modeling with groundwater and surface water applications, Kluwer Academic Publishers,Dordrecht, p. 55-67.
Harbaugh, A.W., 1995, Direct solution package based on alternatingdiagonal ordering for the U.S. Geological Survey modularfinite-difference ground-water flow model: U.S. Geological SurveyOpen-File Report 95-288, 46 p.
Hill, M.C., 1992, A computer program (MODFLOWP) for estimating parameters of a transient, three-dimensional, ground-water flow model using nonlinear regression: U.S. Geological Survey Open-File Report 91-484, 358 p.
Hill, M.C., 1994, Five computer programs for testing weighted residuals and calculating linear confidence and prediction intervals on results from the ground-water parameter-estimation program MODFLOWP: U.S. Geological Survey Open-File Report 93-481, 81 p.
Yoon, Y.S. and Yeh, W.W-G., 1976, Parameter identification on an inhomogeneous medium with the finite-element method: Journal of the Society of Petroleum Engineers, v. 16, no. 4, p. 217-226.



V. Further information in the World-Wide-Web



VI. Additional remarks


Last review of this document by: 26.June 1997
Status of the document:
last modified by Tobias Gabele Wed Aug 21 21:44:46 CEST 2002

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