PUBLICATIONS--Release of two new reports documenting numer models

In Reply Refer To:                             November 17, 1987
WGS-Mail Stop 411


Subject:  PUBLICATIONS--Release of two new reports documenting
                        numer models

The two subject recent reports are:

1.  Lappala, E. G., Healy, R. W., and Weeks, E. P., 1987,
    Documentat computer program VS2D to solve the equations of
    fluid flow variably saturated porous media:  U.S. Geological
    Survey Wa Resources Investigations Report 83-4099, 184 p.

2.  Lefkoff, L. Jeff, and Gorelick, Steven M., 1987, AQMAN:
    Linear quadratic programming matrix generator using two-
    dimensiona ground-water flow simulation for aquifer
    management modelin U.S. Geological Survey Water-Resources
    Investigations Repor 87-4061, 164 p.

The report by Lappala, Healy, and Weeks (1987) documents a
numerical model that simulates isothermal, two-dimensional
movement of liquid variably saturated porous media.  The
mathematical model of this phy process is developed by combining
the law of conservation of fluid m a nonlinear (partially
saturated) form of Darcy's law.  The resultan mathematical model,
or flow equation, is written with total hydrauli as the dependent
variable.  This allows straightforward treatment of in which part
of the domain is saturated and part is unsaturated.  I the model
can simulate "difficult" nonlinear problems, such as those by
infiltration into dry soils and by discontinuities in permeabilit

The numerical features are such that the model can analyze
transient in one and two dimensions with planar or cylindrical
geometries.  No boundary conditions treated by the code include
infiltration, evapor and seepage faces.  Extractions by plant
roots is included as a nonl term.

The report by Lefkoff and Gorelick (1987) documents the computer
program AQMAN.  The purpose of AQMAN is to determine the
distributio pumping and/or recharge that minimizes or maximizes a
management obj subject to constraints.  The computer program AQMAN
provides a link a modified version of the two-dimensional ground-
water flow model of Pinder, and Larson (1976) and any standard
Mathematical Programming input format.  AQMAN uses the modified
Trescott model to solve the basic ground-water flow equation to
determine aquifer responses to both the stresses that cannot be
controlled because of physical limitations or legal or socio-
economic demands (the unmanaged stresses) and to the stresses that
can be controlled (the managed stresses).

The program, AQMAN, creates the input files to be used by an
optimization program.  These input files contain all the
hydrologic information and managemen objectives needed by an
optimization program to solve the management problem. AQMAN is
written to handle either a linear or quadratic objective function.
Various types of constraints can be defined for pumping and/or
recharge rates and on ground-water heads, gradients, and

One copy of each report is being sent under separate cover to all
District offices, State offices, and some Subdistricts.

                                    Eugene P. Patten
                                    Chief, Office of
                                      Ground Water

WRD Distribution:  A, B, S, FO, PO