Demonstration version	Order No: TPS-12-1	Price: $25
Standard version	Order No: TPS-12-2	Price: $995
FemMesh Module	Order No: TPS-12-4	Price: $300
F3Model module	Order No: TPS-12-5	Price: $300
FemCat module	Order No: TPS-12-6	Price: $495
FemInvs module	Order No: TPS-12-8	Price: $650
Complete package	Order No: TPS-12-7	Price: $2330
Contact IGWMC for university discounts

Micro-Fem is an integrated large-capacity finite-element modeling system for steady-state and transient simulation of ground-water flow in multiple aquifer systems. The software supports iteractive mesh generation, input preparation, model computation, graphic postprocessing and plotting of results. Micro-Fem simulates two-dimensional horizontal flow in multiple layers using the finite element approach, and one-dimensional vertical flow between the layers using a finite difference technique. It can handle multiple time-varying sources and sinks, as well as spatially and temporally varying boundary conditions, including connected and unconnected streams, drains, and evapotranspiration linearly varying with depth to ground water. The model supports heterogeneous aquifers and aquitards, and anisotropic permeability conditions. The Micro-Fem software consists of various modules for mesh generation, model setup, input preparation and editing, equation solving, postprocessing, graphical interpretation and plotting. Confined, semi-confined, phreatic, stratified and leaky multiple aquifer systems can be simulated with a maximum of 16 aquifers. The program handles up to 12,500 nodes.

Its capacity, ease-of-use, and flexibility in representing complex field geometry has made Micro-FEM the most widely used ground-water flow modeling package in The Netherlands. Data manipulation, grid design, and grid editing is supported by a flexible graphic interface with zoom capability. Both simple and sophisticated grid generators are available. The program comes standard with the FemGrid generator for irregular geometries. For complex grids requiring gradually changing node-spacing to accomplish high contrasts in spacing between different parts of the model, the optional FemMesh grid generator is available.

The standard version of Micro-FEM support steady-state simulations; postprocessing includes the display of contour lines for heads and velocity vectors. The standard version includes the modules FemCalc for computation of heads and internal and external fluxes, FeMerge to merge existing models with new grids, and FemPlot for plotting map views.

Optional modules are available for transient flow calculations (FemCat) including display of time series of heads for selected nodes, and for three-dimensional particle tracking with display of individual flow lines or a series of evenly distributed flow lines in two or three dimensions (F3Model).

FemInvs has been developed to automatically calibrate steady-state Micro-FEM models with horizontal flow in up to 16 layers. Models may include anisotropy and toplayers with drains and streams. The method used in FemInvs is based on nonlinear regression and the Marquardt algorithm. A maximum of 1200 head values can be used with 12 parameter values to be optimized. These parameters are relative values related to log-transformed transmissivities and resistances, discharges and other boundary conditions. Results include optimized parameters and their standard deviations, deviations between measured and calculated heads, correlation matrix, and eigen values and eigen vectors of the covariance matrix.

Micro-FEM is a DOS-based program which includes extensive, integrated pre- and postprocessing capabilities supported by a highly user-interactive graphic interface. It includes printing/plotting and screen display of finite element mesh, head contours, horizontal and vertical flow components, water balances of selected parts of the model, flow vectors, flow lines, and travel-times. Micro-FEM reads and write files in different formats, including HPGL, DXF, and various ASCII formats, facilitating easy interfacing with plotters, GIS, data bases, spreadsheets, and CAD programs. MICRO-FEM distribution includes run-time versions of the programs, and example data files. The documentation consist of installation instructions, model background, and user's instructions. A reduced-problem size, operational demonstration version is available.

SYSTEM REQUIREMENTS

Intel 80i86 based computer, 640 Kb RAM (for PC version; extended memory -- ext -- version available); 1 Mb free disk space to load program; for large problems you need ample additional data space; DOS 3.3 or higher, EGA or VGA Graphics, math coprocessor recommended.

Authors: C.J. Hemker and H. van Elburg (The Netherlands).