Freeware

PM is graphical interface for simulation of threedimensional flow and solute transport problems. It supports the preparation of input files and analysis of simulation results for a range of MODFLOW-related programs including MODFLOW itself, the particle tracking programs MODPATH and PMPATH, the transport program MT3D, and the parameter estimation program PEST. PMWIN includes a version of MODFLOW (including the PCG2 solver, and the HFB, CHD and IBS packages), PMPATH, PMDIS (interpolation and kriging), and limited-capability educational versions of MT3D and PEST. Full-featured versions of MT3D and PEST are supported, but not included (see elsewhere in this catalog).

PMWIN can handle up to 80 model layers and a grid of up to 2000 x 2000 cells. The model grid can be overlain on DXF maps. Model data can be assigned on a per-cell basis, a per-zone basis, or automayically using the included interpolation program.

PM provides postprocessors to generate head and drawdown contours with on screen or in HPGL, DXF and SURFER format, to calculate sub-regional water budgets, and to display and export hydrographs and other time-dependent graphs.

PMPATH for Windows is a three-dimensional particle tracking model. It retrieves the results files from the U.S.

Geological Survey three-dimensional groundwater flow model MODFLOW. It uses the same semi-analytical particle tracking scheme as the U.S. Geological Survey MODPATH model to calculate groundwater flowpaths and travel times. PMPATH does forward and backward particle tracking in a steady-state or transient, two- or three-dimensional flow field. It graphically shows the groundwater model along with DXF base maps and different colored grid cells for indicating different boundary or hydraulic conditions, e.g., constant head boundary, wells, rivers, etc.

Through the interactive graphical modeling environment of PMPATH, the user can place particles and perform particle tracking with just a few mouse clicks. While some of the most popular particle tracking models require postprocessors for visualization of computed paths and times data, PMPATH calculates and shows the pathlines and travel time marks simultaneously. Moreover, PMPATH provides various on-screen graphical output options including contours of MODFLOW-generated heads or drawdowns, and velocity vectors for any selected model layer and time step.

Both forward and backward particle tracking are allowed for steady-state and transient flow simulations. For transient simulations, particle tracking can start for any time step. The time length of a single particle tracking step and the allowed number of tracking steps can be specified. Furthermore, each particle can have its own color and retardation factor. With these features, PMPATH can be used to simulate advection transport in groundwater, to delineate contaminant capture zones, injection zones and wellhead protection areas or to find the origination of water in specified zones.

SYSTEM REQUIREMENTS

Intel 80386 processor and math coprocessor, 8 Mb RAM, DOS 5.0 or higher, Windows 3.1 or later, at least 5 Mb free disk space for program files, VGA graphics or better.

Author: Wen-Hsing Chiang (Hamburg, Germany).