GoPhast is a graphical user interface (GUI) for the USGS model PHAST.
PHAST simulates multicomponent, reactive solute transport in three-
dimensional, saturated, ground-water flow systems. PHAST can model both
equilibrium and kinetic geochemical reactions. PHAST is derived from
HST3D (flow and transport) and PHREEQC (geochemical calculations). The
flow and transport calculations are restricted to constant fluid density
and constant temperature. The complexity of the input required by PHAST
makes manual construction of its input files tedious and error-prone.
GoPhast streamlines the creation of the input file and helps reduce
errors. GoPhast allows the user to define the spatial input for the PHAST
flow and transport data file by drawing points, lines, or polygons on
top, front, and side views of the model domain. These objects can have up
to two associated formulas that define their extent perpendicular to the
view plane, allowing the objects to be three-dimensional. Formulas are
also used to specify the values of spatial data (data sets) both globally
and for individual objects. Objects can be used to specify the values of
data sets independent of the spatial and temporal discretization of the
model. Thus, the grid and simulation periods for the model can be changed
without respecifying spatial data pertaining to the hydrogeologic
framework and boundary conditions. This report describes the operation of
GoPhast and demonstrates its use with examples. GoPhast runs on Windows
2000, Windows XP, and Linux operating systems.