S.S. Papadopulos & Assoc., Inc.
7944 Wisconsin Avenue, Bethesda, MD 20814 Phone: (301) 718-8900
A general particle tracking program for calculating ground-water paths and travel times in steady-state or transient, 2D and 3D flow fields. The program can be used to simulate the movement of ground-water and the advection of contaminant solutes in ground-water. The program is particularly useful for delineating contaminant capture zones or well-head protection zone. Includes: a velocity interpolator which converts the hydraulic heads calculated at discretised nodal points into a velocity field in which the velocity in a given time step is determined as a function of position (x,y,z); and a numerical solver for tracking the movement of fluid particles in ground-water flow systems. PATH3D uses the head solution of MODFLOW but can also be modified to work in conjunction with any other block-centred finite-difference flow model. Output files: the x,y, z coordinates and the components of the seepage velocity at different travel times along the path of each individual particle; the x, y, z coordinates of all particles at selected times; and the initial and final positions of those particles captured by various sinks, or sources in the case of reverse particle tracking. Output files can be imported into most commercial graphic packages for plotting the pathlines of individual particles, the positions of displacement fronts of capture zones at desirable times, and the distribution of captured particles. All input is performed via input menus. Several post-processing programs are included to facilitate the use of a graphic package, including commercial contouring packages.