Order No: BAS 03
Version: 5.0 (September 1995)
RWH is an analytical version of the widely used RANDOM WALK flow and solute transport model, specifically designed for screening and educational purposes. It simulates solute transport from one or more sources in a homogeneous, isotropic, confined aquifer of constant thickness and infinite extent. It accounts for one- or two-dimensional steady-state regional ground-water flow and the superposed effects of varying-rate production and injection wells using the transient Theis equation. The transport equation is solved via the particle-in-a-cell technique for convection and the random walk technique for dispersion. Options for linear retardation and first-order decay are included. A user-defined number of particles, each with their own mass, are introduced at one or more linear, rectangular or circular sources. Particles are removed from the system through one or more discharging wells (i.e., sinks) or a no-stress line sink. At each time step the program calculates the position of each particle and provides optional particle mapping, calculation and graphic display of the spatial concentration distribution, global mass balance, and file output of results. It also provides an option for calculating the concentration over time in a sink.
This menu-driven program facilitates interactive data entry and editing and includes graphic screen display of simulation progress and results. Data can be entered manually or from a file prepared by the program in an earlier session. Results are saved in ASCII text files, including files for further postprocessing.
RWH is proprietary to IGWMC. Distribution includes source code, runtime version, and example data sets. The documentation contains installation instructions and a user's manual.
Intel 80i86 based computer, 640 Kb RAM, DOS 3.0 or higher, VGA graphics, math coprocessor.
Author of RWH: P.K.M. van der Heijde (IGWMC).