Description |
RAND3D is a 3D version of the random walk algorithm for solving ground water solute transport problems includes: calculation of horizontal advective transport using one of three different velocity interpolation schemes; calculation of vertical advective transport based on linear interpolation between the input vertical velocity vectors at the top and bottom of each layer; calculation of dispersion using constant dispersivities, longitudinal, transverse, and vertical; calculation of zero-order, first order, or variable-order- decay, or volatilisation from the water table; calculation of linear adsorption (retardation); ability to represent complex areal sources; calculation of solute concentrations exiting the model at sinks (wells or gaining stream); cross section or plan view contour mapping in user selected areas of the model; output of gridded solute concentrations by layer for plotting; interactive screen graphics - plume movements, geographic features (using special coordinate files) and screen slides; saving and restart of model parameters at any time; transient flow simulation capability, by running multiple time steps; particle splitting to improve resolution by adding increased particles based upon a multiple of the original number of particles selected; particle transfer to simulate solute transport problems at different scales and pass particles from one sized RAND3D model to another sized RAND3D model as an input file. Velocity vector files are created using a pre-processor PREMOD3D which takes MODFLOW. Output from multiple time steps can be used to run RAND3D in transient mode. |