A Q-BASIC PROGRAM FOR MODELING ADVECTIVE MASS-TRANSPORT WITH RETARDATION AND RADIOACTIVE DECAY BY PARTICLE TRACKING

PATH.BAS is a Q-BASIC program that calculates arrival times, arrival l ocations, and arrival concentrations of dispersion-free mass transport in heterogeneous media at a control area by particle tracking. Retard ation and radioactive decay effects are included. The transport proces s and cumulative breakthrough curve are displayed dynamically on the s creen. A new particle tracking method which uses a constant displaceme nt scheme is proposed and shown to be faster, more efficient, and more accurate than the traditional scheme which uses a constant time step. The program provided is flexible and easy to modify for different spe cific transport situations. The implementation of PATH.BAS is demonstr ated in an example.