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 locations, and arrival concentrations of dispersion-free mass transport in heterogeneous media at a control area by particle tracking. Retardation and radioactive decay effects are included. The transport process and cumulative breakthrough curve are displayed dynamically on the screen. A new particle tracking method which uses a constant displacement 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 specific transport situations. The implementation of PATH.BAS is demonstrated in an example.