Abstract: A new method is presented to solve the three-dimensional advection dominant advection-dispersion equation, in which not only the advective-dispersive actions, but also the adsorption,radioactive decay and sources(sinks) are considered. Operator-splitting(OS) technique is used to split the equation over a time step into three parts, which are respectively solved by the method of constant variation (CV), the matched artificial dispersivity (MAD) method and the alternating direction implicit (ADI) method. Finally, the new method is applied to a synthetic three-dimensional contaminant transport problem. The simulated results are satisfactory by comparison with the analytical and the improved characteristic (IC) method solutions.

Key words: advection domination, three-dimensional advection-dispersion problem, metched artificial dispersivity method, operator-splitting technique