Abstract
Macroscopic dispersivity is most important factor to analyze advection dispersion equation (ADE) at the field scale. Any appropriate method for determining this parameter has not been established yet. In this study, artificial heterogeneous hydraulic conductivity fields were generated with the stochastic fractal model (f-ζ model) that was proposed by Saito and Kawatani (2000). Macroscopic dispersivities were evaluated for generated two-dimensional and three-dimensional fields from ADE simulations. Results showed that macroscopic dispersivity depends on two scales, the contaminant source length and the travel distances, and field characteristics such as variability of hydraulic conductivity for one-dimensional flow. Finally, we proposed useful diagrams to estimate macroscopic dispersivity quantitatively based on 2-dimensional and 3-dimensional numerical experiments.
