Abstract
It is known that observed macroscopic dispresivity depends on observation scale, so that a single value cannot represent the field property for dispersion. In this study, numerical simulations of the advection dispersion phenomena in various random-permeability fields generated by using stochastic fractal model were carried out to investigate the relationship between spatial distributions of hydraulic conductivity and dispersivity. The results show that various concentration distributions occur even when the hydraulic conductivities of flow fields are statistically the same. It is also shown that a dispesivity distribution model expressed by function of scale can well reproduce the ensemble mean of concentration distributions.
