Abstract
Conservative and sorptive transport simulations were conducted in heterogeneous aquifers to assess characteristics of macrodispersion. Heterogeneities in subsurface materials were represented as randomly correlated hydraulic conductivity and sorption partition coefficient fields. Transport computations were based upon a random walk particle tracking model linked with temporal and spatial moments. The simulations demonstrated that control plane and its middle element provide almost identical macrodispersivity estimates in terms of transverse mixing, but differ markedly from estimates of longitudinal mixing. The results also indicated that the increase of the physical or chemical heterogeneity provides the increase of the longitudinal and transverse macrodispersivities and affects late traveltimes of particles reaching a control plane, leading to the increase of the second-order temporal moment and relevant macrodispersion.
