Examples of complex, heterogeneous models and their benefits

In heterogeneous systems, complex plume behavior can complicate plume detection and the interpretation of concentration data. Additionally, heterogeneity leads to apparent non-Fickian transport affecting plume longevity. In such cases, the advection dispersion equation may only apply at a local scale. Examples of models wherein consideration of complex, fine-scale heterogeneity elucidates these phenomena will be reviewed. Instead of complicating communication as one might expect, the use of these complex models provided a foundation to explain variability inherent in the data, to improve understanding of plume evolution, and to directly answer questions regarding plume longevity.