ABSTRACT
This chapter presents an evaluation of the uncertainty in predicting advective-dispersive solute transport. Three different kinds of uncertainties are considered: parametric, geological, and combined uncertainties. There are several approaches to study the propagation of the uncertainties of the input parameters to the output variables: first-order analysis, spectral-perturbation analysis, and Monte-Carlo method. The parametric uncertainty does not show remarkable difference in the plume shape in comparison with the geological case. The irregular shapes of solute plumes in aquifers, due to the heterogeneity of the natural formations and the inability of characterizing these heterogeneities in a deterministic sense, suggest that it may be more realistic to make predictions in a probabilistic context rather than in the traditional deterministic framework. In case of geological and both geological and parametric uncertainty: the results of three single realizations are displayed. The three different realizations show considerable scatter in the longitudinal variance.
