EULERIAN-LAGRANGIAN ANALYSIS OF TRANSPORT CONDITIONED ON HYDRAULIC DATA .2. EFFECTS OF LOG TRANSMISSIVITY AND HYDRAULIC-HEAD MEASUREMENTS

In paper 1 of this series we described an analytical-numerical method to predict deterministically solute transport under uncertainty. The m ethod is based on a unified Eulerian-Lagrangian theory which allows co nditioning of the predictions on hydraulic measurements. Conditioning on measured concentrations is also possible, as demonstrated by Neuman et al. (1993). In this paper we condition velocity on log transmissiv ity and/or hydraulic head data via cokriging. We then combine an early time analytical solution with a pseudo-Fickian Galerkin finite elemen t scheme for later time to obtain conditional predictions of concentra tion and lower bounds on its variance and coefficient of variation. Th e pseudo-Fickian scheme involves a conditional dispersion tenser which depends on information and varies in space-time. Hence the predicted plumes travel along curved trajectories and attain irregular, non-Gaus sian shapes. We also compute a measure of uncertainty for the original source location of a solute ''particle'' whose position at some later time is known from sampling. Spatial maps of this ''particle origin c ovariance'' provide vivid images of preferential flow paths and exclus ion zones identified by the available data. We illustrate these concep ts and results on instantaneous point and area sources.