Predictive modeling of flow and transport in a two-dimensional intermediate-scale, heterogeneous porous medium

As a first step toward understanding the role of sedimentary structures in flow and transport through porous media, this work deterministically examin es how small-scale laboratory-measured values of hydraulic conductivity rel ate to in situ values of simple, artificial structures in an intermediate-s cale (10 m long), two-dimensional, heterogeneous, laboratory experiment. Re sults were judged based on how well simulations using measured values of hy draulic conductivities matched measured hydraulic heads, net flow, and tran sport through the tank. Discrepancies were investigated using sensitivity a nalysis and nonlinear regression estimates of the in situ hydraulic conduct ivity that produce the best fit to measured hydraulic heads and net flow. P ermeameter and column experiments produced laboratory measurements of hydra ulic conductivity for each of the sands used in the intermediate-scale expe riments. Despite explicit numerical representation of the heterogeneity the laboratory-measured values underestimated net flow by 12-14% and were dist inctly smaller than the regression-estimated values. The significance of di fferences in measured hydraulic conductivity values was investigated by com paring variability of transport predictions using the different measurement methods to that produced by different realizations of the heterogeneous di stribution. Results indicate that the variations in measured hydraulic cond uctivity were more important to transport than variations between realizati ons of the heterogeneous distribution of hydraulic conductivity.