HR: 1340h
AN: H33F-0524    [Abstracts]
TI: Nonlocal Analysis of Mean Non-Reactive Solute Transport in Bounded Randomly Heterogeneous Media
AU: * Morales-Casique, E
EM: emorales@hwr.arizona.edu
AF: Department of Hydrology and Water Resources, The University of Arizona, 1133 E North Campus Drive, Tucson, AZ 85721 United States
AU: Neuman, S P
EM: neuman@hwr.arizona.edu
AF: Department of Hydrology and Water Resources, The University of Arizona, 1133 E North Campus Drive, Tucson, AZ 85721 United States
AU: Guadagnini, A
EM: alberto.guadagnini@polimit.it
AF: Dipartimento di Ingegneria Idraulica Ambientale e del Rilevamento, Politecnico di Milano, Piazza Leonardo Da Vinci 32, Milan, 20133 Italy
AB: Solute transport in randomly heterogeneous media is described by stochastic transport equations that are typically solved by Monte Carlo simulation. A promising alternative is to solve a corresponding system of statistical moment equations directly. The moment equations are generally integro-differential and include nonlocal parameters depending on more than one point in space-time [Neuman, 1993; Zhang and Neuman, 1996; Guadagnini and Neuman, 2001]. We present recursive approximations, and a numerical algorithm, that allow computing lead ensemble moments of non-reactive solute transport in bounded, randomly heterogeneous media. Our recursive equations are formally valid for mildly heterogeneous aquifers with $\sigma$_{Y}$^{2} <$ 1 where $\sigma$_{Y}$^{2}$ is a measure of log-hydraulic conductivity variance. Our algorithm utilizes a finite element Laplace transform method (FELT) valid for steady state advective velocity fields. Computational results in two spatial dimensions compare well with Monte Carlo results when $\sigma$_{Y}$^{2}$ and the grid Peclet number are small. As these parameters increase, the quality of our moment solution deteriorates. In principle, one should be able to control $\sigma$_{Y}$^{2}$ through conditioning on data and the Peclet number by selecting appropriate space-time discretization intervals.
DE: 3230 Numerical solutions
DE: 1832 Groundwater transport
DE: 1869 Stochastic processes
SC: Hydrology [H]
MN: 2004 AGU Fall Meeting