HR: 1340h
AN: H23G-1709    [Abstracts]
TI: Diffusion, Dispersion, and Uncertainty in Anisotropic Fractal Porous Media
AU: * Monnig, N D
EM: nmonnig@mines.edu
AF: Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401,
AU: Benson, D A
EM: dbenson@mines.edu
AF: Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401,
AB: Motivated by field measurements of aquifer hydraulic conductivity (K), recent techniques were developed to construct anisotropic fractal random fields, in which the scaling, or self-similarity parameter, varies with direction and is defined by a matrix. Ensemble numerical results are analyzed for solute transport through these 2-D "operator-scaling" fractional Brownian motion (fBm) ln(K) fields. Contrary to some analytic stochastic theories for monofractal K fields, the plume growth rates never exceed Mercado's (1967) purely stratified aquifer growth rate of plume apparent dispersivity proportional to mean distance. Apparent super-stratified growth must be the result of other demonstrable factors, such as initial plume size. The addition of large local dispersion and diffusion does not significantly change the effective longitudinal dispersivity of the plumes. In the presence of significant local dispersion or diffusion, the concentration coefficient of variation CV={σ_c}/{\langle c \rangle} remains large at the leading edge of the plumes. This indicates that even with considerable mixing due to dispersion or diffusion, there is still substantial uncertainty in the leading edge of a plume moving in fractal porous media.
DE: 1832 Groundwater transport
DE: 1839 Hydrologic scaling
DE: 1847 Modeling
DE: 1869 Stochastic hydrology
DE: 1873 Uncertainty assessment (3275)
SC: Hydrology [H]
MN: 2007 Fall Meeting