In this paper we describe a stochastically-derived, deterministic model of solute transport in randomly heterogeneous geologic media. The model allows for local dispersion, linear equilibrium sorption, and radioactive decay or biodegradation. It utilizes an analytical-numerical approach to deterministically predict the spacetime evolution of concentrations conditioned on measurements of hydraulic conductivities (transmissivities) and /or hydraulic heads. We solve the conditional transport problem analytically at early time, and use a pseudo-Fickian approximation at later time. We illustrate the model by considering instantaneous point sources in a two-dimensional domain with a mildly fluctuating, statistically homogeneous, lognormal transmissivity field. Though we take the unconditional mean velocity to be uniform, conditioning on log transmissivity and hydraulic head data renders the velocity field statistically nonhomogeneous with reduced variances and correlation scales, renders the predicted plume irregular and non-Gaussian, and generally reduces both predictive dispersion and uncertainty.
|Original language||English (US)|
|Number of pages||7|
|Journal||Models for assessing and monitoring groundwater quality. Proc. symposium, Boulder, 1995|
|State||Published - 1995|
ASJC Scopus subject areas
- Earth and Planetary Sciences(all)
- Environmental Science(all)