Stochastic analysis of contaminant transport Page: 2 of 11
This report is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided to Digital Library by the UNT Libraries Government Documents Department.
The following text was automatically extracted from the image on this page using optical character recognition software:
A reliability algorithm is used to develop probabilistic
(stochastic) models of contaminant transport in porous media. The
models are based on advective-dispersive transport equations, and
utilize the reliability algorithm with existing one- and two-
dimensional analytical and numerical solutions. Uncertain variables
in the models include: groundwater flow velocity (or permeability
in the numerical model), dispersivity, diffusion coefficient, bulk
density, porosity, and solute distribution coefficient. Each
uncertain variable is assigned a mean, covariance, and marginal
distribution. The models yield an estimate of the probability that
the contaminant concentration will equal or exceed a target
concentration at a selected location and time. The models also
yield probabilistic sensitivity measures which identify those
uncertain variables with most influence on the probabilistic
The objective is to examine the basic behavior and develop
general conclusions regarding transport under uncertain conditions
as modeled using a reliability approach. A wide range of
statistical input and problem assumptions is assumed for some
hypothetical problems. Results indicate that simplification of the
analysis is possible by a preliminary determination of
probabilistic sensitivity measures. Those variables with low
sensitivity can effectively be treated as deterministic constants.
In analytical models, flow velocity is usually the most important
uncertain variable; dispersivity can often be treated as a
deterministic constant. Numerical model results, however, indicate
dispersivity has more probabilistic influence than permeability if
dispersivity is treated as a single global variable while the
permeability is treated as a discretized variable. In reactive
transport, the bulk density, fluid density, and distribution
coefficient are always very important uncertain variables.
Here’s what’s next.
This report can be searched. Note: Results may vary based on the legibility of text within the document.
Tools / Downloads
Get a copy of this page or view the extracted text.
Citing and Sharing
Basic information for referencing this web page. We also provide extended guidance on usage rights, references, copying or embedding.
Reference the current page of this Report.
Cawlfield, J.D. Stochastic analysis of contaminant transport, report, February 1, 1992; United States. (https://digital.library.unt.edu/ark:/67531/metadc1095379/m1/2/: accessed April 21, 2019), University of North Texas Libraries, Digital Library, https://digital.library.unt.edu; crediting UNT Libraries Government Documents Department.