Persistent Link:
http://hdl.handle.net/10150/191120
Title:
Stochastic analysis of high-permeability paths in the subsurface
Author:
Silliman, Stephen Edward Joseph,1957-
Issue Date:
1986
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Subsurface fluids may travel along paths having a minimum permeabilility greater than the effective permeability of the rock. This may have an important impact on contaminant migration. A stochastic approach related to percolation theory is advanced to address the question of what is the probability that a high permeability path extends across a given volume of the subsurface. The answer is sought numerically through subdividing the volume of interest into a three-dimensional grid of elements and assigning a random permeability to each element. Four permeability processes are considered: 1) Stationary with independence between grid elements; 2) Stationary and autocorrelated; 3) Nonstationary due to conditioning on measured values; and 4) Random rock volume included in grid. The results utilizing data from fractured granites suggest that in large grids, at least one path having a minimum permeability in excess of the "effective" rock permeability will cross the grid. Inclusion of autocorrelation causes an increase in the expected value of the minimum permeability of such a path. It also results in a significantly increased variance of this permeability. Conditioning on field permeabilities reduces the variance of this value over that obtained by unconditional, correlated simulation, but still produces a variance greater than that obtained when independence was assumed. When conditioning is performed, the mean of the minimum permeabilities along these paths is dependent on the principal axis of the path. Finally, including a random rock volume by allowing the length of the grid to be random increases the variance of the minimum permeability.
Type:
Dissertation-Reproduction (electronic); text
Keywords:
Hydrology.; Hydrology -- Computer simulation.; Soil permeability.; Diffusion in hydrology.; Groundwater flow.
Degree Name:
Ph. D.
Degree Level:
doctoral
Degree Program:
Hydrology and Water Resources; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Neuman, Shlomo

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleStochastic analysis of high-permeability paths in the subsurfaceen_US
dc.creatorSilliman, Stephen Edward Joseph,1957-en_US
dc.contributor.authorSilliman, Stephen Edward Joseph,1957-en_US
dc.date.issued1986en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractSubsurface fluids may travel along paths having a minimum permeabilility greater than the effective permeability of the rock. This may have an important impact on contaminant migration. A stochastic approach related to percolation theory is advanced to address the question of what is the probability that a high permeability path extends across a given volume of the subsurface. The answer is sought numerically through subdividing the volume of interest into a three-dimensional grid of elements and assigning a random permeability to each element. Four permeability processes are considered: 1) Stationary with independence between grid elements; 2) Stationary and autocorrelated; 3) Nonstationary due to conditioning on measured values; and 4) Random rock volume included in grid. The results utilizing data from fractured granites suggest that in large grids, at least one path having a minimum permeability in excess of the "effective" rock permeability will cross the grid. Inclusion of autocorrelation causes an increase in the expected value of the minimum permeability of such a path. It also results in a significantly increased variance of this permeability. Conditioning on field permeabilities reduces the variance of this value over that obtained by unconditional, correlated simulation, but still produces a variance greater than that obtained when independence was assumed. When conditioning is performed, the mean of the minimum permeabilities along these paths is dependent on the principal axis of the path. Finally, including a random rock volume by allowing the length of the grid to be random increases the variance of the minimum permeability.en_US
dc.description.notehydrology collectionen_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.typetexten_US
dc.subjectHydrology.en_US
dc.subjectHydrology -- Computer simulation.en_US
dc.subjectSoil permeability.en_US
dc.subjectDiffusion in hydrology.en_US
dc.subjectGroundwater flow.en_US
thesis.degree.namePh. D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineHydrology and Water Resourcesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairNeuman, Shlomoen_US
dc.contributor.committeememberSimpson, Eugene S.en_US
dc.contributor.committeememberDavis, Stanleyen_US
dc.contributor.committeememberMyers, Donalden_US
dc.identifier.oclc213416718en_US
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