Application of the Sagar method for the solution of the inverse problem in ground water hydrology

Persistent Link:
http://hdl.handle.net/10150/191612
Title:
Application of the Sagar method for the solution of the inverse problem in ground water hydrology
Author:
Skrivan, James A.
Issue Date:
1975
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:
The flow of ground water through porous media can be described by partial differential equations involving potentiometric head as a function of space and time together with aquifer parameters. The direct problem is to calculate heads, given these parameters and initial and boundary conditions. The alternating direction implicit procedure with finite-difference approximations is a numerical technique used for the solution. The inverse problem is to determine aquifer parameters from measured heads. The Sagar method treats parameters as unknowns and the partial derivatives in head as knowns, using spline-function interpolation and a least-squares optimization technique. The Sagar method has been tested by employing heads generated in a finite-difference model to try to recover the transmissivity (T) distribution used in the model. Storage coefficient and pumping were assumed known. For the cases presented, T was recoverable from model output, particularly for homogeneous T. For T heterogeneous and isotropic, many estimates had relative errors within ±30% error using three measured-head distributions, and the errors were significantly improved by adding a fourth head distribution to the procedure. But the distributions used must be the result of different areal pumpage in order to produce better estimates of transmissivity.
Type:
Thesis-Reproduction (electronic); text
LCSH Subjects:
Hydrology.; Aquifers -- Mathematical models.
Degree Name:
M.S.
Degree Level:
masters
Degree Program:
Hydrology and Water Resources; Graduate College
Degree Grantor:
University of Arizona
Committee Chair:
Simpson, Eugene S.

Full metadata record

DC FieldValue Language
dc.language.isoenen_US
dc.titleApplication of the Sagar method for the solution of the inverse problem in ground water hydrologyen_US
dc.creatorSkrivan, James A.en_US
dc.contributor.authorSkrivan, James A.en_US
dc.date.issued1975en_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.abstractThe flow of ground water through porous media can be described by partial differential equations involving potentiometric head as a function of space and time together with aquifer parameters. The direct problem is to calculate heads, given these parameters and initial and boundary conditions. The alternating direction implicit procedure with finite-difference approximations is a numerical technique used for the solution. The inverse problem is to determine aquifer parameters from measured heads. The Sagar method treats parameters as unknowns and the partial derivatives in head as knowns, using spline-function interpolation and a least-squares optimization technique. The Sagar method has been tested by employing heads generated in a finite-difference model to try to recover the transmissivity (T) distribution used in the model. Storage coefficient and pumping were assumed known. For the cases presented, T was recoverable from model output, particularly for homogeneous T. For T heterogeneous and isotropic, many estimates had relative errors within ±30% error using three measured-head distributions, and the errors were significantly improved by adding a fourth head distribution to the procedure. But the distributions used must be the result of different areal pumpage in order to produce better estimates of transmissivity.en_US
dc.description.notehydrology collectionen_US
dc.typeThesis-Reproduction (electronic)en_US
dc.typetexten_US
dc.subject.lcshHydrology.en_US
dc.subject.lcshAquifers -- Mathematical models.en_US
thesis.degree.nameM.S.en_US
thesis.degree.levelmastersen_US
thesis.degree.disciplineHydrology and Water Resourcesen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.chairSimpson, Eugene S.en_US
dc.identifier.oclc212882064en_US
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