Velocity prediction errors related to flow model calibration uncertainty [electronic resource]

At the Savannah River Site (SRS), a United States Department of Energy facility in South Carolina, a three-dimensional, steady-state numerical model has been developed for a four aquifer, three aquitard groundwater flow system. This model has been used for numerous predictive simulation applications...

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Online Access: Online Access
Corporate Authors: Westinghouse Savannah River Company (Researcher), United States. Department of Energy. Savannah River Site (Researcher)
Format: Government Document Electronic eBook
Language:English
Published: Washington, D.C : Oak Ridge, Tenn. : United States. Dept. of Energy. Office of the Assistant Secretary for Defense Programs ; distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy, 1990.
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Summary:At the Savannah River Site (SRS), a United States Department of Energy facility in South Carolina, a three-dimensional, steady-state numerical model has been developed for a four aquifer, three aquitard groundwater flow system. This model has been used for numerous predictive simulation applications at SRS, and since the initial calibration, the model has been refined several times. Originally, calibration of the model was accomplished using a nonlinear least-squares inverse technique for a set of 50 water-level calibration targets non-uniformly distributed in the four aquifers. The estimated hydraulic properties from this calibration generally showed reasonable agreement with values estimated from field tests. Subsequent model refinements and application of this model to field problems have shown that uncertainties in the model parameterization become much more apparent in the prediction of the velocity field than in the simulation of the distribution of hydraulic heads. The combined use of three types of information (hydraulic head distributions, geologic framework models, and velocity field monitoring) provide valuable calibration data for flow modeling investigations; however, calibration of a flow model typically relies upon measured water levels. For a given set of water-level calibration targets, the uncertainties associated with imperfect knowledge of physical system parameters or groundwater velocities may not be discernable in the calibrated hydraulic head distribution. In this paper, modeling results from studies at SRS illustrate examples of model inadequacy resulting from calibrating only on observed water levels, and the effects of these inadequacies on velocity field prediction are discussed. 14 refs., 6 figs.
Item Description:Published through the Information Bridge: DOE Scientific and Technical Information.
01/01/1990.
"wsrc-ms-90-124"
" conf-9009254--2"
"DE91005651"
International conference on calibration and reliability in groundwater modeling, Hague (Netherlands), 3-6 Sep 1990.
Stephenson, D.E.; Buss, D.R.; Duffield, G.M.
Physical Description:Pages: (14 p) : digital, PDF file.