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RECORD NUMBER: 214 OF 1515

OLS Field Name OLS Field Data
Main Title Computerized Procedure to Determine Aquifer Characteristics.
Author Knowle, Tommy R. ; Clabor, B. J. ; Well, Dan M. ;
CORP Author Texas Technological Coll. Lubbock. Water Resources Center.
Year Published 1972
Report Number WRC-72-5; DI-14-01-0001-1993; OWRR-C-2101(3363); 06508,; C-2101(3363)(1)
Stock Number PB-217 865
Additional Subjects ( Aquifers ; Computerized simulation) ; Computer programs ; Permeability ; Water distribution ; Optimization ; Finite difference theory ; Mathematical models ; Steepest descent method ; Water wells ; Texas ; Ogallala Aquifer
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Library Call Number Additional Info Location Last
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Status
NTIS  PB-217 865 Most EPA libraries have a fiche copy filed under the call number shown. Check with individual libraries about paper copy. NTIS 06/23/1988
Collation 111p
Abstract A digital computer procedure to determine aquifer parameters is developed. The values of permeability and storage coefficient at specific points were of interest rather than functions which describe the spacial distribution of these parameters. The procedure adjusts initial estimates of permeability and storage coefficient to reduce the differences between the measured and simulated water levels. The parameter adjustment procedure uses a steepest descent optimization procedure to minimize the errors in simulating water levels. The partial derivatives necessary for the steepest descent procedure are determined by differentiating the finite difference equation with respect to the acquifer parameters. The net amount of water removed from each node was included as a parameter. The adjustment procedure is iterative in that for each year the model simulates water levels, calculates simulation errors, and adjusts parameters. This procedure is repeated twice using the adjusted values of the parameters. Each year's adjustment of parameters results in a different set of parameter values. These values were averaged and the program was executed using these average values. This resulted in less simulation error than was present when the original values of the parameters were used. (Author)
PUB Date Free Form Dec 72,
Category Codes 8H; 13B; 64H; 60I
NTIS Prices PC A06/MF A01
Document Type NT
Cataloging Source NTIS/MT
Control Number 326556338
Origin NTIS
Type CAT