Unsteady Drainage with Variable Drainage Porosity
Publication: Journal of Irrigation and Drainage Engineering
Volume 120, Issue 4
Abstract
Presently available solutions of the one‐dimensional unsteady‐state ground‐water flow equation (Boussinesq equation) have been obtained by treating the drainable porosity as a constant. Experimental evidence however, indicates that is a function of hydraulic head . An experimentally determined relationship was incorporated in the Boussinesq equation. The equation was solved by using the extrapolated Crank‐Nicholson's difference scheme for predicting the spatial and temporal water‐table behavior. The predicted hydraulic heads were compared with the other available solutions of the Boussinesq equation obtained by treating as a constant and with the observed data in two different sand tank model studies. The average absolute deviation between the predicted and the observed water‐table depths was reduced by over 70% when the present approach was used as compared to when was treated as a constant.
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Information & Authors
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Published In
Journal of Irrigation and Drainage Engineering
Volume 120 • Issue 4 • July 1994
Pages: 703 - 715
Copyright
Copyright © 1994 American Society of Civil Engineers.
History
Received: Oct 15, 1992
Published online: Jul 1, 1994
Published in print: Jul 1994
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