Modeling of Variably Saturated Flow in Response to Pumping from an Unconfined Aquifer: Numerical Evidence of Gravity-Delayed Drainage and Its Parameterization
Publication: Journal of Hydrologic Engineering
Volume 21, Issue 2
Abstract
A numerical model of variably saturated axis-symmetric radial flow is employed to simulate and parameterize the gravity-delayed drainage, viewing it as the vertical accretion over falling water table. Numerical experiments are conducted to simulate the head fields at advancing discrete times as pumping is sustained at the assigned well. The head fields are invoked to generate the corresponding time series of water table elevation and the accretion rate over it. Employing these time series, the optimal structure/parameters of gravity-delayed drainage equation are estimated by the least-squares approach under a variety of hydrogeologic/geometric conditions. It is revealed that generally, a two-parameter gravity-delayed drainage equation reproduces parsimoniously the accretion time series.
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Published In
Journal of Hydrologic Engineering
Volume 21 • Issue 2 • February 2016
Copyright
© 2015 American Society of Civil Engineers.
History
Received: Mar 13, 2015
Accepted: Aug 21, 2015
Published online: Oct 22, 2015
Published in print: Feb 1, 2016
Discussion open until: Mar 22, 2016
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