Water table waves in an unconfined aquifer: Experiments and modeling

Cartwright, N. B., Nielsen, P. and Dunn, S. (2003) Water table waves in an unconfined aquifer: Experiments and modeling. Water Resources Research, 39 12: SBH4-1-SBH4-12. doi:10.1029/2003WR002185

Author Cartwright, N. B.
Nielsen, P.
Dunn, S.
Title Water table waves in an unconfined aquifer: Experiments and modeling
Journal name Water Resources Research   Check publisher's open access policy
ISSN 0043-1397
Publication date 2003-12
Sub-type Article (original research)
DOI 10.1029/2003WR002185
Volume 39
Issue 12
Start page SBH4-1
End page SBH4-12
Total pages 12
Editor A. F. Spilhaus
Place of publication Washington, DC, United States
Publisher American Geophysical Union
Collection year 2003
Language eng
Subject 290802 Water and Sanitary Engineering
770402 Land and water management
0905 Civil Engineering
Abstract [1] Comprehensive measurements are presented of the piezometric head in an unconfined aquifer during steady, simple harmonic oscillations driven by a hydrostatic clear water reservoir through a vertical interface. The results are analyzed and used to test existing hydrostatic and nonhydrostatic, small-amplitude theories along with capillary fringe effects. As expected, the amplitude of the water table wave decays exponentially. However, the decay rates and phase lags indicate the influence of both vertical flow and capillary effects. The capillary effects are reconciled with observations of water table oscillations in a sand column with the same sand. The effects of vertical flows and the corresponding nonhydrostatic pressure are reasonably well described by small-amplitude theory for water table waves in finite depth aquifers. That includes the oscillation amplitudes being greater at the bottom than at the top and the phase lead of the bottom compared with the top. The main problems with respect to interpreting the measurements through existing theory relate to the complicated boundary condition at the interface between the driving head reservoir and the aquifer. That is, the small-amplitude, finite depth expansion solution, which matches a hydrostatic boundary condition between the bottom and the mean driving head level, is unrealistic with respect to the pressure variation above this level. Hence it cannot describe the finer details of the multiple mode behavior close to the driving head boundary. The mean water table height initially increases with distance from the forcing boundary but then decreases again, and its asymptotic value is considerably smaller than that previously predicted for finite depth aquifers without capillary effects. Just as the mean water table over-height is smaller than predicted by capillarity-free shallow aquifer models, so is the amplitude of the second harmonic. In fact, there is no indication of extra second harmonics ( in addition to that contained in the driving head) being generated at the interface or in the interior.
Keyword Environmental Sciences
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 18 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 0 times in Scopus Article
Google Scholar Search Google Scholar
Created: Wed, 15 Aug 2007, 01:42:11 EST