Internet-First University Press >
Symposia, Workshops, Conferences >
Hydrologic Discovery Through Physical Analysis Honoring the Scientific Legacies of Wilfried H. Brutsaert and Jean-Yves Parlange >
Hydrologic Discovery - Oral Presentations (Videos) >
Please use this identifier to cite or link to this item:
|Title: ||B1. Laplace - Boussinesq: 3-1.|
|Authors: ||van de Giesen, Nick|
Steenhuis, Tammo S.
|Keywords: ||groundwater flow|
|Issue Date: ||May-2012|
|Publisher: ||Internet-First University Press|
|Abstract: ||In 1993, Jean-Yves Parlange developed a very generic solution for the Laplace equation in the archetypal drainage geometry of an aquifer on an impermeable layer between two parallel drains with linearized boundary conditions. The solution is based on Eigenfunction expansion and has as main advantage that it can accommodate any spatial and temporal distribution of recharge into the aquifer and any shape of the initial groundwater table. A parallel solution was developed for the Boussinesq equation. As such, the solutions provide a nice “toy model” to test the validity of the Dupuit assumption that the vertical pressure distribution in an aquifer is basically hydrostatic, which underlies the Boussinesq equation. The good news is that Boussinesq is indeed valid as long as the underlying assumption is valid. There are, however, also cases in which Boussinesq fails. The presentation will go in some detail to show where trouble is to be expected, and where safe sailing reigns. Although the geometry and the linearization of the boundary conditions do not allow for a complete analysis, the analysis does have clear heuristic value. For example, at short times after sudden drawdowns, vertical water movement and associated energy losses are very relevant, limiting the validity of the Boussinesq equation. The same holds when the aquifers, or drained fields, are relatively deep in comparison to theirs widths, as is the case in the raised beds found in the wetlands of Rwanda that prompted the original research.|
|Description: ||Once downloaded, these high definition QuickTime videos may be played using a computer video player with H.264 codec, 1280x720 pixels, millions of colors, AAC audio at 44100Hz and 29.97 frames per second. The data rate is 5Mbps. File sizes are on the order of 600-900 MB. (Other formats may be added later.) Free QuickTime players for Macintosh and Window computers may be located using a Google search on QuickTime. The DVD was produced by J. Robert Cooke.|
|Appears in Collections:||Hydrologic Discovery - Oral Presentations (Videos)|
Items in eCommons are protected by copyright, with all rights reserved, unless otherwise indicated.