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Generation of 3D Spatially Variable Anisotropy for Groundwater Flow Simulations
Author(s) -
Borghi Andrea,
Renard Philippe,
Courrioux Gabriel
Publication year - 2015
Publication title -
groundwater
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.84
H-Index - 94
eISSN - 1745-6584
pISSN - 0017-467X
DOI - 10.1111/gwat.12295
Subject(s) - hydraulic conductivity , anisotropy , streamlines, streaklines, and pathlines , isotropy , bedding , geology , tensor (intrinsic definition) , bed , sedimentary rock , flow (mathematics) , groundwater flow , matrix (chemical analysis) , rotation matrix , perpendicular , geometry , mechanics , geotechnical engineering , groundwater , soil science , materials science , physics , aquifer , mathematics , optics , paleontology , biology , horticulture , composite material , soil water
Sedimentary units generally present anisotropy in their hydraulic properties, with higher hydraulic conductivity along bedding planes, rather than perpendicular to them. This common property leads to a modeling challenge if the sedimentary structure is folded. In this paper, we show that the gradient of the geological potential used by implicit geological modeling techniques can be used to compute full hydraulic conductivity tensors varying in space according to the geological orientation. For that purpose, the gradient of the potential, a vector normal to the bedding, is used to construct a rotation matrix that allows the estimation of the 3D hydraulic conductivity tensor in a single matrix operation. A synthetic 2D cross section example is used to illustrate the method and show that flow simulations performed in such a folded environment are highly influenced by this rotating anisotropy. When using the proposed method, the streamlines follow very closely the folded formation. This is not the case with an isotropic model.