title: Generation of 3D Spatially Variable Anisotropy for Groundwater Flow Simulations.
abstract: 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.
authors: Currently at GoCAD Research Group, Laboratoire GeoRessources, 2 Rue du Doyen Marcel Roubault TSA 70605, FR-54518 Vandoeuvre-Lès-Nancy, France.
authors: Andrea
authors: A
authors: Borghi
authors: Center For Hydrogeology and Geothermics (CHYN), University of Neuchâtel, 11 Rue Emile Argand, CH-2000 Neuchâtel, Switzerland.
authors: Philippe
authors: P
authors: Renard
authors: BRGM, Centre scientifique et technique, 3 avenue Claude-Guillemin, BP 36009, FR-45060 Orléans Cedex 2, France.
authors: Gabriel
authors: G
authors: Courrioux
mesh_terms: D016880:Anisotropy; D019015:Geologic Sediments; D060587:Groundwater; D008962:Models, Theoretical; D014872:Water Movements