HR: 15:25h
AN: H22F-08    [PDF]
TI: 3D Geological Mapping : a Pioneering Tool for Underground Water Management
AU: Dhont, D
EM: damien.dhont@univ-pau.fr
AF: University of Pau et des Pays de l Adour, CNRS-FRE 2639 : Imagerie geophysique CURS-IPRA Avenue de l'Universite, Pau, 64000 France
AU: * Luxey, P
EM: dglfrance@nerim.net
AF: Dynamic Graphics Inc., 1015 Atlantic Avenue, Alameda, CA 94501 United States
AU: Chorowicz, J
EM: jean.chorowicz@lgs.jussieu.fr
AF: Paris 6 University, CNRS-UMR 7072: Laboratoire de Tectonique Case 129 4, place Jussieu, Paris cedex, 75252 France
AB: Modern geology needs accurate representation of underground volumes. Because 3D geological mapping was so far based on the interpretation of expensive 2D and 3D seismic surveys, it has not been much used in water exploration and exploitation. We present a pioneering way to generate accurate and efficient 3D geological maps using already existing and inexpensive data sets, in a context of fresh water management in the Beirut watershed (Lebanon). Our approach is based only on surface information coming from a published geological map, remotely sensed data, and a Digital Elevation Model (DEM). In order to generate the 3D geological map, we used a 3D geological modeler (EarthVision developed by Dynamic Graphics Inc.) that combines and extrapolates the surface information into a coherent 3D data set, to represent volumes. Once the 3D map has been calculated, graphical representations allow the user to examine it from various directions, slice it to generate cross-sections, or disassemble it to examine individual geological units. Such 3D geological map is a powerful tool to understand both the regional geological settings and the local relationships between faults, horizons and topographic surface. A major advantage of our 3D map is that it offers the possibility to attribute rock properties to each geological volume unit. In order to illustrate how ground water reserves can be quantified, we simulate the porosity of one water reservoir leading to the calculation of rock pore volume. We also calculated a cellular grid in conjunction with the porosity model that quantifies the water circulation within the reservoir. These results are of major significance when planning future wells or for any water and reserve management tasks. Any other underground resources could also be described by such a 3D geologic model. This methodology can be applied to other parts of the world, using the same kind of input geological map, complemented with field and remote sensed data when needed and available.
DE: 1829 Groundwater hydrology
DE: 8040 Remote sensing
DE: 9320 Asia
SC: Hydrology [H]
MN: 2003 Fall Meeting