19^th International CODATA Conference
Category: Data Visualization

3D geological mapping as a new method to visualize subsurface data: a case study of the Algarve region/South Portugal

Dr. Pascal Luxey (dglfrance@nerim.net), Dynamic Graphics Limited, France
Inga Moeck (inga.moeck@gp.tu-berlin.de), Dr. Heinz Schandelmeier (schandelmeier@bg.tu-berlin.de), TU Berlin, Institut für Angewandte Geowissenschaften, Germany

The constantly increasing demand for groundwater in the Algarve region of Southern Portugal is basically due to a growing tourist oriented and agricultural infrastructure. Consequently there is the requirement of sustainable groundwater management entailing essential decisions of both scientific and political level. For this purpose the huge amount of geo-scientific data should be represented in an understandable fashion for a wide public. This may be achieved by applying systematic 3D modeling and visualization techniques that are based on high quality 2D geological maps and vertical 2D sections. We introduce a new method to generate an accurate 3D geological map based on existing data sets.

In a first step the topography and geological boundaries are digitized and transformed into a so-called scattered data using the 3D modeling software EarthVision (DGI). The geometry of the geological planes is calculated using EarthVision minimum tension gridding technique to produce 2D grids that are integrated in a 3D volume model. Calculation of this model reveals that the geological surface of the 2D map rarely corresponds to the geological surface of the 3D map because of geometric inconsistencies between topographic and geologic boundaries in the 2D map. Therefore the input dataset needs to be corrected while calculation the 3D volume model. Once a coherent 3D model is developed, the user can visualize the model from various perspectives, slice it, calculate cross sections or present isolated horizons. Furthermore, additional data can be integrated within the 3D model such as well bore data or specific horizon properties, e.g. hydrochemical parameters. Our regional 3D geological model reveals the characteristics of underground geometry, in this case of groundwater reservoir rock.

As information on precise underground geometry is increasing in demand, 3D geological models calculated as described are the answer as they can be applied to any region and problem, providing high quality geological inputs are available.