Gocad Workflows for Expert System Decision Making.

John McGaughey and Gervais Perron and Sharon Parsons and Tim Chalke. ( 2009 )
in: Proc. 29th Gocad Meeting, Nancy

Abstract

We present two examples of Gocad workflows that interrogate 3D earth models to assist critical geoscience business decision making. In both cases the general principle is to combine multiple model properties to determine spatial locations with desired statistical characteristics. The objective is to find (x, y, z) locations, otherwise difficult to discern, where certain special combinations of conditions exist. Targeting Workflow presents optimum targets to an explorationist seeking discovery. It takes as input multiple pre-computed properties and proximity relationships interpolated on a 3D grid (either voxet or sgrid) and outputs a classified and ranked list of targets. Typical input properties are lithology, formation, physical and geochemical rock properties, proximity relationships of structural and topological model objects, proximity to existing boreholes, and presence, proximity, and classification of geophysical anomalies. Geohazmap Workflow evaluates and monitors areas of potential geotechnical hazard. It is intended for use in underground or open pit mines as well as engineered rock structures for civil applications, such as tunnels and slopes. It takes as input a multitude of earth model objects such as rock quality models, stress, joints, faults, and excavation geometry. It also provides real-time monitoring of observations such as microseismic data, ground deformation, radar, and laser sighting. As with Targeting Workflow, it outputs a classified list of spatial locations, although in this case to be interpreted as zones of potential ground failure rather than as exploration targets. Geohazmap Workflow uses Gocad surfaces, rather than 3D grids, for supporting and computing the output properties, because geotechnical hazard is a natural property of surfaces rather than volumes. In both cases the workflows guide the user through the complex sequence of steps required for input data designation, characterization, quality control, normalization, and possible re-classification. Proven tools from the field of 2D-GIS spatial expert systems are deployed in 3D on either grids (Targeting Workflow) or surfaces (Geohazmap Workflow). These include the knowledge-driven techniques of Boolean Logic, Index Overlay, Multi-Class Index Overlay, and Fuzzy Logic, as well as the data-driven techniques of Weights-of-Evidence. Future work is contemplated to include other techniques such as Logistic Regression and possibly Neural Networks.

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BibTeX Reference

@inproceedings{MacGaugheyGM2009,
 abstract = { We present two examples of Gocad workflows that interrogate 3D earth models to assist critical geoscience business decision making. In both cases the general principle is to combine multiple model properties to determine spatial locations with desired statistical characteristics. The objective is to find (x, y, z) locations, otherwise difficult to discern, where certain special combinations of conditions exist. Targeting Workflow presents optimum targets to an explorationist seeking discovery. It takes as input multiple pre-computed properties and proximity relationships interpolated on a 3D grid (either voxet or sgrid) and outputs a classified and ranked list of targets. Typical input properties are lithology, formation, physical and geochemical rock properties, proximity relationships of structural and topological model objects, proximity to existing boreholes, and presence, proximity, and classification of geophysical anomalies. Geohazmap Workflow evaluates and monitors areas of potential geotechnical hazard. It is intended for use in underground or open pit mines as well as engineered rock structures for civil applications, such as tunnels and slopes. It takes as input a multitude of earth model objects such as rock quality models, stress, joints, faults, and excavation geometry. It also provides real-time monitoring of observations such as microseismic data, ground deformation, radar, and laser sighting. As with Targeting Workflow, it outputs a classified list of spatial locations, although in this case to be interpreted as zones of potential ground failure rather than as exploration targets. Geohazmap Workflow uses Gocad surfaces, rather than 3D grids, for supporting and computing the output properties, because geotechnical hazard is a natural property of surfaces rather than volumes. In both cases the workflows guide the user through the complex sequence of steps required for input data designation, characterization, quality control, normalization, and possible re-classification. Proven tools from the field of 2D-GIS spatial expert systems are deployed in 3D on either grids (Targeting Workflow) or surfaces (Geohazmap Workflow). These include the knowledge-driven techniques of Boolean Logic, Index Overlay, Multi-Class Index Overlay, and Fuzzy Logic, as well as the data-driven techniques of Weights-of-Evidence. Future work is contemplated to include other techniques such as Logistic Regression and possibly Neural Networks. },
 author = { McGaughey, John AND Perron, Gervais AND Parsons, Sharon AND Chalke, Tim },
 booktitle = { Proc. 29th Gocad Meeting, Nancy },
 title = { Gocad Workflows for Expert System Decision Making. },
 year = { 2009 }
}