Geological Visualisation - the intelligent picture?

at BGS Keyworth

Recently there has been a rapid advance in the capability of computer hardware and software to process large geological data sets, enabling the creation of complex models using aesthetic images.The aim of this meeting is discuss the merits of presenting geological interpretations using state of the art mapping and visualisation systems. Have these tools improved geological interpretation and subsequent communication of modelling ideas to specialists and non-specialists? Will the development of virtual reality and simulation systems using more powerful processing resolve these issues?

• Programme
• Registration
• Publication
• Location
• Accommodation

Programme

09.00 Registration, coffee and computer displays

10.00 Introduction, welcome and keynote theme

10.10 The application of geological modelling systems in radioactive waste disposal projects

Mathew J. White (QuantiSci, Melton Mowbray, Leicestershire)

Geological modelling systems are families of software programmes which allow the construction of integrated 3D models of site investigation data, including subsurface geology, surface geography and engineering features. These systems concentrate upon the development of static models which aim to produce a descriptive representation of the surface and subsurface and thereby provide the user with the ability to increase his understanding of the area of interest and to predict away from data locations. The paper discusses the application of Earth Vision to the disposal of radioactive waste. EarthVision is a commercially available computer system which has been applied to several sites during radioactive waste disposal projects.

Six principal applications of EarthVision are reviewed in this paper. These are quantitative discrimination between areas during site selection, advancement of geological understanding during investigations, provision of data to performance assessment models, visualisation of the results of performance assessment models, communication of technical information to stakeholders and data management.

The application of EarthVision to site selection, performance assessment and research and development are illustrated using examples taken from the Spanish radioactive waste disposal programme. The application of EarthVision has focused on the construction and analysis of models of igneous and sedimentary environments. These models include complex geological relationships not previously included in 3D computer models applied to radioactive waste projects, including thrust faults which terminate within the modelled region, metamorphic aureoles and hydrochemical models related to sub-surface structure and hydrogeology.

10.40 Computer modelling of Sellafield geology

Titus Murray (U.K. Nirex Ltd)

In its investigations of the Sellafield area, Nirex has developed a series of computer-based models of the geology at a potential location for an underground repository for radioactive waste. These geological models are displayed in real time as 3D visualisations directly derived from the underlying data sets. The modelling systems are flexible enough to deal with future expansion to incorporate major amounts of additional data. At present, data includes information from surface geological and seismic surveys, core and wireline logging from vertical, deviated and inclined boreholes and seismic tomograms between boreholes. The most detailed model of dimensions 2km x 2km x 1.5km depth covers the Potential Repository Zone and displays the geological structure and all the recognised geological units to member level. Both these models have provided input to design of underground excavations and modelling and interpretation of groundwater flow. More regional models of dimensions of tens of kilometres are under development for use in regional groundwater flow modelling.

11.10 Simulation and visualisation of flow and transport in fractured rocks

Lingli Wei (Golder Associates UK Ltd) and W. Hatton (KRJA Systems Ltd)

Groundwater flow and solute transport in fractured crystalline rocks are dominated by small discrete flowing fractures, as well as large geological structures such as faults. This paper presents an integrated approach for discontinuity analysis, and simulating and visualising flow and transport through both small and large scale features, based on the discrete fracture network concepts. The discontinuity data analysis and simulation of flow and transport are accomplished by using the software package FracMan, linked to advanced visualisation using the VULCAN package.

A generic site study for a deep geological disposal of radioactive waste in fractured crystalline host rock is conducted to demonstrate the proposed approach.

11.40 Site-ASSESS: A tool for visualising and interpreting a priory information for the assessment of contaminated sites

C.C. Ferguson (CRBE, Nottingham Trent University), P. Tucker (University of Paisley), A. Abbachi and C.P. Nathanail (CRBE, Nottingham Trent University)

The investigation of potentially contaminated sites requires the integration of diverse spatial information in order to develop a conceptual model of the ground conditions and history of previous site use. This information is used to develop spatial sampling strategies.

An integrated visualisation system called Site-ASSESS has been developed to help site assessors compile and display a priory information collected during desk study and walkover surveys of potentially contaminated sites. A digital image of the site is used to provide a framework within which indicators of potential contamination (e.g. leaking tanks, waste storage areas or stressed vegetation) are mapped. A statistical approach based on Bayesian theory is used to design sampling strategies (i.e., number of samples and sample locations) to locate hotspots of a given size with prescribed degree of confidence. The total number of sample locations is then computed, locations are optimised to minimise overlapping areas of influence and distributed over the site to reflect the prior information. The user is presented with a map of the site showing the recommended sampling locations.

The performance of the system in a number of case histories has shown that it facilitates consistency and rigour in designing sampling strategies and assists in reporting the basis on which the investigation was carried out.

12.10 Knowledge-based geological visualisation using AVS

Iain M. Brown (GIS & Hypermedia Research Group, University of Glamorgan)

The Application Visualisation System (AVS) is being used as part of a research project developing a 3-D GIS and visualisation tool for situations where available data are limited or uncertain (e.g. the reconnaissance stage). The principle is to assist the geologist in considering different interpretations of the data by utilising computer-based graphics and geometry building techniques to produce working models. Possible ambiguities of interpretation are then resolved by the addition of geological knowledge.

Initially, borehole logs are linked by a method of automated correlation from which are derived a series of x,y,z horizon co-ordinates and a variety of interpolation algorithms can then be utilised to produce a realistic impression of the lithology. Once the initial model has been constructed, data can be displayed in conventional 2-D or 3-D formats, or alternatively, more complex manipulations can be made such as volume visualisation.

12.40 Data Management in the proposed RCF

H. Lee (United Kingdom Nirex Ltd, Curie Avenue, Harwell, Didcot, Oxfordshire OX11 0RH)

As part of its investigations into the suitability of a site near Sellafield to host a deep waste repository, Nirex has applied for planning permission to construct an underground Rock Characterisation Facility (RCF). Nirex is awaiting the outcome of a Public Inquiry into that application.

This presentation will describe the current concept for management of the data that are expected to arise from the RCF. Vulcan (a UNIX-based 3D geological package) will be used for visualisation, checking, and handling of most of the scientific data. Data from monitoring the construction activities, such as grouting, probe drilling, blasting, and shaft lining will also be handled using Vulcan. Vulcan will be linked to a relational database using Oracle.

Because the data will be generated in an environment of integrated and simultaneous activities, it is important that the data are integrated in time and space so that their validity, and their meaning can be readily assessed. The strategy for developing an efficient data model, for links with other databases, for operation of the database, and for managing changes in database requirements as the RCF proceeds, will be described.

13.10 Buffet lunch and computer displays

14.00 Introduction

14.05 Three-Dimensional modelling and visualisation in structural geology: New techniques for the restoration and balancing of volumes

S.S. Egan, T.S. Buddin, S.J. Kane & G.D. Williams (Basin Dynamics Group, Department of Earth Sciences, Keele University, Staffs.)

The 2D restoration of cross-sections is a validation technique commonly used in structural geology. It assumes, however, that deformation occurs in the plane of section, which is not always the case in real geological examples. The main aim of this project is to develop new methods for the restoration of structural volumes, using a combination of numerical/computer modelling and visualisation techniques. A SUN SPARC station - GeoQuest Charisma software system is being used to interpret 3D seismic data from different tectonic regimes. Fault and horizon surfaces are then exported to a SiliconGraphics workstation-Midland Valley 3D Move software system which enables pseudo-3D restoration and the visualisation of structures in 3D. These systems have been used to identify the inadequacies of 2D restoration methods and to develop new methodologies for 3D restoration. Flexural flattening is a geometric restoration technique that has been developed which superimposes a mesh of triangles upon a hanging wall surface. The triangles are then rotated to a horizontal plane and fitted back together with no change in the area of the surface. A second method uses fluid flow theory to simulate hanging wall deformation due to movement over a fault surface. Both methods will be evaluated in the context of the restoration of real geological examples.

14.35 If a picture paints a thousand words....

Paul Nathanail (CRBE, Nottingham Trent University)

Ground conditions always influence and sometimes dictate the degree of risk posed by contamination to human health, eco systems and water resources. The new Environment Act 1995 provides an explicit risk management framework for dealing with contaminated land. Soil and groundwater contamination costs UK plc billions of pounds. Great opportunities exist for sustainable development by re-using previously industrialised, contaminated sites.

Inputs to risk assessment and remediation selection include a model of site conditions based on site investigation. The construction of such a model is hampered by the three dimensional nature of the problem and the ubiquitous inadequacy of site investigation data. The better the model of ground conditions, the more likely it is that a reliable risk assessment will be carried out and an appropriate and cost-effective remediation strategy selected.

Although three dimensional modelling and visualisation is routinely used in natural resource exploitation, a dearth of tools tailored to soils and industrial contaminants is preventing the take-up of 3d modelling of ground conditions for environmental risk assessment. There are great potential savings for UK plc in terms of less misdirected site investigation and more cost effective remediation. These savings can make the difference between a project being funded or not, a site being purchased, or indeed the UK being selected for inward investment.

15.05 Visualising mineral operations using computer graphics and virtual reality

D. Schofield, B. Denby and D. McClarnon (AIMS Research Unit, Dept. of Mineral Resources Engineering, University of Nottingham)

Mining Companies are increasingly turning to computer graphics to visualise complex minerals operations from a variety of different viewpoints. Advances in computing power, and a reduction in the price of computing hardware has allowed minerals companies to use more advanced computer graphics technologies and Virtual Reality (VR) solutions. In the past decade a large amount of new environmental legislation has appeared forcing opencast mining companies to plan each new site with special attention to environmental detail. Using a mixture of computer animations, still photography, video and sound editing facilities planners gain a powerful visualisation tool which helps to sway public opinion in planning enquiries.

Mine planners often use complex simulations to study potential production, operational and safety problems for a new mine layout. It is possible to use interactive computer graphics simulations to analyse these scenarios and identify potential problems in any proposed mine design.

The AIMS Research Unit at the University of Nottingham has developed a number of computer graphics and VR tools which have been successfully used in a range of mineral industry applications. This paper intends to discuss the applications of computer graphics solutions to minerals companies and demonstrate their use in a number of practical mining scenarios.

15.35 Tea and computer displays

16.00 Design of a 3-D model for mine planning in a geologically complex ore body

G. Norton et al. (Minerals Group, British Geological Survey)

VULCAN, a 3D geological and mine planning software system, has been used to create a 3D visualisation of a structurally complex orebody and current underground mine design. Predicted extensions to the orebody have been modelled using geological and borehole data to give an estimate of potential reserves, and investigate the optimum solutions for future mine development. Implementation of the techniques developed in this project has enhanced geological understanding of polyphase deformation and improved the daily mine planning operations.

16.30 Pitfalls of 3-D visualisation in the context of complex geological modelling

A.D. Kittridge (Dynamic Graphics)

3-D modelling and visualisation has increased our ability to investigate and communicate patterns of complex geology but the process is not without shortcomings and pitfalls. A common understanding of a 3-D product is needed but no commonly agreed definition has been accepted. Three dimensions, implies a continuing distribution throughout the entire X,Y,Z range of interest and only when this condition is satisfied is there true 3-dimensional portrayal.

Images on the workstation screen command unwarranted credibility. Even a fully honest and open investigator can use them to mask as much or more than they convey. More than a "pretty picture" is needed, it must be used to create output that is both valid and useful. This means contour maps, cross sections volumetric calculations, etc. Visualisation is not and should never be the goal or an end in itself.

17.00 Discussion and concluding remarks

17.10 Wine reception and computer system displays

18.00 Close of meeting

Extensive demonstration and exhibition space will be available for technical and commercial displays. Please contact Bill Hatton if you would like to make a reservation.

Registration

The fee for commercial displays and computing stands will be £100.

Please contact any of the following convenors if you wish to register or book a display area.

Select the following link to generate a hard-copy of the registration form.

Convenors

JRA Giles
British Geological Survey, Kingsley Dunham Centre, Keyworth, Notts, NG12 5GG
Tel: 0115 936 3100
Fax: 0115 936 3200
E-mail: J.Giles@bgs.ac.uk

MJ McCullagh
Department of Geography, University of Nottingham, University Park, Nottingham, NG7 2RD
Tel: 0115 951 5447
Fax: 0115 951 5249
E-mail: lgzmjm@vax.nott.ac.uk

Publication

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Electronic Journals Ltd.

Venue

Location

The British Geological Survey in Keyworth is located to the South of Nottingham, close to the A52 Nottingham Ring Road.

By ROAD

KEYWORTH

BGS is located along Nicker Hill, which is on the north eastern edge of Keyworth close to the A606 Nottingham to Melton Mowbray road.

By RAIL

Main line rail stations at Loughborough and Nottingham.

By AIR

East Midlands Airport is located near Castle Donnington 8 - 10 miles south west of Keyworth.

Accommodation

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