For modelling of mechanical properties of structures, finite element analysis has become the conventional numerical tool. The object to be modelled - be it a bridge, a building, or an unstable hillside, is discretized by defining a series of points which are linked by a network of lines. These lines usually form a triangular (in the two-dimensional case) or tetrahedral (three dimensional) net. Mechanical (and other) properties are assigned to the links - compressive and tensile strengths, for example - and the behaviour of the structure under applied stresses is determined by a series of computations, using simple Newtonian physics, around each node.

Although this method is very powerful in modelling the behaviour of homogeneous bodies, and has found application in geotechnical engineering, it does not lend itself to modelling local variations in bulk properties, as the discretization into point nodes and the linear connections between nodes is unsuitable for representation of volume-related properties.

Although finite difference models share many features with finite element models - including many similarities in the numerical solutions - they have a fundamentally different structure. Normally space is discretized using grids or blocks. This allows volumetric properties to be modelled properly. Finite difference models have been used not only for mechanical modelling, but also - more importantly in geology, for modelling of fluid flows within permeable media.

It should be noted that, as in finite element modelling forces are computed at each node, so in finite difference modelling mass transfer (or forces, or any other properties) are computed across block boundaries (edges in 2D or faces in 3D). It is therefore essential to use a model structure which allows efficient storage and handling of adjacency information. For this reason, simple block models are used rather than the more complex partial- or sub-block models used to represent detail in static geological modelling. In

order to look in detail at a particular region, therefore, it is quite common to use grid spacings which vary over entire rows or columns rather than have the added complication of handling adjacency data for sub-blocks.

In finite difference modelling packages used in geology, such as ITASCA's FLAC, it is possible to model deformation of the blocks by storing the actual spatial coordinates separately from the predefined topological grid structure. This allows the development of a very powerful model which can simultaneously represent deformation (in non-homogeneous geology) and flow of fluids through the modelled region. Nevertheless there remain problems. For example, the deformations possible are necessarily continuous - the grid topology cannot be broken - and so faulting cannot easily be included. It is possible only to include pre-existing faults in the model setup.

A radically new approach to geological modelling has been made possible in recent years by the development of particle flow codes (PFCs). In this type of model, discretization takes the form of a large number of  particles of assumed spherical form. These particles can if desired be envisaged as space-filling - even though real spheres must leave some spaces however closely packed they might be. The model particles are deemed to interact with each other depending on their separation distance and a set of definable physical properties and rules. To that extent they may seem to be similar to finite element nodes. However, PFCs allow particles to move relative to one another, and the sets of nearest neighbours will change as they move so that the net of links between them must be defined dynamically. The size of a particle has no relationship with the size of real atoms or molecules but can be defined simply as a computationally convenient and geologically meaningful size, in the same way as a block in a conventional orebody modelling system.

The flexibility of the PFC model means that it can be used to model discontinuities as well as continuous phenomena - and it has been used, for example, to simulate crack propagation in solids under stress. It is possible, because of the freedom to define interactions between particles, also to model chemical behaviors such as metasomatism or weathering.

PFCs are currently being used in geomechanical and geodynamic modelling by a number of groups. Possibly the most experienced of these is a team led by Dr Alison Ord at the CSIRO Geomechanics Laboratory at Nedlands, Western Australia, where particle flow codes have been in use since 1996. The method is being developed by CSIRO as a tool in large-scale geodynamic modelling for predictive mineral discovery.

However, there seems to be a clear opportunity for the application of this most powerful new technology to revolutionize the modelling of ore deposits and to allow the integration of the conventional grade model with rock mechanics and hydrogeological models.

Stephen Henley, Resources Computing International Ltd. 185 Starkholmes Road, Matlock, Derbyshire DE4 5JA, UK tel:+44(0)1629 581454 fax:+44(07092 145875. e-mail: steve@silicondale.co.uk Web: www.SiliconDale.com  www.G-EXEC.com 

 Some software companies rent or lease the use of their software rather than selling it. The rental option is especially attractive to a small company that needs a high priced software. Also, with a rental, the latest version and technology is always available. Rental is also an option if a company wants to try a software product for more than a brief time without making a major commitment.

 Geosoft

 One company offering on-line subscription access to their software is Geosoft. A variety of mapping, seismic analysis, and image processing software is offered on a subscription basis. A subscription includes full use of a selected software application for one year as well as access to technical support by e-mail.At Geosoft, one-year subscriptions are available for the following software applications:  ...

 iPOGO 

 Interactive Point Oriented GeOmetry is a suite of programs and utilities for calculating property boundaries, subdivisions, roads, railroads and construction stakeout. It supports users from experts to novice. ...

C&G Survey for Windows interfaces to more than 25 different data collectors, including CG-FieldPlus. Conversion requirements are built in to the software. Data can be entered manually or from a spreadsheet in a fieldbook-like format. Adjustment options include Least Squares, Compass Rule, Crandal Rule or Transit Rule adjustment. A Star*Net ready file can be created directly from the raw data file. All calculations are double precision numbers, carried to 16 decimal places. ...

Hydrology Software
Waterloo Hydrogeologic, Inc.

 Waterloo Hydrogeologic, Inc. develops software applications to meet the advancing technology requirements of groundwater and environmental professionals around the world.  Software solutions are provided for:

... FEFLOW groundwater modeling software package combines powerful graphical features with sophisticated analysis tools and robust numerical algorithms  ...

 FLOWPATH II for Windows 95/98/NT

 This 2-D groundwater flow model includes contaminant transport. The latest version of FLOWPATH has been radically improved with many new features and enhanced graphical display to give you more power, flexibility and control. ...

 Century Systems software products have streamlined the operations of many mining and exploration operations world wide. Applications have been developed to increase productivity in field exploration and at the mine site. These mining and exploration applications, work seamlessly together and with other leading applications and tools that use borehole and map data for analysis and reporting.

DHLogger™-  This program is provided for logging borehole data and can be adapted for engineering, mine geology, environmental and petroleum applications. It allows for quick and accurate data collection directly at the worksite which results in productivity gains, time-savings, error reduction and improved analysis capabilities ...

 Borehole Manager™  -The Borehole Manager™ ensures all of your valuable data is stored centrally and securely in one place. With logon security, only authorized personnel can make changes to the data. Business Units allow for varied groups to use the same database securely. ...

 MineMapper™- This program captures all mapping data including face, back, walls, bench, etc. It is a drawing tool that spatially captures all geology, mineralization, structure and assay data. Using portable Windows 95/98/NT pen-based computers, it can be used right at the working face, back, walls or open pit. Geology, structure, ore and samples can then be drawn in and their attributes assigned. The system calculates areas with customizable formulas and weighted averages and other user-defined information is calculated instantly. Results can be used immediately, maps can be printed, and information can be brought directly into your mine modeling software. ...

 Lab Module™

 The Lab Module™ streamlines integration with an internal or external. The lab enters data directly into the system electronically and there is no additional typing is required to get the information into the central database. The Lab Module controls it all. The Lab Module allows the transfer of data to/from analytical labs via local area networks or Email. ...

 Borehole Path™

 The Borehole Path™ will give an estimate for drilling targets. It transfers data from any text file or ODBC datasource. This is a data transfer and conversion tool for easy, efficient movement of information between different databases and/or files. The program provides the ability to copy or convert data from one source to another.

 Palm Logger™

The Palm Logger™ is for collecting basic drill hole data from a Palm Pilot® and hot-syncing to DHLogger.

Century Suite™ includes DHLogger, MineMapper, Borehole Manager, Lab Module, Borehole Path and DataMapper. ...

 Geosoft is a software and services company that serves the international earth science community. The company develops solutions for earth sciences, including many advanced technologies for storing, manipulating and visualizing large-volume spatial data. Geosoft solutions are based on Oasis montaj™, a powerful technology for working with spatial data. Solutions are individually designed.

Mineral exploration software applications

Oil and gas exploration applications 

Environmental Applications include the following:

Earth Science Mapping and Interpretation - provides Earth Scientists a variety of cost-effective tools for mapping, visualizing, integrating, and interpreting spatial data and information from multi-disciplinary sources.

Earth Science Geophysics - enables Earth Scientists to process and map geophysical data for environmental and other uses.

UXO detection applications ...

This software is a development environment that allows you to understand and visualize what your data means. Applications can be customized so you can import, manipulate and analyze your data. Included is a sophisticated set of analysis routines, based on the IMSL Libraries.The software is suitable for data analysis, visualization, test and measurement, mathematics and statistics, research and development. Rapid data analysis and visualization are combined with flexibility and power. ... 

Stat/Transfer is a program that moves data between worksheets, databases, and statistical packages. It handles missing data, value and variable labels and all of the other details that are necessary to move as much information as is possible from one file format to another. The software provides both an easy-to-use menu interface and a powerful batch facility. A simple table from Excel can be moved to SAS or megabytes of survey data can be moved between statistical packages....

This is a technical graphing package for scientists, engineers and business professionals. It can create publication-quality graphs quickly and easily. Graph types that can be created include: line graphs, symbol graphs, step plot graphs, bubble plot graphs, bar charts, floating bar charts, function plots, hi-low-close graphs, polar graphs, rose diagrams, pie charts, histograms, and ternary diagrams.  ...

The Millennia-DX Monitoring System from Rel-Tek is a renovated and enhanced version of the already powerful and easy to use version of the EZ-Trol/DX TM real time monitoring and control software. The company provides complete systems of monitoring equipment, computer, and software integrated into a package. The systems include safe sensors and barriers along with advanced data acquisition telemetry and computer logging. ...

Gary Clifton and Jeff Campbell, are the owners of Clifton-Campbell Imaging Inc., a provider of Landsat imagery to the mining and oil industries. They have over 400 full 7-band unprocessed scenes in stock available for overnight delivery. Most are cloud free and geocoded. The website offers tremendous discounts on regional coverages in North and South America. Imagery is supplied on CDROM or high density DAT tape. For more information contact Clifton-Campbell Imaging Inc. P.O. Box 470, Coleville, CA 96107. E-mail: info@tmarchive.com.  Web: www.tmarchive.com 

RADARSAT International has been officially approved as a U.S. Geological Survey business partner. RSI can commercially distribute North American and International data from the LANDSAT 7 satellite archived at the Eros Data Center. RSI processes the image data at headquarters, providing very fast response to orders. Other LANDSAT 7 information services are also available including thematic land classification, geological interpretation, forest inventory and agricultural analysis. Their toll-free number in North America is 888-780-6444. Web: www.rsi.ca. 

NASA is distributing a free software tool (misr_view) for visualization of MISR (Multi-angle Imaging SpectroRadiometer) and AirMISR data files. This is an IDL-based and graphical user interface display and analysis tool for use with many types of MISR data. The tools include simultaneous display of several data planes of satellite data through color assignment, contrast enhancement, data value query, image rotation, creation of stereo anaglyphs, zooming, and linked analysis and view windows. It is available for download free of charge from Jet Propulsion Laboratory upon completion of a license agreement. More information is available on the web at: http://osa.jpl.nasa.gov/MISR_SW_LICENSES/license.visualization.  

MISR is part of NASA’s Terra spacecraft, launched into sun-synchronous polar orbit on December 18, 1999. MISR measurements are designed to improve our understanding of the Earth’s environment and climate. Viewing the sunlit Earth simultaneously at nine widely spaced angles, MISR provides radiometrically and geometrically calibrated images in four spectral bands at every angle. New algorithms for the retrieval of atmospheric aerosol, cloud, and surface geophysical properties have been implemented to capitalize on this unique observational capability. For more information visit the NASA Web site at: http://eos.nasa.gov. 

The TNTmips Project Workbook guides you step by step in learning geospatial technology by doing a real-world model project from beginning to end. The 180-page workbook includes over 20 color illustrations, other illustrations, and an extensive project-data CD with input data and the author’s "answer" data. The workbook is based on over 10 years experience with TNTmips while doing geospatial research and teaching remote sensing, image processing, and geospatial analysis for small groups, workshops, and university classes. Some of the topics include visualize geospatial data as information or imagery, extract information from multi-spectral image data for quantitative land-cover mapping, georeference imagery or geospatial data in 9 different ways, resample georeferenced rasters to remove distortions, correct Landsat image brightness data for terrain slope and aspect effects, and much more. The price is $45 with a Data CD plus an additional $5 for MicroImages’ TNTlite CD (software). For more information contact Paris & Associates, Inc., 1172 S. Main St., #255, Salinas CA 93901. Phone: 831-769-9840. E-mail: paris@redshift.com. 

A new version of the Understanding Contouring book written by Betty Gibbs and Steve Krajewski is available. The book is a collection of the essence of computer algorithms and hand contouring methods. It includes a poster showing over 60 different contour maps generated by computer from the same data set. The poster very graphically illustrates the variability of different contouring algorithms and constraints. For more information, contact Gibbs Associates, P.O. Box 706, Boulder, CO 80306. 303-444-6032. E-mail: gibbsb@wwdb.org.  Web: www.miningsoftware.com.