| GIS Moves Into the Third Dimension
Two dimensional GIS software is customized to fit a three dimensional environment for a mining project in New Mexico
By David Mason During the Cold War the nation's defense program developed, tested, and produced a great number of nuclear weapons. As a result, the question of how to dispose transuranic (heavier than uranium) waste grew into a major problem.
The Waste Isolation Pilot Plant (WIPP) near Carlsbad, N.M., is a U.S. Department of Energy facility designed to dispose transuranic waste (which mostly consists of laboratory gloves, tools, etc.) deep underground in natural salt beds. These natural salt beds were chosen because they are in stable geological areas, there is no groundwater flowing through them, they are easy to mine, and they "heal" their own fractures. All of these properties make deposits of salt stable enough to hold nuclear waste.
For more than 20 years the U.S. Department of Energy has tested many variables related to the deposits of salt in the WIPP repository. This thorough testing is required at the WIPP before any nuclear waste can be approved for storage in the repository. Testing the many variables requires thousands of instruments to be mounted throughout the WIPP repository.
The testing in the repository will monitor the effectiveness and safety of the repository's structure, as it relates to disposing of transuranic waste. Some of the variables the engineers are measuring at the WIPP are ground movement and deformation. Salt naturally "creeps" under pressure and openings in salt deposits become smaller over time. The engineers are interested in the rate of closure of the mined portions of the repository and the loads placed upon rock surfaces within these spaces.
For instance, if there is a large room in the repository that shows signs of rapid closure, the engineers might want to know what the effects will be if a similar room is mined out next to it. Some instruments measure tension or compression in the rock. If the engineers decide to place hardware such as wire mesh or bolts to support a sagging roof other instruments measure the loads placed on the hardware.
Readings from some of these instruments are measured automatically by computers on the surface. Readings from other instruments, though, must be measured by hand and then entered into a database by the engineers.
In the past data have been stored in database files, and instrument locations have been drawn on CADD (Computer Aided Design and Drafting) drawings. For years engineers have relied on visual comparisons between these drawings and database files to analyze information about the testing. If engineers wanted to study a particular portion of the repository, they first had to locate the correct set of drawings relating to that space and then determine whether the instruments shown in the drawings were active instruments at that time. They would then manually enter the data collected from the drawings into a database program and then export those data to a spreadsheet to analyze the results. This tedious process cut down on productivity due to the amount of time it took to create and analyze data and the quality control procedures required to ensure that the data gathered were correct.
More problems arose if engineers wanted to compare results from an instrument that had previously been removed from a mine space with one that was active in the same space. The engineers would first have to identify each instrument on the CADD drawings, locate the database files, and start the comparison.
Knight Piˇsold LLC's GIS Group in Denver has taken on the task of providing the engineers at the WIPP a GIS package that will provide all the benefits of conventional GIS with the three dimensional representation needed for the conditions in the almost half-mile deep underground repository. Customizing existing two dimensional GIS software to a three dimensional environment while maintaining and enhancing the powerful database tools available in GIS packages was all a part of creating the SrGIS - Spatially-Referenced Geotechnical Information System - for the WIPP. Why Three Dimensions?
Previous to the SrGIS, instruments in the WIPP were mapped in two dimensions. Experienced engineers knew where some instruments were typically placed in the repository, but the distinction between instruments mounted in the roof, walls, or floor was difficult to discern. Enabling engineers to visualize where instruments were placed was one of the main tasks for the SrGIS. Although GIS software packages such as ESRI's ArcView and ARC/INFO are very powerful tools, they are not three dimensional in nature so customization was necessary.
The repository at the WIPP lies in mostly north-south, east-west trending spaces and, for the most part, is fairly level. This being the case, it was possible to divide each space into three component dimensions: plan views in XY coordinate space, north-facing profile views in XZ coordinate space, and west-facing profile views in YZ coordinate space. Therefore, accompanying the plan views of the repository are six optional views to any space: floor and back (roof) views both seen from above, north rib (wall) and south rib views both seen from the south, and east rib and west rib views both seen from the east.
Using these directional views, the SrGIS is able to convey the three dimensional spaces in the WIPP repository visually. Because each instrument appears in only one of these directional views the SrGIS eliminates the question of the instrument's location.
Using Windows NT version of ArcView 3, a UNIX server running ARC/INFO and customized programming, the SrGIS is able to take two dimensional survey drawings, scanned images, and attribute data for spaces in the repository and convert them into GIS coverages, or layers. These coverages then become the three dimensional views and tabular databases that provide a robust GIS database. This conversion takes place as a backend process that is invisible to the user at the WIPP.
Moving to three dimensions with GIS is the only way to relate GIS tools and technology to a mine or repository like the WIPP. Using three dimensions in GIS will enhance the data gathered from the instruments throughout the repository with spatial data that is accurate visually. Beyond 3D
Taking the WIPP project into the third dimension was not to be the stopping point for the SrGIS. Enhancing the powerful database and spreadsheet tools for the WIPP engineers to make the three dimensional data useful was also an important part to the creation of the SrGIS package. Creating a new environment for using the three dimensional data in a more user friendly environment will cut down data processing time spent at the WIPP repository processing data.
Previous to the SrGIS, engineers had to take a database file, run a query, then export the results to a spreadsheet application with a previously written macro to create a chart. With the SrGIS the engineers will be able to use one inclusive package to view the three dimensions of the repository and easily process data to create useful spreadsheets and charts.
The programmers at Knight Piˇsold were able to create this new, powerful software package by using ArcView's own scripting language, Avenue, and the Rapid Application Development technology and database management tools of Delphi 2.0. Along with these programming tools the SrGIS incorporates ESRI's ArcView, ARC/INFO and Microsoft Excel with the front end running on the Microsoft NT operating system, to give the WIPP engineers a powerful GIS package.
When engineers at the WIPP repository start the SrGIS, Delphi forms guide them through the multiple software packages seamlessly. The users may wish to update spatial data about the repository using ARC/INFO on the UNIX server, but they will never actually see the UNIX interface.
These same engineers may wish to create a chart showing all the data retrieved in the past year from a particular instrument. Using ArcView to select the instrument in a three dimensional view users are taken through a point and click environment to create a chart that is automatically brought to view in Excel.
These powerful tools would be meaningless to the WIPP engineers if such a user friendly environment were not present. The time saved processing the data gathered in the repository increases the productivity and knowledge gained at the WIPP repository. Moving Forward
The needs of the mining industry pose several problems in the creation of useful GIS software. Underground mining, in particular, precludes the type of data that can be gathered by remote sensing. This along with the surveying challenges posed within the underground mine make three dimensional GIS a good answer to managing underground mine spatial and tabular data.
The ease of use and three dimensional graphical environments found in the SrGIS is the path GIS manufacturers will need to follow to enter the mining industry with a permanent future. GIS has already proven itself as the future for spatial and database interpretation but the move to representing three dimensions will catapult its prevalence throughout all Earth observation and geographical sciences.
Taking the process one step further will be the implementation of a "virtual reality" GIS. Within such a GIS program underground mining spaces may be represented to the users exactly as they are viewed underground. Virtual reality will certainly increase the comprehension of an underground mine, and the data collected from it, by those who have never even stepped inside the mine. For situations such as the WIPP repository, virtual reality GIS can increase the accuracy of data source locations in the computer representations and in the engineer's perception. For situations such as partially, or completely, robotized mines, virtual reality can provide the feedback to human operators not otherwise possible.
Knight Piˇsold LLC's GIS Group has taken the first step toward three dimensional GIS with the SrGIS and will continue to build upon the technology until the three dimensions can be viewed as virtual spaces. Because of these advances the Waste Isolation Pilot Plant will be on the forefront of this technology. About the Author:
David Mason is a technical writer under contract at Knight Piˇsold in Denver. He is currently working on user documentation and interface design for the SrGIS program. He may be reached at 303-629-8788. Back |
