This paper presents an overview of how the Illinois State Geological Survey (ISGS) is using Geographic Information System (GIS) technology to generate map and database products. In this paper we summarize our experience with GIS-based map products and describe our GIS operation, the existing system configuration and map production techniques. In addition, we provide specific information about costs and other resources that are required to maintain and support the GIS map production environment.
The Illinois State Geological Survey has a long history of using computer technology to build databases in support of its research and service mission. During the 1960s and 1970s, a number of methods were developed to convert map and tabular information into digital files, including ILLIMAP (Swann et al., 1970), an automated system used to produce base maps of the Public Land Survey (township and section lines) for the state. At about that time a project was started to build a keypunch computer database of selected information from records for wells and borings drilled in Illinois. The ILLIMAP system, and the well database was begun almost 30 years ago and is still used and maintained by ISGS staff.
The establishment of the Illinois Geographic Information System (Illinois GIS) in 1983 marked the beginning of the most recent era for ISGS computer mapping applications. The Illinois GIS began as a multi-agency effort to compile information about coal resources and the impacts of coal mining in Illinois. As part of this effort, a common hardware/software solution was implemented in five state agencies to support data compilation and analysis needs. Arc/Info software was selected as the primary GIS software for the system and it continues to be used for most applications and projects. The Illinois GIS now consists of a distributed network of Unix workstations. Software and databases are shared among many divisions of the Illinois Department of Natural Resources including the ISGS, Illinois State Water Survey, Illinois Natural History Survey, and the Waste Management and Research Center, in Champaign, Office of Mines and Minerals, Illinois State Museum, in Springfield and some other units of the DNR elsewhere in the state. Development of the Illinois GIS is documented in several publications (e.g., Krumm, Erdmann, and Joselyn, 1991).
The Illinois GIS database includes information input from published maps, commercial data sets, digital data provided by the U.S. Geological Survey, geologic data from well logs on file at the ISGS, and data from many other sources. Of the many map layers or data sets that provide statewide coverage (Greene, 1990), most were digitized from maps published at scales of 1:500,000 or 1:250,000. The statewide database includes base map information (the public Land Survey grid of ILLIMAP), infrastructure, bedrock geology, soil associations, Quaternary deposits, aquifers, surface water bodies, wetlands, coal resources, structural features, and many others. In addition to these geologic and hydrologic data sets, digital map data are available for many cultural features including municipal boundaries and census information. Many gigabytes of data are maintained by the participating agencies and many Illinois statewide GIS databases (Arc/Info export files, documentation and GIF images) are available on the Internet at http://www.inhs.uiuc.edu/gis/igishome.html. The statewide databases are also available on a set of two compact disks (CDs).
Within the Illinois State Geological Survey, the current computing environment includes networked workstations and personal computers. A network of 34 SUN workstations is primarily used for GIS analysis, cartographic processing, and database management. Arc/Info is used on the Sun network, and ArcView is used on both the Sun systems and on PCs running WindowsNT to access the GIS database across the network. Five workstations from Silicon Graphics, Inc. are primarily used for surface modeling, subsurface and three-dimensional geological modeling and analysis, and for groundwater and oil reservoir modeling. Our workstation environment also incorporate VAX workstations that act as a database server and clients for the ISGS Oracle well database and for subsurface modeling and mapping. The ISGS maintains its database on nearly 60 gigabytes of on-line disk storage and on optical disks and CDs. Data input devices include a number of digitizing boards and small-format scanners. Output devices include large-format color plotters, small-format color printers, laser printers, film recorders, and a CD mastering device.
The GIS expertise at the ISGS is primarily provided by the Geospatial Analysis and Modeling Section, a group of ten full-time geologists and GIS specialists and several interns and students. The role of this section is to maintain the GIS databases, provide digital data coordination, provide GIS expertise for internal projects and external requests, provide training, develop applications, and produce maps. Some ISGS staff members in other sections (Coal, Quaternary Geology, and Groundwater) are also skilled GIS practitioners involved in a number of projects.
We are using GIS and other software to support projects that include detailed (1:24,000 scale) geologic mapping, county mapping (1:100,000 scale), and statewide mapping and screening efforts. In addition to basic geologic mapping of USGS 7.5-minute quadrangles, we are also using the GIS to map shallow aquifers, assess aquifer contamination potential, compile information on man-made and geologic hazards (i.e., underground coal mines and landslides), screen counties for geologically capable sites for municipal landfill siting, evaluate mineral resources and reserves, model land surface and bedrock surface topography, analyze land cover analyses, map the extent of floods, and compile maps of regional seismic history and potential earthquake hazards.
Many ISGS projects generate maps for general distribution and as final project deliverables. Maps are also required for presentations (e.g., poster sessions) and for other in-house needs, such as quality control review during the GIS database compilation process. Our map production approach has evolved over the years to take advantage of available technology. Initially, our map production techniques were dependent on available Arcplot routines and pen plotters. Early versions of the Arc/Info software (e.g., revs. 2.4, 3.2) provided a basic suite of cartographic plotting tools, however, pen plotters limited the ability to produce maps with solid color fill and high quality text. Although we made heavy use of the pen plotters to produce maps and graphics for poster presentations, few of these maps were published or released for general distribution.
The sophistication and quality of our map products improved markedly with the purchase of an electrostatic plotter and later releases of the Arc/Info software. The electrostatic plotter technology, and enhanced Arcplot capabilities, provided many options for map production, including solid color fill, improved text quality, an abundance of standard point symbols and line types, and the ability to combine and display vector and raster data. This combination of hardware and software provided our staff with the tools needed to create higher quality map products that could be plotted on an as-needed or on-demand basis.
The ISGS Open File map series provides staff members with a mechanism to publish and distribute computer-generated maps. This series includes of maps showing aquifers with potential for development of public water supplies in Kane County (Vaiden and Curry, 1990), near-surface geologic units for a region of southern Illinois (Greenpool and Berg, 1992), features associated with one of the major coal seams in the Illinois Basin (Treworgy and Bargh, 1993), wells and borings for the entire state (McKay and Denhart, 1993), and the thickness and lithology of geologic units in Will County (Abert et al., 1993). These and many other maps were produced using Arcplot routines and a Calcomp electrostatic plotter. Because of the cost of plotter maintenance (about $12,000/year) and supplies, these maps sold for about $20 each. This per unit cost was significantly higher than that for printed maps (typically $5/map). However, the higher cost was balanced by the ability to update maps as new information became available. In addition, maps could be printed to meet demand so that the organization was not burdened with the costs and storage requirements for a large stock of printed maps.
Although the quality of the maps was good, the electrostatic plotter presented a number of disadvantages, including the necessity of a climate-controlled room (for temperature and humidity), the special handling and disposal of the toner (classified as a toxic substance), and frequent, and sometimes lengthy, interruptions caused by mechanical failure that required the services of a factory trained technician.
After several years of use, we started to experience considerable downtime with the electrostatic plotter. In 1995 we investigated options to retool the plotter operation and decided to purchase a Hewlett-Packard 750c inkjet plotter. When compared to electrostatic plotters, the inkjet technology offers a number of advantages, particularly high overall reliability and low cost of maintenance. While there has been heavy demand on the inkjet plotter, we have had only one service call in 16 months. Other plotters now being used at the ISGS include one large-format pen plotter (HP DraftMaster) and one small-format color inkjet printer (HP PaintJet XL300) The HP 750c meets about 95% of our daily plotting demands. The HP DraftMaster is used to generate relatively simple line plots that are predominantly used to check map digitizing efforts.
Three staff members (one system administrator and two staff) provide plotter support. We estimate that their combined effort is equivalent to one half-time staff member. The duties involve plot queue management, loading ink and paper, maintaining adequate supplies, plotter accounting, and system trouble-shooting. During the last year, we have purchased approximately $6,000 worth of plotter supplies including several types of paper and ink cartridges. Maintenance for the inkjet plotter is about $400 per year. The overall plotting operation costs about $26,400 per year, including staff salaries and benefits, supplies, and maintenance.
During an average one-month time period, the inkjet plotter will generate about 260 plots. With an average plot length of 2.65 feet, monthly paper usage is about 690 linear feet, or about seven rolls of paper (100 feet per roll).
Most of the recent digital map products are plotted on demand and are available as open-file maps. Others have been printed from having four color separates made from the digital files. Although our current map production techniques involve using Arcplot, we also use CorelDraw, ImageMagick, Larson, Ghostscript, xv, and Microsoft Word. For most maps, Arcplot is used to produce the overall cartographic framework consisting of thematic maps, images, legends, text, scale bars, north arrows, and neatlines. Other software packages are used to take advantage of select capabilities or functions. For example, Coreldraw may be used to add text blocks, tables, or graphics to maps. The maps, Karst Terrains and Carbonate Bedrock of Illinois (Weibel and Panno, in press) and Coal Industry of Illinois (Damberger, Stiff, and Hines, 1997) both were produced using a combination of Arcplot and CorelDraw.
We view all of the available software as a tool chest containing many cartographic design and graphic file processing tools to improve the overall quality of map products and/or to make the map production process more efficient. For example, images can be incorporated onto maps using image conversion tools such as xv and ImageMagick. These tools, which are shareware, allow images downloaded from the Internet or from a digital camera to be converted into other image formats (e.g., tiff or others) and used with many software packages. These conversion tools can also be used to convert Arc/Info graphics files (.gra files) into images that can be displayed on the Internet or imported into a package such as CorelDraw. The graphics files can be converted to Postscript files, and then to any image format, usually GIF. The GIFs can be easily imported into CorelDraw for compilation to produce poster displays or smaller fliers or brochures.
Several maps initially compiled and released in the ISGS Open File Series were later printed because of increased demand. One example is the Shaded Relief Map of Illinois (Abert, 1996). The publication and printing process involved the creation of a "final" Arc/Info graphics file version of the map. The graphics file was then converted to a Postscript file, written to tape, and transferred to a company that created the negatives. The negatives were provided to a printing company for production. To help keep printing costs low, it was decided to create only a black and white map. The cost of the map for consumers dropped from $20.00 for the print-on-demand electrostatic plotter version to $4.25 for the printed version.
Many of our clients have indicated that paper maps remain important to their work, but other people have started to request digital data. These requests are usually from government agencies, consultants, or other companies with in-house GIS capabilities. We expect that the number of these businesses and agencies will continue to increase as the overall GIS market expands. In addition, GIS databases are being identified as one of the deliverables for some of our contracts with other agencies including the USGS and the National Forest Service.
When we provide GIS databases in Arc/Info format, part of the project deliverable will be project files that can be used with the ArcView software. Creating useful ArcView project files involves a number of cartography and database design skills. By employing efficient database design and basic cartographic principles, we believe that the ArcView project files and GIS databases will be more useful and meaningful, especially to non-technical users. The project files can contain a number of themes that all reference the same coverage yet show different interpretations of that basic information. For example, one theme can be used to display all information on a geologic map and another theme can be used to display all units ranked by their relative capability for a particular land use (e.g., relative capability for a landfill) or a concern (e.g., groundwater protection).
The Illinois State Geological Survey has been using the Arc/Info GIS software since 1983 to support a variety of projects, and many of these projects have resulted in computer-generated maps. Many maps have been released through the ISGS Open-File publication series and plotted on-demand. Our map production techniques have evolved with subsequent releases of the Arc/Info software and the availability of new plotter technology. Our current map production environment features a combination of software, including Arcplot, CorelDraw, ImageMagick, xv, and others, we use whatever capabilities of these software packages will best support the map production process. We expect that our map production techniques will continue to evolve to take advantage of new software or enhancements to existing packages. We will continue to use large format inkjet plotters to produce maps, and recently ordered another HP 750C plotter to incorporate into the in-house plotter operation. This additional plotter was purchased to make it easier to plot multiple copies of map products, and to serve as a backup to the existing plotter. We are particularly interested in new technology that will allow us to print a variety of high quality maps on-demand. Printing maps on-demand with existing inkjet plotter technology is relatively slow and more expensive than traditional printing. We will also continue to make digital data available via the Internet and on CD. For future publications, we have also discussed the possibility of providing a CD that contains GIS data, scanned graphics (e.g., cross sections, figures and other diagrams), and information from databases or spreadsheets.
Abert, C.C., R.J. Krumm, M.H. Riggs, M.M. McLean and E. D. McKay, 1993. Thickness of Quaternary Deposits, Southern Will County [map], Illinois State Geological Survey Open File Series 1993-9c (scale 1:100,000).
Abert, C.C., 1996. Shaded Relief Map of Illinois. Illinois State Geological Survey, Illinois Map 6 (scale 1:500,000).
Damberger, H.H., B.J. Stiff, and J.K. Hines, 1996. Coal Industry in Illinois [map], Illinois State Geological Survey Open File Series 1996-10 (scale 1:500,000).
Greene, A.V., 1990. Illinois Geographic Information System: An index to automated statewide databases. Illinois State Water Survey Circular 175.
Greenpool, M.R., and R.C. Berg, 1992. Paducah 1 deg x 2 deg Quadrangle, Geologic Materials at the Surface [map], Illinois State Geological Survey Open File Series 1992-11, (scale 1:250,000).
Krumm, R.J., A.L. Erdmann, and M.G. Joselyn, 1991. Illinois Geographic Information System: Applications to environmental management. Illinois State Geological Survey Environmental Geology 140.
McKay, E.D., and S. L. Denhart, 1993. Wells and Borings in Illinois [map], Illinois State Geological Survey Open File Series 1993-4 (scale 1:500,000).
Swann , D.H., P.B. DuMontelle, R.F. Mast and L.H. VanDyke, 1970. ILLIMAP-A computer-based mapping system for Illinois. Illinois State Geological Survey Circular 451.
Treworgy, C., and M.H. Bargh, 1993. Features associated with the Springfield Coal in the Illinois Basin [map], Illinois State Geological Survey Open File Series 1993-2 (scale 1:750,000).
Vaiden, R.C., and B.B. Curry, 1990. Aquifers with Potential for Development of Public Water Supplies, Prairie Aquigroup, Kane County [map]. Illinois State Geological Survey Open File Series 1990-2a (scale 1:62,500).
Weibel, C.P., and S.V. Panno (in press). Karst Terrains and Carbonate Bedrock of Illinois [map]. Illinois State Geological Survey, Illinois Map series, (scale 1:500,000).