Indiana Geological Survey
611 N. Walnut Grove
Bloomington, Indiana 47405-2208
Telephone: (812) 855-3951
Fax: (812) 855-2862
e-mail: sowderk@indiana.edu, hill2@indiana.edu, irwinp@indiana.edu
There are always unexpected problems in a Geographic Information System (GIS) project that arise and must be dealt with -- sometimes in innovative ways. But once the data have been neatly tucked away in themes and fields, rows and columns, the final problem remains of how to present them to the general user. Consideration should be paid to the end-user who may not have access to GIS software and an adequate or existing Internet connection. The method described here has provided a new format for the Indiana Geological Survey (IGS) to present, distribute, and publish its GIS data. GIS data are versatile, but expensive to create. Making this information easily accessible and widely available to a large client base fulfills an essential part of the IGS mission and is a good business practice.
In 1999, a project was undertaken by the IGS in cooperation with the Illinois State Geological Survey and Kentucky Geological Survey to convert the data from the 1994 Gas Research Institute (GRI)/Illinois Basin Consortium (IBC) publication "Gas Potential of the New Albany Shale (Devonian and Mississippian) in the Illinois Basin" into a GIS. This project, which was funded in part by GRI, is the focus of this presentation. The original GRI/IBC publication consisted of an 83-page illustrated report, bibliography, reference section, and seven large-format plates of the study area. Six of these plates were maps at a scale of 1:1,000,000, and the seventh plate was a series of stratigraphic cross sections spanning the Illinois Basin. Early in the process it was determined that the report would be scanned and converted into PDF format, and the map information (originally in AutoCAD format) would be converted via ArcCAD and ArcView into a GIS format. However, the project at this stage did not consider the abilities of all potential users of the information.
The problems of how to present the data lingered. The decision was made to include Acrobat Reader (a no-cost application) as a means of viewing the final text files and cross sections in a PDF format. ArcView users were provided with the ArcView project file to access the data. Users not familiar with ArcView were supported by providing ArcExplorer software (also a no-cost application) as a means of viewing the Environmental Systems Research, Inc. (ESRI) shape files. Views and layouts from the ArcView APR file were recreated in ArcExplorer AEP format. The creation of the AEP files presented a new set of challenges, as the database structure for several coverages did not lend itself to easily establishing ranges and color ramps in ArcExplorer. To compensate for this, fields were added to the databases to create ranges for displaying the groupings of data. This allowed for easy display and color ramping of these pre-established ranges. The appearance of the ArcExplorer layouts and the ArcView layouts was kept as similar as possible.
The cross sections from the large plate were scanned in sections, reassembled, saved in TIF format, and exported into PDF format. The TIF files were also provided for those users who have large-format plotters and would like a high-resolution plottable file. The PDF files were then hot-linked in the ArcView project file so that the appropriate cross section opens when the displayed line on the corresponding map is selected with the "lightning bolt" icon. This required additional programming in ArcView. However, the PDF is much easier to manipulate and view than the more sizeable TIF file, which was an important outcome because the cross sections were originally as much as forty inches in width.
CD-ROMs were the chosen media for distributing the information because this simplifies pricing and sales, allows for easy and fast access to the information, and avoids using web resources on a long-term basis. Additional CD-ROMs can be reproduced easily and economically; the information on this media is also secure and static.
A user-friendly interface between the data and the end-user was deemed desirable. Originally, a web browser interface was evaluated. The low cost of creating HTML files and the ability to make the interface attractive and interactive was appealing. The web browser interface, however, is not readily made compatible across different browsers and different browser versions. After researching several options, Demo Shield software was chosen. Any Windows 95, 98, NT, or 2000 platform user can access the information through Demo Shield"s interface. Navigation buttons and menu screens were created to ease the installation of ArcExplorer and Acrobat applications. Links to files also allowed for the viewing of ArcExplorer plates and metadata in HTML format. Additional buttons and screens also allowed for graceful integration of legal information such as disclaimers, copyrights, and agreements of use. The ArcView project file cannot be directly viewed using a navigation button, but a Windows explorer screen can be automatically launched, allowing the end-user to double-click on the file and launch ArcView.
Once all the data files were reviewed and received final approval from the three cooperating state surveys, the ArcView and ArcExplorer project files were opened in Microsoft WordPad and "relative-pathed" to enable opening and access on any Windows-based PC from the CD-ROM drive. All files were then copied to CD-ROM and 1,000 copies reproduced for sale. The CD-ROM will start upon insertion if the user has the Autorun option selected on his PC. The CD-ROM has a finished appearance and professional look, and provides a means of easy access to all data.
The project data on CD-ROM can be purchased from the following:
Publication Sales
Indiana Geological Survey
611 North Walnut Grove
Bloomington, Indiana 47405
Tel: (812) 855-7636
Fax: (812) 855-2862
e-mail: igsinfo@indiana.edu
Kentucky Geological Survey
228 Mining and Mineral Resource Building
University of Kentucky
Lexington, Kentucky 40506-0107
Tel: (859) 257-5500
Fax: (859) 257-1147
Information Office
Illinois State Geological Survey
615 E. Peabody
Champaign, IL 61820
Tel: (217) 244-2414
Fax: (217) 244-0802
e-mail: isgs@geoserv.isgs.uiuc.edu