Renee Nagy, James Hester, and Chris McGarry
Illinois State Geological Survey
The Illinois State Geological Survey (ISGS) maintains a large GIS database of statewide and regional data. Coverages of aquifers, mineral resources, structural geology, well data, hydrology, infrastructure and other data maintained on-line require approximately 50 to 60 gigabytes of disk storage. The coverages are used to create base maps for more detailed geologic studies and figures in publications, as general reference tools, and for spatial analysis. In the past, the GIS user base at the ISGS consisted of a relatively small group of ArcInfo users. Recently, many other staff members have become interested in viewing and manipulating the digital databases for their work, but without having to become GIS experts. Using ArcView on PCs running Windows NT, these staff members have a menu-driven environment to access the GIS databases stored on a number of UNIX workstations. The Samba freeware program is used to redirect PC disk drives to UNIX filespaces.
Making the GIS data sets more accessible to our colleages involved introducing them to the ArcView software and instructing them in how to access the GIS databases. Based on the results of interviews with many staff members, a series of ArcView projects were developed for the coverages requested most frequently. Two training sessions were presented. The first introduced ArcView to new users and the second instructed them how to access and work with the project files. This paper summarizes the process, problems, and successes that we experienced while making the extensive GIS database more accessible to staff who are interested in incorporating GIS techniques into their projects.
The Illinois State Geological Survey (ISGS) started using GIS in 1983 as part of a multi-agency effort within the Illinois Department of Energy and Natural Resources (now the Illinois Department of Natural Resources). Since then, our use of GIS has expanded, and the technology is used to support many research and service programs. The ISGS has compiled an extensive on-line GIS database that consists of statewide geospatial data sets of aquifers, mineral resources, structural geology, well data, hydrology, landcover, infrastructure and other data. This information is used to create maps for regional and site-specific geologic studies, to produce figures for publications, for spatial analysis, and as a general reference tool.
During the last year, many ISGS staff members have shown considerable interest in incorporating desktop mapping and spatial analysis techniques into their projects. In the past, the time investment in learning GIS Software often precluded staff from taking full advantage of this emerging technology. The ArcView software (AV) provides a more user-friendly platform for these staff members, because they don't have to be GIS experts to access and use the vast data holdings. In addition, ArcView3 (AV3) provides more analysis, manipulation, and viewing capabilities than previous versions. In response to this interest, a multi-step program was designed to provide AV training and access to the GIS databases. This involved preparing a questionnaire and interviewing staff members to identify user needs, developing AV project files, configuring hardware/software, and conducting internal training sessions.
To better define user needs, a questionnaire was prepared and distributed to staff members; this was followed up with one-on-one interviews. Responses provided useful information concerning the data sets that were of interest, how the data sets and/or software were to be applied, and the type of hardware that would be used. The interviews also provided an opportunity for novice users to become more familiar with AV capabilities and the available GIS databases.
A summary of interview responses and comments allowed us to gauge interest in specific databases and applications. Data sets identified most frequently as being of potential use to staff included base map features (e.g., county boundaries, township and section lines), surface hydrology, infrastructure, well data, geologic maps, wetlands and watershed information, coal resources, oil and gas data, and larger-scale data sets, some of which have not yet been developed. Staff responses concerning the desired uses of AV to access data sets included combining or overlaying data sets, visualizing spatial components of the data, adding a geographic element to existing tabular databases, merging database files to map features, surface contouring, and performing spatial queries on the data sets.
The interview results also identified two distinct groups: staff with no experience with GIS technology, and staff with some AV experience who were primarily interested in accessing specific data sets. Based on the interview results, the decision was made to present two training sessions that addressed the needs of people in the two groups. The first training session, geared towards new users, would be an introduction to AV. A second session, for more experienced users, would focus on how to access specific data sets or project files.
The interviews also indicated a general need to upgrade or replace a number of computers. The hardware platforms being used include PCs, Macintoshes, and UNIX workstations. To address concerns about accessing data over the network (using a PC to access data stored on a UNIX system), it was suggested that PCs be upgraded to WindowsNT. Both UNIX workstations and PCs with WindowsNT were provided for the training sessions. Macintosh users were addressed on an individual basis.
Several AV project files were designed to provide all users (PC and UNIX) with a standard technique to access the GIS databases. Based on the results of the interviews, 51 geospatial databases were incorporated into six separate project files for both the UNIX and PC environment. These projects files consisted of themes showing aquifers, base maps, geology, geomorphology, oil/gas and coal resources, and geologic materials encountered to a depth of 15 meters. Development of individual project files kept the size of the files small and minimized the time required for loading.
Project files were customized to make the databases easier to understand and use. New tables of text attributes were created by relating existing numeric attributes through a series of table joins and theme definition queries to present users with feature codes that were more descriptive and easier to understand. One disadvantage to this is that the table joins delay project file loading time. It was opted to not display several attribute table items (e.g., cover#, cover-id, rpoly, lpoly, etc.), because this information is not crucial to work with most themes. The views and legends were designed to resemble printed versions of the data published as figures and/or maps. The themes were also converted into shapefiles, and the project files were modified to use the shapefile themes. This allowed users to load the project files more quickly.
Hardware and software configuration recommendations for AV users were a 486 or Pentium PC running WindowsNT with 32MB of RAM and a CD drive. Although WindowsNT has the capability to access UNIX drives using "network neighborhood", AV3 does not provide for network access, and only local drives (e.g., "a:", "b:", etc.) are recognized. Samba, a freeware package that emulates network drives as local drives, was used to access the UNIX network drives from the WindowsNT PCs. The exact location of the data sets must be used when configuring the local drives, since WindowsNT does not recognize UNIX "links." For example, most of the data sets are located in the UNIX directory "/illinois". However, the actual location of the data sets is on several disk drives, and pathnames are re-directed using links so that the data appear to be located on one drive. Each UNIX disk drive referenced in the project file must be assigned to a local PC drive ("e:" through "z:"). This configuration can be saved by the users so that these drives are automatically re-established when logging in. Only network drives managed by a UNIX workstation running Samba may be accessed.
Using X-Window emulation software on a PC was considered as a way for PC users to access the AV software on a UNIX system. This option was not selected due to the costs of multiple copies of the X-Window software. Additional CPU and I/O traffic (on the UNIX systems) would also affect the productivity of workstation users. In addition, most PC users are more familiar with the Microsoft Windows-type of interface with UNIX interfaces.
Although the UNIX workstation user base primarily consists of ArcInfo users, the utility and simplicity of AV was needed on the UNIX platform as well. For this reason, the project files were originally created using UNIX workstations and then converted to the PC platform. This conversion involves mapping the PC drives "e:" through "z:" to recognize the UNIX drives. A program was created to open the project file and then perform a find-and-replace to map the PC drive letters to the equivalent UNIX drives. Limitations of this process are that all the pathnames in the project file have to be known, and the "e:" through "z:" drive configuration needs to be consistent for all PC systems.
To accommodate staff members in field offices or others who want this information on a laptop for use in the field, a CD was pressed containing the projects files and associated shapefiles. Several project files with appropriate path names ("b:", "c:", "d:", etc.) were created so that the CD could be used on machines with various designations for the CD drive. The drawback of this method of data acquisition is the static nature of the data, because CD project files reference ArcInfo coverages that may be updated occasionally.
Two AV training sessions were presented. The first was a one-day session to introduce AV to new users, and the second was a one-half day session that focused on working with the project files. To allow hands-on training, four PCs and two UNIX workstations were provided to accommodate approximately two to three staff members per machine.
During the first session, new users were given a brief overview of the capabilities of the software and guided through an introduction of the AV environment. A certified instructor used the "Introduction to AV GIS" manuals and sample data sets so that users could work through some example exercises and become comfortable with the software. Four experienced users served as class assistants to support the new users as they worked through the exercises. An emphasis was placed on tasks that were identified in the questionnaire and interview as being important to staff, such as making maps (layouts) and adding graphics. Other areas that were emphasized included copying themes and views from one project to another, querying data sets, and modifying legends. Users were also provided with information on how to create output files and send these files to a large-format plotter or printer.
During the second session, users were informed about configuring additional drives on their PCs so that the pathnames to the coverages in the project files would be recognized. Using the WindowsNT Explorer, the Map Network Drive Option was used to assign UNIX drives to PC drives. In the Map Network Drive environment, the UNIX machine name was first specified, and then the hard drive on the machine was assigned to a PC hard drive. For example, some of the coverages referenced in the project files are located on the "/sgs26" drive located on the UNIX machine named "ripple." Using the Map Network Drive, the "v:" drive on the PC was selected and then assigned to the UNIX "/sgs26" drive. The UNIX pathname of "/sgs26" corresponds to the PC pathname of "v:\\RIPPLE\sgs26". All configurations were performed using the same procedure of selecting a local drive on the PC and then assigning it to a drive on the designated UNIX machine.
Once the drives were configured, users were introduced to the six project files. The projects consisted of base map features, geologic maps, aquifers, oil/gas and coal resources, landforms (geomorphology), and geologic material encountered to a depth of 15 meters (stack unit map). Sources of additional data were also presented including a two-volume set of CDs published by the Illinois Department of Natural Resources which contains data for individual counties, landcover information, and additional statewide GIS data sets.
An example was presented that allowed users to work through an exercise of how they might use the standard project files to select themes and create a new project file for a specific study area. In the example, users copied and pasted selected themes from the six basic projects into a new project file, added a table containing XY coordinates and elevations to a view, created a point theme from the data in the table, and then contoured the data using the spatial analyst extension.
The goal of this internal training program was to introduce AV and make GIS data sets more accessible to ISGS staff. The decision to prepare project files for the ArcInfo coverages was influenced by the need for new users to have data that they could use immediately. These standard project files are relatively easy to use and maintain. With the project files, users don't have to be concerned about the location of various geospatial data sets that are located on many UNIX disk drives. By using AV to make GIS data sets more accessible, it is hoped that more staff will be encouraged to take advantage of these vast databases. Also, by introducing AV, additonal staff may begin to use GIS techniques to develop and maintain their geologic data collections (such as the ISGS's clay mineral database). Staff will also be able to use AV to access the ISGS's Oracle well database. One drawback to the described approach is that the initial development of new project files was labor-intensive. When new users become interested in other existing data sets, new projects will need to be developed and drives configured. For each project file that is developed, a conversion must also be performed to support both the Unix and PC platforms. Another concern was that the loading time for some of the larger project files that did not use shapefiles was up to 20 minutes when using a 66 MHz, 486 PC. While providing the data on a CD as shapefiles improved the loading time dramatically, the availability of in-house PCs with CD-ROM drives is limited.
Another approach that was considered was to use X-Window emulation software. This approach would have eliminated the need to convert the Unix project files into PC project files. Another advantage is that the actual physical location of coverages residing on re-directed drives does not have to be known. This approach, however, was not pursued due to the cost of multiple X-Window emulation software packages and the effect that a large number of PC users would have had on the limited number of UNIX servers.
Currently, a new approach is being considered using the AV Internet Map Server or a spatial Data Engine (SDE) linked to our web site. This approach would eliminate the need to configure PCs. The data sets would also be more easily and widely accessible, especially to the satellite offices. One concern about this approach is the possibility of losing many of the functions normally supported in the standard version of the AV software. Consequently, users may be limited to simply downloading the data they are interested in and then working with that data locally. By using the web to distribute rather than manipulate data, multiple copies of the same data sets would be created throughout the network system. Also, maintaining the GIS web page may be more labor-intensive than our current approach. Project files might still need to be developed and incorporated into the web environment. While our current approach was successful in making the data sets more accessible, other alternatives continue to be considered and explored.
Renee Nagy
Assistant Staff Geologist
Illinois State Geological Survey
615 East Peabody Drive
Champaign, Illinois 61820
Telephone: (217) 244-7412
Fax: (217) 333-2830
Email: nagy@webb.isgs.uiuc.edu
James Hester
Assistant Staff Geologist
Illinois State Geological Survey
615 East Peabody Drive
Champaign, Illinois 61820
Telephone: (217) 244-2504
Fax: (217) 333-2830
Email: hester@ripple.isgs.uiuc.edu
Chris McGarry
Assistant Staff Geologist
Illinois State Geological Survey
615 East Peabody Drive
Champaign, Illinois 61820
Telephone: (217) 244-7413
Fax: (217) 333-2830
Email: mcgarry@bert.isgs.uiuc.edu