Geographic Information Systems

By Richard W. Boss

Geographic Information Systems (GIS) consist of hardware and software that make it possible for spatial data (digitized maps) to be overlaid with tabular data. The most common technical definition is that it is a system for capturing, storing, checking, integrating, manipulating, analyzing, and displaying data which are spatially referenced to the earth.

Depending on the complexity and size of the files and the number of users, the hardware may be a PC or a high-end server. The software, which is available from any one of several suppliers, is an applications package that includes a graphical user interface, a database management system, and an editor.

Much of the data used in GIS has been available for many years, but it is now available in new formats, including digitized maps, machine-readable census data, and other machine readable data—including locally produced machine-readable statistics. The idea is to display a digitized map and then to add information to the map from census data and/or other machine-readable sources. For example, GIS might be used in the planning of library facilities and services by layering the various sources of information: a map of the service area; overlaid with census data showing income, race, primary language, and number of children; and on top of that data about library use.

Not only does presenting the information visually make it easier to understand, it also makes it possible to ask questions that will result in additional layers of information being added. For example, one might ask where there is the greatest concentration of young children with a primary language other than English in order to determine where to offer special programming.



Hundreds of public and academic libraries are now using GIS in their planning. Academic libraries have also been offering GIS to patrons for their research for at least a decade. Public libraries are now beginning to do so. The research applications might include overlaying clusters of illness on a digitized map showing the distribution of potential environmental hazards; overlaying income on a digital map for planning retail locations; or overlaying home values on a map of highways to determine whether proximity to a highway affects value.

Hardware:

The hardware for use in library planning can be almost any PC rated at 2.0 GHz or higher with at least 256MB of memory, although any new machine purchased for GIS should be rated at a minimum of 3.0 GHz with at least 512 MB of memory. The monitor should be a 21-inch or larger high-resolution monitor. The printer should be a photo printer capable of a resolution of at least 1,200 by 1,200. It is also desirable to add a scanner for entering information that is not already in digital form. The total cost for hardware will be at least $4,800. A server that accommodates multiple users will cost a minimum of $8,000, plus the cost of the desktop devices.

A library has the choice of providing standalone workstations or installing a server for patron use. While the hardware costs are slightly less per concurrent user when the applications software is mounted on a server, individual workstations allow a library to begin with one or two and increase the number as needed. The cost per user for software licenses tends to go down as the number of users increases. However, a server generally is not cost effective with fewer than eight concurrent users.






Software:

There are four major GIS software providers, three of which have been used by libraries:

ESRI (www.esri.com), which offers ArcInfo/ArcGIS Server. The former product operates on a desktop and the latter on a server. The company offers software, training, maps and data sets.
Autodesk (www.autodesk.com), which offers Autodesk Map3, a desktop software product, and training, but not maps or data sets.
MapInfo (www.mapinfo.com), which offers MapInfo, a desktop product, training, and a number of maps and data sets.

The fourth company, Intergraph (www.intergraph.com), offers GeoMedia to large-scale users in specific industries.

The typical base package includes a graphical user interface for downloading and viewing GIS information, including such simple interactions as magnification and measuring distances; a viewer for formulating queries and simple editing, including selection based on attributes or location, changing color and resolution, merging, labeling, and creating reports; and an editor for data manipulation and editing, including layering. Each company offers a suite of products that make it possible to perform a much wider range of functions than is available in the base package.
The operating system environment for standalone systems typically is Windows XP or Win 2000; the operating system environment for server-based systems typically is Win 2003 or UNIX.
The average price for a single copy of the software is approximately $1,700. The
price is slightly less per concurrent user when a multi-user version is purchased.


Data:

The data used in GIS often includes U.S. government data, especially that available from the U.S. Geological Service (www.usgs.gov and key in “digital geospatial data”) and the U.S. Census Bureau (www.census.gov). These two government agencies are not the only ones to offer spatial data; more than 80 percent of all government data has a spatial component.

The most widely used government source is TIGER (Topologically Integrated Geographic Encoding and Reference} from the U.S. Census Bureau. The URL is www.census.gov/geo/www/tiger/index.html. [Googling TIGER will result in reaching www.tiger.com, a commercial firm].

An excellent shortcut to data is available at http://ncl.sbs.ohio-state.edu/5_sdata.html. It includes links to the USGS, Census Bureau, NOAA, EPA, NASA, the United Nations and a number of states’ digital data.

Staffing Implications

GIS is complex. It takes the assistance of a well trained technician to maintain and one or
more librarians who are skilled in the use of the software—a skill that comes not only from training in the software, but also from regular use of the software and the data sources. There are few people in libraries that are qualified at this time; therefore, a library may need to train members of its own staff. The consensus among those who have worked with GIS is that it takes a minimum of 20 hours to learn the basics of GIS.

While that is not daunting for a library that wants to use GIS in planning, it is when service to patrons is being considered. Can the library afford to provide the training or should it merely make the facilities and data available to those patrons who have already mastered GIS? Even when expertise by patrons using GIS is assumed, anecdotal evidence suggests that requests for help are commonplace. In fact, one academic library reported that as few as five users can keep a librarian with experience in GIS busy full-time. Assistance in the use of GIS is far more time-consuming than any reference service libraries have historically provided.

If a library decides to limit its role to providing hardware, software, and data, it should be prepared for complaints. One way of ameliorating the complaints is to provide information about GIS training opportunities in the community.

Training is offered by many community colleges and universities. It is also available online. The largest online program is operated by ESRI, the dominant vendor in the GIS software market. Their course, which costs $125, begins with an overview of basic image and remote sensing science concepts. It then presents six modules:
Understanding imagery and image analysis
Accessing and displaying image data
Rectifying and “mosaicking” images
Extracting and classifying features
Image analysis
Applying the image analysis extensions

The reason for presenting the outline is to illustrate how much there is to learn.

Announcing the Availability of GIS

When announcing the availability of GIS, a library should describe what GIS is, its potential uses, and the scope of the services the library offers. If it only provides hardware, software, and data, it should make that clear—and why it cannot provide point of use assistance.



A library may want to consider purchasing the self-guided tutorial developed by the provider of the GIS software, but should make it clear that it is limited to use of the software and does not explain how to use the various data sets the library has acquired. It should also make available the guides that may be available from producers of the data sets.

Coordinating With Local Government

Many local governments, both municipal and county, have GIS programs. Public libraries should, therefore, coordinate their efforts with any that may be underway in their jurisdictions.

Sources of Information

The vast majority of the articles in the professional literature are out of date. With rare exception, articles published more than three years ago should be ignored, not only because of their age, but because the deal almost exclusively with GIS in academic institutions. The best single source is to be found at www.gis.com, however, realize that the site is sponsored by ESRI, the largest vendor in the GIS software industry.

There is an excellent GIS portal available at www.gisportal.com. It organizes more than 1,000 Web sites that deal with GIS into broad categories. One of the categories is governmental Web sites. The site also has a comprehensive list of commercial GIS product and service providers.

The University of Edinburgh’s Department of Geography and the Association of Geographic Information (UK) have created an alphabetic index of useful GIS Web sites. The URL is www.geo.ed.ac.uk/home/giswww.html. While it takes time to find sites in a particular category, it is worth consulting this site because it includes many sites not available through the aforementioned portal. [Revised May 15, 2006]