GIS Central

A common warehouse for geographic data transforms GIS in North Dakota from an esoteric application to a widely accessible business tool.

by / June 27, 2003 0
Rod Bassler knows all too well what it's like to stand between people and their data. As a GIS analyst and cartographer at several public agencies for 15 years, he has often found himself the lone expert who can extract information from a GIS.

"Mapping requests and things like that always came through me," said Bassler, GIS coordinator at the North Dakota State Water Commission. "I was the central focus point and also the choke point because you get overloaded and can't keep up with 100 people and their requests."

Even for experts, assembling GIS data can be difficult. The State Health Department and the State Game and Fish Department might need data maintained by the State Water Commission. But each agency might use a different geographic projection to represent the earth's three-dimensional features on a two-dimensional display, said Bob Nutsch, GIS coordinator for the state of North Dakota.

"When that data was shared, there could also be quite a bit of time spent converting it to a format that was useful to another agency," Nutsch explained. Also, users didn't always know if they were receiving the latest available information.

In North Dakota, you don't need to ask an expert if you want maps of lakes, data on cell tower locations, information on legislative districts, or a wealth of other location-related facts. You don't have to contact another agency, worry about incompatibilities or wonder if someone else might provide more up-to-date information.

State government users now draw all their GIS data from a single well, the North Dakota GIS Hub. This central warehouse stores the state's GIS files, developed according to a single set of standards. End-users throughout state government can tap the files easily, either through a direct connection or over the Web. Local governments, businesses and members of the public can also access state GIS data using a Web interface website.

In the past, each North Dakota agency that used GIS maintained its own files and built its own storage infrastructure. Several years ago, agency officials decided they wanted an easier way to share GIS data and deliver it to end-users. They also wanted a less expensive and more efficient way to store and manage the vast quantities of data they were developing, such as the collection of aerial photographs they are stitching together to provide a seamless view of the state.


Redundancies Boost Costs
As agencies invested separately in systems to create and store GIS data, they created unnecessary redundancies. When that happens, Nutsch said, "it doesn't take long for the costs to really start to grow." A government organization that wants its own GIS infrastructure should be allowed to have one, he said. "However, when there is no centralization, those agencies that have fewer people and smaller budgets are forced to duplicate this infrastructure" whether they want to or not.

In 2001, at the request of state agencies and the North Dakota Information Technology Department (ITD), the state Legislature approved funding to develop the GIS Hub. The project received $700,000 from the state and an additional $450,000 from the Federal Emergency Management Agency (FEMA) through the North Dakota Division of Emergency Management.

A GIS Technical Committee, made up of staff from seven state agencies, spearheaded the development of the Hub. The committee worked with a consultant, SchlumbergerSema of Denver, on the design and development. The ITD provides the infrastructure to host the Hub, which is based on the Oracle database management system, working in conjunction with ArcSDE from ESRI. Oracle holds the information. ArcSDE is used to index and manage spatial data and present it to the user. These two applications run on a Sun Solaris server.

Another ESRI product, ArcIMS, runs on several Windows 2000 servers and pulls data from ArcSDE to generate a Web page. The infrastructure also includes several Linux Web servers and a storage area network (SAN).

As of April, the Hub held between 300 GB and 400 GB of data, but Nutsch said that will climb dramatically. The project to merge 6,000 aerial photos, for example, will produce a data layer of about 240 GB. The system's capacity is unlimited as long as the state keeps adding more storage devices, he said.


Versatility
There are three ways to obtain data from the Hub.

Employees working behind the state's security firewall can access the warehouse through a direct link, using ESRI's ArcGIS software to display and manipulate data. Users outside the firewall can obtain streaming data over the Internet and view it with ESRI's ArcExplorer or ArcGIS. These tools allow people to modify the way they view the data ? changing the color or thickness of the lines representing highways, for example. They can also download the streaming data onto their local hard drives.

In addition, some state data is available through Hub Explorer, an Internet browser tool. Users visiting the state's GIS Web site can view maps showing communications towers, transportation networks, political boundaries or environmental features. Each map displays several layers of geographic information ? such as cities, counties, state and federal roads, and geological features on the surface geology map ? and provides details on individual features.

To develop the Hub, members of the GIS Technical Committee had to agree on standards for geographic projections and naming conventions. They also developed standards for metadata, which provides details on when, how and by whom a file was created. One technical project they did not have to tackle was converting large numbers of files into a common data format, Nutsch said. Most agencies, it turned out, had been using compatible GIS software to create their files.

One important challenge the agencies faced was cultural. When they started discussing a GIS Hub seven or eight years ago, state agencies initially seemed reluctant to share proprietary information, Bassler said. "What made this committee gel were committee members reminding not only each other, but also directors and employees from their respective agencies, that this was a team effort."


Incentive to Cooperate
Government agencies are most willing to cooperate when they see clear benefits for all involved, Nutsch said. In the case of the GIS Hub, they had a strong incentive. "When I came to work here in August 2001," he said, "I think people were at the point where they were so fed up having to spend all this extra time and effort just to get the data, they were really wanting to work with each other."

Three North Dakota agencies ? the Department of Transportation, the State Department of Health and the State Water Commission ? piloted the Hub in the first half of 2002. The system went live for general use in October 2002.

The Historic Preservation Division of the State Historical Society of North Dakota is using the Hub to develop a digital file of nearly 50,000 archaeological, historical and architectural resources in the state. Accredited contractors and planners use this data to conduct cultural resource surveys, and to assess the impact that proposed development?to widen a road, for instance, or erect a communications tower ? will have on recorded cultural resources in the area.

"The Hub provides us with easy one-stop shopping," said Timothy Reed, a research archaeologist with the Historic Preservation Division. "Digital raster graphic topographic maps ? 1:24,000 ? for the entire state are there, all seamed together. Geopolitical boundaries, sections, townships and county boundaries, and road coverages, and even aerial photos for about half the state are all in one spot." Without the Hub, he said, "I would have to pull all these coverages from the separate agencies that develop them."


Fast, Up to Date
The Hub provides fast access to much more data than any one agency could store locally, said Brian Hosek, GIS specialist with the North Dakota Game and Fish Department. "The speed issue has been great, plus the database is always up to date." But he added, "the best part about it is probably that everyone in the agency can access that centralized database."

As the agencies add more data to the Hub, they're also working to improve its capabilities. Soon users will import data from the Hub into a wider range of applications, such as computer-aided design (CAD) systems, Nutsch said. They also plan to add geocoding, so a user can find a location on a map by entering its address, and they're exploring ways to make Hub data more accessible to people with disabilities.

In the future, the GIS Technical Committee will work more closely with counties and cities, so they can take better advantage of the Hub and perhaps contribute data to it as well, Nutsch said.

All these efforts will put North Dakota's geographic data in the hands of many more users. No longer a tool just for specialists, Nutsch said, "GIS within the state agencies might someday become as common as spreadsheet software."

Contributing Writer Merrill Douglas is a freelance writer based in upstate New York. She specializes in applications of information technology.
Merrill Douglas Contributing Writer