Building your GIS from the ground up

Over the last 20 years, GIS has evolved from a luxury into an inevitability. Originally used as a planning and mapping tool, it has now become an essential item in the local government toolbox, used for everything from helping manage welfare reform to helping fill potholes.

THE LOCAL GOVERNMENT MODEL Every city and county is unique; logically, therefore, every local government GIS is unique. All, however, possess common characteristics that provide a framework for designing, implementing, growing and managing a local government GIS. Consequently, understanding the local government GIS development model is the first step in creating an effective system.

The model for most city and county systems is a multipurpose, enterprise-wide system, based on large-scale map data, centered on parcel information with overlays and linkages to other land-related data and databases. Ultimately, most local governments need large-scale, parcel-based data to serve all their GIS needs.

This “enterprise” model supports the wide range of applications typically performed by a local government. Those basic concepts were introduced before GIS was widely used, and the model has been refined, modified and tailored to individual organizations’ needs.

Variations on the local government GIS model take into account the urban or rural characteristics of the land, available data and initial applications needs. The specific accuracy of the base map and parcel data may vary, and the applications overlays and land databases will differ, particularly in the early stages of GIS development.

IMPLEMENTATION PROCESS GIS implementation involves designing, acquiring, installing and implementing the necessary data, software and hardware, and ensuring that the correct people and procedures are involved. Certain basic principles apply to most situations.

* Planning. Project planning involves developing a “vision” about how GIS will fit into the organization’s future operations, considering any implications of that vision and determining the resources and activities required to achieve those goals. The organization must establish the scope of the GIS, identify the development team, gather background information and develop a preliminary implementation plan. The planning phase represents the “top-down” view of what the GIS will beand how it will be implemented.

* Requirements analysis. Requirements analysis represents the “bottom-up” view which involves looking at the details required to fulfill the planned system goals. During this phase the functional and data requirements for the GIS applications and users must be determined; resources must be assessed; and opportunities and constraints within the organizational and institutional environment must be identified.

* Design. In the design phase, all the information from previous activities is coordinated to develop a detailed picture of GIS. A conceptual design for the system, database, applications and organizational components must be determined, and that design must be integrated with set goals and requirements. A detailed cost/benefit analysis can be performed and detailed component implementation plans developed.

* Acquisition and development. Software, hardware and data specifications for system selection and acquisition must be developed and the resulting systems installed. * Operation and maintenance. Finally, the GIS must be integrated into the organization’s operating environment. This phase involves supporting users, and managing ongoing data and systems development and maintenance.

ALTERNATIVE APPROACHES For many years, the prescribed approach for building a local government GIS was to directly apply the model and implementation process for the entire system. An organization would invest in the creation of large-scale, high-accuracy basemap and parcel data; comprehensive user requirements analysis; integrated system and database design; and incremental application development. Unfortunately, that approach can require millions of dollars and many years.

Today, many cities and counties are looking for alternatives that fit the realities of their situations, implementing single, low-cost, high-priority applications rather than comprehensive systems. For example, many applications needed by local governments do not require high-accuracy data and complex software. In fact, a number of planning activities can be performed with small-scale data, and many operations, such as siting and demographic analysis, can be performed with relatively simple software.

Low-cost data offerings for everything from street networks to high-resolution satellite imagery are growing every year, as is low-cost technology. Powerful software is now available on desktop systems. The cost of peripherals is dropping while quality is increasing, and low-cost global positioning systems are providing data and operational capabilities for many applications.

IMPLEMENTATION AND MANAGEMENT ISSUES Like models and equipment, management strategies are crucial to the success of any GIS project. They include:

* Cost/benefit and risk analysis. A detailed cost/benefit analysis is usually a required component of a local government’s GIS development process. Many local governments have found, however, that the cost/benefit analysis does not play out as expected. Early on, a number of city and county GIS developers found that their cost and time estimates were too low, their benefits estimates were too high, and the timeframe for realizing them was unrealistic.

That was partly a function of being behind the learning curve. Today’s methodologies and information for GIS cost/benefit evaluations are much improved over earlier ones.

Challenges do remain, however. Cost/benefit components must be tracked through the system development and operation; methods must be established for capturing operational benefits and applying the cost-savings to GIS maintenance and operation; and explicit methods are required for identifying and mitigating risks. A reliable cost/benefit and risk assessment and tracking methodology can help an organization understand the impacts of GIS, see the timeframe of those impacts and plan accordingly.

* Coordinating GIS participants. Much of the power of GIS is derived from the databases, system facilities and skills that are shared among users in different departments. Sharing GIS facilities among many users, however, can create a complex environment. Coordinating multiple GIS users within an organization involves addressing the varied interests of the participants and establishing lateral management in a vertically structured organization.

Most local governments developing enterprise-wide systems use committee and team structures to coordinate participants and guide GIS development. The common model addresses different levels of participants’ interest in the GIS. For example, an executive committee provides policy guidance in support of the GIS; a technical committee provides the input for development and operations of the GIS; and a users’ group is often formed once the GIS is operational, providing an open forum for user discussion and input. A GIS manager coordinates committees or groups and manages the system’s implementation and operational efforts.

* Communication. Communication is crucial to the success of a multiparticipant GIS, and its requirements grow with the number of participants and their differences in applications, professional backgrounds, priorities, organizational interests and personal agendas. Carefully tailored and timed education and training must be provided to the various participants, and they must be informed of project developments and receive GIS education and updates on a regular basis.

* Leadership and support. In a large, multiparticipant GIS project, two types of leadership are crucial to success. Someone must manage the GIS implementation and operation, and someone has to provide support and influence at the policy level. The GIS manager coordinates the network of committees and participants.

Among the many technical and managerial qualifications a GIS manager must possess, he or she must be able to work with diverse individuals and groups, manage teams, educate, motivate and lead. In addition, a project champion is needed to provide executive level support and influence.

* Management and control. In local government settings, maintaining a centralized GIS management while providing for distributed operation is a challenge. Centralized management involves coordination of participants’ needs and activities, system and database development, data management, system support, staff coordination, training and user support. Decentralized user activities usually include GIS operation and use, data creation and maintenance (within established guidelines) and some application development.

One of the biggest factors affecting the success of that balance — and of the GIS itself — is the organizational location of the GIS management. Those involved in GIS management can be in a line organization, in a support area or at the executive level. Each location has its advantages and disadvantages.

Location in a line organization places GIS management within an operating unit such as planning or public works. Advantages include the direct connection of the GIS to an operational need and budget and autonomous control of the development effort.

Such a location can be a disadvantage in terms of coordination difficulties, lack of inherent authority, lack of visibility and, possibly, a weak budget position.

Location in a support unit that includes such departments as information systems, technology support or management services offers the institutionalization of GIS within an existing support environment. It also ensures a professional and objective image for the GIS and its personnel and separation of the GIS budget and operations from that of the line departments. A potentially weak budget position, difficulties in integrating GIS into the operational units, and the perception that the GIS staff is removed from operational needs of the organization are the disadvantages.

At the executive level, the GIS manager reports to one of the top decision-makers in the organization, such as the county executive or mayor. Advantages include high visibility, inherent authority, top executive support and a strong budget position. Disadvantages include too much visibility in a highly political atmosphere, difficulties in integrating GIS into operations, and a perception by users that GIS management is too far removed from operational concerns.

Placing GIS within the Information Services or Information Technology department is a recent trend in local government. Cities and counties are recognizing that spatial data is a valuable resource that must be integrated and managed along with the organization’s other data and IT resources.

GIS projects and programs often move within the organization over time. The common move is “up” from line levels to support or executive levels.

When projects are initiated as multiparticipant efforts, they are usually placed at higher levels in the organization than when they are initiated as single-purpose systems. GIS management may also move when the project passes from the developmental stage to the operational stage.

* Personnel issues. Most GIS managers attribute their successes to skilled personnel and their failures to lack of trained staff. Cities and counties often are the training grounds for GIS personnel, and, in order to avoid the revolving door syndrome, local governments must carefully design and implement a GIS staff plan with special attention to staff retention and knowledge transfer. Establishing staff responsibilities, staff configuration, position requirements and pay scales, job classes, career paths and training is critical.

* Data access. Data-sharing has always been a major reason for GIS development, and it is gaining importance every day, as more organizations and individuals are realizing the benefits of access to each other’s data. Additionally, the value and potential marketability of GIS data is driving many activities and debates related to data access and financial issues.

Rights to access and fees aside, the major data-sharing issues focus on relevant standards and procedures. GIS metadata (information about the data relating to source, quality, limitations and other aspects), partnerships, data standards, data transfer procedures and system interoperability will be key factors in the data access and sharing environment of the future.

* Timing. In GIS implementation, timing is an art. Certain components must be completed before dependent ones, like technical changes, can be developed.

Beyond the obvious scheduling dependencies, however, successful progress, adoption and use of GIS is the result of strategic timing that takes into account various factors. Many local GIS efforts have developed successfully because they started quietly, without formalized activities or funds.

There is no single key to successful GIS implementation and management. While no single factor can ensure GIS success, the absence of any single factor could cause failure. All aspects must be managed simultaneously. The GIS implementation and management strategy for each city or county must include a unique combination of these factors.

Rebecca Somers is president of Fairfax, Va.-based Somers-St. Claire, a GIS management consulting firm.

Cities and counties are starting their GIS implementations in different areas. While short-term needs and conditions often determine the initial applications, database, and software, long-term needs and plans will determine whether those initial components successfully integrate into the larger system.

Investments built on an inappropriate technology or database could become a loss. Those who choose the right GIS building blocks for their situation should be able to grow their GIS incrementally.

* High-accuracy mapping. Large-scale, high-accuracy base maps and parcel maps compiled photogrammetrically or through survey methods are a good starting point. Everything that is later added should fit geo-graphically. That route will result in pieces that come together as a whole, technically. The major problem for many organizations is that that approach can require a large initial investment.

* Converting existing parcel maps. Some local governments start their GIS databases by digitizing or scanning existing parcel maps. While that approach may provide immediate functionality for parcel-based applications, its ultimate success depends on the accuracy and condition of the existing parcel maps, the conversion methodology and the accuracy ultimately required by the GIS.

* Digital orthophotos. Digital orthophotos are used to provide basemap information for many cities and counties. Those data sources are readily available and relatively inexpensive in many areas of the country. The images include many basemap features that would cost a jurisdiction hundreds of thousands of dollars to collect photogrammetrically or through digitization.

Vector information can be constructed as needed through photogrammetric means on digital orthophotos or sketched with lower degrees of accuracy (although that method should come with a warning label). Organizations that take that route should be aware of the resolution and, therefore, the accuracy limitations of such data sources. If properly planned and managed, however, later data layers should fit.

* Street network databases. Enhanced street network databases are available from many sources. Although they vary by source, most databases contain single-line representations of the street network for an area, along with address range information, some routing information and various basemap features.

Many applications, particularly those that involve routing, address matching, and manipulation of demographic and other polygon-based statistical information, can be performed with that kind of data alone. When adding to such databases and applications, organizations need to be aware of the limitations of street-based databases. Transitions can be made, but they can be technically tricky.

* Desktop mapping. Every GIS is not created equal. Some so-called desktop mapping and desktop GIS systems can handle all the needs of a local government. In fact, some desktop mapping and GIS systems that worked for an organization’s limited initial applications may make the transition or provide a migration path to handling new data and applications. Others, however, may hit a brick wall.

There are no “good” or “bad” GIS starting points. It may be necessary to start small, but the specific data or technology an organization chooses as a starting point should be in keeping with its long-term plans.

Jefferson County, Colo., has grown more than 900 percent since 1950. Construction of new roads, houses, shopping centers and commercial buildings has produced an ever-changing landscape. County officials, therefore, realized that they would have to maintain a current inventory of features upon which local governments and their citizens could depend. A GIS, obviously, was the answer.

It took Jefferson County three years to collect and process the imagery that comprises its GIS. That data, which illustrates the county’s growth, was collected using aerial photography.

The advent of high-resolution satellite technology makes it possible for the same geographic area to be covered within minutes at a fraction of the cost of aerial photography. Additionally, satellites provide quicker updates to and faster availability of the data.

Jefferson County is now in the process of replacing its aerial imagery with space imagery from Space Imaging EOSAT, Thornton, Colo. Space imagery offers local governments the ability to access digitally derived “layers” by incorporating one-meter resolution, orthorectified aerial imagery. Consequently, the county is better able to monitor changes in its natural and man-made features, so it can effectively plan for future growth. Space imagery can help cities and counties plan for the future by making several applications available. Applications may include fire hazard maps, vegetation management maps or construction maps.

One-meter resolution panchromatic and four-meter multispectral imagery make the GIS useful for creating fire hazard maps. Additionally, high-resolution, near-infrared imagery helps the forest service identify and distinguish vegetation types to aid in determining where fire risks are greatest. After fire strikes an area and damage has occurred, the imagery helps determine areas requiring immediate attention to prevent erosion.

Vegetation management is another useful application. The imagery helps detect infestations and diseases by distinguishing healthy vegetation patterns from unhealthy vegetation patterns, enabling the forest service or agricultural monitoring firms to apply remedies to the specific areas that need attention.

In addition to managing its vegetation, Jefferson County can help developers monitor and manage change by using high-resolution, high-accuracy imagery at regularly scheduled intervals on a quarterly or annual subscription program. It can use the imagery to efficiently map the area for the construction of housing developments, commercial zones, community or recreation areas and parks, without having to do on-site visits or rely on traditional line maps, which can be time-consuming and expensive to update.

Eventually, Jefferson County GIS Director David Gallaher will provide imagery to citizens who will want access to information about their city or township.

Kim DiNapoli, a geocode technician for the county’s GIS department, reports that she receives regular requests from new homeowners and commercial developers for exact locations and addresses of homes as well as malls, grocery stores, restaurants and other facilities in the local infrastructure. “The first thing county agencies would like to do when people or companies move to the area is pull up a photo on their computer screen so they can visualize the newcomers’ location, thus providing better customer service,” she says.

A number of questions surround local government GIS. How prevalent is it? How fast is it growing? How successful is it?

The responses depend on who is answering. Over the years, various surveys have indicated varying levels of activity and growth. The design and execution of the individual survey, response rates and quality of responses, interpretation of results and intent of the undertaking all affect the outcome.

All, however, point to a high instance of activity and growth. In fact, the most recent survey, “Geographic Information Technology in Cities and Counties: A Nationwide Assessment” by American Forests, indicates that 87 percent of cities with populations greater than 25,000 and counties with populations greater than 50,000 have acquired GIS software. Conference presentations, industry publications and vendor announcements also indicate great activity.

Many local governments, however, are engaged only in limited GIS activity. The American Forests survey, which was conducted in 1996 and released in 1998, showed that the number of departments in the responding cities and counties using GIS averaged out to 2.5. Many of those were using GIS only for single applications. “I often hear about a municipality’s GIS that turns out to be a GIS manager in a 10-by-12 room laying street centerlines over a digital ortho of the town,” wrote Chris Harlow, editor of the Harlow Report, a GIS newsletter.

Quality of GIS use is also an important issue. Studies that examine the actual number of GIS applications and users’ satisfaction and perceived benefits still show that many fall short of expectations.

On the other hand, many large cities and counties have been developing their systems for years and are now achieving wide-spread enterprise use of their GIS in many different departments. In those cases, the GIS is serving a spectrum of functions from operations to decision support.

Those cities and counties lend credence to the models for GIS implementation and reinforce the industry’s confidence in it as a tool for local government. It takes longer to achieve full-scale GIS implementation, but the results make it clear that cities and counties view it as a positive development.

Many local government officials think of GIS as a big-project, big-ticket item, and it certainly can be just that. A number of cities and counties, however, are finding a number of uses for GIS that involve shorter-term projects with no requirement for local government expenditures.

In Osceola County, Fla., for instance, an old mapping system prevented any designation of wetlands as a “land use” category. With a GIS, the importation of existing files from water management districts allowed both tabulation of area and cartographic display of wetlands categories so they could be used in the county’s planning process.

Hillsborough County, Fla., too, is using GIS to complete a wetlands type and area assessment. Under the auspices of NASA’s Visiting Investigator Program Extension at the University of South Carolina’s Department of Geography, the Hillsborough Wetland Conservation Area is exploring the applications of GIS and remote sensing in analyzing wetlands for mitigation and other purposes. The project’s goal is twofold:

1) To use historical and current remotely sensed data (from the National Aerial Photography Program) and NASA/Calibrated Airborne Multispectral Scanner hyperspectral imagery to identify high-priority wetlands; and

2) To develop a method to integrate remotely sensed imagery with other information in a GIS.

Wetlands issues, however, are not the only small-scale GIS applications. In Flagler County, Fla., GIS is being used to combine data from the local zoning board with regional data sources to help site multi-family housing in the predominantly single-family retirement community.

LaQuinta, Calif., has used GIS to initiate a pavement management system that helps it prevent pavement problems and provides objective and systematic procedures for setting maintenance priorities and allocating resources.

Local governments also can benefit from federal GIS projects. For example, the United States Geological Survey has used a GIS to combine road network and earth science information to analyze the effect of an earthquake along the base of the Utah’s Wasatch Mountains on fire and rescue squad response time in Salt Lake City. Fire station locations were plotted on a road network, and a GIS network analysis was used to calculate the time needed for emergency vehicles to travel from those stations to various parts of the city.

This article was written by Walter Smith, director of the surveying and mapping division of Berryman & Henigar, Orlando, Fla.; and Christine Papandreas, project manager/senior planner in the company’s Tampa, Fla., office.

American Forests, a Washington, D.C.-based conservation organization, has completed a five-year effort to map, measure and analyze the size, condition and value of urban forest ecosystems. By using GIS to analyze urban tree cover, the organization has been able not only to measure landscape changes, but also to place a dollar value on the loss of tree canopy.

Dollar estimates are derived from established research and engineering information. For example, natural tree cover and soils reduce the total flow and timing of stormwater. A dollar value can be placed on the tree cover equal to the cost of building structural containment devices.

By conducting a detailed ecological analysis, a community can take advantage of existing natural resources and reduce management costs. To help cities and counties conduct such an analysis, American Forests has developed Citygreen, a GIS application for desktop computers.

For information, contact the organization at P.O. Box 2000, Washington, D.C. 20013 or visit its web site at www.amfor.org.

In 1991, Tuscaloosa County, Ala., developed a GIS program to map the county’s 80,000 land parcels and ownership records for tax assessment purposes. As the amount and types of information in the system grew, the tax assessor’s staff began to create countywide specialty maps.

According to County Tax Assessor Doster McMullen, the system significantly reduces the time staff members spend revising maps. “In the past, we would finish our mapping revisions for the year around June,” McMullen says. “Now we finish up in February. Our staff can then begin to work on the next year’s revisions.”

In addition to developing a successful GIS program for the tax assessor’s office, the county has created site maps that identify supporting infrastructure such as transportation and utilities. It also has prepared a series of maps that allows it to visually link all the positive aspects of the community: school locations, fire protection, recreational assets, cultural advantages, demographics and political subdivisions.

Tuscaloosa County’s GIS has become so popular with the county residents that the county has created a formal mechanism for producing and selling the maps. The revenue has helped fund GIS expansion and allowed the assessor’s office to add additional map products and services. Maps of recreational areas such as Lake Tuscaloosa and educational facilities like the University of Alabama were particularly popular with citizens.