Geographic Information Systems in LocalGovernment: A CommentaryRebecca SomersHDR Infrastructure, 8404 Indian Hills Drive, Omaha, NE 68114

(Source: National Research Council, 1980)

Alternative 'Model

Parool basedApplications

(non-graphic)

Street and NetworkInventory (non-graphic)

Parcel basedApplications

(graphic)

Network and Aogregale levelApplications

variations of this model exist, but most of these share the samebasic concepts and features. This model is based on the parcel asthe central entity in the GIS. The ownership parcel, or cadastre,is the entity with which most local government operations andapplications are concerned. The components of this model include:

• A spatial reference framework. This framework consists of a networkof geodetic control points, and provides the geographic referencefor the data in terms of X-Y coordinates.

• A large scale base map. This map or map series provides the baseby which the cadastral information is related to the geodeticreference framework and to base map features.

• A cadastral overlay. This component depicts the parcel boundaries,and comprises a graphiC overlay on the base map.

• Linkage mechanisms. These provide linkage or correspondencebetween the elements of the cadastral overlay (the parcels) and toother land related data, based on unique parcel identifiers.

• Land related data. These include the local government's informationconcerning land, usually configured as a variety of applicationspecific data sets and other overlays of parcel related data.

Figure 1 represents a simplified version of the multipurposecadastre model and another similar model. The basicmultipurpose cadastre model is implemented in a fairly

0099-1112/87/5310-1379$02.25/0©1987 American Society for Photogrammetry

and Remote Sensing

Multipurpose Cadastre, Simplified

FIG. 1. Local Government Data Models.

INTRODUCTION

LOCAL GOVERNMENTS in urbanized environments are facedwith many issues and problems related to information han­

dling. There is constant pressure to improve services while re­ducing costs, and to be more efficient and effective in dailyoperations and management activities. Some local governmentsare faced with the management of rapid growth, while othersmust cope with a diminishing tax base. Even with relativelynormal growth patterns, the management of resources, facilitiesand operations becomes more demanding as these elementsincrease in number. Geographic Information Systems (GIS) of­fer a solution to many of these problems. Most of the issuesand operations with which a local government are concernedrelate to land or location. For example, land, or tax parcels arethe primary source of income; utilities, such as electric powerdistribution and sewers, service parcels of land; individuals,whether they are voters, school children or mass transit users,are spatially distributed; services, such as schooling, police, andeconomic development incentives are provided by defined geo­graphic areas. It has been estimated that 70% to 80% of theinformation and activities with which a local government is con­cerned are location related. A GIS provides the tools to manageand use information concerning land or location related phe­nomena.

This commentary presents an overview of the use of GIS bylocal governments. Current practices and trends are discussed,and related issues and challenges are identified. The Urban andRegional Information Systems Association (URISA) is an organ­ization of professionals involved in the development and useof GIS in local governments. The interests, activities and plansof URISA, and its perspective on the future of GIS in localgovernments are also discussed.

PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING,Vol. 53, o. 10, October 1987, pp. 1379-1382.

GIS DEVELOPMENT AND APPLICATIONS

A major goal of most local government GIS efforts is to im­plement a multipurpose, integrated system that will serve theneeds of a variety of users. The objectives include reducingduplication of effort in order to reduce costs, centralizing com­mon data to eliminate discrepancies and unnecessary effort in­volved in maintaining multiple copies of the same information,increasing efficiency in daily operations, increasing manage­ment control, and providing information for decision supportand policy formation. Local government systems are successfulin some of these areas, while other goals are more difficult toattain.

Some basic system models and development approaches haveemerged as the result of several years of GIS development bya number of local governments. Most GIS projects are under­taken as independent efforts, and since there are no prescribedapproaches in this relatively new field, each organization hasapproached the project in a manner unique to its needs andsituation. The combined results of these independent efforts,however, indicate some models and approaches that are mostsuccessful.

CONCEPTUAL MODEL

The basic conceptual model for GIS in local governments isthat of the multipurpose cadastre (National Research Council,1980; National Research Council, 1983; McLaughlin, 1984). Several

1380 PHOTOGRAMMETRlC ENGI EERI G & REMOTE SENSING, 1987

straightforward manner in systems that consist of a turnkey,layer-based mapping system and other operational databaseson the same machine or on another (non-graphic) system. Thesecond model in Figure 1 is one variation on the multipurposecadastre model, and represents the basic components of a localgovernment GIS in a manner that most easily translates intosome of the newer technology involving relational databases,and graphic information (maps) stored in terms of databaseinformation rather than as graphics files (Somers andEichelberger, 1987). The components of this model include:

• A Geographic Index. This provides the location and relationshipinformation for geographic entities at the street network and blocklevel of geography.

• A Cadastral Graphic Database. This provides the location andrelationship information for geographic entities at the cadastral orparcel level of geography.

• Land Records Database. This contains the non-graphic informationfor parcels.

• Geodetic Control Database. This provides the geographic referenceframework for the model. The data in this database is used toregister new map data into the system and to improve the positionalaccuracy of existing data, when possible.

The two models are based on the same basic conceptsconcerning GIS in local governments. The models include ageographic reference framework, the linkage of graphic andnon-graphic parcel related data, and applications overlays andsystem access in both graphiC (map related) and non-graphiC(e.g., queries and output specified as text) form. The modelsalso allow an integration of two levels of geography - streetnetwork level (including data aggregation areas of block sizeand above) and parcel/lot level. These linkages are accomplishedby direct overlay of the graphic data or by linkages establishedwithin the database structure. Finally, a core of basic geographidcartographic data is established, with the fleXibility to add newdata or access the database based on applications requirements.This provides centralized control of data that is required by anumber of users, and a developmental approach that is basedon information resource management.

GIS DEVELOPMENT PROCESS

In order to achieve the objectives of the conceptual model,local government GIS are usually developed through a structuredprocess involving the determination of the organization'srequirements and the design of a system to best meet theserequirements. Elements of this development process includethe determination of the intended users' functional and datarequirements; examination and evaluation of existing systemsand data sources; design of the GIS database; design of the GIScomponents, including software, hardware, and organizationalrequirements; development of cost-benefit analyses; developmentof an implementation plan; data collection and conversion; andthe phasing in of the system implementation. Because GIS usuallyinvolve a sizable investment, pilot projects are often used invarious parts of the development process. Pilot projects are usedto evaluate database design, develop cost-benefit data, evaluatepotential software and hardware products, and to evaluateplanned operational processes.

The GIS developmental strategy in local governments usuallyinvolves a phased approach. This approach includes the provisionof early deliverables, which are crucial to the development ofsuch systems as a means of maintaining user, political, andfinancial support. The creation of a full parceVlot level databaseis very time consuming, and may not show full results for manyyears. During this development time it may be possible toimplement simpler databases and system functions, such asgeocoding based on the street network and block data, thematicmapping, and basic computer aided drafting facilities. Theproduction of such early deliverables and provision of someaccess to the system capabilities help maintain project credibility,confidence and support during a long data creation timeframe.

The integrated, data-based approach usually requires new

organizational structures to accomplish the development of asystem that meets all user needs in an efficient manner. Commonorganizational structures created to implement local-governmentGIS include committees composed of representatives fromparticipating departments in the organization, inter-governmentalagreements such as city-county arrangements, and consortiaconsisting of public and private organizations. Even within anorganization or department, organizational changes may benecessary in order to implement and utilize the GIS to its fulladvantage. Existing organization structures and operations wereinstituted and evolved in response to the manual methods ofhandling data. Such structures and operating procedures maynot be the most effective for making use of the new automateddata handling capabilities. In some cases they may even preventor interfere with the implementation of the system.

ApPLICATIONS

Local government GIS implemented according to these modelsand processes provide support to all levels of organizationactivities. These include operational, managerial, and decisionand policy making activities. Functions supported at theoperational and managerial level have the most clear cutapplications and benefits. Increased efficiency in functions suchas utility map production, permit issuance, and title searchesare easily quantified. At the policy making level, the GIS canprovide useful information, although such information is onlyone component of the information and considerations in thedecision making and policy development process. The GIS mayprovide more complete and more timely information to thislevel of activity, and thus improve decision making, but theseeffects are difficult to measure. Furthermore, other componentssuch as public interest and political considerations are alsoinvolved, further complicating the measurement of thecontributions of the GIS.

Some of the major applications supported by a localgovernment GIS include property management; propertyassessment and taxation; land use planing and developmentmanagement; license and permit issuance; inspections; planningand management of services such as police, transportation andutilities; facility management; provision of public information;and mapping. The procedural and managerial and relatedfunctions of municipal governments are fairly similar.Dangermond has classified these functions into 33 categoriesand cross referenced these to the data required for these functions(Dangermond and Freedman, 1984). Other examinations andclassifications of local government GIS applications have beendiscussed by other authors (McLaughlin and Nichols, 1987;Somers and McKay, 1987; Holstein, 1984; Linders, 1984).

Many of these functions use the same data. In a GIS systemdesign and development process, system requirements are oftenexamined through the use of a function/data matrix. Such amatrix cross references data items with functions employingthose data items. The development of this matrix reveals whichdata items are used by a number of applications and thus form"common" or core data, and which data items serve only oneapplication and thus are "application-specific" data. Such ananalysis usually leads right back to the initial data model,indicating that the most commonly used data consists of parcelllot related data and street network data. Although each localgovernment has unique characteristics, these sets of functionshave been found to apply to most local governments.

Several local government GIS implementations provideexamples of the variety of applications served by GIS. TheWyandotte County LANDS System was developed with anemphasis on land records management and mapping, and wasinitially used for base mapping and assessment and taxation(Crane, 1986). The City of Toronto Central Property Register isbased on a corporate database for all properties in the City, andprovides centralized data management, data and system linkage,and support for a variety of applications (Mitchell, 1986). The

GEOGRAPHIC INFORMATIO SYSTEMS I LOCAL GOVER MENTS 1381

City of Calgary and the City of Edmonton GIS projects aremultipurpose systems providing mapping and data linkage andprocessing, based upon a very precise base mapping facility(Somers, 1986; Rhyason and Samler, 1985). The San Diego RUISproject is a joint City-County effort, and represents thedevelopment of a mUltipurpose GIS, including mapping andseveral integrated applications (Dangermond et al., 1986). Manyother multipurpose and special purpose GIS implementationsin local government exist, and references can be found in thepublications of URISA, American Society for Photogrammetryand Remote Sensing, American Congress on Surveying andMa pping, Au to-Carto, Au toma ted Ma pping/Facili tiesManagement, the Canadian Institute of Surveying, the CanadianCartographic Association, National Computer GraphicsAssociation, and other organizations dealing with geography,cartography, information systems, and public administration.

DEVELOPMENT AND IMPLEMENTATION FACTORS

Several factors influence the character of a specific GISimplementation. These include the degree of system integration,the relative mix of mapping and geographic analysisrequirements, the required data precision, costlbenefit factors,and political factors.

The degree of integration varies widely. Some GIS activitiesare intended to be isolated. For example, computer aided dispatchfor emergency services may operate off a simplified databaseand an isolated computer system in order to achieve the requiredspeed and reliability. An isolated GIS may not realize the fullbenefits of the technology, but if it is truly a stand aloneapplication, there is no harm done. A more difficult situationarises when an isolated system is intended to be integratedlater, without a plan for doing so. It is not uncommon to findseveral independent GIS and geoprocessing activities withinone local government organization. Furthermore, these systemsare often incompatible, or not capable of being integrated at alower cost than that of rebuilding them.

The relative mix of mapping and geographic data analysisneeds is another factor that determines the character of a localgovernment GIS. These two requirements constitute two endsof a continuum. Different system development orientations andthe commercially available systems could be mapped along thiscontinuum. At one end are systems designed for optimalefficiency in map creation, maintenance, and output, withexcellent drafting capabilities, but no support for geographicdata analysis functions. On the other end are systems whichperform geographic analysis most efficiently, but do not producehigh quality maps, and are difficult to use in a map maintenanceactivity. Functionality in one area would be sacrificed forperformance efficiency in the other area because different datastructures are involved in these two activities. Recently, however,commercial systems and users' implementations of these systemshave made this mapping/analysis split less definite, as capabilitiesin both areas can be achieved. Still, a GIS will be developed toperform the most critical functions most efficiently. For example,many local government systems in operation today wereimplemented with the mapping function being of primeimportance. Such systems maintain cartographiC data in graphicsfiles in a layered structure, with cross-references to associatedattribute databases. Geographic analysis capabilities in suchsystems are performed using the cartographic and attribute data.Such systems do not perform such analysis as efficiently as theydo map production, maintenance and output.

The precision required of the GIS is also a determinant of itscharacteristics. In local government applications, engineeringand assessment functions require more positional precision thando planning functions, for example. A system developed withgreater precision will require more money and time, but willalso serve the needs of the users requiring less precision. Systemsdeveloped with less precision may be quicker and less expensiveto implement, but will not serve the needs of users requiringhigher precision.

Cost and benefit factors also determine the nature of any localgovernment GIS. AS mentioned above, precision may besacrificed for lack of funding, or by the need for a shorter paybackperiod. Furthermore, benefits in terms of cost avoidance inoperational functions are easier to determine than are the benefitsderived from improvements in policy making and somemanagement functions. This situation often causes systems tobe built to fulfill these opera tional needs, wi thou t dueconsideration in the system design for managerial and decisionmaking needs.

Political factors also play a role in GIS development andapplication. The conflict concerning pressure to reduce spending,while providing better information, is always present. Thispressure can work for or against GIS development efforts. Thepolitical aspect is also very important in achieving the supportnecessary to develop intra-organizational and inter-organizationalcooperative arrangements necessary for the development ofmultipurpose GIS.

CHALLENGES AND FUTURE DIRECTIONS

One of the biggest challenges in the development and oper­ation of local government GIS is the adaptation of the organi­zation to the new technology. This is not to say that theorganization should be technology driven, but that some neworganizational structures and operations may be required totake fullest advantage of the benefits that GIS can offer. Pre­automation organizational structures reflect the manualprocessing environment. Simple substitution of automated pro­cedures for manual ones does not make the best use of GIScapabilities. Changes in the organizational structure and oper­ation may be necessary to make best use of the GIS, but suchchange in public organizations is not easily accomplished. Thechallenge is to make the GIS and the organization adapt to eachother. This subject has been addressed recently by several au­thors, including Chrisman, Dueker and Saarinen (Chirsman,1987; Dueker, 1987; Saarinen, 1987).

There are also a variety of legal issues related to data access,ownership, and privacy. GIS technology has made it possibleto store, retrieve, manipulate, and analyze land related data,yet there still remain important questions and issues concerningwhether these functions should take place. Several authors haveaddressed this subject (Chatterton and Epstein, 1984; Roitman,1987).

The appropriate use of topological data structure for localgovernment GIS functions is currently an important issue. Al­though topological data structures have long been recognizedas an effective means for representing geographic data, it isfairly recently that such capabilities have been available on com­mercial GIS software systems, and there is now opportunity touse topological data structures in local government GIS imple­mentations. Topology can provide for powerful data access andmanipulation capabilities, but it involves a high data storageand processing overhead. In local government applications,where data update and many standardized operations exist, afull topological encoding of the data may not be practical. Forsome operations it will be the most effective means of structur­ing the data. For others, such as simple map production, theimplementation of the data in a topological structure may nothelp, and may even hinder the process (Exler, 1987).

Implementing a logical and effective GIS development processis a challenge in the face of local government organization, pro­cedures, mandates, and budgets. Often, the department withthe most money drives the development process. Since GISneeds vary among departments, a GIS implemented by onedepartment may not serve the needs of the others. The chal­lenge in the GIS development process is to meet immediateneeds to the extent possible, while ensuring that the systemcan be adapted and extended to meet the future needs of otherusers.

Finally, one of the biggest challenges faced in local govern-

1382 PHOTOGRAMMETRJC ENGI EERI G & REMOTE SENSING, 1987

ment GIS is the integration of such systems with other systems,operations, and data existing within the organization. Althoughthe local government GIS model is coherent, it is an open sys­tem. When most local government GIS development efforts be­gin, there are other systems - manual and automated - alreadyin place. Since the organization relies on these systems for itsoperations, they cannot be easily disturbed. Consequently, al­though the GIS conceptual model potentially accounts for all ofan organization's land related data and operations, the actualGIS is often implemented in relative isolation from these othersystems. Interfaces are often established using magnetic trans­fer media only. Thus, one of the most challenging issues inlocal government GIS is the integration of these systems intothe organization with respect to organizational structure, data,existing systems, and organizational operations.

URISAThe Urban and Regional Information Systems Association is

an organization of professionals involved in developing andapplying local government GIS, and in related issues. Foundedin 1962, it is one of the oldest and largest professional organi­zations dealing with GIS. URISA serves to bridge the gap be­tween users and providers of information for public operationalsystems and decision making. The membership is composedprimarily of administrators and technical staff in municipal,county and regional governments. Many URISA members servein federal, state, and provincial agencies. The remaining mem­bers include university faculty and students, employees of com­puter vendor and service companies, consultants, and electedofficials.

As URISA reaches its 25th anniversary, its members are ex­amining local government GIS development and application is­sues such as those discussed above. Through the annualconference and continuing workshop, seminar and publicationservices, as well as professional networking, the members ex­change information, share experiences, and examine methodsof making local government GIS more effective. Issues that arecurrently receiving a great deal of attention are GIS develop­ment methodologies; system evaluation; integration of GIS intoorganizations; educational requirements and directions for stu­dents in the field of GIS; strategies for communicating GIS ben­efits to elected officials and top management; legal issuesconcerning data access; automated mapping; and the effectiveuse of GIS capabilities in application fields such as planning,transportation, public works, property assessment, emergencyservices, and infrastructure management.

The field of GIS and its applications in local governmentshave developed rapidly in the past few years. Less than a dec­ade ago, technological problems were of primary concern. To­day, many of these have been solved, and newer, more powerfultechnological tools are available. While there are still areas ofthe technology that must be developed further, many issues ofimportance today involve the appropriate application of theavailable technology and the integration of GIS technology andoperations into the organization. URISA provides a forum andinformation source to help individuals in this field implementand apply GIS technology successfully. For further informationabout URISA, contact the URISA Secretariat, 319 C Street S.E.,Washington, D.C. 20003; Telephone (202) 543-7141.

REFERENCESChatterton, W.A., and E.F. Epstein, 1984. Legal Issues in the Devel­

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Cadastre: Modernizing Land Information Systems in North America. Uni­versity of Wisconsin-Madison, p. 203-209.

Chrisman, N., 1987. Design of Geographic Information Systems Basedon Social and Cultural Goals, Photogrammetric Engineering and Re­mote Sensing (this volume).

Crane, E. 1986. A Multi-purpose Land Data System for WyandotteCounty, Kansas, State and Local Government Systems - The State ofthe Art. URISA, p. 10-18.

Dangermond, J., and C. Freedman, 1984. Findings Regarding a Con­ceptual Model of a Municipal Data Base and Implications for Soft­ware Design, Seminar on the Multipurpose Cadastre: Modernizing LandInformation Systems in North America. University of Wisconsin-Mad­ison, p. 12--49.

Dangermond, J., et aI., 1986. The Conceptual System Design Process inPractice: The San Diego Regional Urban Information System Ex­perience, Papers from the 1986 Annual Conference of the Urban andRegional Information Systems Association. URlSA, p. 187-201.

Dueker, K., 1987. Multipurpose Land Information Systems: Technical,Economic, and Institutional Issues, Photogrammetric Engilleering alldRemote Sensing, Vol. 53, No. 10, pp. 1361-1365.

Exler, R., 1987. Appropriate Applications for Topological Data Struc­tures, Papers from the 1987 Annual Conference of the Urban and RegionalInformation Systems Association. URISA, in press.

Holstein, L.c., 1984. Local Government Land Information Systems ­An Australian View, The Decision Maker and Land Information Sys­tems, Papers and Proceedings from the FIG International Symposium.Canadian Institute of Surveying, p. 293-304.

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