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ST/ESA/STAT/SER.F/79Department of Economic and Social AffairsStatistics DivisionStudies in MethodsSeries FHandbook on geographicinformation systems anddigital mappingUnited NationsNew York, 2000-i-No. 79

NOTEThe designations used and the presentation of material in this publication do not imply theexpression of any opinion whatsoever on the part of the Secretariat of the United Nations concerning thelegal status of any country, territory, city or area, or of its authorities, or concerning the delimitation ofits frontiers or boundaries.The term “country” as used in this publication also refers, as appropriate, to territories or areas.The designation “developed regions” and “developing regions” are intended for statisticalconvenience and do not necessarily express a judgment about the stage reached by a particular countryor area in the development process.Symbols of United Nations documents are composed of capital letters combined with figures.Mention of such a symbol indicates a reference to a United Nations document.ST/ESA/STAT/SER.F/79UNITED NATIONS PUBLICATIONSALES No. 00.XVII.12ISBN 92-1-161-426-0-ii-

Prefaceb) support data collection and help monitor censusactivities during enumeration; andThe United Nations has, over the years, issued aseries of handbooks and technical reports intended toassist countries in planning and carrying outimproved and cost-effective population and housingcensuses. These handbooks and reports have beenreviewed from time to time to reflect newdevelopments and emerging issues in census taking.The present handbook is part of a series of handbooksthat have been developed to assist countries in theirpreparation for the 2000 and future rounds ofcensuses. The other handbooks in the series include:c)facilitate presentation, analysis and disseminationof census results, during the post-enumerationphase.The publication is divided into three chapters.The structure reflects as closely as possible the censuscycle. The first chapter gives an introduction andoverview of geographic information systems anddigital mapping. The second chapter discusses, interalia, cost-benefit analysis of an investment in digitalcartography and GIS, plans for census cartographicprocess, digital map database development, qualityassurance, database maintenance, and use of GISduring census enumeration. The last chapter describesthe role of GIS and digital mapping in the post-censalphase and deals with tasks after the census and duringthe inter-censal period, such as database maintenance,dissemination of geographic census products, andgeographic analysis of census data.(a) Handbook on Population and Housing CensusEditing (ST/ESA/STAT/SER.F/82);(b) Handbook on Census Management for Populationand housing censuses (ST/ESA/STAT/SER.F/83).The Principles and Recommendations forPopulation and Housing Censuses – Revision 1(United Nations, 1998) make reference to theemergence of new technologies for censusoperations. One of the new technologies is theapplication of geographic information systems (GIS)and digital mapping in censuses since technicaldevelopments in computer hardware and mappingsoftware have already encouraged many statisticaland census offices to move from traditionalcartographic methods to digital mapping andgeographic information systems.The handbook is as comprehensive as possiblewithout overloading the reader with too muchtechnical presentation, which is dealt with in theannexes. The annexes provide technical aspects suchas an overview of GIS, coordinate systems and mapprojections, geographic data modelling, and thematicmapping.The purpose of this publication is to assistcountries by providing a reference document thatfocuses on digital mapping aspect when conductingpopulation and housing censuses. Traditionally, therole of maps in the census has been to supportenumeration and to present aggregate census resultsin cartographic form. In addition to enabling moreefficient production of enumerator maps and thematicmaps of census results, GIS now plays a key role incensus data dissemination and in the analysis ofpopulation and household data.During the revision process, the United NationsSecretariat consulted cartographic and GIS expertsrepresenting all regions of the world to review andfinalize the handbook. The handbook also presents,some examples of country practices in the applicationof GIS and digital mapping used in censusescontributed by some of these experts. The presentpublication was drafted by Mr. Uwe Diechmann, aconsultant for the United Nations Statistics Division.In particular, the objectives of the publication areto provide guidance to countries on how to:a) ensure consistency and facilitate censusoperations, particularly at the preenumeration phase;-iii-

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ContentsChapterPageAbbreviations and acronyms .viiiI.Introduction and overview. 1A.B.C.D.The role of maps in the census. 1The mapping “revolution” . 1Increasing demand for local area statistical data . 2Scope, purpose and outline of the handbook. 3II. Pre-enumeration . 5A. Introduction. 5B. Cost-benefit analysis of an investment in digital cartography/geographic. 51. Costs . 62. Benefits . 10(a) Efficiency benefits . 10(b) Effectiveness benefits . 113. Critical success factors. 13C. Planning the census cartographic process . 131. Overview . 132. Needs assessment and determination of mapping options . 14(a) User needs assessment . 14(b) Determination or output products . 15(c) Mapping options . 153. Institutional issues in setting up a digital mapping program . 16(a) Staffing, responsibilities and training requirements. 16(b) Institutional cooperation . 18(c) Equipment and software for census mapping applications . 20(d) Decentralization of census mapping activities. 25(e) Timing of census mapping activities. 25(f) Process control . 274. Definition of the national census geography . 27(a) Administrative hierarchy. 27(b) relationship between administrative and other statistical reportingor management units. 28(c) Delineation of enumeration areas. 29(d) Delineation of supervisory (crew leader) areas. 30(e) Consistency with past censuses. 30(f) Coding scheme . 305. Geographic information system database design . 31(a) Scope of mapping activities . 31(b) Implementation choices . 35(c) Definition of the geographic information system database structure . 36(d) Metadata development. 40(e) Data quality issues . 41(f) Tiling of national territory into operational zones . 44(g) The digital administrative base map . 44(h) Dealing with disjoint area units . 44(i) Computing areas . 45-v-

D. Digital map database development . 461. Overview . 462. Cartographic data sources for enumeration area mapping (secondary data acquisition) . 48(a) Types of maps required. 48(b) Inventory of existing sources. 49(c) Importing existing digital data . 493. Additional geographic data collection (primary data acquisition) . 50(a) Field techniques overview . 50(b) Global positioning systems. 50(c) Aerial photography . 55(d) Satellite remote sensing . 604. Geographic data conversion. 63(a) Conversion of hard-copy maps to digital data . 63(b) Digitizing . 63(c) Scanning. 65(d) Editing . 68(e) Constructing topology. 685. Digital map integration . 69(a) Introduction. 69(b) Georeferencing . 69(c) Projection and datum change . 70(d) Coding . 71(e) Integration of separate map segments . 71E. Quality assurance, enumeration area map production and database maintenance . 721. Overview. 722. Draft map production and quality assurance procedures . 73(a) Matching boundaries and attribute files and printing overview maps. 73(b) Quality assurance.