7. Full summary
Maps and GIS for the Population and Dwelling Census 2000 in Estonia
Teet Jagomägi, REGIO Ltd. 1997, 121 pages, 40 figures, 28 in color, 9 tables
Estonian Board of Statistics has started the preparations for upcoming population and dwelling census in year 2000. The paper was written within the framework of Census preparation and serves two tasks:
1) to give an overview of GISes and digital mapping for employees of the Board of Statistics, and
2) discuss specific questions of GIS implementation in the Board of Statistics and propose solutions.
Chapter 2 has been devoted to introduction of GIS technology, principles of thematic mapping and quality measures in GIS and mapping. The description of GIS implementation phases, structure of GIS specification and practical guidelines for supervising GIS-project are given. The paper describes different types of thematic maps and gives guidelines for selection an appropriate presentation technique.
From the point of view of the Census GIS has three tasks: 1) assist during Census preparation, 2) enable analysis and presentation of Census results, 3) provide data dissemination. However, application of GISes in Board of Statistics should not be limited to population statistics division, internal spatial database should be open for all kinds of statistical analysis.
As a side effect, census GIS gives unique opportunity to create digital maps for urban areas which cannot invest into GIS, update data in the registry of buildings and provide verified data for GISes and cartographers. Due to large number of potential beneficiaries the study of their needs is important. Perhaps adding 10% to the project cost will increase the attractiveness of the project results and double the number of customers.
All services cannot be subcontracted, therefore Board of Statistics has to invest into GIS hardware, software and data. Characteristic configurations of GIS computers are given. The typical GIS budget splits as follows:
Poor budget neglects the big share of data and organisation, therefore decisionmakers are called to include these criteria also in the GIS project tendering process. The market value of GIS-project depends on the (quality and structure of) data, not on the price of software and hardware. Stages of GIS project implementation are described, which will help to deal with subcontractors.
Detailed specification of GIS database and well-planned project implementation may save a lot of money in future. This also gives certain warranties to potential customers who can plan their activities accordingly to the announcements made by Board of Statistics.
Dissemination of data and relations with other database owners requires well-defined standards and identifiers, particularly important for population and dwelling census are identifiers of buildings. One algorithm for this purpose is given in the paper. In addition to identifiers, human-readable address system must be worked out before the Census.
Possibilities of GIS analysis are described in the paper, and two examples of possible pitfalls in the population data analysis and presentation are given: 1) Estonian placenames have moved few kilometers during last 60 years, and users must be aware, whether data of two placenames or two geographical locations is compared; 2) enumerator areas are far from the ideal for presenting data on thematic maps and tend to distort the peak values. Mapping all buildings is inevitable for overcoming these issues.
Criteria for evaluating GIS database quality and thematic map quality have been described.
Chapter 3 describes geographical data dissemination issues, both legal and technical. Legal questions pertain mostly databases and copyright, technical ones data exchange standards, data quality, and distinct features of Internet and CD-ROMs.
Recent directives of European Union will affect Estonian legislature in longer run, and it makes sense to predict changes as soon as possible. The area is acute, as National Board of Statistics has started ordering digital mapping and GIS services already.
Estonia does not have Catalogue Act (as most of Scandinavian countries do), therefore legal protection of databases created for Census GIS need special attention. Most likely they cannot be protected with copyright law, and the Board of Statistics is encouraged to work out precise contract forms before starting of dissemination services.
Statistical data dissemination must ensure that data is kept confidential and privacy protected. Any form of leakage may result in serious loss of credibility and will for cooperation. The paper describes ways of keeping data confidential during spatial analysis. It is not advisable to distort maps for this purpose, more favourable way is to maintain constant nomenclature of geographic areas for aggregating attribute data. This prevents from infringement of confidentiality with help of overlay of polygons.
Data should not be kept secret "just in case", all refuses must be well-explained.
The pricing system of (geographical) data affects the development of whole GIS community in the country. The Board of Statistics is not encouraged to choose cost-recovery policy, at least before the Census.
Internet is gaining more and more importance as a data dissemination means. GIS software vendors have recently completed tools for generating maps from their data formats "on the fly". Short comparative analysis is given for major products, but as the technology is not mature yet, the topic should be revised in a year.
Simple mapping features should be added to CD-ROMs with census results, in addition data should be made available in 1-2 most wide-spread GIS data formats for advanced users. Development of new neutral data exchange format is not feasible, definitions of GIS database elements should be standardized instead.
Chapter 4 describes maps and GISes in Estonian perspective. An overview is given, how maps were made for previous census in 1989 and what data is available for census 2000. All old maps are on paper which is not appropriate for archive use and they may vanish within 5-10 years. Therefore extensive scanning should be planned in order to ensure compatibility of statistical data over decades.
The survey, organised by Board of Statistics in summer 1996 among Estonian towns showed their great interest in participating in any GIS activities as long as it brings no additional expenses to them. Without the lead of Board of Statistics maximum 10 towns (out of 96) would invest into digital mapping during next years. Participation of local municipalities can reduce the cost of GIS database development and maintenance significantly. For this purpose a special programme must be worked out. From the point of view of the State it may make sense to support the Board of Statistics in the mapping effort rather than subsidize every local community with small amounts of money.
Ensuring constant inflow of reliable GIS data is critical success factor for census mapping program. First maps are completed 2 years before the last ones, simple and inexpensive way of updating created maps must be set up. Abovementioned cooperation program with local municipalities and other interested parties (private sector) may help to keep data up-to-date.
Detailed timescale is given for necessary preparatory tasks. The factors contributing into the cost of census GIS program are outlined and total cost estimated. Census GIS implementation differs from other GISes in Estonia, because the deadline is very strict.
The strategy of census GIS is given in few pages. The strategy can be used for building information system, preparing materials for tenders, and estimating project cost. The key points of proposed GIS strategy is 1) mapping all (inhabited) buildings in Estonia, and 2) generation of new enumerator area borders.
Most of European countries maintain building registry and have added location of buildings into the registry or set up a connection between registry and base maps. In Estonia the building registry is not complete and only partially digital. Therefore identifiers of buildings must be generated by census GIS administrators and later distributed to other registries. Mapping of all buildings and scanning data from previous census maps will make statistical analysis independent from border changes.
New enumerator area borders must be generated. Old borders are poorly documented on old maps and their shape not reasonable in year 2000. Actually, during census preparation, during census itself, for data analysis and for presentation users need areas based on different criteria. In case GIS goes down to building level, areas can be generated on whatever criteria and still maintain data compatibility. New borders can be presented as Estonian NUTS-borders, based partly on functional criteria.
Author suggests wide use of subcontracting rather than developing powerful GIS and mapping department into the Board of Statistics. However, small and highly skilled team is necessary for coordination and verifying of subcontractor's work. The Board of Statistics is suggested to distribute GIS database as widely as possible at a nominal fee. This helps to achieve the role one of the most influential GIS centers in the state. The dissemination should be started as early as possible, as the data gathered during the preparation process ages quickly.
The Board of Statistics must pay a lot of attention to publicity among GIS and map users and local municipalities in Estonia. This means regular progress reports, but also technical data (identifiers developed etc.). Current level of GIS implementation brings Estonian Board of Statistics at the level, which permits regular presentations on the European seminars and conferences.
As readers of this paper are not necessary experts in the GIS or mapping area, list of terms in Estonian with explanations and translations into English is given in Chapter 5. The dictionary includes 240 terms. The selected bibliography in the area of census GISes and census mapping (including abstracts) is given in Chapter 10 for those wishing further study the area. The list includes 110 references.
Author is very grateful to the employees of Estonian Board of Statistics (Ms. Inge Nael, Lembit Mr. Tepp and Mr. Mati Sundja) for strong support and providing valuable data for writing this paper. Reviewers Mr. Jüri Roosaare and Raivo Aunap (Tartu University, Institute of Geography) and Heikki Pisuke (Ministry of Legal Affairs, Department of International Law) improved the quality of paper significantly.
Viimati muudetud: 09/11/97
Copyright © 1997, Teet Jagomägi
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