Jan van Est
Louis Smit
The spatial dimension
of an information system
for the MVRO
lanologisch diecentrum TNO earch centre
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The spatial dimension of an information
system for the MVRO
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Delft.june 1981
Planologisch Studiecentrum TNO Schoemakerstraat 97/Postbus45 2600 AA Delft
Tel. 015- 569330 Bib !iot.heek. TU De lf t.
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C 1995968This naper is the summarlzlng result of a project on geocoding, charged by the tlinistry of Housin g and Physical Planning. The material contained in this paper does not necessarily reflect the views of the Ministry. All errors remain the responsibility of the authors.
The authors gratefully acknowledge the useful remarks of the steering comnittee of this project, viz. drs. ing. A.J. Driesen, ir. N.A. Claessen, drs. P.F. de Noord, ir. J. Brouwer, prof. dr. ir. M.J.M. Bogaerts and drs. A. Elsenaar. eenstructi ve comments and suggestions were received from Hugo Geusebroek, Hans Heida, Michel Horrevoets and Frans de Vroege. The manuscript was carefully prepared by Brigitte Andoetoe and Trees Jordaan.
One of the major Droblems of research and planning and policy making is the lacking of the availability of information. Modern analysis is of ten hampered by this, due to the fuzzy locational identification of the data. Many variables and attributes are only measured (i.e. available) on geographical areas of different sizes, which are overlapping as well. If the data are available and if they can be linked to each other then it still is a.very time consuming process to derive the required information.
The above reveals some evidence that gives rise to a new line of thinking, in which the existence of a spatial dimension is accounted for: geocoding. The spatial structure, described by points (addresses) and segments
(streets) and polygons (zonal areas) , can be combined with locational data files within the framework of a spatial oriented information system.
The existing data files remain the source of information and the segments of the network structure function as data carriers for manipulating the data. Hith new methods and techniques administrative data systems can now be used in a much more efficient and decentralized way.
Started in 1967 in New Haven, USA, many countries are benefitting from this new concept. For that reason the Ministry of Housing and Physical Planning wanted to draw up an inventory of possible geocoding methods. In 1979 and 1980 the project has been carried out. In this paper a summary is presented.
3. METHOOS OF GEOCOD ING. 10
3.1. General. 10
3.2. The three basic methods of geocoding. 12
3. 3. Aggregation procedures. 15
3.4. A spatial-oriented information system. 16 2. CHARACTERISTICS OF THE INFORMATION REQUIREMENTS OF IMPOR- 2
TANCE TO THE MVRO.
2. 1. General. 4
2.2. Departments within the MVRO. 5
2.3. Conclusions regarding the information
require-ments of the MVRO. 7
1. PROBLEM FORMULATION AND OBJECTIVE OF THE INVESTIGATION.
4. CONCLUSIONS AND RECOMMENDATIONS (FOR A SPATIAL-ORIENTED
INFORMATION SYSTEM FOR THE MVRO). 20
Final Remarks. 28
Appendix A: The Unique Property Reference Number, UVRN. A-I
Al. Propose of the UVRN. A-I
A2. Applications of spatial identifications. A-2 A3. The integration of property administrations. A-4
A4. Application of the UVRN. A-6
is directed towards "the best-imaginable mutual adaption of space and
envi ronment and socitety". The aspect of "mutua1ity" in thi5 descri
p-tion is essential. On the one hand, social processes result in pat-terns of activities and interactions which almast always have a
spa-tial component in the farm of a demand on land and a particular
loca-tion for the activities concerned. On the other hand, those social activities are influenced by the characteristics of the area in which
they take place, the activity space. Because of this, physical
plan-ning is concer ned with the activities of individuals, groups and
in-stitutions as well as the characteristics of the activity space it-self .
In the Netherlands, physical planning is to a large degree out of the
tasks of the central government. The policy regarding planning
assu-mes a deliberate involvement in social developments which concern the
use of the land, and it therefore requires clear definitions during
policy-making process. The continuous management and control of
deve-lopments always requires reliable and extensive data. Within the
Mi ni st ry of Housing and Physical Planning (MVRO) there are a number
of information systems which are concerned with the activities of the
governmentand of real property owners. They are partly concerned
with the activities of the Ministry itself and partly intended for
other official bodies at various levels of government.
- One of the most important tasks of the Mi ni s t ry lies in the field
of space destination and activity allocations. This concept can be
described as the establishment of the aims of land usage. For this purpose, facet and sector plans, amongothers, are developed. In the destinat ion and allocation, a number of developments have taken place
whi ch entail an increased need for data. In addition to the changed
attitude towards planning, there is an increase in the scale of phy-sical-planning activities which is illustrated, for example, by a growing co-ordination of developments between planning units of vari-ous scales, which formerly pursued their own developments in relative
independence . The approach to process planning requires information
concerning not only the initial situation and the desired end situa-tion, but also the time-scale connecting the two stages. Well moni-toring apracess (progress analysis) - which is inherent to the new concept of planning - requires a continuous flow of information re-garding the spatial developments taking place.
- The Ministry has an important task in the field of planning and designing the spatial structure. In the case of urban developments the information is indispensable for public housing. Sa far as allo-cation and design is concerned, it involves the setting up and matainance of land re-allotments administrations. The latter are in-tended to assist in the planning of changes in legal status. Good co-ordination with the activities of the Ministry of Agriculture and its information systems is necessary.
- Where spatial management is concerned, the Ministry has its own
task with regard to public housing. The management of government
information for the needs of spatial management in general . For e
xam-ple , the large-scale basic map of the Net her l ands is becoming an un-missable feature for proper management of distribution networks above and below ground.
- An important task of the NVRO is to secure legal property rights.
This is provided via the Services of the Register of Real Property and Public Registry (KADOR), which make the legal status of property accessible to the public. This requires the maintainance of a good information system covering land lots, real entitlement and real rights. Developments in this field are to be expected due to an in-creased demand for information regarding the status of property in public law and its use.
In addition to these important functional aspects of the real estate situation other topics can be mentioned, such as property rates, the charging with the waterboard rates, etc. for which the MVRO is an im-portant source of information. A number of information systems exist
within the Ministry, such as those of the Central Directorate of Housing (CDV), the Government buildings Service and the Information System for Physical Planning in the Netherlands (Insyron) maintained by the National Physical Planning Agency (RPD). For the proper functioning of the MVRO it is important that there should be the optimum transfer of information between these services.
The investigation described here arose out of the need of the MVRO to draw up an invent ory of possible geocoding methods. The core of the matter is the requirement for methodsof location identification which will permit the most effective recording of the data involved and required so that the various streams of information can be rela-ted to each other and, as far as possible, can be integrated. In other words, the GEOCODING investigation deals with the spatial aspect of an information system which is of importance for the func-tioning of MVRO. The manner in which location identification is in-corporated in a spatial-oriented information system determines the
possibil ities of that system so far as the provision of spatial
in-formation is concerned . It is not acceptabel that the application of a particular method of geocoding should block the use and/or coupling of other methods, so that certain needs for information could not be met. For this reason, it is necessary to investigate the possibilities for and consequences of several methods of geocoding. The objective of the investigation was therefore defined as:
The aequisition of an insight into the eharaeteristies of
inf ormat i on requiremen ts and the possibilities of data
st or age and pro ee s sing so that the ehoiee of an optimum
geoeodi ng method is possible for the different levels of
geograp hi ea l seale whi eh are of importanee tothe fune t i
on-ing of the MVRO.
To attain the objective it is necessary to consider the characteris-tics of MVRO's information requirements and the possibilities of geo-coding in meeting them. The two components are indissolubly bound to-gether. An information systems does not exist for its own sake; it is intended to provide answers to existing and future questions. The functional usefulness of the system is therefore determined by the extent to which it can supply such answers, or by how far the system meets the needs for information. In the case of a spatial-oriented
information system for the MVRO, this means that the information system must be able to answer questions concerning the allocation design and management of environment and in relation to the secu
-rity of legal property rights.
Investigations, and acquaintance with methods developed and put into practise elsewhere, make it possible to arrive at a justified choice of an effective method of geocoding, which will make optimum use of
the data collected and recorded by many departments and organisations for meeting information requirements in the field of Physical Planning. Due to the wide-ranging and complex nature of the investigation it has been divided into th ree phases:
1. The preliminary investigation
In thlS phase an lnventorizatlon is made of on the one hand the charac-teristics of the existing information requirements, and on the other hand the characteristics and possibilities of various methods of geo-coding which may be of importance for the functioning of the MVRO. The information requirements arise at various spatial levels of physical planning, so that it is necessary to examine how that can be assembled at each level, how different data files at such levels can be integra-ted with each other and how the data concerned can be processed to yield the information requested. In this analysis, only the technical aspects and methodology are considered. Organizational and economic aspects are beyond the scope of the preliminary investigation; they form a discussion point in the succeeding phase (see also p. 27). This investigatory phase will result in a further elaboration of the problem-definition and concrete proposals for the following phases of investigation.
2. A comparative investigation of geocoding methods
In thlS phase a number of geocoding methods selected in the prelimina-ry investigation will be more-closely compared as regards their poten-tial for meeting the needs of various demands for information, and the possibilities for (dis)aggregation as necessary for different policy level s.
3. The preparation of a number of case studies
Several case studles wll1 be made ln order to support the results of the 2nd phase of investigation. They will include practical tests of the utility of specified geocoding methods in different possible appli-cations.
In 1979 the Ministry of Housing and Physical Planning commissioned the Research Centre for Physical Planning to carry out the first phase of the investigation. The report describes the inves t i gat i on and the most important results are given in the Summary.
2. CHARACTERISTICS OF THE INFORMATION REQUIREMENTS OF IMPORTANCE TO THE MVRO.
2.1. General
Within the Ministry of Housing and Physical Planning (MVRO) informa
-tion is collected, processed and disseminated for several purposes and at different locations. Usually, information with a spatial di-mension is involved. In the first phase of the study the question posed was that of the optimum method of spatial references in the variously-oriented collections of data. A background factor was the desire to arrive at a spatial-oriented information system which could meet the information requirements of the MVRO. In the analysis of the information requirements it was decided, mainly for practical considerations, to perform a funct ional analysis of the MVRO in ge-neral and of the departments invol ved - RPD, CDV and KADOR - in part
-icular, since they can be regarded as impor t ant users and publishers of information within the Ministry.
The starting points are the existing organization and departments with their explicit and implicit (policy) objectives. Subsequently, a description and first analysis of the various possible methods of geocoding were made. Comparison of the results from these two start-ing points led to a number of conclusions regardstart-ing the method of locational identification which would offer optimum possibilities for use in a spatial-oriented information system for the MVRO.
The total of the spatial units forms an entity. This is the spatial system, and can be described as "a collection of connected elements of the built-up and unbuilt-up areas, and the activities and actors therein contained with their mutual relationship and interactions". The spatial system has, therefore, aspects of location and relation. The policy with respect to physical planning is thus also concerned with the locational and relational aspects of the spatial system.
It is the concern of on one side various levels of government and on the other of various departments on the same level. Each level has its own primary responsibilities, subject however to the e
xami-nation and management powers of the higher levels of government. The intervention of Government in one sphere of activity usually has an effect on other spheres. This introduces the need for horizontal and vertical co-ordination.
The Ministry is responsible for the central co-ordination of act
iv-ities regarding physica l planning and housing: the facet policy for physical planning and the sector policy for housing. Co-ord ination
of both the sector and facet poli ci es is essential. In order to im
-plement such co-ordination properly, it is necessary that the required information should be obtained and transmitted. The infor-mation to be acquired and supplied by that process is of essential importance for the degree to which such co-ordination can be achived. Due to the independent relationships regarding the provision of in-formation, the acceptance of a uniform spatial-oriented information system is precisely the major factor in the functioning of physical planning in the Netherlands. The possibility of participating in such a uniform information system would stimulate further acceptance by the lower levels of government and the social and economic part-ners.
The argument for this is two-fold:
- the importance of unity of information for government departments concerned in the preparation and execution of a given policy; - the incidence for the information suppliers (local government) since they could themselves make use of the information system or a part of it.
2.2. Departments within the MVRO
The National Physical Planning Agency (RPD) is charged with policy preparation at the national level: the policy of creating conditions in the long term, and the policy of regulation in the short term. For this purpose, it carries out investigations and gives advice regarding physical planning, and is active within the framework of the general supervision of the observance of the Physical Planning Act. The groundwork for the task, which is laid on the RPD, is the collection, analysis and evaluation of information concerning deve-lopments in Netherlands' society in which a spatial component can be recognized. For the national policy, the national developments are of primary importance, together with regional differentiations (pro-vinces, regions), followed by developments in urban areas (urban regions). Information concerning this multiplicity of scale levels is required. Among others which can be mentioned are information in the field of urban renewal, living and environmental conditions, growth centres, intraregional and interregional migration, popula-tion figures etc. Great attenpopula-tion is paid to investigapopula-tions sup-porting policy preparation, as well as to the policy preparation it-self.
On the one hand the investigations are directed towards relation-ships within the spatial system, such as migration phenomena and welfare provisions, and on the other hand towards the procedural aspects, such as the decision-making and planning processes. An in-formation-supply system is being developed to gather and process the required information within the RPD.
The sub-division Information System for Physical Planning of the RPD is responsible for the development of an Information System for Physical Planning in the Netherlands (INSYRON). This aims at "the creation of a central point from which relevant information can be supplied to support investigative, planning and policy activities in the field of Physical Planning". Started in 1968 as a ~o-ordi nation of infrastructure programmes, it must now form a basis for the acquisition of more insight into the function of the spatial system as regards research, planning and policy. For this purpose, data of a demographic, economic, socio-cultural and ecological nature are recorded at regional and national levels. As far as pos-sible, the aim is to achieve decentralized data storage and cen -tralized co-ordination of the data files. Since it is not intended to include all necessary and desirable information in INSYRON it-self, significant effort is made to trace information held by third parties, to make it accessible and, 50 far as possible, to harmonize it. Precisely because of the facet character of the service, every attempt is made to hold the methods of geocoding open and to make
in-formation suitable for planological objectives.
The Central Directorate of Housing (CDV) is charged with the prepara-tion and execuprepara-tion.of housing policy: "the promotion of an optimum living situation for every inhabitant". The general policy is formula-ted at national level, the practical execution of it is at municipal level.
This requires good co-operation between the various levels of govern-ment, for which an efficient exchange of information is of fundamental
importance. The wishes of the individual as regards living and housing conditions are the starting point for the policy to be formulated. In order to establish the requirements for housing and living space, regu-lar investigations are made by means of opinion surveys.
The municipalities are also requested to carry out a census as necesa-ry. On the basis of this sort of data, building forecasts and program-mes can be drawn up. For the formulation of the CDV policy it is
desi-rable and necessary to link the individual dwelling/inhabitant and dwelling quality living conditions etc. to the more general (macro-scopie) starting points and applications of policy. This generally requires information regarding population, births, deaths, migration and dwellings. The character of the CDV's information requirements with respect to the RPD is less multilateral, but more specific. For this reason it is particularly unfortunate that, for example, data are available on the total number of dwellings but not on the compo-sition of th at total. This phenomenon can also be observed in the case of other parameters, such as migration. It is therefore of essen-tial importance for the functioning of the CDV, that the supply of information should be improved, and from the source onwards - from micro to macro.
The Department of the Register of,Real Properties and Public Regis-tries (KADOR) is a governmentally-established public record of pro-perty, or alternatively, a government service for performing tasks of a public legal nature in the sphere of Physical Planning, land re-allotment, water boards, levying of taxes etc.
The main objectives of the cadaster are:
- promotion of legal security and protection of real rights concerning
properties. '
- to make a contribution to an optimum policy for Physical Planning. The working unit of the cadaster is usually the parcel. Data concer-ning this are collected and issued for the benefit of government or third parties in cases of title registry, (land), re-allocations, ur-ban and rural land use and similar. In this case the geographical scale-level is mainly large scale, or the micro-level and, in the ag-gregate, the regional level.
The cadastral map, the cadastral ledger and the registers form the basis for the activities of the cadasters. They provide a framework for the administration of property. Since, together, theyreveal the legal status and the constitution of property, they perform a key function in the administration of data concerning real rights and dues. In addition, they are used for public and private legal purpo-ses (levying of taxes and clearance on endorsements).
in addition to providing a basis for tax levies it also provided a
contribution to legal security. However, the fiscal purpose of regis
-tration has in the course of time retreated into the backg round . The
KADOR has become a department for the collection, processin g and
dissemination of localized information. The KADOR can now be regar ded as an important souree of information regarding real estate, and for both private persons and government department. In the activities of
KADOR, the stress lies on the provision of data and services , in contrast with the CDV and RPD which request info rmation in order to prepare and execute spatial policy. The data which can be provi ded are concerned with the use of land (cul t i vat i on) , the type of bui l-di ngs and the real rights to the land which were and are exercised.
These data are used in the designation of property, land re- al l otment, rural and urban provisions and the provision of major inf rastructu ral
works, the determination and management of the legal situation c
on-cerning properties. The parcel register of the cadaster is thus an important souree of data, for both the CDV and RPD. Incoper at i on
of these data into spatial-oriented information systems can therefore
be considered as of extreme importance.
2.3. Conclusions regarding the information requirements of the MVRO Since the National Physical Planning Act came into force, it has been possible to observe th at a gigantic acceleration has taken place in
the consideration of the approach to socio-economie developments of
space, bottlenecks and possible solutions. Also observable are an
in-creasing interlocking of oriented facet policies and
spatial-affecting sector policies, and the consequent need for co-ordinatio n.
The funct i ons descriptions of the MVRO services involved showthat thes etasks differ not onl y in the content of the rel evant data, butal so
in the spatial scale-levels at which the data were processed and i s-sued. Within the scope of this study it is therefore concluded that , in order to satisfy the information requirements and the co-ordina-ting functions of the MVRO, a "common spatial-oriented language"is
necessary, and that the data concerned should be made useable for several purposes.
Although the differences in the three MVRO departments can be large ,
they also have much in common. Great similarities can be seen with
regard to information requirements concerning inter alia mi gr ati on, number of dwellings and urban renewal. In general it can be stated that all three departments, in spite of their differences, have an interest in and a need for a more-integrated form of information regarding the spatial system and its functioning.
What is involved is the spatial dimension of society as a whole and society's space organization in all its pluriformity.
It is not intended, within the scope of this study, to indicate pr e-cisely which elements should be included in a spatial-oriented info
r-mation system. Because of the complex nature of the spatially soc
io-economie problems, and the in principle inexhaustible needs for in-formation (still unknown so far as the future is concerned) this is in fa ct impossible.
Any geocodi ng met hod considered must be so fl exi bl e that all localized
dat a and any of thel r rel at i onal aspects which are relevant to the MVRO, now or in the fut ur e, must be in principle be enterable in the
inf ormat i on system. In addition, it is essential that optimum pro-cessing of the dat a must be possible, so that the various information requirements can be met; that is to say, it must be possible to des-cribe the spatial system as such, to perform statistical calculations, to prepare topographical and thematic maps, to draw up forecasts and estimates, to evaluate possible alternative developments and to
fol-low , to analyse, to interpret and to evaluate systematically (i.e. to monitor) the actual developments of the spatial systems.
It is not practisable to incl ude all disaggregated or micro data in one comprehensive central and integral information system.
What is important is the linking of disaggregated items of data to a aggregated spatial scale-level. The optimum usefulness of a spatial-oriented information system for the MVRO therefore demands that the starting point should be, not one data base or geocoding method for a more-or-less aggregated spatial scale-level, but to maintain the possibilities of aggregation by various relevant divisions and of linking methods. It is proposed in general that, for the functioning of the MVRO in the sphere of housing, land registration and Physical
Pl anni ng , it is of great importance to set up an information system such that it remains possible to interrelate data from the different sources at the level of the individual dwelling/and or occupant, and at the various aggregated scale-levels such as housing market areas, urban agglomerations, provinces, etc, such data concerned with popul-ation, number of dwellings, housing needs, migration, births, deaths
and suchlike.
If , at the start, when an item of data is generated (e.g. parcel, address etc.), it is given a geOgraghical key identification and appro-priate aggregation procedures are a ded, the lnformation can, in prin-ciple, be derived at all spatial scale-levels. In other words, a con-sistent and uniform aggregation/disaggregation taxonomy is requirea--ln order to permit mutual adjustment, reconclllatlon and compatibili-ty, so that unity is preserved along the micro-macro data line. In that event, the co-ordinating function of the MVRO can be satisfied, together with its extentions at various spatial scale-levels with dif-ferent area divisions relating to its management and planning activi-ties.
Introduction of the geographical key in the common spatial-oriented language must make it possible to include relational aspects as well as locational aspects in the information system. The purely locatio-nally-dlrected data links are suitable for administrative purposes; for planning and policy, however, it is a necessary requirement that the relational aspects should be added to those files. The combi na-tion of these aspects in a spatial-oriented informana-tion system must therefore be considered as essential. These necessary conditions for the establishment of a suitabel spatial-oriented information system almost speak for themselves.
It should be remarked here that a spatial-oriented information system involves not only the incorporation of a spatial dimension; suitable
processing programs are of equal importance. On the basis of given criteria it must be possible, for example, to characterize (new) areas, such as areas in which there is a shortage of dwelling of a particular type.
Existing zonal divisions of ten fail to satify the requirements of planners and researchers. The definition of new areas such as housing market areas must be possible in order to meet those requirements. New data files must be built up for newly-created zonal divisions. In addition to the ability to form the required areas and the creation of data files, different analyses must be capable for application. To name a few: accessibility and feasibility analyses, allocation ana-lyses, network anaana-lyses, progress analyses (process monitoring). The results of these analyses must then be publishable in the form of thematic maps and tables, etc. These present the information reques-ted. In practise, the above-named are far from satisfied, due to the absence of the spatial dimension in existing information systems. It is therefore useful and necessary to discover which gaps and problems exist, and whether it is possible to find solutions. For this purpose, the possibilities of the various methods of geocoding should be exa-mined.
3 3
3. METHOD5 OF GEOCODING. 3.1. General
For the description of locational and relational aspects it is of im-portance to link a spatial dimension to the data, as far as it is relevant. This also offers the possibility of including the spatial structure (a map) in a spatial-oriented information system. This structure can be defined by means of the structural relationships be-tween the pysical objects by using (infrastructure) networks. In this way the relational characteristics as well as the locational charac-teristics can be linked to a infrastructure network. The relational characteristics in particular must be regarded as fundamental for the information system, since the physical spatial policy is to an impor-tant degree determined by spatial separation, the relative locations. For object reference, two types of relationships can be recognized: 1. geometrical relationships, in which the ·l ocat i on and the form of
the objects are lncluded in a common co-ordinate system (the abso-lute location or co-ordinate structure),
2. toeological relationships, in which the location of the reference obJects are established with respect to each other (the relative location or relationaT structure).
Networks are providing the means of connecting the two types of re-lationships in practice. With these, particular spatial operations can be performed either separately or together. The topological op-erations, based on graph theory, offer the possibility of 'path finding' , allocation programming, zonal formation and zonal circum-scription. Geometrical operations make it possible to localize his-tori cal data, whereas the topological identification no longer exists. The two types of relationships therefore supplement each other. In combination they will provide, in principle, the spatial dimension in a spatial-oriented information system. The question is then: in what manner can these relationships be included in a spatial-oriented information system?
With the aid of geocoding methods, a reference system can be built up with which property objects and (socio-economic, statistical) data can be localized. Various data can then be established and linked together on a spatial basis; spatial-related statistical ana-lysis can also be carried out and the results obtained (anaana-lysis) presented graphically by means of topographical or thematic maps. The technical aspects, such as the intrinsic characteristics of soft-ware, are beyond the scope of this study; what is of concern here are the possibilities and results offered by methods of geocoding and different applications. The three starting points which are of in-terest in differentiating the various methods of geocoding are: a. choice of basic spatial units: the smallest geographical and/or
administrative units to which information can be added;
b. methods of representtng reality (i.e. the spatial system) in the information system;
c. methods of locational identification. a). The basic spatial units.
In general , the choice of the basic spatial unit as the locational aspect of the spatial'st ruct ure can be made from the following
geo-graphical and/or administrative units:
1. administrative areas, such as provinces and municipalities; 2. functional areas, such as catchment areas, census tracts and
post code sectors;
3. blocks, such as areas surrounded by roads, waterways and rail-ways and other separating features;
4. segments, such as intersections of roads and other networks; 5. objects, such as buildings and parcels.
These areas do not form a hierarchic system, so that much overlap-ping is possible. The choice of the basic spatial unit at a small-scale level or more-regional level is therefore subject to restric-tions from two sides:
- there is no information available concerning smaller units, - there is a restriction on the possibilities of aggregation into
larger units (because only combinations of those units is possi-ble) .
Careful consideration of the consequences is therefore advised in the choice of a basic spatial unit. For the majority of CDV and RPD applications it is the regional or small-scale level; for KADOR the parcel or large-scale level is of interest. In this connection it should be remarked th at different zonal systems are of ten used in parallel at one spatial scale-level. For this reason, these spatial units at small-scale level cannot determine the choice of basic spatial unit of an information system for the MVRO. The functioll-ality and applicability of a spatial oriented information system are determined by the degree of detail of the data since, given a particular level of detail, the division of data at a lower level of aggregation cannot be performed satisfactorily or at all. In other words, just as in the research of the characteristics of in-formation requirements, the maintainance of the micro-macro data line is again essential for the functioning of an information system. The micro-level should therefore be the starting point in the choice of the basic spatial unit. A basic spatial unit is a locatio-nal aspect of the spatial structure. A network has in fact no loca-tional function; a network introduces, via the tcoo loqtcal relation-ship, the relational aspect of the basic spatial units or aggrega-tions of the latter. In this context, a network cannot be regarded as a basic spatial unit. The basic spatial units are, so to speak, suspended from the segments of a network; they act as information carriers.
b). r1ethods of representing reality in the information system. In the description of the spatial structure the relationship between the real situation and the representation of the real situation should be kept in mind. The real situation can be thought of as consisting of objects such as buildings, superficial areas such as administrative areas, and networks such as roads. These three ele-ments can be represented by the three basic eleele-ments of those methods of representation, namely points, polygons and lines respec-tively. It is however possible to represent areas by points. Gener-ally speaking the th ree figurative elements derived from the reality and the three methods ofrepresentation lead to a total of nine com-binations (see figure 1). Only the th ree combinations in which the
represent at i on corresponds to rea1ity are acceptab1e in a
spatia1-oriented information system, i.e. objects represented by points,
areas by po1ygons and networks by 1ines. In the other cases either
di s t or t i on or 10ss of information occurs. The consequence of the
proposed representation is that a spatia1-oriented information system wi11 represent the spatia1 structure by using points, 1ines
and po1ygons. On1y when all th ree basic e1ements are used together
a complete representation of rea1ity wi11 be obtainab1e from the information system.
A1most all the information systems in the Netherlands are on1y based on at most two of the three basic e1ements and they are therefore not adequate1y suitab1e as a spatia1-oriented information system for the MVRO. An attempt to arrive at an integration of these three basic e1ements must therefore be regarded as not on1y desirab1e but essentia1. On1y then wi11 it be possib1e to link up with each other
the information systems which a1ready exist in the various
depart-ments of the MVRO.
cl. Methods of 10cationa1 identification.
Objects and subjects can be given a 10cationa1 identification in
two ways, viz. by an externa1 index or by a co-ordinate
identifica-tion. In the case of the externa1 index a code number is given to a
particu1ar area, e.g. school district 23. The geographical 10cation
of school district 23 is impossible to find without the use of a
map. When a co-ordinate identification is used the map is, as it were, transferred to the data file. In this case, all manner of geometrica1 operations can be performed, such as distance and
accessibility ca1cu1ations. There is a1so the poss i bi 1i t y of
auto-matic cartographic reproduction.
3. 2. The three basic methods of geocoding
Various methods of geocoding can be achieved with the aid of the
three basic e1ements. For the sake of good understanding the report
first discusses the methods of geocoding based on separate e1ements. The point method can be used as a reference for objects and areas. By addlng the co-ordinates, the point can a1so be reproduced carto-graphica11y and geometrie operations are possib1e. When the objects and/or areas are sufficient1y smal1 there is in addition a good agreement between rea1ity and representation. As the areas become 1arger the degree of abstractness increases and the point acquires on1y asymbolie va1ue.
In any case, only the reference points of the areas concerned are known, and not their 1imits, so that without additiona1 information (e.g. a map) there is no know1edge of the size of the areas or of their re1ationships with their neighbourhood.
In addition, the use of the point method a10ne is not to be recom-mended, since it cannot represent any network at all. The re1ationa1 aspects of the spatia1 structure cannot therefore be represented, so that an information system based on the point method suffers from many 1imitations.
The point method can, however, be a good aid for the exchangebi1ity and comparabi1ity of basic spatia1 units, such as addresses and simi1ar. By subsequent1y 1inking the point and 1ine method (for
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stance by means of projection) the earlier mentioned limitations can
be removed to a large extent.
The line method is used to represent (geographical) networks, such as road systems and boundaries. In a spatial-oriented information system
networks have in fact a two-fold purpose. On the one hand networks
represent the physical structure of the spatial system and on the other hand they can be used as a reference for certain, more indi-vidual, data, such as addresses. The information is, as it were,
attached to the lines or segments. A network is in fact a mixed type
of information, consisting of intersections and lines; the interact-ions are points, nodes, (usually provided with co-ordinates) and the connections between the nodes are the lines, which are also known as segments or links. By adding co-ordinates to the nodes the seg-ments become fully localizeable. The network consists of segseg-ments from which directions can be recognized. This creates the possibility of distinguishing the sides of the segments and of linking data to each side. The latter can be achieved by projecting the points in-volved upon the segments. The data, which are now linked to the
seg-ments, are of two kinds, namely the characteristics of the segments
(infrastructure) themselves and the remaining characteristics of the spatial system, i.e. the physical or property elements, lying on or
in the neighbourhood of the segments. The segments can then function
as information carriers in the data file. They are in fact a
distri-bution key referring to other data files and as a carrying unit they can function in analytical and planning methods. The segment file thus functions as a geographic base file, with which a number of operations are possible. In particular, topological and geometrical relationships can be established; this is a great advantage compared with the point method.
The polygon method is a method by which a given area is identified by describlng its contour and in which that area is considered as a
basic spatial unit too. The information is concerned with the area
as a whole and not over the distribution within it. From a
methodolo-gical point of view, the polygon method (also called the area method)
is an extension of the point method, since in addition to a nominal code (external index) for the area, the boundaries are defined too. In spite of the defined boundaries of the areas, the polygon method
is limited in its possibilities. This·method allows only the
loca-tional aspects of the spatial structure to be indicated. Without linking the line and the polygon method, the matter is not useable for a spatial-oriented information system, since it does not include
any relational aspects. With the polygon method two types of areas
can be distinguished, i.e. those with equal size and shape and other
areas. Use of the first type of area is well known under the name of grid method. A grid of squares, to which the information is linked, is laid over the area under consideration. In the case of irregular
si zes and shapes, the concept "organi c areas", or zones is used. In
general, information is required on organic areas, in which cases
squares are used to represent these areas.
Consideration of the individual basic methods of geocoding shows that
each of them has it s limitations. These methods can only supplement
each other and need to be integrated obviously. Therefore a spatial-oriented informationsystem forthe MVROschould be aimedatsuch integration.
3.3 . Aggre gatio n procedures
As far as the spatial dimension is concerne d, a spat ial-orie nt ed information sys t em can be build up in a central ized and a modular manner. All data files based on the point method, such as addresses , can remain as independent units. By adding only the re l evant segment code, a spatial structure is int r oduced , linki ng with other files is achi eved and the basis is laid for application to small scale level s, such as housing market areas and urban areas. Thi s type of appli ca-tion has become possible thanks to the very important addition of the segment method in the American DIME (Dual Independent Mappi ng Encoding) system (see figure 2). The application of the line me th od also implied the creation of blocks ; these are the areas which are surrounded by the smallest possible number of segments . The rel evant data are then either linked to the segment side of a bl oek , or lin ked in combination to the bloek, or both.
Starting form these possibilities, aggregation towards large r units can take place. This is very important sincemany appli cati ons of the MVRO involve the small scale level. The segmen ts are the infor-mat i on carriers and they can be easily integra ted into blocks, neigh -bourhoods and other types of areas.
The aggregation of segments can be divided into two groups:
a. locational aggregation, in which segments are combi ned on the basi s of land use or other criteria on each side of the segme nt .
b. relational aggregation, in which segments are eliminated on the basis of characteristîcs of the segments themselves.
Locational aggregation can in turn be divided into two categories , i.e. block aggregation and segment aggregation. In the last case grouping can take place by combining segment sides, on the basi s of parti cula r criteria, to form arbitrary new areas. In sueh cases it is possible to locate the boundary in the middle of the road, i.e. the segment, or in a manner of speaking to set the boundary behind the entrance of the buildings along one of the two sides of the road. In the case of block aggregation, the information is in fact added to the segments beforehand, forming block information , whic h, by combining blocks forms group information. Since, at the start of the process, no difference is made as far as the information on the di f-ferent segments is concerned, block aggregation can be considered as a fairly crude form of aggregation. In contrast, aggre gation on the basis of segments is much more precise. When cri teria accur acy and the differences at the boundaries are impor tant , segment aggre-gation is perferrable. The two locational aggreaggre-gation methods are aggregations in which the intrinsic characteristics of the network structure play no part; it is concerned rather with the characteris-tics of the land use on each side of the segments. The newly-fo rmed areas are, true enough, surrounded by segments but the latte r now have the function of boundary instead of a function as channel of communication. In order to preserve the characteristics of the spa-tial structure in the information, it is necessary to aggregate the segments as well as the land use , 50 th at a suitable small-scale
network remains. Such aggregation of segments for relational consi-derations generally takes place by removing segments of low order. The degree to which segments are removed depends on the applications
aims. There are thus two lines of aggregation, i.e. locational and relational aggregation. In this manner, for example, the urban area division and the corresponding traffic infrastructure can be derived. After the aggregation procedure it is necessary to connect both lines with each other, so that the areas created can again be linked to the infrastructure of the reduced networks.
The simplest method of doing so is to project the reference points of the areas (i.e. centroids) upon the segments. Following this, normal applications of statistical and geometrical analyses can be used.
3.4. A spatial-oriented information system
With the aid of the aggregation methods described above all interim stages of the micro-macro data line can be reached, and thus cross-sections of the spatial structure can be taken at any scale-level. If a spatial-oriented information system is set up in such a way that the requirement to preserve the micro-macro data line is met, the preceding aggregation and th us also the disaggregation procedures are uniform and consistent. For obtaining a cross-section at a given spatial level, in principle two methods of approach are possible. An aggregation can be made starting form the micro level and from the macro level disaggregation can be carried out. In other words, a spatial scale-level is attainable by means of a "bottom up" or "top down" approach; the choice of approach depends on the aim of the application and on practical considerations. From the foregoing it appears that various zonal divisions are possible at different scale-levels. The following division can be envisaged. The first half con-cerns all the divisions lying between national level and the muni-cipalities, and the second half involves divisions of an intramuni-cipal nature. The last group of intralocal zonal divisions is achiev-able by means of a polygon aggregation from the microlevel (the "bottom-up" approach), whi 1e the fi rst group can be thought of as an aggregation from the municipal level, supplied with municipal data
(the "top down" approach).
The top down approach can be regarded as an independently created zonal division at a higher level than the municipality linked to an (infrastructural) network, which can be sub-divided as necessary. In spite of the limitations, since a considerable amount of data is available at local level and the construction of regional networks is fairly simple too, so that the use of the top-down approach with the municipality as the basic spatial unit is very attractive. This system can be made operational in a very short time. Such an approach with zonal divisions at a regional level, all kinds of statistical analyses can be carried out and information can be provided for policy-making questions. In addition, this approach is very attractive be-cause, when the bottom-up approach becomes possible for an increasing number of municipalities, it can be absorbed in the top down approach very simple. The two methods of approach offer possibilities for the development and creation of a spatial-oriented information system, because of their consistency and uniform properties. It is, however, not necessary that the system should solely and completely be based on the micro-level. A start can be made from the macro-level
simul-taneoûsly. When certain scale-levels with given zonal divisions are repeatedly required, a sub-system of the spatial oriented informa-tion system can be developed by proper choice of a reduced network and associa ted zones (areas and/or grids). For example, use can be made of a trunk road network of the Netherlands with the pr ovi nces and/or housing mar ket areas linked to it. In addition, a provincial infrastructure network can be constructed, to which urban areas can be linked, or an urban networkwith dictrict areas. The informati on already available can then be added to the inf ormat i on systemand supple mented with the additional information resultin g from the bottom-up approach.
The to~-down and bottom-up approaches are in fact supplementary to each other. The setting up of a spatial-oriented informatiollsystem on the basis of the bottom-up approach alone would be a ti me-consumi ng activity. It would then take too long before suffic ien t information will be available at a regional level. For this reason, the bottom-up approach shoulá be selectively used in areas where the urgency is great. The top-down system would then takecare of a national approach. For the realization of a spatial-oriented in -formation system (see figure 3) the spatial system should be in-corporated in the information system through two lines as regards both structure and function. One line follows the network structure of the spatial systemand the other one indicates the ki nd and location of the activities concerned.
On the basis of a representation of the actual situatior., a network structure is derived via a topographical map and geocoding methods. This establishes the localisation of the various physical eleme nts as well as the related activities. For this, thre e sub-structures are derived, viz.: '
a. a mapping structure, showing the network and the co-ordinates, so that cartographic representations and manipulations are feasable.
b. a relational structure, in which the relationships between the spatial units, such as blocks, school districts, census tracts and similar are established.
c. a traffic structure, in which the technical characte ristics of the networ k are assembled.
These network structures together form the geographic base file, in which the whole structure of the spatial system is built up. From this file nodes, segments and all kind of zoning systems can be derived.
The relevant information can be suspended from these elements with the aid of spatial distribution keys, and later compared and ex-changed. The spatial-oriented information system is aimed firstly at improving the basic inf ormat i on by recording the locations of spatial activities in a number of base files. Examples which can be mentioned include files for population, empl oyment , property, labour vacancies, commuting relationships, migration, energy con-sumption, etc. Such files can be set up and managed either inde-pendently or in common. What is essential is that they should relate to the basic spatial units and should also be provided with locat'ional identifiers, the spatial-distribution key. From these base files many types of working files can be derived.
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linked and, as necessary, to be aggregated and sor ted into file s
with segments, co-ordinates, blocks, designated areas, regi ons, et c .
Wi t h the wor king files thus obtained various applica tions can be
carried out. As examples of such there are many types of st at i st i
-cal -calculations, e.g.correlations, feasability studies, dete
rmi-nation of catchment areas, planning the allocation of facilities,
thematic cartography and similar. For each information system,
application programs are required in order to perfarm the
necessa-ry calculations and thus obtain the desired information. From
dis-cussions on the different applications it appears that good appl
i-cation software can be found, such as DIME, NIMS, TRAMS, GIMMS,
ODYSSEY and others. These software packages, developed abroad,
were mostly prepared for special purposes and later generalized.
Same of them are also reasonably transferrable for different types
of computers. There is also a gradual realization of the need, caused by the specific application possibilities, to integrate these packages from different countries. This has already been succesful in a number of cases. In this connection, attention is
drawn to current developments in software. Apart from an e
xten-sion of applications at local level, the software is being made
suitable for applications at regional level. Collaboration in this
development would result in a good opportunity to implement appli
-cations software in the Netherlands which would help towards a suitable spatial-oriented information system of interest to the
4. CONCLUSIONS AND RECOMMENDATIONS (FOR A SPATIAL-ORIENTED INFORMATION SYSTEM FOR THE MVRO)
Recent years have seen important developments in methods of data pro-cessing. Until a short time ago the computer was used only as a calcu-lator, but due to the spectacular development of the equipment and the increased insight into the possibilities of use, there is now a gene-ral tendency towards use as a genegene-ral store for large amounts of data. Present-day society can scarely continue to function without the in-formation required by the policy-makers. This inin-formation must be re-levant, butmust al so be available quickly and timely, so thatdecisions can be made in an effective manner.
Due to the usually specific purposes of the various data files, no di-rect linking is possible. Great problems arise in the provision of in-formation due to, in particular, the choice of different spatial units (for establishing data), such as blocks, neighbourhoods, CBS census tracts and 500 metre squares. In many studies the greatest amount of time (and thus costs) is spent on collecting and building up data files, which can hardly be used for other purposes. It of ten appears impossible - due to the different methods of locational identification-to relate data identification-to each other. For the MVRO, where the needs of Physical Planning and Housing require much data and information at various spa-tial scales for different and of ten overlapping zonal divisions, the requirement arose for an examination of the method or methods of
geo-coding which would be applicable to meeting such multivarious needs.
The object of the study for the MVRO is to arrive at a mutal agreement, and if possible co-operation, between the various departments in the
field of a spatial-oriented information system. Accordingly, this
study has been directed towards the characterization and possibilities of the various methods of geocoding as regards meeting those needs for information.
It has become obvious that although various basic methods of geocoding,
exist, separate application of such methods - as a basis for a spatial-oriented information system - fails to make use of a large number of possibilities and can in general even result in a blocking of the
in-formation supply. For this reason, and from social and technical points
of view, an integration of these methods is to be preferred.
The most important conclusion from this study is that an integration of the various methods of geocoding (point, line and polygon) will make possible an agreement and co-operation between the MVRO departments in
the fields of spatial-oriented information provision. This conclusion
can be drawn despite the of ten large differences in the information needs at various scale levels. The possibility of the agreement is of-fered via the concept of a consistent and uniform construction of the micro-macro data line, making use of a 'common spatial-planning
lan-guage' and suitable aggregation procedures. The different data files
and information systems of MVRO departments can then be integrated in a simple manner.
It can be said that the KADOR is most concerned with the information at the micro-level (large-scale level), the RPD on the large scale
(dwelling/address files and 500 metre squares) and at small-scale le-vel, and CDV with information on individual housing needs, housing quality and object and subject subsidies mainly at municipal and
re-gional (small-scale) level. The data files built up by these depart-ments are mainly locational in character. These data files can be
use-fullly employed by the addition of a relational component.
On methodological grounds it appears that a common spatial-planning
language for the both location and relational aspects of data and a consistent micro-macro li ne form the sufficient and necessary conditi-ons for a spatial-oriented information system. There is also a syner-getic side-effect, since an information system which meets these con-ditions is also useable for a number of objectives of the various de-partments of other ministeries as well as the provincial and local authorities. In this connection, the recording of traffic accidents, infrastructural property (street lamps, trees etc), hospital patients energy consumption, subsidies, etc. can be envisaged.
This studyhas produced a general inventorization and evaluation of me-thods of geocoding. This is only the first step on the road to a spa-tial-oriented information system (for the MVRO). A number of conclu-sions have been formulated with regard to the requirements which must be set for an effective spatial-oriented system to produce agreement and co-operation of the various MVRO departments in the field of in-formation supply.
Different lines of research have been set out to provide the basis for the agreement and best-possible integration of existing sources of in-formation and systems, in such a manner that the formulated require-ments can be met. It is now important to consider what are the
condi-tions for the various existing information systems to remain or to
be-come decentralized and to be mutually adjusted with respect to the
spa-tial dimension.
Precisely by the use of existing data files and information systems, and by making use of developments in automation at the local level,it is possible to arrive at a spatial-oriented information system at rela-tively low cost, with the minium of modifications and in the short term. A single comprehensive and integrated information system to meet all the needs for (localized) information is thus to be avoided.
The second step concerns a further study of the different aspects.
In the succeeding phase the practical implications connected with such a (decentralized) system should be examined. In this respect it is also important - apart from the insights into content - to obtain an insight into the organizational and financial consequences. For this reason, nine research proposals have been formulated. The objec-tives of these is to attain:
A. a Unique Property Reference Number. For the administrative
co-ordi-nation of registration of address and parcels (see appendix A); B. a Unique Property Reference Number, provided with co-ordinates, to
make possible geometrical and topological operations (see appendix A);
C. a segmented spatial-oriented information system for the consistent and flexible processing of data according to any required zoning system at any spatial scal e-level;
D. a regional spatial-oriented information system using the
municipa-lities as the basic spatial unit which will produce an operational
spatial-oriented information system in the short term;
t.
a local/regional spatial-oriented information system with districts and/or squares as the basic spatial-unit as a particularization of the regional set up;F. orientation, implementation and development of software for
(re-gional) spatial-oriented information-systems and testing out the
use in the Netherlands of program packages developed abroad; G. organizational conditions for the vertical co-ordination required
for a consistent and uniform supply of information for the MVRO. H. comparibility of polygon structures (districts) in time so that
spa-tial developments can be analyzed;
I. comparability of different polygon structures on a cross-sectional basis to discover how squares can be adjusted to division by
dis-tricts.
Proposals A, Band C involve the large-scale level. A and B are ai~ed
at making it possible to link and interchange address and parcel admi-nistrations. The creation of such a relationship between the two met-hods of locational identification, which are by far the most important
at that scale-level, offers the possibility of an important gain in
information, including the qualitative characteristics and ownership
relationships of the (existing) housing stock. Proposal C entails the
development methodology for the consistent and flexible reduction of data at this scale-level to provide the information required for any
policy-relevant regional.division. In practice this proposal makes it
possible to expand administratively formed files into planning and
policy directed information systems. Proposal C therefore links up
with the first two proposals. However, it remains loose from them. The
development of a segmented geographic base file is possible without the existence of a linking between the parcel and address administra-tions, although the information gain mentioned in connection with
pro-posals A and B would not be obtained. Proposal C is also free in time
from A and B; this research can be carried out without the need to
know the results of A and B.
Another line of research is provided by proposals D and E. These are
based on a somewhat more limited objective since municipalities and
districts are used as the basic spatial unit. Balancing the limitation
imposed by the relatively small scale of the basic spatial unit used is the advantage that with this line a spatial-oriented information system for supplying regional information can be achieved in the short
term. By setting up this system in the manner proposed, a complete in
-tegration with a system set up along the large-scale line is assured at a later stage.
The optimum and effective use of the possibilities of an information system requires a coherent collection of computer programs, or
soft-ware packages. This is needed so that the information can be supplied
to the user in the form required.
Several such program packages have been developed in other countries
(Sweden, the U.S., England and Germany, for example).
The third line of research proposed is the examination of the applica
-bility of these packages to the situation in the Netherlands
(propo-sal F.). This proposal must be regarded as the basis for all preceding
proposals and must therefore be given a high priority.
Proposal G is of a completely dif f erent type to the foregoing. While
the latter were directed towards content, this proposal has a more
organizational character. Because the munipalities are on the
thres-hold of the automation of their data files, it is of great importance to the MVRO to ensure that they retain their access to the supply of
exchangeable and comparable data.
Proposals 11 and I concern particular applications of certain data structures. These two proposals form a logical follow up from
propo-da1 E. - .
A more-detailed form of the propasals is: Proposa1 A: A Unigue Property Reference Number
For the recording of real property elements, two methods of locatio-nal identification are used, namely the exterlocatio-nal index and co-ordinates.
The address and the cadastral parcel number are two important exter-nal indices. If the purpose of the record is aimed at the property objects the cadastral parcel identification is of ten used for iden-tification, while records concerned with persons and activities generally use the address as identification. To bridge differences in identification, an administrative linking of address and cadastral parcel number is required through a Unique Property Reference Number (UVRN). Property elements can thus be recorded in a relevant and un-ambiguous mannel'.
A cadastral parcel is a legal unit and may contain one, several or no addresses. In general , a park has no address, while an individual may own several adjacent dwellings. In that case those addresses may belong to a single parcel. The result is that different property administrations may be based on differently identified basic spatial units.
Many such administrations have been established and are controlled by different organizations. There is thus no central organization for address records. Although the municipality is to be regarded as the initial source of addresses, the necessary co-ordination does not occur, so that, particularly as a result of ad hoc mutations, there is ambiguity in the records. For example, the Revenue Office gathers information regarding the collection of taxes, and the Central Directorate of Housing also gathers much information concerning dwel-lings in connection with the building programme and the provision of subsidies, etc. With the recording of cadastral parcels, the actual legal status of property information, the registry functions as a central organization for many departments. In the case of address records, such an organization is unknown. It appears that many address files are compiled, processed and used at various levels of govern-ment. The necessary consistency is, however, still lacking. It does not appeal' likely that one of the lower levels of government will be able to act as the central co-ordinating body for the real property
data files. The conclusion can there be drawn that, in order to im-plement an improvement in the provision of information in the field of Physical Planning, the central co-ordinating role in the provision of information on property matters for the purpose of Physical Plan-ning should be assigned to a single central government organ. At the moment the RPD, in co-operation with the Central Bureau for
Statis-tics and the Postoffice is working on a qeoqr-aphicaTly-oriented address file. This is a locational data file in which addresses have been or are being linked to many types of zonal divisions. A linking through the UVRN would bridge the differences between addresses and parcel records. With a UVRN it is possible to take into consideration
