The Dutch Cooperation Between NSI and NMA
The Dutch co-operation between NSI and NMA
(Niek van Leeuwen)
Abstract
Statistics Netherlands co-operates with the Topographic Service of the Netherlands (TDN) from 1994 on different projects. De delineating of de neighbourhoods within communities is incorporated and harmonised with the map of the community borders of the TDN to produce comparable area and density statistics. From 1998 on the digital geometry and topographical features of the topographical map of the NMA, scale 1:10.000, are used as a base for achieving land-use statistics. Benefits of this product are harmonised geo data between the land-use map and the topographical map and a severe lowering of the costs of achieving this statistics. For both products, the land-use map and the combined community and neighbourhood borders, an arrangement has been made to provide these two digital products of the NSI for low additional costs to governmental and public users of NMA digital vector data.
Introduction
Statistics Netherlands (NSI) has a long history of statistics on land-use and statistics on neighbourhoods of communities.
The use of products of the Dutch NMA dates back to 1975 when analogue topographical maps at scale 1:10.000 were used in land-use surveys. This paper describes both the system of neighbourhood borders and the acquisition of land-use statistics and depicts the history and present use of these products and the publication of two combined products of the NSI and the NMA.
System of neighbourhood borders
The system of dividing communities into districts and neighbourhoods dates back to the census of 1947 and has been updated every census. From 1983 onwards the system of assigning addresses to neighbourhoods was yearly updated. Reason for this was that the Geographical Base Registration (GBR) was used as a sample survey for enquiries on persons and families. The GBR contains an address with postal codes, neighbourhood and community codes and a 500 x 500 m co-ordinate.
Since 1995 the NSI produces statistical data on a selected number of subjects for neighbourhoods. An aid in calculating statistics is the digital map of the neighbourhoods and districts, an integrated map of neighbourhood and community borders. The first version dates from 1994. This map provides in combination with the land-use map, figures of area of land and water, land-use and population density per neighbourhood. Furthermore, it is used for presentation purposes.
The map of the community borders of the NMA is also used in delineating communities to produce area statistics on land and water. The Ministry of Finance accepts the map of the community borders as a standard for several of the criterions, related to spatial subjects, in the system of funding communities by the central government.
The NMA produces and updates the map of community borders every year. The neighbourhood borders are harmonised with this map and the combined product is being sold to the public. The costs merely represent the cost for the NMA for producing the changes in community borders. The additional neighbourhood borders are provided by the NSI for small additional costs.
System of land-use statististics
The first inventories of land-use were obtained by administrative surveys. In 1975 the topographical maps were introduced in obtaining land-use information. Local authorities were asked to indicate the type of land-use and to delineate this on the analogue maps (scale 1:10.000). Planimeters were used for measuring the area of the different types of land-use for the communities. Performing the planimetry was done by the NMA until 1978, when the NSI took over this work.
Since it was discovered that the interpretation and assignment of types of land-use differed between local authorities, the NSI, at the end of the 80’s, also took over the task of interpreting the type of land-use for the country as a hole. Land-use statistics were produced every 3 or 4 years. The existing types of land-use were, for the first time, put into a GIS and areal statistics of land-use were derived from the digital maps. The first survey, produced this way, was the 1989 survey, using analogue aerial-photo’s.
In the 1993 survey the digital land-use map was revised, digitising from the latest edition of the topographical map at scale 1:10.000. In the 1996 inventory the method of obtaining land-use changes was improved once more by the use of digital monoscopic aerial photo’s. Changes in land-use were digitized on the screen.
In the year 1998 the digital topographical map at scale 1:10.000 (TOP10Vector) became nation–wide available from the NMA. This publication contains all the information of the Digital Landscape Model and therefore contains area and length information on topographical features, physical features that can be objectively observed in the field.
The production process of the land-use map changed again dramatically in the publication of the year 2000 survey. The digital landscape model of the topographical map made it possible to use this geometry as a base for survey. Some of the information of this digital map could be used for the land-use survey, making own inventory work superfluous. But also other developments justified co-ordination between the NMA’s TOP10Vector and the NSI’s digital land-use map.
First, a policy development on standardisation in the provision of geographic information calls for streamlining geographical data. TOP10Vector was recommended the status of a national standard for digital geographical information on mid-scale level (RAVI, 2000). The ministries responsible for the distribution of central government funds to local authorities make use of the TOP10Vector from 2001 on. The digital land-use map should therefore be in line with this standard map.
Second, users made combinations in a GIS of the topographical map and the land-use map, which before the year 2000 survey, implicated numerous differences in the positioning of common features (slivers) and therefore less accurate statistics.
Third, making use of the digital geometry speeded up the production of the statistics. In the 1996 survey some 3 to 4 persons were working in daily production for 3 years on a survey. The 2000 survey was produced by some 2 to 3 persons during a 2 year production cycle.
For the NSI it was therefore necessary to get access to the topographical map for the production of her land-use statistics and to perform a conversion process to transfer land-use codes to topographical digital geometry. Organisational problems had to be solved to provide the land-use map at low costs, which is an important policy of the NSI.
The NMA is a part of the Ministry of Defence. From 2004 the NMA will be merged with the Cadastre, the Dutch organisation responsible for registering the delineating of real estates and their ownership. This newly formed organisation will be called “Topografische Dienst Kadaster” and is not an governmental organisation but a self-reliant organisation
To organise the continuing access to the topographical map as a base for land-use survey, a third party, the Ministry of Housing, Regional Planning and the Environment is involved. The Ministry is the key user of the land-use map and land-use statistics. This Ministry is also responsible for the geographical information policy in the Netherlands. The covenant between the NSI and the Ministry of Housing, Regional Planning and the Environment demanded public access to the land-use map for third parties at low costs.
An agreement between the Ministry of Housing, Regional Planning and the Environment and the NMA was drawn up. The use of TOP10Vector by the NSI is provided by this agreement between the Ministry and the NMA and includes a license for the use of TOP10Vector in the production of the land-use map. The NSI is allowed to produce the statistics derived from the land-use and topographical map. The parties agreed that the NMA will be responsible for further distribution of the land-use map. License holders of TOP10Vector will obtain the product at delivery costs, while users who do not have a license for TOP10Vector can obtain the land-use map for EURO 1,000.- per NUTS2 region.
References
CBS 2000, Process redesign of area-based statistics: The role of the digital topographical map. Paper prepared for the Working Party “Geographical Information Systems for Statistics”, Luxembourg 2000. Document E/GIS/33/EN.
RAVI (Netherlands Council for Geographical Information) 2000. Troefkaarten in de informatie-structuur. Haalbaarheidsstudie Authentieke Registratie Geografisch Kernbestand. (Trump cards in the information infrastructuur. A feasibility study Authentic registration Geographical Base File) RAVI report 01-02.
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