I
surveying bureaus in the country. In order to meet the
demands of users this triangulation network is now
being densified with the aid of integrated polygon
networks to establish a fourth level of national control
points.
A second activity started more than 50 years ago with
making a contribution to land consolidation projects. In
these projects a reconstruction of rural land on the basis
of a re-allocation of land property is performed. The
Cadastre actively participates in the organization of
these projects. Its main task concerns the planning of
the new land use and property situation. Mr. Sonnen-
berg will explain this particular activity of the Cadastre.
A third special activity of the Cadastre concerns cadas
tral renewal. The often bad state of the original maps of
1832 has made it necessary to renew the maps comple
tely. The fact that the cadastral maps are also used by
other institutions resulted in more stringent require
ments having to be imposed as regards their quality.
Moreover, the original maps were not based on the
national grid system which presented ever increasing
problems in their use.
Especially after the second world war an intensive
renewal programme was drawn up. So far about 30% of
the cadastral maps have been renewed and matched to
the national grid system as a result of cadastral renewal
and land consolidation projects.
In spite of the intensive renewal programme the need
for good maps has only partly been met for several
reasons. One of them is the island form of the map,
which is not suitable for many external users. Further
more the contents of the cadastral map were not suffi
cient for some users, because only buildings and
property boundaries are represented and hardly any
topography is shown. Moreover, the renewal program
me has not been systematic, but project oriented, and
thus the renewed maps form an irregular pattern.
This is one of the reasons why about seven years ago
the government decided to give the Cadastre the task to
make, keep up-to-date and publish a large scale basic
map of the Netherlands.
The large scale basic map is a map series, matched to
the national co-ordinate system, systematically divided
into map sheets in window format, representing basic
topographic information. The purpose of the map is to
produce a standard for all users in need of large scale
maps, who can add their specific information to the
map, for instance underground networks. It is clear that
such a basic map can reduce the cost of mapping since
they will be shared between users. Moreover, the use of
the basic map by all users makes the exchange of map
information much easier.
The principal characteristics of the large scale basic map
are:
- map sheets with a format of 50 x 100 cm corres
ponding with the national grid system;
- the scales are 1 2000, 1 1000 or 1 500 depending
on the density of topographic detail; the scale 1 1000
is generally preferred;
- the basic topographic information on the map com
prises buildings, roads, water, ditches and some
semantic information, such as street names, house
numbers and symbols.
NGT GEODESIA 82
The mapping programme has resulted in the production
of about 5000 maps since 1975, which means that about
8% of the area of the Netherlands has been mapped in
this way. A start has been made with the production of
another 5000 maps.
Although the philosophy underlying the large scale
basic map is generally accepted by the map users in the
Netherlands, realization of the map is still confronted
with serious financing problems. Up to now a separate
contract has been drawn up for each project with diffe
rent specifications in respect of quality and contents to
suit the requirements of the users and with different
provisions for the division of cost. Efforts are now being
made to develop a policy based on general financing by
the government and selling the maps to the users at
standard prices.
The present cadastral tasks show that the multi-purpose
cadastre is already very much a reality. Nevertheless
there are possibilities for new tasks in the near future.
Especially the growing demand for land information for
many purposes can largely be fulfilled by the Cadastral
Service. This statement can be illustrated by a descrip
tion of the government tasks for which land related
information is needed:
- The legal task of the government involving the regis
tration of deeds and in connection with it the regis
tration of real rights on real estate in respect of prop
erty. This task is already being fulfilled by the Cadas
tral Service.
- The government task of regulation of land use, which
means that the future use of property is laid down as a
result of physical planning. Cadastral information and
maps are needed for this task at local government
level.
- The reconstruction of land concerns in fact the reali
zation of the designated land use. The Cadastre
already plays an important role in land consolidation
projects. Urban development is mainly carried out by
local government and private companies. But it is still
necessary for the Cadastre to supply information to
this end.
- The real estate planning concerns the government
and private activity of changing the property rela
tions. The cadastral information is indispensable for
this task and in case of land consolidation the
Cadastre itself provides the re-allocation of land
property.
- The actual use of land is an important element of
information for several government tasks, such as
physical planning, housing, agriculture etc.
- Land management is an important government task
in which the Cadastre can play a role as supplier of
information.
- A traditional government task is the levying of land
taxes. The Cadastre often provides the basic infor
mation for this.
To meet government requirements for land information
properly, it will be necessary to build up an integrated
information system in order to answer quickly and flexi
bly demands for information.
For this reason a cadastre-based land information
system is now being developed. The basic structure of
this system is shown in this diagram:
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