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astral parcel
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parcel also
Jed property
including buildings and structures located within it.
However, in this paper, the discussion is mainly
focused on land parcel.
For each cadastral parcel object, the following classes
of basic information can be distinguished:
- Spatial description
- Ownership or stewardship
- Use and resources
- Economic value
- Subject (person, persons or institution)
Spatial description relates to location and shape of
parcels including topological information.
Conventionally this information is normally gathered
and presented in a large scale cadastral map where
unique parcel identifiers are indicated. In some
countries, the field sketches for each parcel are also
included and attached to a deed or a title.
In digital database environment, parcels are digitised
or constructed through coordinate lists, and modeled
in topological relationships. Each parcel is constructed
from three or more boundary lines. The boundary line
is made by joining two boundary corners who
locations are known in term of local or national
geodetic coordinate reference system. In addition to
these information, in some forms of cadastre, we need
information regarding distances and azimuths for each
boundary lines, and topological information.
Restrictions such as minimum parcel size imposed by
planning rules or boundary restrictions imposed by
construction rules are also recorded.
Ownership or stewardship consists of detailed
description of legal rights, freehold, leasehold,
easement, mortgage, use rights, or any restrictions on
these rights.
Landuse and resources are another important
elements for the cadastral parcels. Sometime it only
concerns present landuse (or permitted land use
established by planning rules). Environmental
information such as pollution, hazard, etc is also
possible.
Parcel values are indicated for assessment of
economic resource. The values are normally
computed based on an appropriate valuation model.
In a fiscal cadastre tax rate and value are also
included.
The subject is the one who owns and enjoys the rights
on the one or more cadastral parcels, and also
suffers to all consequences that follow on the parcels.
This class can be specialized into three subgroups
namely individual, institution and government.
Individual can be further classified into single person
and group of persons. Institution represents such as
trust, public and private institution, tribe, community,
etc. Government implies any state enterprises and
offices. The information such as name, address, date
of birth/date of establishment, profession, etc. are
International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B3. Vienna 1996
included in the database.
3. BOUNDARY CONCEPTS
There have been always a debate or confusion
between general boundaries and fixed boundaries in
the processes of adjudication, demarkation, surveying
and information managment.
In defining parcels, uncertainty or problem arises due
to the non-contiguous areas, non-clarity on
administrative boundaries, changes in natural
features, differences in tenure and use, delimiting
limited interests and delimiting public lands.
3.1. General boundary
In this concept a boundary line between adjoining
parcels is left undertermined. The English system
relies mainly on physical boundary features, man-
made or natural. The precise position of the boundary
within the physical features depends on the "general"
land law of the country. Physical boundaries could be
one side of hedge or fence, or the other side, or down
the middle. There is , in effect, a strip of unspecified
width and uncertain ownership left between each
parcel. For instance, in Kenya, parcel boundaries are
deliberately kept vague to prevent argument and the
proverbial splitting of hairs. The advantage of general
boundaries lies primarely in the less demand of
standard in surveying. In this way, land registrar can
have a possibility to ignore small changes in the
position of a boundary agreed between two parties,
whilst guaranteeing the title. This means that there
has been a way to handle fuzziness of the spatial
boundary.
In many countries access to land are getting more and
more difficult especially in urban areas. Recent trends
have been observed in such areas that even a small
piece of land is valuable due to the tremendous
increase of land prices. Thus the requirements with
which the boundaries should be defined, have to be
compatible to the client's needs and satisfications.
3.2. Fixed boundary
The term fixed boundary is often used when a land
surveyor surveyed accurately so that any lost
boundary coners can be recovered from the survey
measurements accurately. Legally it also means that
boundary points become fixed in space when
agreement is reached at the time of adjudication or
alienation of the land. Then the location of boundaries
cannot change without some document of transfer
(Dale and Mclaughlin, 1989). This is the principle that
is adopted under the Torrens system. The advantage
of such system is the confidence which land holders
can have as to the precise extent of their properties.
The choice between "general" and "fixed" boundaries
depends on the pace of creating or updating the
system, the existence of physical features, disputes to
be expected, the amount of necessary security and
