Geoscience Reference
In-Depth Information
social sciences and many others to more and more grasp phenomena with a
geographic component. Applications used to analyze these phenomena
usually require the use of multiple geographic databases, which may
represent the same geographical space but in different ways. One of the
major limitations in the reuse of geodata is that a given geographic entity
can be conceptualized and represented in different ways, depending on the
database producer's point of view. The representation in databases of real
world entities is related to the approach adopted in the conceptualization of
these databases and in the establishment of their specifications (Fonseca et
al. 2003). This consequently leads to a certain level of "semantic
heterogeneity of data” (Partridge 2002). Discovering data and assessing
their fitness for use thus becomes an issue of first importance (Flewelling
1999)(Bruin et al. 2001). The goal of the approach presented in this paper
is to be able to answer a query of a user who is wondering where and how
are represented, in one or several geographic databases, the entities of the
real world that may be of interest for her/him.
Mapping agencies, such as
IGN
(
Institut Géographique National
) in France,
usually produce and supply various geographic databases. All these
databases represent the geographical space, but each of them with its own
specification. The variety of data and the complexity of specifications may
cause some difficulties for any user in assessing and understanding the
content of these databases. Moreover, the rise of the Internet and
associated technologies allows a growing accessibility to spatial data via
web portals, such as the Géoportail
1
in France. Even if this allows users to
better understand the available data, a number of information are not
available through geoportals for a more knowledgeable user, such as a user
specialist of a given field who wishes to assess and compare the content of
available databases with respect to her/his specific needs. In this context,
researches are undergone in the
COGIT
laboratory in
IGN
, particularly in
the framework of the
GéOnto
project (Constitution, alignment, comparison
and exploitation of heterogeneous ontologies). This project deals with the
issue of geographic data semantic interoperability and has, among others,
two objectives: building an ontology of topographic concepts and
1
http://www.geoportail.fr/
