Geoscience Reference
In-Depth Information
From an operational point of view, multiple computing formalizations have been
created. Usually developed for a specific question, they have mobilized “object” or
“field” formalisms of space. Developed approaches are based either on the
identification of objects' change or on events definition and identification of
associated spatial and temporal componants [YUA 99, YUA 01, PLU 11].
Consequently, the “Spatio-temporal Object Model” proposed by Worboys
[WOR 94] describes the change of an object on the basis of spatio-temporal atoms:
the aggregation of these atoms forms the object in 3Ds (two dimension (2D) for
space and one dimension (1D) for time). This model is suitable for an object-
oriented approach. In parallel, Peuquet and Duan proposed in 1995 a field-oriented
model, “Event-based Spatio-Temporal Data Model”, which models change through
the events associated with sets of localizations (pixels) (ESTDM) [PEU 95]. We can
also mention the model developed by Raper and Livingstone [RAP 95], the “Object
Oriented geomorphologic model” proposing an object-oriented system based on
points integrating geomorphological events. The spatio-temporal data model
(STDM) model proposed by Wachowicz [WAC 99] can also be quoted, object-
oriented and inspired by the developments of “Time Geography”
12
. It proposes a
very original framework of objects' representation: by merging the spatial and
temporal dimensions, the objects are represented according to a spatio-temporal
trajectory in which states, events and changes succeed to each other.
The totality of these developments leads to approach the concept of identity with
precision, and to refer to the objects in their
endurant
characteristic. Some
developments have focused more specifically on the question of the object's
identity, reaching beyond the single notion of identification and giving it a more
philosophical meaning, just like the case of the ship of Theseus
13
. This question
essentially concerns the object-oriented approach. When do the alterations on each
of its components affect the object itself, namely its identity? The change may affect
only the characteristics of the object, or the object itself: the change of culture of a
land plot changes its status without changing its identity. What happens if the plot
changed ownership? If the single point of view of the plot is considered, then the
owner may only be a qualitative attribute of the plot. But from the owner's point of
view, ownership will be a determining factor in the definition of the plot's identity,
and this change can then be regarded as a creation, after the destruction of the
previous one. The notion of identity then becomes central. Several works have been
12 The “time-geography” paradigm, introduced by Hägerstrand in the 1970s in Sweden, will
be illustrated in Chapter 2, section 2.4.3 and discussed again in Chapter 4.
13 The metaphor of Theseus's ship has been used by philosophers since the antiquity for
questioning the identity and change from an ontological point of view [LEN 09]. The story is
told by Plutarch: the ship of Theseus would have remained docked in Athens, the rotted
planks being changed gradually. Once all the planks have been replaced, is it still the same
boat? And what if the worn planks had been kept aside and then used to reconstruct the boat,
“which would be the true ship of Theseus?” [LEN 09].
