Geoscience Reference
In-Depth Information
Figure 1.5.
Three representations of the urban sprawl of a city
Terminology
Endurant
Continuant
“snap”
Perdurant
Occurent
“span”
Entity types
Objects (fixed or mobile)
Properties
Trajectories
Processes and events
Ontological point of view
- Individuals (human
beings), ships, herds;
- Cities;
- Rides, crossings, journeys;
Thematic point of view
- Urbanization, congestion,
growth;
- Creation, recomposition
(former Yugoslavia),
disappearance;
- Bushland expansion,
salinization;
- Traffic.
- Countries;
- Forests, lakes;
- Roads.
Table 1.2.
Entities' various relationships with time:
ontological and thematic points of view
Galton [GAL 04] relates these
endurant
and
perdurant
entity
conceptualizations
to the way of conceptualizing time, space and space-time. Therefore, he extends to
time the dichotomy made between field and object approaches mobilized above for
space. Thus, he presents a parallel between the spatial concept of field and the
temporal concept of duration, on the one side, and between the spatial concept of
object and the temporal concept of event, on the other side. This approach results in
two conceptions to take into account simultaneously space and time. The first can be
qualified of space-time and corresponds to a conception often noted “3D + 1”: the
objects are considered with their coordinates (
x
,
y
and
z
), referring to their position
in space, and then time is added. In this conception, objects can be followed in time
as well as in their transformations. This approach corresponds to the case where
time-space is designed as existing
a priori
. Objects, events and processes are then
