System : B
totality organized of
components in
interactions
Physical plan (phenomena)
Figure |. The three plans of a general system
(adapted from Schwarz 1994)
- A physical plan that includes the components, either, in
the case of the territory (elements or facts);
- A logical plan, non visible by our senses, that is the one
with relations between components, that determines the
working and the evolution of the system;
- A holistic plan that is the one where the system is
considered like a complex all, an indivisible unit without
which components and relations would not produce the
observed evolution. Say otherwise, the all, either in a way
the identity of the system that emerges from interactions
between components, gives a sense to these interactions.
3.2 Application Of The Systemic Approach To The
Territory
If we apply the systemic approach to the territory, we can
distinguish the three plans of existence of a system plan :
- The physical plan that contains systems (or subsystems)
composing the territory, as well as the human's actions on
this territory;
- The logical plan or concepts that are composed of
theories and models that we make from reality, as well as
methodologies that we conceive to intervene on;
- The holistic plan that represents the territory in its proper
identity, its directionnalities, its values.
3.3 Application of the systemic approach to the GIS
A GIS is a type of system constituted of computer
components - material and software - of data, procedures
and methods, of resources - financial human or scientific -
that interact to do some tasks, to answer to requests and to
produce information. We can also distinguish there above
the three plans of existence of a system such as definied
below :
- the physical plan that contains data acquired from
observations or measures, digital maps or documents, of
pictures integration or orthophotoses, as well as the useful
information notably to the development of projects, to the
decision making or the simple information of the
population;
- the logical or conceptual plan that is composed of models
shaping the different architectures of a GIS (organization,
technique and information), which permit to elaborate
processing methods (statistical or spatial analysis for
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International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, Vol XXXV, Part B-YF. Istanbul 2004
example) and of exchange principles (diffusion modes or
rating for example);
- the holistic plan that represents specific identity of the
GIS and that expresses its privileged values (the
exchange between partners for example), its finalities (to
be a helpfull tool to the consultation, the management and
the decision).
The SRT can be defined as follows: The Systemic
Representation of the Territory is defined as an
interdisciplinary model of the territory (interdisciplinarity =
multi - partners vision) based on the determination of
phenomena and relations that composes it and that are
applicable in the setting of the management, the planning
and the scheduling of the territory. it takes into account their
temporal evolution to avoid redundancies and incoherences.
From this fact, it is considered as the most adequate to
represent a territory in a GIS. The SRT constitutes a setting
of reference for making an exchange network between
partners possessing cartographic data (geographical
information) and being called to work together in the setting
of the planning and the management of the local territory.
3.4 Hierarchical organization of the SRT
The Systemic Representation of the Territory recognizes six
hierarchical levels of organization for its components
(domain, sector, activity and clement, thema, class of
entities, entity). This organization is not exhaustive. it
covers aspects of the territory that we well know (according
to investigations) or those for which we could take
advantage of the specialist contribution (for what concerns
natural habitations, activities, infrastructures, and the
regional development). This organization has also a merely
operational goal, which is to facilitate the access to
informations, hence it plays the role of a of a navigation tool
within the GIS.
3.5 Access Management according to the hierarchical
organization of the SRT
Some data are of confidential type and cannot be consulted
by all the system users. These data remain under the
exclusive responsibility of partners that provided them. The
control of accesses first of all rests on the definition of
groups users. These last are based on the administrative
organization of partners. A specific group is formed of the
set of users possessing the same privileges of consultation
and modification of information of the system. If a group
has access to a specific class (buildings for example), it also
has access to the set of entities of this class (the set of
buildings of the territory). However, it does not necessarly
have access to the set of attributes describing this entity
(Fig. 2).
Domain
Secfor
Activity and element
Thema
Class [1]
Figure 2. Example of a tree associated to rights of
information consultation
In
