In this way the criteria used to include "goods" within
the second category are properly fulfilled. Undoubtedly,
the Danube Delta needs a very special protection aiming
at representative and unique ecosystem maintenances.
That is why, to be a master of the natural equilibrium
mechanisms and their dynamic constituent monitoring,
our investigation is focused on the main environmental
factors: water, soil and vegetation (floating reed islet
formations and destructions, lake surface variations,
impact of the fish breeding agricultural and touristic
arrangements a.s.o.) using upgraded techniques and
methods.
1.2 Information Sources, Used Products
According to the "natural patrimony" concept, there are
two main information sources: (1) graphical information,
i.e. data to be represented on maps and photomaps; (2)
descriptive information, i.e. statistical and other
(monographic, morphographical a.s.o.) data describing
some object and phenomenon qualities, which are
located on the investigated territory.
To study all these cartographic and descriptive data in
close correlation, they have to be input in the same data
base pointing out connections among them.
While space information is derived from the existing
cartographic and photogrammetric products, the
descriptive one is based on the statistical data on
population, climate, people's jobs, (in our case, fishing,
reed harvesting, a.s.o) the historical and legal
background, etc. As Grindul Caraorman has been chosen
as our test area for this stage, descriptive information
also includes the Danube Delta ecosystem features (Sion
et al.,1992).
So, data has been collected from: (1) geographical stu-
dies on the Danube Delta and its reservations:(a) "Mor-
pholohydrographic Features of the Danube Delta"
(authors: Petre Gá:lescu et al); (b) "The Complex
Caraorman Forest Reservation" (prepared by the Institute
for Geography); (2) The Romanian Statistic Year Book;
(3) Other documents on Tulcea Country: (a) The
Touristic Guide of Tulcea Country; (b) The Complex
Danube Delta Arrangement (under the care of the
Romanian Academy, 1953); (c) Contributions to the
Vegetation of the Danube Delta (authors: V. Sand and A.
Popescu, in Hydrobiology 1983, pp. 61-69); (d) Forests
of the Danube Delta (Pence, 1971).
2. THE STRUCTURE OF THE NATURAL
PATRIMONY INFORMATION SYSTEM (NPIS)
2.1 GIS Concept and Technique Application
A Geographical Information System (GIS) is an
ensemble of equipment, software geographic and
personal data able to efficiently collect, store, update,
handle, analyse and visualise any geographic
information. On the other hand, a GIS should be
considered as a real life model developing, testing, and
choosing some future evolution scenario. There are main
graphical and descriptive already mentioned data within
a GIS.
A GIS strength is derived from its possibility to also
locate descriptive data in the space by relationally
correlating them with the geographic ones established by
their own coordinates directly. Thanks to this locating
concept, a GIS technique properly answers our needs in
the desire to know the natural patrimony condition and
change; at the same time, it carries some bivalent
(graphical and descriptive) information we are interested
in, which could be visualized as suggestively as possible.
2.2 The GIS General Structure and Main Functions
Question types for which GIS users could get answers by
properly handling the five main subsystems are briefly
shown in Figure 1. Those subsystems correspond to some
elementary functions (collecting, editing, analysing,
managing and plotting) being the only one way to the
data base, in fact, the GIS information core.
Figure 1. Concept organisation of a GIS
Besides the five elementary functions defining GIS all
together, we can point out another four basic (general
and complex) functions related to the general user's
requirements. So, considering the GIS user standpoint,
the basic functions are the following: (1) supply of the
general geographic information related to the established
territory; (2) extraction of all objects and phenomena
belonging to a desired topic; (3) available information
usage to find some special correlations among various
topics and objects, based on pre-established algorithms;
(4) supply of various outputs (maps, tables, diagrams and
graphics, images).
2.3 Advantages in Using GIS Technique
When a NPIS is structured, the advantages in using GIS
techniques are the following (Balotä,1992): (1) they
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International Archives of Photogrammetry and Remote Sensing. Vol. XXXI, Part B4. Vienna 1996
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