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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