phy, photoindex, photomosaics, etc) has its own diff 
erent value but not less important than the others, 
except in objective function and work scale. There 
since most of the success depends on knowing how to 
choose and giving priority to the use of remote sen 
sors documents, since, summing up, reality can be 
considered as the interaction of partial aspects 
reflected in each document. 
Pattern mapping of Parana and Paraguay abandoned 
river valleys was one of the former works performed. 
(Canoba, Popolizio 1968). It was basically reflected 
by vegetation physiognomy; changes of scale perception 
allowed the detection of these courses displacement 
dynamics which were of capital improtance for engi 
neering projects in this zone. Lately Popolizio (1973) 
elaborated a work on genesis and evolution of Parana 
river valley from Corrientes to Esquina by means of 
a combined analysis using Geographic Militar Institute 
.cartography and photoindexes from Corrientes Province. 
'That was the base for the studies of the "Plan Maestro 
de Defensa de la ciudad de Goya", stability of river 
banks and protection studies (Popolizio 1978; 198§) 
In these works the cartographic problems were per 
ceived, particularly when the considered area was 
relatively large, running the risk of loosing out 
standing aspects of dynamic character which could be 
inferred in those original documents. 
Since 1967 and following Ab'Saber experiences (San 
Pablo, Brasil) Popolizio has elaborated a paper on 
geomorphological cartography by which he tried the 
first aproximation towards morphogenetic, morphogra- 
phic, morphometric, morphodynamic and morphocronolo- 
gical aspects representation which was adapted for 
the large plains cartography, employing the support 
of aerial photographs. Such method was shown in post 
graduated courses which took place in Corrientes, Po 
sadas and Resistencia with an important interest and 
receptivity. This method was sistematically applied 
for the first time on a study about "Cuenca del Rio 
y Estero del Riachuelo" (Popolizio 1973), for hydric 
resources arrangement and flo.o.ds cOoiftrxJ.l. 
It was also used in a geomorphological applied study 
related to road design project in the area "Dique el 
Cadillal",Tucuman Province (Popolizio, Canoba 1970). 
Both experiences let us know from the beginning the 
need of adapting cartography, particularly the symbo 
logy, to objective and scale of work. Moreover the 
difficulties for the cartography of processes dynamic 
and its tendencies, fundamental factors for engineering 
projects and natural resources management, could 
clearly be perceived. 
These problems were also the means of preocupation 
of different geomorphologists .-and Canoba was the one 
who had the opportunity of knowing and training him 
self under the guide of Prof. Verstappen and Dr. Van 
Zuidam in 1974 in the use of the named ITC System for 
Geomorphological Survey (1968) which also tackles the 
mentioned problems and constitutes an excellent 
aproximation for its resolution. 
A highly important step due to work magnitude and 
the theoretical generation that it caused, was the 
Geomorphological Study of Bajos Submeridionales (Po 
polizio et al 1976) 
The first fundamental aspect of this study is the 
clear perception of the importance of paleopatterns 
related to climatic conditions different from nowa 
days ones, that even when it compelled the mapping 
rerun of the third part of the area, was the starting 
point of a conceptual and methodological review. On 
the other hand space division in taxonomic geomorpho 
logical units was applied in a systematic and rigorous 
way. 
To fulfill this task it was necessary to establish 
first the criteria for classification and consequently 
to determine the priority order of each geomorpho 
logical subsystem in its type : and patterns. Second 
the level perception of geomorphology, hydrology 
and phytogeography for each unit had to be also de 
termined . 
Then it was necessary to study the whole conceptual 
and methodological tool intended to elaborate legend 
and cartography adapted to previously mentioned aspects 
The result of what was already exposed was the 
clasification, typification and corresponding legend 
of the surface run-off systems (Popolizio 1973a) and 
also of the surface run-off network typification (Po 
polizio 1973b) by means of a combined matricial scheme. 
By this way a method that allowed to state dynamic 
and tendency of natural and anthropic processes through 
typology, patterns and legend, especially in what 
concerns to surface run-off systems was obtained. 
This fact has not been casual but it responds to 
intrinsic factors of geomorphological plains system 
where surface run-off systems and corresponding nets 
constitute a circulatory system analogy and so its 
detailed analysis allows the understanding of the 
major part of the geomorphic system global dynamic. 
Finally, the recently shown evaluation has origina 
ted an immediate consecuence: restatement of geomor- 
phologic concepts from the point of view of the 
general system theory and including logically the 
interaction between the anthropic and natural univer 
ses . 
By this way the whole perspective of the problem 
was modified and it was considered as multivariable 
in space and time. But moreover, criteria introduced 
a new problem: how to interpret through static image 
ry a dynamic reality which has memory and which sub 
systems present different times of responses, so that 
imagery are not a present but a reflection of different 
past upon which present acts and both are projecting 
the future. 
The return to the origin of the problem allows the 
reinforcement of the idea about the employment of all 
remote sensing resources, generated imagery and 
produced cartography, improved reality perception, 
since they are optative shapes of reality that we 
intend to aprehend and moreover, as many as the shapes 
perceived are, as nearer we are to the essence. 
From this point of view we should remark that while 
Popolizio and his collaborators in Centro de Geocien- 
cias started from the analysis towards the synthesis, 
Pasotti, Canoba and their colleages from Instituto de 
de Fisiografía y Geología started from the synthesis 
to the análisis in adjacent areas which constitute a 
geomorphic unit of first magnitude. 
Results convergence let the establishement of di 
fferently used imagery potentialities and its comple 
ment for the study of large plains and also for prac 
tical application. 
METHODOLOGICAL CRITERIA 
Work Objective 
According to the questions stated in the introduction 
(a) which is work objective? Which is the reality 
observed?, What is reflected from this reality on the 
available imagery? Which scale is to be used in the 
presentation of work results?, the first problem to 
be solved is the clear visualization of work objective 
to be performed.This idea is directly related to the 
involved geomorphological unit size (fig. 2)as it was 
considered in a former work (Popolizio 1981) the im 
portance of bioclimatic conditions, lithoestructural 
conditions and anthropic influence is different in 
relation to the relief size considered, particularly 
on plains. 
Actually, it is not really the specifical objective 
the one to be considered especially, but the space 
dimension engaged by the objective and the intrinsic 
imagery capability matching to these scale and dimept- 
sion, so as'to reflect by means of the patterns, the 
aspects of reality which influence upon objective. 
That is to say, it has been stated that this ob 
jective spatial aspect automatically circumscribes 
types of document and the aspects that can be detected 
through these documents. 
At the regional level, plain dominant factors are 
lithoestructure and large vegetation units which 
frequently respond to major climatic controls. 
Satellite imagery, photoindex or photomosaics 
assemblies reduced or perceived at the same scale of 
those, coni 
obtention < 
tailed ana! 
This fir: 
with all o1 
graphy, ve< 
tion, etc.] 
cular espec 
rrelations 
transition; 
With a w< 
be obtainec 
aspects of 
introduced 
ing naturai 
concrete pc 
tive and w: 
related bel 
tendency ù 
A 
Relati' 
Figure 2: i 
with proce: 
At zonal 
mum as it c 
nant factor 
rank, makii 
This is ali 
documents 1 
them presei 
was said, 1 
tic and ant 
sequently t 
are concret 
For that 
ly those cc 
off system 
the problen 
imprescindj 
(edaphic, £ 
them with t 
the the int 
systems car 
pic univers 
tendency ar 
lastly repr 
jective cor 
In local ( 
bioclimatic 
portant the; 
level, into 
in a spatia! 
Documents 
to the obje< 
to its high 
ter adapted 
the requirer 
to distingu: 
unit). 
In the gee 
areas , pat1 
systems (Poj 
quently take 
658