AERIAL PHOTOGRAPHS AND SATELLITE IMAGES
AS ARCHIVES (INFORMATION POWER IN HORIZONTAL AND
VERTICAL SENSE)
Prof.Dr.L.DAELS
Laboratory for Regional Geography and Landscape Science
University of Ghent.
Abstract
It is well known that aerial photographs and satellite images are rich sources of information about the
present day situation of the earth surface phenomena.
The title "aerial photographs and satellite images as archives,is indicating the historical value of these
documents. The "horizontal" archives mean that the spatial distribution of the landscape elements produces
important information about the historical developments of the concerned areas. The "vertical" archives
point to the fact that the evidences of the past are present into soils as different layers. These
buried evidences are creating different conditions at the surface which can be read upon aerial photo-
graphs and satellite images.
The information thus obtained shows that most of the history books must be adapted urgently.
1. Remote Sensing and landscape research
The applications of Remote Sensing, including ae-
rial photography, are numerous in the different
fields of the Earth Sciences. The use however for
the study of the landscapes and the associated
settlements is not so frequent and this for two
evident reasons.
The initial ground resolution of the satellite ima-
ges was not sufficient for this research and the
interest for landscape studies was not very high.
These two reasons vanished completely the last ten
years. The ground resolution of the satellite ima-
ges improved greatly and the interest for landsca-
pe studies was growing tremendously over the ten
past years. The following motives can be conside-
red for explaining the revival of the landscape
research.
1.1. Finally the planners and the decision makers
understood that the solution for some large
scale and urgent problems must be sought in the
understanding of the environment.
Highly specialised research is needed but even so
the holistic approach of the landscape study. A
landscape is indeed the result of the interactions
between the physical and the human environment.
The physical processes were modeling the landscape
since millions of years. Man was interfering only
since some thousands of years. The landscape is
preserving the evidences of these processes and is
testifying of the failures and successes of men.
The landscape may be considered as the collective
memory of humanity. This memory must be consulted
carefully before decisions are taken which can ha-
ve an impact upon the rural and urban landscapes.
The information, needed for the formulation of
sound projects in relation with landscape - or
agricultural reforms, is present in the landscape
and must be made available by a good landscape
examination. The failure of some projects is clear-
ly the result of a lack of knowledge about the
landscape and the negation of the personality, the
undividuality and the potentialities of the land-
scapes. Some of the directives of the European
communities for the agriculture in the Mediterra-
nean area resulted in a reversed outcome, as f.i.
in Greece an accelerated soil erosion. The reason
was that these directives were to general and not
adapted to the possibilities of the different me-
diterranean landscapes.
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1.2. Interesting psychological research was carried
out about the influence of landscape and
recognition upon the human and especially upon the
mental evolution of the youth (R.KAPLAN, 1977;
W.NOHL, 1980; KRUSE L. and R.ARIT, 1984; GIFFORD,
1987). Studies were also performed in relation
with the visual management and the landscape
aesthetics and the importance for the arts (POR-
TEOUS, D. 1982; USDA Forest service 1974; WOHLWILL,
J.F., 1979; SANCAR. F.H., 19895).
It is indeed most important that the individual
feels part of the environment in which he lives.
An identification between landscape and man must
be established.
1.3. It is evident that the landscape plays an
important role in the different activities of
recreation and leisure and forms thus an actif
factor in the proces of self development (BOER-
WINKEL, H.W.J., 1988; GIFFORD, R. 1987).
It is superfluous to focus the attention on the
influence of the landscape upon the different ex-
pressions of art : music, poetry, litterature and
painting (SVOBODA, H., 1985; SALTER, C.L. and
W.J.LLOYD 1977; POCOCK, D.C., 1984).
2. Possibilities of Remote Sensing documents for
Tandscape research.
The combined use of satellite images and aerial
photographs proved to be a highly efficient tool
for the exploration of the landscape archives.
Some properties and technical possibilities, both
digital and analogue, create new viewpoints and
insights for the landscape research.
2.1. The multi-scale concept. With the Remote
Sensing documents one can study the landscape
upon a macro, meso and micro level.
Image format Image scale Area covered per frame
-Low altitude
aerial photogr.
(230x230mm)
-High altitude
aerial photogr.
(230x230mm)
-Landsat scene
(185x185mm)
(after Lillesand and Kiefer, 1979).
1/20.000 21 km2
1/120.000 760 km2
1/1.000.000 34.000 km?
