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in an almost continuous linear way. Climatic factors played a basic role in this by
providing moisture and temperature elements, with the ratio of aquatic plants
rising in August due to the high number of sun accelerating the growth and density
of the plants.
The increase of variation and differentiation in reflectance and in the spectral
behaviour of plants (crops and trees) within the coverage of August was greater
than that found in the May data.
Grapevine lands were classified under the orchard class. This was a new type of
agriculture cultivation in the study area, which started at the beginning of this
present decade in limited areas.
The appearance of some tree-lands (especially, the orchards) on satellite images
is unclear, although these areas were irrigated and took on a regular and organized
engineering shape. This was because of the disproportion among adapted distances
in the cultivation of trees and their spacing from each other, and the available
spatial resolution of the used remotely sensed data. They were in most cases
classified as fallow or sometimes as a type of crop, although not to tree class.
The problem of classifying poplar trees was represented in that a land plot may
be planted with trees of differing ages. Additionally, permanent cutting of part of
these trees to be used in the paper, pulp and wood industry led to a mixture in
classification from poplar trees to fallow. The problem lay not in how to separate
these areas spectrally but in spatial separation resulted in continuous alternation
between the two classes within small spatial areas, which allowed some errors to
occur in evaluation and the calculation of distribution area. The spatial resolution
of the available remotely sensed data did not have the ability to represent this
alternation and introduce the spatial boundaries to separate the two classes. This
coverage was found to be the best for separation between the uncultivated areas
and the fallow areas.
LANDSAT-TM-August-2007 data. Sand storms emerged on the August data,
which caused great changes in the spectral characteristics of the elements that
needed to be classified. This impact was on p172r035 acquired in 07.08.07 along
the extended area between Arraqqa and Deir Azzour.
It was noticed that in the past years within the irrigation projects (for instance,
the previously referenced project of 21,000 ha), the cultivated areas with specific
crops were significantly smaller (Fig.
6.9
) in contrast to the beginning of these
projects' establishment and for long periods, where regular agricultural policies
were followed. The reason for this is likely to be that the governmental founda-
tions who established the projects have since transferred management of the
projects in favour of the farmers, who are not, in turn, committed to any agrarian
policy and rotations accredited by the Ministry of Agriculture. This matter had a
critically negative impact on the crops' classification using available data. The
spatial resolution became less effective because of the limited area specified for the
various crops' cultivation. This was the same negative impact in consideration to
the spectral factor, because of the increase in the types of crops seen in this area
(possibility of setting two comparative scenes of 1987 and 2007).
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