Results, Analysis and Discussion - Historical Land Use/Land Cover Classification Using Remote Sensing - page 173

15 m were tried on large area fields, and the outcomes of spectral separability and
classification were compared with data outcomes of the TM/6-bands/30 m. The
result was that the high spatial resolution 15 m could be dispensed with, without
lowering the spectral separability among crops.
But, a high spatial resolution data, such as ASTER/ETM+-15 m, was found to
be useful when studying ancient and tiny agrarian areas, such as those centred
along the banks of the Euphrates (from the Euphrates Dam to the border with Iraq).
For this kind of research, it may even be preferable to use even higher spatial
resolution while preserving the six spectral bands.
TERRA-ASTER-August-2005 data fused with LANDSAT-ETM+2August-
2005 data. The appearance of fruit, poplar and other trees within dwelling areas
and their margins were seen in a better and clearer way on satellite images
acquired during summer (August) (Fig. 6.8 ) in contrast to those images acquired in
April and May. There was a severe decline in the spectral properties of forest trees
that previously existed in multiple places along the banks of Lake Al-Asad and the
Euphrates River, in favour of the power and superiority of the spectral reflectance
of light soil. This is due to the lowering of moisture and the dryness of the green
mass of the forest trees (some are even crusty), in addition to an increase in
sunshine levels.
The appearance of fields within the irrigated agriculture projects in very light
colours made them look as if they were bare areas, while they were in fact wheat
and barley fields seen after harvest (covered by the green mass of ex-crops that
remains a very light yellow colour). These fields had been left for grazing purposes
or the residue would be collected for use as hay during winter. In summer, these
fields appeared after harvesting as a black colour as if they were water surfaces
because of the residue left after burning. Here, the importance of the analyst's role
in knowing his or her study area is important.
The third appearance the wheat and barley fields after harvesting was in a form
in which the dry yellow remains of green mass (straw) of the 2 crops interacted
with several kinds of natural plants that grew in these fields, benefitting from the
remaining soil moisture. This occurred when the fields were not tilled. This field
shape had a negative impact on summer crops classification, as the growing natural
plants have a high vegetarian intensity, high vital mass and similar spectral
behaviour as the some of the summer crops' spectral response. These fields were
classified as fallow.
The cultivation of trees for agriculture purposes was centred in particular within
the irrigation projects (especially poplar trees), in addition to their distribution
along the main streets, between the agrarian fields (as separators between the fields
or as wind barriers), and along some irrigation canals that were largely within the
irrigation projects or reclaimed lands. This also related to the agriculture of forest
trees (pine and cypress) in particular on Lake Al-Asad's banks.
Aquatic plants appeared clearly and were distributed more evidently within the
August coverage in contrast to May, either in the Euphrates River waters (mosses
were seen in shallower locations) or within prevailing swamps stretching out along
the river, where the deserted river elbowed. These were seen along the river's bank