Data - Historical Land Use/Land Cover Classification Using Remote Sensing - page 58

For this study, the major related field-work/s was: the 1987-GPS points
(ICARDA); the 2005-GPS points (GORS); the 2007 and 2009 GPS-points
obtained from two excursions; Spectrometer-measurements (GORS); and the
NDVI-measurements (GORS). (see Chap. 5.4 ).
4.2.2 Maps
Thematic maps of LULC-types should be a part (especially in the visual inter-
pretation) of the selection of training samples and the gathering of testing sites for
accuracy assessment when there is no alternative. They are generalized informa-
tion with two drawbacks, in that they are probably based on unlike designations for
classes, plus an unlike minimum unit (cell or pixel) size than that which is being
used in a specific study. So, most maps are considered unreliable and unacceptable
for use as reference data, other than for a general understanding of the area
(McCoy 2005 ).
Soils and thematic maps are reproduced from previous studies (from ICARDA-
Aleppo), as well as topographic maps with various scales from 1/25,000 to 1/
100,000, which cover the whole study area. These were purchased from the
General Organization for Military Survey in Damascus. Some aerial photos for
small areas in the Aleppo were also obtained from the military survey.
4.2.3 Statistics
The analysis of spatial distribution of agricultural features were based on: statis-
tical data taken at both village and the administrative district level for the years of
1975, 1987, 2005, and 2007; on previously achieved studies relating to the study
area; and on the field observations. They were checked and proven. They are the
basic foundation of Syrian agricultural statistics. These data are collected by
agrarian engineers working in counselling units centred in the administrative
sectors.
Also, there are general information and agricultural statistical records for the
period 1970-2010. These are useful to understand the geographical history of the
study area in relation to nature and human activities, and especially the historical
development of the irrigation projects in the ERB. Each of these information and
statistical records has a periodical annual publication, issued by the CBC in
Damascus. The agricultural statistical records are collected on various levels,
including village, administrative region, governorate, agricultural stable zones and
the whole area of Syria.
Detailed information and statistics for the period 1970-2010 about the agri-
cultural irrigation projects were obtained from IGDEP in the city of Arraqqa.