effectively minimizing seasonal variability in the imagery 
(Healey et al., 2005). 
The purpose of the disturbance index is generally to measure 
vegetation degradation that results from any number of natural 
or human induced causes such as forest fires or forest-insect 
infestations (Hais, et al., 2009). But, in the study area it also 
exemplifies the contrast between irrigated agricultural fields and 
bare ground. In our study, disturbance-index images were 
generated for the dates between 1992 and 2011 and were used 
to characterize spatiotemporal patterns of irrigated agricultural 
fields on Harran Plain based upon the original reflectance 
images—brightness, greenness and wetness (Table 2). 
Table 2. Landsat imagery used for creation of the cumulative 
disturbance indices. 
  
Date Sensor 
05.09.1992 Landsat TM 5 
21.08.1998 Landsat TM 5 
24.08.1999 Landsat TM 5 
26.08.2000 Landsat TM 5 
28.08.2002 Landsat ETM+ 
27.08.2006 Landsat TM 5 
30.08.2007 Landsat TM 5 
04.09.2009 Landsat TM 5 
22.08.2010 Landsat TM 5 
25.08.2011 Landsat TM 5 
  
Furthermore, meteorological datasets were obtained from 
Adiyaman (North of Ataturk Dam) and Sanliurfa (South of 
Ataturk Dam) stations for the analysis of climate data on the 
dam lake and the Harran Plain within the period of 1894 to 
2011. 
4. RESULTS AND DISCUSSION 
During the Atatiirk Dam construction period between 1984 and 
1992, spatial variations of agricultural fields and water reserve 
were determined (Fig. 3). By the year 2011, it was found that 
367.65 km? of the agricultural area (about 45% of the dam-lake 
surface area) has been inundated. The total filling of the 
reservoir results in a lake area of 800 km? (Fig. 4). 
en # Water Reserve 
8 Agricultural Fields 
         
7 
1984 
1985 1986 1987 1990 1991 1992 
Fig. 3 Spatial variations of agricultural fields and water reserve. 
For the Harran Plain and the Atatürk Dam Lake, different 
meteorological datasets were used. Monthly averaged values of 
air temperature, humidity and rainfall observed at the Sanliurfa 
and Adiyaman meteorological stations (Fig. 2) were used for 
years between 1984 and 2011. 
It is expected that one of the prominent difference of the 
meteorological parameter between these regions is the 
temperature (Fig. 5). 
Fig. 4 Water reserve changes on the Atatiirk Dam Lake between 
the years 1984 to 2011. 
  
Temperature (°C) 
  
t2 
oo 
—Sanliurfa Station 
i —-Adiyaman Station 
26 i aie 
  
  
  
1984 1988 1992 1996 2000 2004 2008 MN 
Fig. 5 Annual temperature distribution of Dam Lake and Harran 
Plain Regions. 
For the other part of the study, change detection is performed 
using the Disturbance Index for Harran Plain in order to 
characterize spatiotemporal patterns of irrigated agricultural 
fields. When the Landsat time series analyses are examined, the 
contrast between irrigated agricultural fields and bare ground 
has been clearly seen (Fig. 6). 
  
  
    
It ha 
incre: 
2011. 
  
exp 
Occ 
and