The Lower Euphrates Project is one of the seven GAP 
(Southeastern Anatolia Project) sub-projects on the Euphrates 
River. It consists of the most important schemes of GAP like 
the Atatürk Dam and Hydroelectric Power Plant (HEPP), 
Sanliurfa Tunnels, Sanliurfa -Harran irrigation, Mardin- 
Ceylanpinar irrigation, Siverek-Hilvan pumped irrigation and 
Bozova pumped irrigation (Fig 1). 
The Atatürk dam has a great contribution on the agricultural and 
industrial development in the GAP Region. The irrigation 
system of Lower Euphrates Project is based on the Atatürk dam 
reservoir. The construction of the dam was initiated in 1983 and 
the diversion of water through the tunnels started in June 1986. 
The reservoir was filled in August 1990 and the power 
generation was started in 1992. 
= sut 
tts 
  
    
   
E 
e . 
cM MCI, 
Qmm "X. 
An 
e: ze 
^il NA Hasena Bucher ox es e 
torri: xar ET > Ts 
de 
2 Fu 
M Bose n 
  
      
po i etapa 
Ve Arf Ear N à 3* tege Seteoret 
  
a X ker 
Fig. 1 Location of planned irrigation schemes of GAP. (Striped 
areas will be irrigated from Atatürk Reservoir; others will be 
irrigated by other sources) (SPO, 1989). 
The Landsat image archive represents an opportunity to assess 
agricultural monitoring over time through time-series analysis. 
Landsat, with a spatial resolution of 30 m and spatial extent of 
185x185 km per scene, is used widely for mapping biophysical 
vegetation parameters (Cohen & Goward, 2004) and has proven 
useful for monitoring land cover (Wulder et al, 2008) and 
ecosystem disturbance (Healey et al., 2005; Masek et al., 2006). 
Remote sensing is a critical data source for observing and 
understanding the effects of landscape disturbance (e.g. Potter et 
al., 2003; Linke et al., 2008; Masek et al., 2008). Landsat-based 
detection of disturbances (e.g. Cohen et al., 2002; Franklin et 
al, 2001; Seto et al, 2002) commonly use image 
transformations such as the Tasseled Cap transformation (Crist 
& Cicone, 1984; Kauth & Thomas, 1976) to consolidate 
multispectral reflectance measurements and enhance the 
detection of disturbance events. 
The Tasseled Cap transformation reduces the Landsat 
reflectance bands to three orthogonal indices called brightness, 
greenness and wetness, and is a standard technique for 
describing the three major axes of spectral variation across the 
solar reflective spectrum measured by Landsat (Kauth & 
Thomas, 1976). Once an image is transformed into its Tasseled 
Cap data space, image arithmetic and thresholding techniques 
can be used to automatically identify and classify land cover 
changes and land cover disturbance (e.g. Cohen et al., 2002; 
Franklin et al., 2001; Healey et al., 2005). 
Up-to-date and objective information on the spatial distribution 
of irrigated crops as well as changes in their areal extent over 
time can help achieve the goal of efficient water resource 
management. The objective is to map the extent of irrigated 
agricultural fields and assess land-cover trends at the object 
level within a selected study area in GAP region using Landsat 
images from 1984 to 2011. 
Ozdogan (2004) indicates that in Southeastern Turkey, the best 
time to distinguish irrigated lands from other land cover types is 
mid-to-late summer. In the study, Landsat imagery for these 
months were used in order to determine the land cover/use 
changes especially on agricultural fields under the Atatürk Dam 
Lake and also irrigated agricultural fields with water reserve 
changes for ~30 years. 
2. STUDY AREA 
The first focus of this study is the Atatürk Dam Lake with a 
catchment area of 92,240 km? while the impounded land is 817 
km?. The maximum reservoir capacity of the Atatürk dam is 
48.7 x10? cubic meters with the total irrigation area of 8,724 
km“. The minimum level of water in the reservoir is 526 m. The 
second focus is the Harran Plain, which is irrigated from the 
Atatürk Dam Lake and is located in the south-central part of the 
GAP project within the Sanliurfa - Harran Irrigation District. 
The Plain is 2756 km? and is located in a region of rolling hills 
and a broad plateau that extends south into Syria (Fig 2). Two 
meteorological stations that have been used in the study are 
shown as red stars in Fig. 2. 
387350"E Won "E 
a M 
z 
: 
5 
38°0 
    
31930'0"N 
STSFIFOUN 
  
IHN 
  
  
  
    
38°30 39°0'0"E 
Fig. 2 Landsat TM images of the study area (August 201 1). 
Inset shows mean annual temperature of Turkey with the study 
area outlined by a black rectangle. 
The study area has the major climatic features of the Eastern 
Mediterranean with a strong continental influence. The annual 
  
  
  
  
  
    
  
  
   
  
   
  
  
  
  
  
   
   
    
    
   
  
   
  
  
      
  
  
   
  
   
  
  
  
  
  
  
  
  
  
  
   
    
   
    
  
   
  
  
   
  
  
  
  
   
  
  
   
  
  
  
  
     
averag 
mm. 1 
most | 
area r 
irrigat 
The S 
scherr 
broug 
syster 
with 
m° /se 
in 19 
are al 
Sever 
veget 
variet 
any 8 
Rem 
irriga 
locati 
requi 
chan; 
and 1 
2001 
Mon 
irrige 
data. 
agric 
have 
Rese 
ident 
imag 
Afte 
reser 
anal 
Lake 
last 
seas 
chan 
on t 
appt 
beer 
dete 
clim 
incli 
tran: 
refle 
data 
Tas: 
Lan 
(Cri 
coe; 
to E 
to v 
Lan 
into 
ET! 
bet 
Vo