Fatehi, Ahmad 
  
were taken in different (or the same) land covers with different distances from the source of the pollution. Based on 
the NDVI profiles of many points, the growing season was distinguished, then the average NDVI of this period 
(February to June) were calculated and new NDVI image were generated. These NDVI images were used to 
calculate changes of vegetation greenness in the study area, figure 1 shows the study area. 
Persian Gulf 
  
Figure 1: the study area. NOAA False Color composite. The Kuwaiti oil wells located in west of the Persian Gulf. 
4 NOAA-AVHRR (GAC) NDVI profiles 
The growing season starts from dekade 1 and ends approximately in dekade 13. In this period the rainfall and 
temperature did not change significantly in 1990,1991 and 1992, therefore year 1990 selected as reference year 
are much less than in 1990,1992 or 1993. Therefore this reduction of NDVI in 1991 and also 1992 was not because 
of rainfall and temperature, but it was due to the effects of the polluted rain. Figure 2 show NDVI profile of point 
S15 (for example) in different years (1989-1993). 
NDVI 
  
0 1 2 3 4 5 6 7 8 9:010 41^12 13/14 15 316 17.18" 19 20 21 22 29 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 
Decade 
  
[—9—1959 ——1990 «i991 1992 ——192923] 
Figure 2: Comparison of NDVI profiles of points S15 (see figure 1) in five years (1989-1993). The elevation of this 
point is 530 metre above sea level. The vegetation type is mixed forbs and bushes. The NDVI values are low in 
1989 because of less rainfall (Jalali et al 1999). The NDVI values in 1991 are lower than 1990 and 1993, while the 
rainfall in 1991 was higher than in 1990. Also the rainfall was higher in 1992 than in 1990 in this area, therefore the 
reduction of NDVI values in 1991 is due to pollution and in 1992 due to very little recovery. 
  
  
428 International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000.