/ Ali Farrag, Farrag 
  
  
Plate 3 Window (12x17km) of 1995 Plate 4 Window (12x17km) of 1998 
image (unsopervised classified) image (unsopervised classified) 
Polution levels (Plates 3 &4) 
mu High density mm Medimum density Low density 
  
Plate 5 Streatched green band o£ 1995 — Plate 6 Streatched green band of 1998 
image (corresponding to Plate 3) image (corresponding to Plate 4) 
Polution levels (Plates 5 &6) 
mm mm High density Medimum density Low density 
  
Back ground 
  
  
International Archives of Photogrammetry and Remote Sensing. Vol. XXXIII, Part B7. Amsterdam 2000. 51