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Using Remote Sensing Data for Assessing the Optical Characteristics of 
Alexandria Coastal Water, Egypt. 
Mahmoud H. Ahmed, Noha S. Donia' and Belal M. El-leithy 
National Authority for Remote Sensing & Space, P.O Box 1564 Alf Maskan, Cairo. 
Institute of Environmental Studies and Researches, An Shams University, Cairo. 
Abstract 
The development of sea surface color data observations has opened new perspectives or the understanding of marine 
environmental processes, due to their great potential for providing novel information on biological, geochemical and physical processes 
of the sea. This paper aims to use Landsat TM imagery as a very efficient way for sea surface color data. Such data can be used for to 
derive optical properties of coastal water of Alexandria Coast, that is subjected to human stress from land base activities. 
Therefore two landsat images of the coastal zone were collected in August, 1990 and May, 2000). The images were processed to 
enhance the water color and to derive surface temperature information of the coastal water. This is accomplished by stretching of the 
bands (1,2 and 3) that are laying in the visible range of the spectrum (bands 1, 2 and 3). These bands are composed and assigned to Blue, 
Green and Red colors respectively, for emphasizing and identifying the optical characteristics of nearshore water. Six sample profiles 
have been drawn for different regions along Alexandria coast from Abou Kir Bay in the east to western harbor in the west while sample 
no | represents the clear water (case 1 water ) collected in the offshore water. On the other hand, to analyze of the impact of different 
land-use activities, the images are enhanced for land-use/land-cover discrimination by stretching bands 2, 4 and 7 and assigned to Blue, 
Green and Red colors respectively. 
Results showed that the anthropogenic input to the marine environment is reflected to different image profile analyses. The 
composite images show marked differences in the distribution water constituents between the oligotrophic character of open sea waters 
(case 1 water ) and the near shore water (case 2 waters). The color-sliced thermal band illustrate the thermal distribution for the 
Alexandria coastal area water. 
Keywords: 
Coastal Water Quality, Remote Sensing, Environmental monitoring 
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