Spectral enhancement of SPOT imagery data to assess marine pollution near Port Said, Egypt

Abstract

Satellite image data were used to detect, monitor and map different pollutants at five study sites along the El-Gamil beach, including El-Debba, El-Manasra, El-Fardous and El-Gamil inlets and the El-Gamil airport. The images were rectified and analysed by ERDAS IMAGINE 8.7. Image processing techniques were applied using ENVI 4.2 to analyse the SPOT image data (10 m resolution) for 2006. Image enhancement, principal component analysis (PCA), band ratios and supervised/unsupervised classifications were applied. Surface water samples were collected during the winter of 2005 and the summer of 2006. Water contamination was found to be higher in the summer than in the winter. SPOT image data from the summer, therefore, was selected to verify the results of metal analysis. Different pollutants detected along the El Manasra and El Debba sites are associated with industrial development, and discharge from natural gas companies and electric power generating stations. Significant water pollution is not unique to this region of the Mediterranean Sea, but is increasingly common at coastal locations throughout the globe. To protect both the marine environment and commercial interests that depend on clean water and beaches (e.g. beach resorts), effective wastewater management practices must be designed, implemented and maintained, along with reasonable development policies. Remote sensing may be an important tool for monitoring the effectiveness of any pollution mitigation strategies.