The use of multi‐temporal Landsat images for the change detection of the coastal zone near Hurghada, Egypt

Abstract

A Landsat 5 Thematic Mapper (TM) image of 1987 and a Landsat 7 Enhanced Thematic Mapper Plus (ETM+) image of 2000 were used to examine changes in land use/land cover (LULC) around Hurghada, Egypt, and changes in the composition of coral reefs offshore. Prior to coral reef bottom‐type classification, the radiance values were transformed to depth‐invariant bottom indices to reduce the effect of the water column. Subsequently, a multi‐component change detection procedure was applied to these indices to define changes. Preliminary results showed significant changes in LULC during the period 1987–2000 as well as changes in coral reef composition. Direct impacts along the coastline were clearly shown, but it was more difficult to link offshore changes in coral reef composition to indirect impacts of the changing LULC. Further research is needed to explore the effects of the different image‐processing steps, and to discover possible links between indirect impacts of LULC changes and changes in the coral reef composition.

Acknowledgements

The authors wish to thank Ghent University and the Fund for Scientific Research‐Flanders (FWO‐Vlaanderen) for supporting the different field campaigns. The Fund for Scientific Research‐Flanders (FWO‐Vlaanderen) is also acknowledged for providing a PhD scholarship to the first author. The useful comments and remarks by the anonymous referees are highly appreciated.