Using Landsat Data to Assess the Status of Coral Reefs Cover along the Red Sea Coast, Egypt

Abstract

The Egyptian Red Sea coast has experienced rapid development since the 1970’s. In particular, the coastal area near the City of Hurghada has been transformed into a long strip of touristic villages and hotels in this short time span. This is an area that has historically had abundant and diverse coral reef communities. To assess possible impacts on benthic coral reef cover in the region, Landsat satellite data collected over the Red Sea from 1973 through 2015 were analyzed to estimate urban expansion in the Hurghada region, shoreline changes, and changes in coral reef cover over time. A time series of satellite observations using Landsat 1-MSS, Landsat 5-TM, Landsat 7-ETM+, and Landsat 8-OLI was assembled, with images acquired in 1973, 1984, 1987, 1992, 1998, 2000, 2003, 2010, and 2015. Images were geometrically, radiometrically and atmospherically corrected, and a water-column correction was implemented prior to comparing images to assess change in landcover. The results show that during the last 42 years, the coral reef cover decreased 6.21 Km² while the built coastal area increased 13.4 Km². These observations were used to compute total economic value (TEV) of coral reef habitats and the cost of degradation in terms of physical losses of coral reef area which equals about18.63$ Billion.