DEMs and reliable sea level rise risk monitoring in Nile Delta, Egypt

This research aims to evaluate the accuracy and reliability of utilizing global Digital Elevation Models (DEMs) in risk monitoring of Sea Level Rise (SLR) in the Nile delta region, Egypt. Such a Geographic Information Systems (GIS)-based assessment process has been carried out using high-precision terrestrial surveys to develop a new local DEM (named SRI18) to precisely identify possible inundated areas by 2025. The presented DEM comparison approach has been performed based on spatial distribution rather than the traditional point-wise method. Based on novel proposed evaluation indicators, it has been found that the reliability of three investigated global models (namely: SRTM1, ASTER, and EarthEnvi-DEM90), in delineating sea level rise flooded areas, is less than 20%. Hence, it is concluded that the utilization of global DEMs may not be optimum in the planning and management of coastal areas in the Nile delta region. Such a methodology could be applied in other low-lying deltaic areas worldwide for investigating GDEMs reliability for SLR monitoring and assessment in coastal regions.