GIS-based approach to estimate sea level rise impacts on Damietta coast, Egypt

Sea level rise (SLR) is considered to be one of the most significant environmental issues globally. Damietta Governorate is likely to face serious impacts due to SLR because of its low-lying sandy coast. This study investigates the actual impacts of SLR and associated shoreline retreat at Damietta coast using the geographic information system (GIS) despite current uncertainties about SLR. In this study, shoreline retreat at Damietta coast was estimated using the Bruun rule. To achieve this, remotely sensed data including cloudless satellite images (Landsat ETM+7) were used. Moreover, this study used elevation data taken from global digital elevation model (GDEM) data derived from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) project. Many thematic layers including maps of administrative boundaries, the rail and road networks, irrigation, and urban areas were used to address the impacts of SLR. The results showed that, if the SLRs 1 m, the inundated area will include approximately 254 km2 of governorate land, which represents 16% of its total area. In a 2-m SLR scenario, the submerged area will expand to 661 km2, which represents 64% of Damietta’s area. Application of the Bruun rule indicated that SLR would have a small effect on coastline erosion. Upon estimation of the annual shoreline retreat, this was predicted to range from 2.7 to 3.8 m/year at Damietta coast under the impact of SLR. SLR thus poses a serious threat to Damietta Governorate as its land is subsiding at a high rate, which is a major factor that amplifies the severity of potential inundation. Thus, there is a serious need to protect Damietta’s coast and its human population from the impacts of SLR.