الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
The coastal strip of the Nile Delta has been suffering extensive erosion and accretion problems. This was achieved after the construction of many water regulation structures across the Nile River as dams and barrages, particularly the Aswan High Dam. It has nearly stopped the sediment load carried by the Nile River to the Delta. This process has caused the Mediterranean Sea to reshape the Nile Delta coastal area. To solve these problems, several hard structures have been built. These structures aided in ceasing the problem in the site of construction but translocated the problem to the adjacent sites.The present study aimed to analyze the shoreline change pattern between the area of Rosetta eastern seawall (ESW) to west El Burullus fishing port with a length approximately 85km. This change was calculated over 36 years during the period between 1984 to 2020. This was achieved by the automated delineation of the shorelines covering this area and period from remote sensing imagery by the MNDWI index. The extracted shorelines were analyzed through the Digital Shoreline Analysis System (DSAS) software. The study period has been divided into different phases according to the construction of the protective structures. The study area was subdivided into three segments. The study revealed that Rosetta Promontory has suffered from erosion with maximum rate -121.22. m/y before the construction of the seawall. Erosion decreased to -43.46 m/y after the construction of the Seawall, -36.22 m/y after the construction of eastern five groins and -32.7 m/y after construction the Ghalyon fish farm (GFF). The study revealed that the net area has changed between the pre-construction and post-construction phases of the protective structures at the promontory tip.The study also, demonstrates the impact of the protective structures on the coastal area. The study estimated the impact of the Ghalyon Fish Farm (GFF) jetties’ lengths on the down drift side and the predicted shorelines using 1-D model (LITPACK). Littoral transport process has been simulated using a MIKE21-DHI Coupled model.Three other simulation scenarios were studied using 1-D model. They involved groin system, seawall and sand nourishment. The numerical model simulation indicated that hard structures are not the final process to mitigate erosion at coastal areas. It is recommended to study the effect of environmental friendly soft structure for coastal protection as protective dunes instead of hard structure or using both of them together.The current situation was simulated by 2D numerical model (MIKE21-DHI Coupled model) to show the distribution of waves and current through the study area, also to present the impact of Ghalyon fish farm and its new protective structures on the bed level change. The study conducted that the significant wave height was increase from 0.1 m near the shore line and it was increased in the offshore direction to reach to 1.04 m and the mean wave direction was recorded NW. Current speeds were ranged between 0.1 to 0.13 at the dawn drift area of Rosetta eastern groins system. While, it reached about 0.1 m/s between the outlet and inlet area of GFF. While, bed level changes will be eroded about -0.2 m/y between the inlet and outlet jetties of GFF and from -0.2 to -0.4 at the dawn drift area after last eight groins system. It is recommended to implement 2D numerical simulation models to study the detailed changes in shoreline alterations and study different scenarios for the prediction of future land loss or gaining.