الفهرس 
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Abstract
The Nile Delta is located on the Egyptian Mediterranean coast and extended at a distance of 240 km from Abu Qir headland in Alexandria in the west to Port Said in the east. Along the Nile Delta of Egypt for thousands of years, the River Nile has carried vast quantities of sand derived from the equatorial east of Africa,displacing the Delta coast seaward into the Mediterranean Sea. However, since the late nineteenth century there has been a prolonged period of decrease in the Nile discharge, especially this caused by a dramatic decrease after the construction of Aswan High Dam in the 1960s. Since the construction of this dam, the Egyptian coastline along the Mediterranean Sea has suffered from an increased erosion which has destroyed the coastal roads, recreational facilities and the beach resorts in Alexandria, Rashid and Baltim. Three coastal heads are under the impacts of erosion attack. These heads are: Rosetta and Damietta promontories and Burullus headland. The current study presented the three heads from different aspects: Their location, coastal changes,erosion danger, and previous protection. It discussed extensively the current protection scenario at Rosetta promontory and Burullus headland. It also showed the disadvantages of the traditional protection scenario at these locations. Finally,the current study represented proposed combined system scenarios to protect Rosetta and Burrullus headlands showing their effect on wave heights, current induced waves and bed level changes and giving the advantages and disadvantages of every scenario reaching to the preferred study protection scenario.For Rosetta promontory, the current study showed that from 60-180 million tons of sediments and from 18 X 109 to 55 X 109 m3/year of water were annually transported to the Mediterranean Sea by the Nile before the construction of Aswan High Dam in 1964. Almost no sediment was discharged from the Nile. About 1 to 8 billion cubic meters of discharged water reached the sea after theconstruction of Aswan High Dam forming 70% at Rosetta outlet. Moreover, the current study presented more than seventy-six beach profiles which were surveyed by Costal Research Institute ’CoRI’ in the years of 2002 and 2009 to monitor the coastal surf zone changes at Rosetta promontory. It showed that the coastal changes due to the continuous multiple protection structures would be numerically modeled with five scenarios for Rosetta promontory, in addition to the current one. erosion problems in front of the eastern seawall, western seawall, eastern five groins, western nine groins, and the down-drift of the eastern five groins, and to reduce siltation at the outlet of Rosetta Nile branch. Furthermore, the related studies showed that the third and fifth scenarios were the most effective ones to protect Rosetta promontory from three dangers: Erosion in front of the eastern and western seawalls, siltation at Rosetta branch outlet, and the eastern down-drift erosion. All scenarios were numerically modeled using the finite element model ’Mike 21 Coupled Model FM’, which was based on two dimensional shallow water equation derived from Navier-Stokes equations. Numerical models were calibrated and validated by adjusting bed level changes at the bed profiles. The results of the current study revealed that for the third scenario, the wave heights were attenuated to ’0.12~0.15m’ with a transmission coefficient of 13~22% at the eastern coast of Rosetta surf-zone and to 0.12~0.2m at the lee-side of the western submerged breakwaters with a transmission coefficient of 20~35%. Currents at the lee-side of the submerged breakwaters were ranged from 0.003 to 0.23 m/s with a reduction of speeds ratio of 50~75%. Currents reached ’0.08~0.11m/s’ between the eastern graded groins and the four hundred meters down-drift eastern protection group. The results also showed that for the fifth scenario, the wave heights were attenuated to ’.03~0.17m’ at the eastern coast of Rosetta surf-zone and ’0.11~0.26m’ at the lee-side of the western detached breakwater. Currents were ranged between ’0.02~0.3m/s’ at the lee-side of the eastern and western detached breakwaters, which allowed sediments to be settled on the sea bottom according to the low wave heights. The eastern graded groins reduced the down-drift erosion to be limited in length; about four hundred meters as maximum as 0.13m/s. For Burrullus headland, the current study showed that the Kitchener drain delivered about 18m3/sec of water flow to the Mediterranean Sea. The western coast of the Kitchener drain was protected by fourteen emerged detached breakwaters and nine emerged perpendicular groins which prevented the transported sediments. The shortage of sediment source for the eastern coastal side of the drain allowed the shoreline to be eroded under the dynamic wave impact for five kilometer Omore than 103 beach profiles surveyed annually by CoRI between 2003 and 2013 to monitor the coastal surf-zone changes at Burrullus headland. from these extensive surveys, seventy-six profiles of 100 meters in spacing were selected to cover the coast of the Kitchener drain. Also, three scenarios were numerically modeled for different human artificial
interaction structures, in addition to the current and traditional protection ones, to protect this zone from erosion. All scenarios were numerically modeled using the finite element model ’Mike 21 Coupled Model FM’, which was based on two dimensional shallow water equation derived from Navier-Stokes equations.Numerical models were calibrated and validated by adjusting bed level changes at the bed profiles.The related studies showed that the second scenario ’the submerged breakwater combined with the graded groins’ was the preferred one to protect the shorelinefrom erosion with low currents speed of ’~.005 to .01 m/s’, and low wave heights of ’~0.1m’ behind the submerged breakwater. It also allowed water circulation or tidal currents to pass over the submerged breakwaters.