Sediment Balance in the Nearshore Zone of the Nile Delta Coast, Egypt
Keywords:Volume changes, erosion, accretion, beach profiles, shoreface
Severe erosion of the Nile Delta coast began around the beginning of the present century in response to the construction of dams and barrages across the Nile. The erosion accelerated following the construction of the High Aswan Dam in 1964 which trapped all the flood sediments previously discharged to the delta shores. Volumetric change in the nearshore zone along the coast of the Nile Delta were determined from beach profile surveys at 62 sites covering a 12-year period (1978-1990) at 4-year intervals. The variations in sediment volume along the coast show severe erosion along the Nile promontories (Rosetta, Burullus and Damietta) where waves are more concentrated. The other parts of the shore at Abu Quir Bay, Abu Khashaba, Hanafi, Kitchener Drain, and behind Port Said breakwater receive the eroded material by eastward sediment transport resulting from the prevailing wave approach from the northwest. Greatest erosion is concentrated between Kitchener Drain and Gamasa (-7 X 106m3 , for the period 1978-1981), while maximum accumulation of sediments occurs between Abu Khashaba and Burullus Inlet at Hanafi (9.1 X 106m3 , for the period 1984-1987). The cross-shore volume changes in the nearshore zone indicate that sediment is moving offshore as well as alongshore as littoral drift.