الفهرس 
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Abstract
The present investigation has studied Bottom and shoreline changes on the Nile Delta coast over the present century based on comparison between two bathymetric charts as follow:
1- Observations of long-term change in the shoreline and bathymetry on the inner continental shelf off the northern Nile Delta are based on comparison of two bathymetric maps of closely-spaced soundings from 1919/22 and 1986.
2- The changes are depicted after analyses of 40 bathymetric profiles in water depths as great as 30 m and extending about 30 km from the shore. Comparison ’ among these profiles in terms of changes in water depth, shifting in bottom contours and volumetric changes in bottom sediments, identifies areas of erosion and accretion along the Nile Delta coast.
3- Using a grab sampler a total of 52 samples of surficial sediment from the inner continental shelf off the Nile Delta were collected by the Research Vessel ”Shawatti III” of the Coastal Research Institute (CRI), Egypt in 1984. These samples cover the shelf area from Abu Quir Bay to Damietta estuary
4- Three different environmental and sedimentological variables (sediment textures, slope gradient and water depth) were statistically correlated with vertical bottom changes to assess the influence of each upon the erosion/ accretion distribution.
5- Shoreline retreat along the study area was estimated to be 5.0, 0.4 and 1.4 km at Rosetta promontory, Burullus and Damietta promontory, respectively, whereas shoreline accretion of 1.2, 0.4, 1.1 and 1.4 km was documented at Abu Khashaba, west Burullus, Gamasa and Damietta spit, respectively.
6- The maximum bottom erosion (landward shift) over the period from 1919/22 to 1986 occured at Rosetta promontory (7 km), east Burullus (1 km) and Damietta promontory (2 km). On the other hand, bottom accretion (seaward shift) was detected at east Rosetta (0.6 km), west Burullus (0.7 km) and Gamasa (3.5 km).
7- The sea bottom off the Rosetta and Damietta promontories experienced maximum erosion of 6m and 3m, respectively; while a wide zone of accretion was documented in front of Gamasa stretch. Small patches of stable zones were scattered all over the study area. At Abu Quir Bay the shallow depths were eroded while the outer parts are accreted.