الفهرس 
1.3.1 Main ObjectiveOnly 14 pages are availabe for public view
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Abstract
Improving streams for inland navigation through the Nile River and main irrigation
channels have been recently considered as high priority in Egypt. Navigation channel
hazards are usually associated either with channel adjustment due to natural conditions or
as a result of human activity. Assessment of river channel hazards requires an
understanding of both the natural system operation and the degree of human impact over
extended time periods. Therefore, approaches for determining the risk of hazards
occurrence should depend on the better understanding of the river channel sensitivity to
change so that the proposed solution will cause appropriate response to the type of
hazards and the risk of its occurrence. The navigation channel of Damietta branch has a minimum average channel width of 40
m. However, the last 12 km of the route to Damietta Port is via an artificial canal of water
depth of 4 m and canal width of 40 m at bed level, which is sufficient for two-way traffic
for container vessels. The daily water levels on Damietta branch are dependent on the
actual discharges released downstream the Aswan High Dam (AHD) to satisfy the basic
requirements of irrigations and water intake structures as well as the municipal and
industrial requirements. The waterway design specifications have guaranteed a minimum
water depth for navigation of 2.3 m for uninterrupted period of 365 days a year. This is
achieved through a hydrological study for the water level on the branch for more than ten
year period and the minimum among these years is taken as a design water level. A navigation hazards represented by a DROP in the design water level is reported
downstream Zefta Barrage, which threatens the satisfaction of 2.3 m water depth during
the low discharges seasons. A field reconnaissance was conducted to address the current and future navigation needs downstream Zefta Barrage and other locations. The selected
study reach starts from DS of Zefta Barrage to the Mediterranean Sea, the selected area
was simulated using mathematical model to reach to the best scenario for solving the
navigation bottlenecks. A one-dimensional mathematical model (SOBEK) is selected to
simulate the water surface profiles for the study reach. This thesis studies the navigation bottlenecks, which resulted from passing low
discharges. Previous studies concluded that a DROP in the water level is evident as a result
of excessive dredging activities. The research results introduce regulation works as
alternatives to overcome those bottlenecks such as spur dikes which are applied as a
permanent works. The study also recommended a set of actions for better performance of
navigation channels.