الفهرس 
Nile River in EgyptOnly 14 pages are availabe for public view
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Abstract
Many studies to predict water surface profiles of Nile River downstream Aswan Dam were widely carried out. However, most of these studies were concerned to part of the river (single reach), with rare studies of the Nile River as a whole.
The study in hand was carried out to identify the occurred variations in water surface levels through the whole Nile river flowing in the Nile valley from downstream of Aswan Dam to upstream of the Delta barrages taking into consideration all hydraulic structures constructed through the river including barrages, bridges and lateral structures.
One dimensional mathematical model is built using HEC-RAS software, which was the most suitable to execute the Longitudinal water surface profile for a natural river channel. The daily records of flow discharges and the corresponding water surface levels in addition to the bathymetric survey along the four reaches in the year 2006 were utilized to predict the suitable manning’s coefficients to be applied to the hydraulic model to simulate the consequent river actual conditions.
For calibration process, a steady state simulation for each of the four reaches was conducted separately was built by passing the flows for high demand period (June), average demand period (April) and low demand period (January) which are:
• 80, 160 and 245 Mm3 /day through Aswan Dam
• 63, 161 and 240 Mm3 /day through Esna Barrages
• 60, 147 and 221 Mm3 /day through Nagaa Hammadi Barrages
• 57, 112 and 170 Mm3 /day through Assiut Barrages
The results revealed good agreement between the deduced water surface levels for all the high demand, average demand and low demand periods at locations of gauging stations (observed water levels) along the four reaches and indicated that the average manning coefficients of the four reaches are 0.029, 0.029, 0.028 and 0.033 consequently. The achieved results concluded that the fourth Nile River reach is the roughest as it is the most reach vulnerable to human interventions, which affected its hydraulic efficiency.
Verification of the model was then carried out by executing an unsteady flow simulation plan for the complete river (four reaches connected) with a simulation period of 1 month which was not used in the calibration process (Month of July). The results also showed an encouraging correlation with the observed records.
As an application on the introduced model, two scenarios were applied, one of which was to study the effect of the maximum potential flow of the Nile River, which is around 4051 m3/s, the other scenario was to investigate wave propagation of an accidental flow of 11,068 m3/s on the studied reach downstream HAD and its effect on the four reaches of the river and indicating the wave travel time to the four main regulators.
Finally, inundation maps were prepared for both scenarios to determine the flood prone areas, and to determine the severity of that flood, hazard maps were also prepared for the entire length of the two banks of the river.
The built model can be used by decision makers and other researchers for further studies such as: water resources management, evaluation of accidental pollutants spills in the river, dam break analysis,… etc.