INVESTIGATION ON BANK STABILTY IN THE NILE RIVER AT Km 552.4 D.S ASWAN DAM

Higher current velocities associated with the release of emergency discharges downstream High Aswan Dam may cause degradation in the entire bed of some reaches, particularly in river banks of bend outer curve where many cities and villages are located. Consequently, a severe damage to agricultural properties, urban areas and roads is expected. To overcome such expected damage, velocity profile redistribution is of crucial important to decrease the current values of river bend, protection works against local scour and bank erosion is of crucial important. The purpose of this study is to develop a solution to stop the western bend bank erosion and partial failure in reach at km 552.4 D.S. Aswan Dam. There are two groins perpendicular to the western bank and three big scour holes in the area of about 1200 m long and 100 m width near the western bank along Salam village, 10.5 km D.S Assuit Barrage. Mathematical model was used to simulate the entire reach of 2.8 km on the NileRiver at that area. To improve the flow condition by decreasing the water velocity at the western bank (outer bend), the existing condition during 2008 and four different suggested scenarios were simulated on the model. These scenarios were, removing the located groin, filling the lower part of areas (the scour holes) located at the western part to a level of 40.0 m above MSL, filling the bed and dredging the channel in areas closer to the scour hole until level of 40.0 m above MSL and extending the second groin from 10 m to 60 m length in addition to filling the lower part of scour hole to level of 40.0 m above MSL. The results were compared with the existing condition.