1. Nile Sedimentology 1.096 Preliminary Research Anthony Makana Paris 3.07.04

2. Stages of Sedimentation Erosion Erosion Entrainment Entrainment Transportation Transportation Deposition Deposition Compaction Compaction

3. Erosion: Sources of Nile Sediments Ethiopian Highlands (~90%) Ethiopian Highlands (~90%) Travels through the Blue Nile and Atbara Travels through the Blue Nile and Atbara The sediment load is most significant during flood season (July-Oct.) The sediment load is most significant during flood season (July-Oct.) ~140 million tones per year ~140 million tones per year

4. Transportation I Suspended Load Suspended Load – particulates that travel while suspended in the water column Bed Load Bed Load –particulates that travel by rolling or sliding along the river bed

5. Transportation II As slope of Blue Nile diminishes so does the mean size of transported sediment As slope of Blue Nile diminishes so does the mean size of transported sediment –Friction while traveling –Flow rates decrease Suspended Load Distribution: Suspended Load Distribution: –30% Clay (<0.002 mm) –40% Silt (0.002-0.02 mm) –30% Fine Sand (0.02-0.2 mm)

6. Reservoir Deposition I When river flow enters a reservoir, its velocity and transport capacity is reduced and its sediment load is deposited. When river flow enters a reservoir, its velocity and transport capacity is reduced and its sediment load is deposited. The depositional pattern usually starts with coarser material depositing first followed by the fine creating a delta. The depositional pattern usually starts with coarser material depositing first followed by the fine creating a delta. Factors Factors –Detention Time –Shape of reservoir –Operating procedures

7. Reservoir Deposition II

8. Aswan Figures 134-160 million tones/ yr 134-160 million tones/ yr Monthly Sediment Load (million tones) Monthly Sediment Load (million tones) –Jan. 0.29 –Feb. 0.15 –Mar. 0.11 –April 0.13 –May 0.08 –June 0.09 –July 1.81 –Aug. 56.22 –Sep. 56.64 –Oct. 15.54 –Nov. 2.15 –Dec. 0.53

9. References Vito A. Vanoni. (1975) Sedimentation Engineering. American Society of Civil Engineers. pg. 1 Vito A. Vanoni. (1975) Sedimentation Engineering. American Society of Civil Engineers. pg. 1 V. D. Novozhenin and A. M. Lapshin. (2000) Exploitation of Water and Hydropower Resources of the Nile. Hydrotechnical Construction, Vol. 24, Nos. 8-9. pg. 460. V. D. Novozhenin and A. M. Lapshin. (2000) Exploitation of Water and Hydropower Resources of the Nile. Hydrotechnical Construction, Vol. 24, Nos. 8-9. pg. 460. El Moushid, B. E. F., El Awad, O. M. A. & Ahmed, S. E. (1997) Environmental effect of the Blue Nile sediment on reservoirs and irrigation canals. In: 5th Nile 2002 Conf. (Addis Abada). El Moushid, B. E. F., El Awad, O. M. A. & Ahmed, S. E. (1997) Environmental effect of the Blue Nile sediment on reservoirs and irrigation canals. In: 5th Nile 2002 Conf. (Addis Abada). M. Gamal Mostafa. Sediment Processes in the Nile River. (1981) Water Master Plan. UNDP Technical Report 12. M. Gamal Mostafa. Sediment Processes in the Nile River. (1981) Water Master Plan. UNDP Technical Report 12. Hurst, Black and Simaika. (1978) The Nile Basin, Vol. XI. Egyptian Government Press, Ciaro. Hurst, Black and Simaika. (1978) The Nile Basin, Vol. XI. Egyptian Government Press, Ciaro.