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Nile Sedimentology. 1.096 Preliminary Research Anthony Makana Paris 3.07.04. Stages of Sedimentation. Erosion Entrainment Transportation Deposition Compaction. Erosion: Sources of Nile Sediments. Ethiopian Highlands (~90%) Travels through the Blue Nile and Atbara
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Nile Sedimentology 1.096 Preliminary Research Anthony Makana Paris 3.07.04
Stages of Sedimentation • Erosion • Entrainment • Transportation • Deposition • Compaction
Erosion: Sources of Nile Sediments • Ethiopian Highlands (~90%) • Travels through the Blue Nile and Atbara • The sediment load is most significant during flood season (July-Oct.) • ~140 million tones per year
Transportation I • Suspended Load • particulates that travel while suspended in the water column • Bed Load • particulates that travel by rolling or sliding along the river bed
Transportation II • As slope of Blue Nile diminishes so does the mean size of transported sediment • Friction while traveling • Flow rates decrease • Suspended Load Distribution: • 30% Clay (<0.002 mm) • 40% Silt (0.002-0.02 mm) • 30% Fine Sand (0.02-0.2 mm)
Reservoir Deposition I • 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. • Factors • Detention Time • Shape of reservoir • Operating procedures
134-160 million tones/ yr 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 Aswan Figures
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. 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. Hurst, Black and Simaika. (1978) The Nile Basin, Vol. XI. Egyptian Government Press, Ciaro. References