Author(s): A. Z. Makary; M. El-Moattassem; A. Fahmy
Linked Author(s):
Keywords: Lake Nasser; River Nile; Reservior sedimentation
Abstract: Aswan High Dam (AHD) constructed across the River Nile (1964-1968), 6.5 km upstream Old Aswan Dam (OAD-1902), resulted in the formation of a huge artificial lake of capacity 162 bcm. The river Nile has a length of about 6,825 km from its sources to the Mediterranean Sea. The river Nile, like many other large rivers, has two distinct hydrological phenomena. A short, but high flow period (muddy water) of about 3 months, and a long, but low flow period (clear water) of about 9 months. Before dam construction, it was estimated that mean annual 124 million tons of sediments reached El-Gaafra gauge station 34 km downstream OAD. After the AHD, the mean annual amount of sediment reached El-Gaafra station amounts to 2.5 million tons, which indicated that nearly all the sediment brought by the Nile flow deposited in the reservoir upstream the dam, and that the trap efficiency is about 98%. The purpose of this paper is to compare the different approaches for the estimation of the lake sedimentation since the lake formation (1964) and up to the year 2000. The first approach is the estimation of the suspended load deposited in the inlet lake flow, while the second approach is to calculate the deposited sediment from the actual annual hydrographic surveys. The sedimentation pattern progress indicated that delta formation at reservoir entrance was affected by the drought period (1979/1987). The prospect of dredging some of the deposited sediment and the prefeasibility of utilizing the dredged material for some industrial and/or agricultural propose will also be discussed
Year: 2004