The Environmental Effects of the High Dam at Aswan

11 Pages 2804 Words

INTRODUCTION:
The livelihood and stability of Egypt `s population is directly linked to the
Nile valley and delta. Although these two regions account for less then 5% of
Egypt `s land surface (fig. 1), all its agriculture and water sources are
concentrated in these areas (White 1988). The water sources for the Nile are the
Blue Nile (originating at Ethiopian highland) and the White Nile (draining east
central Africa and Sudan).The river flows through Egypt toward the Mediterranean
sea, forming a delta at its south-east coast.
Fig. 1 - The Nile path after building the Aswan high dam. (White 1988).
Prior to the beginning of emplacement of barrage along the Nile in the last
century, the river had a seasonally fluctuating fluvial regime (Hurst 1964). Its
annually water discharge at the coast was above 8*1010 m3, caring about 10*108
tons of sediments (Eldardir 1994), and was the main sediment source for the east
Mediterranean (Stanley and Wingerath 1996). At the end of the 19th century two
major sediment bearing distributors were active (Damietta and Rosetta, fig. 2)
(Stanley 1996). A series of barrages along the Nile (north of Aswan) were
constructed during the 19th century regulating flow and navigation (Elassiouti
1983). At the beginning of the 20th century the first dam in Aswan, the low dam,
was build. This dam was designed to generate hydroelectric power and, to
decrease the seasonal fluctuations in the Nile flow (without carrying any water
storage over from one year to another). Accordingly, it hasn't stored any
significant amounts of Nile silt.
During the 1950's the Egyptian government had to face a very high population
grow rate (~3% a year). Given its limited resources of arable land in the Nile
valley, Egypt was looking for opportunities to expand its agriculture, energy,
and associated manufacturing production. The easiest alternative was to expand
the irrigated areas and to inc...