IN A DREAM, Pharaoh saw seven ears of grain, fat and healthy, followed by another seven, shriveled and thin and blasted by the east wind. A young slave, Joseph, interpreted Pharaoh’s dream as seven years of plenty followed by seven years of famine.
This biblical cycle of fat years followed by lean years appears to have come true again in the terrible drought and famine that now grip Ethiopia and other countries south of the High Dam on the Nile at Aswan. Alone among neighbors with whom it suffered through millennia of drought, Egypt has been spared famine. The reason is El Sadd el-Aali, the High Dam.
In February of this year (2004) Egyptian authorities reported that the level of water in Lake Nasser, the 500-kilometer-long reservoir behind the dam, had dropped to 30 meters below capacity. Because of the drought, the flow of the Nile—84 billion cubic meters in a year of normal rainfall—was too feeble to fill the lake. Yet water aplenty flowed through the dam for Egypt’s farmers. At top level, Lake Nasser stores nearly 170 billion cubic meters of water, enough to satisfy Egypt’s needs for about three years.
The dam, initiated in 1960, has already saved Egypt from two cycles of dangerous floods in 1964 and 1975 and two threatening periods of drought in 1972-73 and 1983-84. As recently as 1978, engineers feared that the water in Lake Nasser would rise beyond 183 meters above sea level, the maximum the dam can safely hold. But soon the level of the lake started dropping. During the next few years rain clouds failed to reach the edges of the African monsoon envelope, which lies roughly between 15 degrees north and south of the Equator and includes the drought-stricken areas of Ethiopia in the north and Mozambique in the south.
Recent aerial photographs of Lake Nasser reveal bathtub rings of old water levels on wadis and escarpments above a dark deposit of silt, like a landlocked mini- delta, green with new vegetation, between Egypt and Sudan (following pages). Fractures in the rock have been exposed, allowing study of the cause and effect of earthquakes recorded south of Aswan since the filling of the lake.
HIGH-RESOLUTION photographs 0f the Lake Nasser region taken from NASA’s space shuttle Challenger in 1984, and their comparison with Landsat images made from space in previous years, will help us study the changes of lake boundaries and how they relate to cycles of floods and droughts in the interior of Africa.
Before the High Dam was built, 50 percent of the Nile’s flow drained into the sea. Advocates of the dam argue that it conserves this water, prevents floods, is capable of producing 2,100 mega-watts of electrical power, and will increase the agricultural area of Egypt by 1.2 million hectares (2.9 million acres). Critics charge that it has blocked fertile silt of the yearly floods, increased the incidence of the parasitical ailment schistosomiasis among farmers, and caused a rise in groundwater levels in the Nile Valley down to Cairo.
On one point, there can be little argument: The High Dam has preserved Egypt from the famine that grips its neighbors to the south. As Joseph stored grain against the lean years in Pharaoh’s day, modern Egypt stores the life-giving Nile water itself behind the dam.
— FAROUK EL-BAZ
FORMER SCIENCE ADVISER TO
THE PRESIDENT OF EGYPT
Church of the Science of God
La Jolla, California 92038-3131
© Church of the Science of GOD, 1993