Lake Nasser: Alleviating the Impacts of Climate Fluctuations and Change

Abstract

Egypt as a country may not have existed without the Nile River. Its population was 84 million in 2015 and is estimated to reach 124 million by 2050. It is already the largest global importer of wheat. Even after Lake Nasser became operational in 1970, its arable land is still less than 4 % of its land area. The major constraint to expand agriculture is water, not land. Agriculture currently accounts for more than 80 % of total water use. Throughout history, Egypt has suffered from frequent droughts and floods. Construction of a storage reservoir at Aswan allowed it to stabilize significant interannual and intra-annual fluctuations of the Nile. Lake Nasser enabled Egypt to increase its cultivable land by 30 % and allowed cropping intensities to reach 180–200 % in old lands. When it became operational in 1970, it accounted for over half the country’s electricity generation. While this reservoir has effectively taken care of climatic fluctuations, a main issue now is how to seamlessly integrate future climate change considerations with climatic fluctuations. At the present state of knowledge, it is impossible to predict even what will be the direction of river flow changes, let alone their real magnitudes. Three well-respected global circulation models indicate flow increases of 12 and 18 % and catastrophic decline of 77 %. Under such uncertainties, Egypt needs to increase all types of water storage, improve significantly water use efficiencies in all sectors, and monitor river flow changes over years very carefully.