Further rainfalls may not necessary mean more water in the Nile River's riverbed. This increase in rainfalls, which is triggered by high temperatures, will be wasted along with bigger amounts of water because of high temperatures and their impact on evaporation rates. That's the troubling conclusion of a new study led by the US Dartmouth College, saying that a rising population along the Nile will reduce the amount of available water.
The study, published by the college's website in early September, focused on the Upper Nile Basin that includes western Ethiopia, South Sudan, and Uganda. Nearly all of the rain that feeds the Nile's northward flow to Egypt and the Mediterranean Sea falls in this area.
The problem is that the Upper Nile Basin is being affected by two seemingly contradictory effects of climate change. On the one hand, using a mix of available climate models, the study predicts an increase in regional precipitation for the remainder of this century. The researchers expected an upward trend in precipitation comes as a result of increased atmospheric moisture normally associated with warming.
At the same time, however, the study finds that hot and dry years in the region have become more frequent over the past four decades. This trend is projected to continue throughout the century with the frequency of hot and dry years as much as tripling.
As a result, the study finds, increased evaporation from higher temperatures combined with the doubling of runoff demand from a larger population will counteract any projected increase in rainfall. Population in the region is projected to nearly double by 2080, which will impose additional demands on water resources.
According to the study, annual demand for water runoff from the Nile will regularly exceed supply by 2030, causing the percentage of the Upper Nile population expected to suffer from water scarcity to rise sharply.
By 2080, the study estimates that as much as 65 percent of the regional population (250 million people) could face chronic water scarcity during excessively hot and dry years.
In a report published on the college website, Ethan Coffel, one of the study authors, said: "Climate extremes impact people. This study looks not only at high-level changes in temperature or rainfall; it also explains how those conditions will change life for real people."
"The Nile Basin is one of several fast-growing, predominantly agricultural regions that are really on the brink of severe water scarcity. Environmental stresses could easily contribute to migration and even conflict," he added.
The study concluded that "the Nile population has to prepare itself for the crisis by expanding the seawater desalination projects."
Despite plans announced by some countries, including Egypt, to expand the establishment of desalination plants, Dr. Khaled Fouad, professor of Water Resources, Faculty of Agriculture, Zagazig University, says it is not enough.
According to the Housing Ministry, the Egyptian plan aims at increasing the water supply produced by desalination plants to 1.7 million m3 /day by 2020, equaling 6.6 percent of the total drinking water supply.
Fouad underscores the need to use more drinking water in agriculture, which is expected to be significantly affected by the water scarcity scenarios.
But, the challenge facing Fouad's demand is that the establishment of desalination plant is expensive, because most of its components are imported. They also require huge operating costs as they consume huge amounts of fossil fuel.
According to Fouad, the best solution is the fast nationalization of the desalination industry, and the use of solar power instead of traditional fuel to operate these plants.
