In this post, I will be exploring the various environmental challenges facing the River Nile. Due to the amount of detail necessary for a comprehensive overview of this issue, the post will be split into two separate entries, with the background information and context being provided here.
The Nile River is the longest river in the world, crossing 6,600 kilometres from south to north Africa (Said 1993). The source of the Nile begins in the rivers that flow into Lake Victoria (which is located in modern-day Kenya, Uganda and Tanzania), and empties into the Mediterranean Sea more than 4,100 miles to the north (Said 1993). The Nile flows through a total of 11 African countries and approximately 400 million people are dependent on the Nile River basin (NGS, 2019). This is largely because most of these countries have an economy focused on agriculture, so are dependent on the water supply and irrigation coming from the Nile. The Nile’s three main tributaries are the White Nile, the Blue Nile, and the Atbara (Said 1993). The Nile is currently under high levels of water stress (as indicated by the exploitation of the Nubian Aquifer system) and it is predicted that this is likely to be intensified in the future due to environmental changes caused by climate change (NGS, 2019).
The River Nile flow as well as the rainfall in the basin area
are very seasonal with a peak in the late boreal summer (Conway 2017). The
variability in river discharge increases water stress in the area. The river
discharge is also affected by the El Niño Southern Oscillation (ENSO) (Siam 2017).
The ENSO occurs every 2-7 years in the tropical Pacific Ocean and has an
opponent called La Niña. During the ENSO the Nile River basin often becomes
drier. Research demonstrates that the ENSO is responsible for approximately 27%
of the River Nile’s water flow variability (Siam 2017). Studies have also shown
that since the 1970s the river discharge of Nile basin has been shifting and the
mean and standard deviation of the river flow has increased significantly. This
trend is projected to continue until 2040, but soon after this there is a
predicted weakening of the walker circulation which will have a strong
influence on the river flow (Siam 2017).
The High Aswan Dam (HAD) in Egypt was built between 1960-1970 in order to regulate climatic variations affecting river discharge of the Nile as outlined above. It also helps control flooding in the Nile Delta. The HAD is colloquially known as the ‘knozzle’ or ‘valve’ of the Egyptian Nile, essentially regulating the river regime of the Nile delta and Lower Nile (Eldardiry & Hossain 2020). The HAD is enormously important in supporting the current environmental conditions for food production along the Nile, distributing water to 86% of all crops in Egypt (Eldardiry & Hossain 2020). The soil and banks of the Nile delta have traditionally been rich in nutrients due to the large silt deposits the Nile leaves behind as it flows into the sea. Today, 95% of Egyptians live within a few kilometres of the Nile (NGS, 2019). During the drier summer months, the HAD release volume increases to reduce water stress in the region and prevent widescale drought, allowing agricultural practices to continue (Eldardiry & Hossain 2020).
However, between 2011-2020 the Grand Ethiopian Renaissance
Dam (GERD) in Ethiopia was built in order to provide the country with
hydro-electric power, irrigation and flood management. The environmental impact
of the GERD is enormous as it is causing wide scale alterations to the hydrological
cycle and is causing local environmental change both upstream and downstream
(Henshaw & Paisley 2013). This is having a major impact on the management systems
that will be necessary in the HAD in Egypt. The construction of the GERD is
thus a transboundary issue as it is causing tensions between the political, environmental
and social realms of two different African countries (Wheeler et al, 2016).
The GERD is situated upstream of the HAD, and will thus to a certain extent control the flow regime of the HAD and the lower Nile. However, as mentioned previously, the Lower Nile is fed by three different sources: the White Nile, the Blue Nile and the Atbara. The Blue Nile is the main contributor, accounting for approximately 56% of the Nile’s total water flow. The White Nile only accounts for approximately 16%, and the Atbara accounts for an estimated 20% (Wheeler et al 2016). The GERD is situated on the Blue Nile and is therefore on the part of the Nile which contributes most to the overall river flow, and has control of around 53% of the flow into the HAD (Eldardiry & Hossain 2020). This is highly problematic for downstream countries, namely Egypt and Sudan, as these countries are hugely dependent on the water of the Nile, with Egypt sourcing around 90% of all its water from the Nile (Eldardiry & Hossain 2020).
To investigate the environmental challenges facing the Nile linked with the HAD and GERD schemes, scientists have explored different hydrological and climatic developments in order to prepare for changes in the river regime of the Nile and ensuing impacts on the environment. The details of these projections and potential issues will be discussed in detail in the next entry.
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