Climate Variation and Water Sources of the Nile

In this blog I provide the geographical context of the region, to give a better understanding of why there are transboundary water conflicts, and how they could worsen over time as water scarcity grows. 

Climate variability along the Nile stems from the fact that the basin stretches from a latitude of 4° S to 31° N, meaning it spans 35 degrees from the northern subtropics to just below the equator (Camberlin, 2009).  Northern subtropical climates are generally characterised by arid conditions and minimal rainfall, whereas at the equatorial zone there are higher levels of rainfall, and this means that countries north of the Nile are heavily reliant on the rainfall near the equator to recharge the Nile (Onyutha and Willems 2015). It comes as no surprise that the runoff generated by both the Ethiopian highlands and the equatorial lakes provide a large volume of river discharge (Senay et al. 2014). However, as the water flows further north there are large levels of water loss, affecting the downstream countries of Egypt and Sudan, which is part of the issue when discussing water management of the Nile basin.

The two main tributaries of the Nile are ‘The White Nile’ and ‘The Blue Nile’. Both have been named because of the colour that their respective sediments carry and are the largest contributors to the annual discharge of the Nile. The Blue Nile begins in Ethiopia and accounts for roughly 60-70% of the annual discharge of the river (Baldassarre et al. 2011). However, during the dry season of the Ethiopian Highlands, which tends to last 5 months from November to April, the White Nile accounts for 70-90% of total discharge (Baldassarre et al. 2011). The map in figure two shows the mean annual rainfall for the basin, and you can see in Ethiopia the area is mainly arid and semi-arid between November and April, and during this time Lake Victoria (the start of the white nile), is labelled as being mainly per-humid and humid, which means rainfall tends to be above 1,189mm. Both these sources of the Nile are upstream, so as the water flows downstream there are issues such as water abstractions, evaporations losses, as well as a growing population which is combined with diminishing water resource (Senay et al. 2014).

Figure Two

 

To look at the transboundary water politics at work in the Nile basin we can focus on the contrasting interests that the downstream and upstream riparian countries have, and how conflicts are created from this. I will be specifically looking at the Grand Ethiopian Renaissance Dam (GERD), and the conflicts this project has caused, or will eventually cause. The dam is near the border of Ethiopia and Sudan, and the water flows from Lake Tana in Ethiopia which leads to the Blue Nile, as shown by figure three. In upcoming blogs I will discuss, why the dam is being built, the impacts it will have on downstream countries and possibilities for managing new risks created by this dam.

Figure Three