The Nile River Basin is home to more than 160 million people covering 11 countries. The basin is characterized by unique ecological systems with varied landscapes including high mountains, tropical forests, woodlands, lakes, savannas, wetlands, arid lands and deserts. The basin is also characterized by poverty, rapid population growth, environmental degradation and frequent natural disasters. While the population in the basin is projected to increase significantly over the next decades, the water resources are projected to decline, with an increase in environmental degradation. This will be a tremendous challenge in a basin where emerging water demands by upstream countries is demanding for a new formula for the use of the Nile water resources necessitating a new framework of agreement for equitable water sharing. Cooperation is essential for controlling watershed degradation and water quality decline.
The Nile River basin exhibits a varied climate and a spatiotemporal variability in precipitation. The northern part of the Nile Basin is overwhelmingly described as desert, with little to no rainfall. The central portion of the Basin is dominated by occasional though infrequent rainfall; and the headwater regions receive significant seasonal rainfall though with large inter-season and inter-annual variability. Treating the regional hydrological dynamics therefore requires intensive examination of the processes governing water balances, i.e., involving climatic and ecological forcings and feedbacks as well as population and industrialization pressures, both nationally and basin-wide. It is also evident that parts of the basin that receives lesser precipitation and hence little contribution to the basin’s flow utilizes more water from the basin.
Hydrologically, flow of the Nile River is very small compared to the major international rivers of the world like that of Amazon but its historical significance and benefits to many people in the basin puts the Nile in the forefront. Receiving its major annual flow mainly from the Blue Nile River in Ethiopia, the flow is highly dependent on rainy season runoff from the Ethiopian highlands. Various studies have shown that these flows have shown decline over a period of time attributed to factors ranging from poor headwater protection, land degradation to a decline in precipitation.