The Water-Energy-Food Nexus in the Eastern Nile Basin : Transboundary Interlinkages, Climate Change and Scope for Cooperation

With worldwide mounting pressure in the three highly interrelated resources of water, energy, and food (WEF) the 'nexus' concept has emerged as the best approach to address the complex and dynamic problem facing the three sectors. Though the challenge of balancing needs across competing uses and users is global, it is more intense in developing regions like the Eastern Nile basin as most of the riparian countries are faced with high poverty and a serious ongoing security problem with the three resources. In the basin, empirical evidence on the WEF nexus is needed to improve resource use efficiency and avoid adverse impacts of single-sector and unilateral development strategies and actions. Accordingly, this study applies the WEF nexus concept in the Eastern Nile basin to assess and quantify tradeoffs and synergies in the basin across sectors and between riparian countries. To address these objectives, combinations of qualitative (e-surveys and interviews) and quantitative (an integrated hydro-economic model) approaches are used. <br /> Results suggested that cooperation across sectors and riparian countries is crucial for the basin because sectoral and transboundary interlinkages are tight, complex and dynamic. Findings from the qualitative assessments advocated that collaboration across WEF sectors is essential at a national and regional level to improve the efficiency of resource use and management in the basin. The same need for cooperation is suggested by the results of the hydro-economic model where the cooperative (system optimization) scenarios yield the highest economic benefits compared to the non-cooperative (tradeoff) scenarios under various levels of hydropower and irrigation developments in the basin. Results from the non-cooperative scenarios indicated the potential for large sectoral and transboundary tradeoffs in the basin if one sector or country is prioritized over the other. Assuming full cooperation, upstream hydropower developments are found to be beneficial to all riparian countries and could have a synergetic impact by ensuring more regulated year-round river flows, increasing irrigation benefits in downstream countries, reducing evaporation losses, and providing access to a large amount of clean and affordable energy in the region. However, new upstream irrigation developments could compete with existing water uses and potentially inflict costs on downstream riparians, unless measures are taken to improve irrigation efficiency in existing and proposed irrigation schemes. <br /> Climate change will add further challenge and complexity to WEF nexus in the basin. It is highly uncertain how climate change is going to affect the supply of and demand for WEF resources in the basin. Predicted changes of river flow in the basin greatly vary across the ten climate change scenarios considered in this study where some (majority) scenarios forecasted increased flow, while others project a reduction in 2050. Also, most climate change scenarios forecasted higher irrigation water demand in the basin either due to reduced crop yield or increased evapotranspiration rate (both). The increase in irrigation water demand resulted in reduced total basin-wide economic benefits (from hydropower and irrigation) despite the predicted increase in total basin-wide inflow by the majority of the climate change scenarios. As climate change (coupled with population and economic growth) poses high uncertainty to the basin's future, dynamic collaborative efforts are needed among sectors and basin countries. There are various areas where riparian countries can cooperate on to enhance the benefit of future WEF developments in the basin. These include undertaking joint transboundary developments and promoting 'beyond the river' links in the region by strengthening existing technical, economic and institutional ties, and creating new ones.