Including water quality in the water-energy-food nexus: An Upper White Nile case study

The Upper White Nile basin plays a critical role in supporting essential ecosystem services and the livelihoods of millions of people in East Africa. The basin has been exposed to tremendous environmental pressures following extensive population growth, urbanisation, and land use change, all of which are compounded by the threats posed by climate change. The water-energy-food (WEF) nexus provides an integrated solution to sustainable development by minimising the trade-offs between water, energy, and food resources. We apply quantitative and qualitative methods to understand the most pressing WEF nexus challenges within the Upper White Nile basin, how these can be represented in indicators, and how existing WEF nexus modelling tools could address this. This research combines semi-structured stakeholder interviews with a Co$tingNature analysis in order to map the greatest environmental pressures within the basin and disentangle the likely drivers. The findings from these highlight the importance of declining water quality, aquatic and terrestrial ecosystem health, and fish populations as a result of deforestation, growing human population, intensifying pollution, and increasing agricultural intensity within the basin, with most stakeholders expressing concerns for the uncertain impacts from climate change. Furthermore, a review of current WEF nexus modelling tools reveals how existing tools are insufficient in addressing the most pressing environmental challenges within the basin, with a significant gap regarding the inclusion of nuanced water quality and aquatic ecosystem indicators. Subsequently, these findings are combined in order to guide the development of holistic WEF nexus indicators that have the potential to spatially model the trade-offs within the WEF nexus in the Upper White Nile basin under climate change and land use change scenarios. This work demonstrates the use of a novel decision framework for WEF nexus indicator development, which ensures that outputs are fit-for-purpose and respond to the actual needs of stakeholders and policymakers. The outputs aim to strengthen water management decisions that enhance water quality, energy production, food production, and aquatic biodiversity within the Upper White Nile basin.