Optimal Operation of the Eastern Nile System Using Genetic Algorithm, and Benefits Distribution of Water Resources Development

Abstract

The Eastern Nile Basin is facing a number of transboundary issues, including water resources development, and the associated impacts. The Nile Basin, particularly the Eastern Nile Sub-basin, is considered as one of a few international river systems of potential conflicts between riparian countries. The Eastern Nile is characterized by the high dependency of downstream countries on river water generated in upstream countries, with limited or no contribution to the runoff itself. The aim of this paper is to analyze optimal scenarios for water resources management in the Eastern Nile with regard to hydropower generation and irrigation development. A hydro-economic optimization model based on Genetic Algorithm has been used to determine the maximum benefits for two scenarios: (i) non-cooperative management of hydraulic infrastructure by the riparian countries (status quo), and (ii) cooperative water resources management among the riparian countries. The hydro-economic model is developed using a Genetic Algorithm and deterministic optimization approach covering all hydraulic infrastructures in the Eastern Nile, existing and planned, including the Grand Ethiopian Renaissance Dam (GERD). The results show that cooperative management yields an increase in hydro-energy returns for all countries compared to the status quo, with a very high increase in Ethiopian’s returns, as expected. Non-cooperative system management would negatively impact the hydro-energy of Egypt compared to the cooperative management (reduced by 11%), without a significant increase of hydro-energy for Ethiopia. For Sudan, the results show that hydropower generation benefits from the presence of GERD, in both management scenarios. Non-cooperative management of the system, along with the internal trade-off between irrigation and hydropower facilities, would negatively impact irrigation supply in Sudan. The findings support the argument of positive impact of GERD development on the three Eastern Nile riparian countries, Ethiopia, Sudan and Egypt, provided that the three countries agree to manage the system cooperatively.

A hybrid partial and general equilibrium modeling approach to assess the hydro-economic impacts of large dams – The case of the Grand Ethiopian Renaissance Dam in the Eastern Nile River basin

“…The results of the stochastic PE model employed to design the simulation scenarios for the GTAP-W model are similar, but not identical to those reported in other studies (Goor et al, 2010;Arjoon et al, 2014;Digna et al, 2018). The differences are mainly due to changes to the baseline and input data in the agricultural sector, which were made consistent in this study with the data used for the CGE model based on the IMPACT data.…”

“…The substantial increases in irrigation water and land use increases total crop output in the country by 117.8, 419.6, and 132.9 tons, respectively, during dry, average and wet hydrological conditions. Recent studies (Arjoon et al, 2014;Digna et al, 2018) have shown that if the riparian countries were to cooperate under a scenario with large irrigation expansion in Sudan, increased water use in that country could partially be compensated by re-operating the downstream reservoirs at lower pool elevation in order to reduce evaporation losses. In this study, however, although water diversions in Sudan are increasing with GERD online, the difference is not significant enough and HAD does not require to be re-operated at lower pool elevation in order to reduce evaporation losses.…”

Seasonal Rainfall Variability in Ethiopia and Its Long-Term Link to Global Sea Surface Temperatures

“…Generally, the majority of previous studies imply that the teleconnections between SST and Ethiopian rainfall are complicated on both spatial and temporal scales and still not well investigated. Therefore, the objective of this study is directed toward more understanding the characteristics of interannual variability of rainfall in the country and investigating clearly the influence of global SSTs on Ethiopian rainfall peaks at various regions and seasons (summer and spring), to reinforce the skill of rainfall predictions that would be valuable for operations of reservoirs [22], assessment and allocation of water resources [23,24], and for mitigation of disasters related to rainfall such as flooding and drought [25]. Also, better understanding of the rainfall variability plays a key role in several applications including hydrological analysis [26][27][28][29][30][31] and soil erosion risk assessment [32][33][34][35][36].…”

Bias-corrected and spatially disaggregated seasonal forecasts: a long-term reference forecast product for the water sector in semi-arid regions

“…While the Catamayo-Chira Basin is jointly managed by Ecuadorian and Peruvian authorities, coordinated management of water-related infrastructure across the international borders of the Blue Nile and Tekeze-Atbara basins rarely exists (Wheeler et al, 2018). A recent study has analyzed the potential of a joint transboundary water management for hydro-economic sectors particularly through the integration of the newly build Grand Ethiopian Renaissance Dam (GERD) (Digna et al, 2018).…”