Water for Energy and Food: A System Modelling Approach for Blue Nile River Basin

摘要

The world is facing a more water constrained future as a result of urbanisation, population growth, industrialisation and the emergence of climate change. This has direct impacts on the resilience and performance of the energy and food industries, as water plays a key role in electricity generation processes and agriculture production. Water, energy and food dependencies are more evident in transboundary river basins where several countries share the same source of water for irrigation demand and energy production. From the perspective of the upstream users, it would be ideal to store the water for hydropower generation and the agriculture sector while protecting the environment, whereas the downstream users need the supply of water for their agricultural growth and municipal requirements. We aim to develop a system thinking study by focusing on the transboundary Blue Nile River basin where the Ethiopian government investment in the Grand Renaissance dam has led to opposition by downstream users due to potential reduction of water resource availability downstream. We propose a system thinking approach for analysing different water management practices that considers all the available resources and the requirements set by all the users. To simulate this interaction, we use system dynamics to model the linkage between food production, water abstraction and energy generation. We link the simulation model to an optimisation engine to achieve effective management of the reservoir’s operation. The study provides a platform to investigate how the reservoir operating policies can improve an understanding of the value of water in its alternative uses, and shows how different optimal reservoir release rules generate different optimal solutions inherently involved in upstream and downstream users’ requirements. The proposed methodology is an attempt to enable Nile riparian countries to make more informed decisions on water resources policy and management.