WEF linkages are particularly strong at the river basin scale where these competing uses can be found upstream, downstream and sometimes across borders. For example, these uses might include electricity generation (hydropower and cooling), agriculture (irrigation abstractions for food production) and environmental and urban demand. Biofuel production and supporting policies can also lead to both positive and negative effects on water security and food security (pdf). And increased competition for land and water may be an unintended consequence of subsidised biofuels for transport.
Moreover, climate change represents an added layer of complexity in terms of both mitigation and adaptation in the nexus. Water use, and energy and food production generate emissions and climate change will affect water availability and crop yields with wide-ranging implications.
For example, adaptation options can be energy intensive – using desalination in areas of water scarcity, for example – which compounds the problem of global warming.
Trade-offs and co-benefits
There are two important complementary dimensions to any research on the WEF nexus. These are understanding and quantifying the physical links between each element, and then unravelling the management and governance structures involved, in order to inform decision-making and policy.
The first – quantifying the WEF nexus and the links within it – tends to dominate academic research on the topic. Many approaches exist, including life cycle analysis (or supply chain analysis), environmental process models, integrated assessment models, and other types of computational modelling.
There is a trade-off here between the complexity and comprehensiveness of an assessment and its usability. It has therefore been argued that an important feature of good WEF nexus models are flexibility and adaptability across contexts and scales. For graphic visualisation of results, Sankey diagrams are popular, as are maps highlighting resource impacts.
The second dimension – understanding of management and governance structures – is essential to move the nexus beyond research to make it relevant and practical for decision-making. However, this area has received much less attention.
Taking the WEF nexus from a concept to something operational has proved difficult, and to date only a few studies have begun to evaluate and provide useful practical insights into the numerous and complex interactions among water, energy and food.
Recognition of these interdependencies pre-date the WEF nexus movement and integration has been called for by researchers many times, yet significant barriers remain. For example, separate institutional structures are often in place for managing water, energy and food and they are not usually particularly compatible.
The issues around the WEF nexus are perhaps best explored using an example.
Our “Uncertainty reduction in Models For Understanding deveLopment Applications” (UMFULA) research project began in June 2015. Its main objective is to improve climate information for decision-making in central and southern Africa, with a particular focus on Tanzania and Malawi.
One of the project’s two case studies concerns Tanzania. The water sector is at the heart of the government’s development plans and programmes, centring on the Rufiji basin – the largest river basin in the country.