Foreseer: visualisation, decision support and an analytical framework for the water-land-energy nexus
Department of Geography
University of Cambridge
A multi-disciplinary group at the University of Cambridge has been exploring a particular approach to the water-energy-land nexus based on a project called “Foreseer”. This has three inter-related objectives, of (i) developing an analytical framework, (ii) providing policy decision support, (iii) visualising the complexity of the nexus. The visualisation has been based on the use of a form of Sankey diagram that is multi-layered, and potentially dynamic, rather than a static representation. These diagrams traditionally represent how a resource is used, and in this case, enable the flow from a resource to the services it provides; a particular requirement is that the diagram quantities are conservative at all transformation stages. Thus, there are methodological links between the visualisation tool and the analytical framework, which itself has parallels with material flow accounting. The water-energy-land nexus is sometimes treated as a water-energy-food nexus, but it is preferable to begin with land as the underlying resource, and to use a transformation to net primary productivity, in order to connect food production to land use, and thereby to track the carbon footprint and GHG emissions associated with this and the other nexus components (GHG emissions from agriculture having been neglected by the IPCC). Underlying the Sankey diagram representation, at least of the present and recent past, may be a multi-layered GIS of spatially-distributed data on land, water and energy resources and services; however, future scenarios may have to be aggregated because of the uncertainty about predicting future spatial patterns of change. Particular difficulties arise in representing water use (a) because of recycling, and (b) because of water quality variation (although this is a crucial link to the energy resource). A key requirement is therefore to map the connections between the water, energy and land resource systems, and identify coefficients that define these connections. Decision support is provided both by emphasising the trade-offs between resource uses. For example, the UK’s future energy pathways to 2050 have been designed to meet the 80% reduction of CO2 emissions, but the favoured pathway can be shown to have significant negative impacts on land and water use. Decision support is underpinned by the interactive use of dynamic visualisation of multi-dimensional scenarios.