Virtual water or land use is the volume of water or area of land, respectively, used to produce a unit food commodity that is traded. Estimates of future virtual water or land use (as potential mechanisms for mitigating against food insecurity due to resource scarcity) are limited by the need for complex modelling and data requirements regarding trade, for which the data or expertise might be rare or unavailable. This paper presents a simple food balance approach for estimating the status quo food demand and supply and associated virtual water or land use transfers under future conditions. The method is spatially-scalable, accessible to a wider range of users, and illustrated using UK feed barley supply. Key features of the method are: ● Proportionate distribution of a target food item over utilization components is estimated from the FAO Food Balance Sheet of the country of analysis and used to distribute future supply over utilization components. ● The balance between demand and supply is used to estimate the direction and magnitude of virtual water or land use transfers. ● The method can be scaled up from national to regional and global levels and to cover multiple food items.

Water is one of the most important limiting resources for food production. How much water is needed for food depends on the size of the population, average food consumption patterns and food production per unit of water. These factors show large differences around the world. This paper analyzes sub-continental dynamics of the water footprint of consumption (WFcₒₙₛ) for the prevailing diets from 1961 to 2009 using data from the Food and Agriculture Organization (FAO). The findings show that, in most regions, the water needed to feed one person decreased even if diets became richer, because of the increase in water use efficiency in food production during the past half-century. The logarithmic mean Divisia index (LMDI) decomposition approach is used to analyze the contributions of the major drivers of WFcₒₙₛ for food: population, diet and agricultural practices (output per unit of water). We compare the contributions of these drivers through different subcontinents, and find that population growth still was the major driver behind increasing WFcₒₙₛ for food until now and that potential water savings through agricultural practice improvements were offset by population growth and diet change. The changes of the factors mentioned above were the largest in most developing areas with rapid economic development. With the development of globalization, the international food trade has brought more and more water savings in global water use over time. The results indicate that, in the near future and in many regions, diet change is likely to override population growth as the major driver behind WFcₒₙₛ for food.

Water use and agricultural practices in the Mediterranean area are unsustainable. The situation is worsened by the increased frequency of droughts and floods, as well as desertification and soil depletion, associated with climate change. The aim of Partnership for Research and Innovation in the Mediterranean Area (PRIMA) is to foster an integrated programme of sustainable food production and water provision in the framework of the water-energy-food nexus. A monitoring tool developed under PRIMA is based on the Sustainable Development Goals, two of which are specifically dedicated to food security (SDG 2) and sustainable management of water (SDG 6).The 12 indicators that have been chosen to be monitored in the Mediterranean area are: Multidimensional Poverty Index (MPI); population overweight (%); land use (%); GHG emissions (total and AFOLU)(tCO₂ₑ); cereal yield (kg/ha); agriculture value added (US$/worker); fertilizer consumption (kg/haₐᵣₐbₗₑ ₗₐₙd); crop water productivity (kg/m³); annual freshwater withdrawal for agriculture (%); population served using with safely managed water service (rural, %); population served using with safely managed sanitation (rural, %); amount of agricultural residues used for energy purposes (t). Datasets for these indicators are collected by international bodies such as the World Bank, WHO, FAO and UNFCCC; recent series are available for almost all Mediterranean countries and are constantly updated. The aim of the proposed monitoring tool is to keep track of the impact generated in by PRIMA research and innovation projects Mediterranean countries.

As three resources that are necessary for human survival and production, water, energy and food are increasingly closely linked. In recent years, the water-energy-food nexus has attracted special attention from international organizations and academic circles. However, due to the lack of research on its internal mechanisms, there is still controversy on whether the water-energy-food nexus can be used as a new policy basis. The internal mechanisms of the water-energy-food nexus were analysed from the perspective of industrial linkages in this paper and empirically verified by constructing an SVAR (structuralvectorautoregression) model using China’s data. The results showed that there were two forms of conduction in China’s water-energy-food nexus: the water-energy-food nexus with nuclear power participation and that with natural gas participation. The characteristics of China’s water-energy-food nexus were derived. For the interactions of the water-energy segment in China’s water-energy-food nexus, the conduction from energy to water was consistent for different types of energy, while that from water to energy varied depending on the type of energy. Food production always had a negative impact on energy production, while the conduction from energy to food varied for different types of energy. The conduction between food and the water supply was not as significant as was generally considered. Especially, the impact of the water supply on food production was weak. The order of strength intensity and the duration were also available for reference. Accordingly, a new policy basis was presented under the framework of China’s water-energy-food nexus. Both our research design and research findings are significant in contributing to understanding the internal mechanisms of the water-energy-food nexus, and the policy implications are also helpful for achieving better policy effects.

Despite efforts to achieve food security in Sub-Saharan Africa (SSA) since the 1970s, food insufficiency continues to plague the region. As of 2014 more than a fifth of Sub-Saharan Africa’s population remain food insecure according to the United Nations Food and Agricultural Organisation (FAO). The food security challenges in Sub-Saharan Africa are linked to economic, agro-ecological, technological/agronomic, institutional and related factors. These causes however overlay complex interactions and constraints within the key physical resources of Water Land and Energy (WLE), which are necessary for food production, processing, distribution and consumption. The relationship between the WLE interactions and the performance of SSA’s food systems, and the impacts of interventions at different scales are not yet fully understood, particularly in light of the need to maintain essential ecosystem services.This study employs an integrated multi-scale Food System resource analysis approach to examine Uganda’s WLE resource constraints vis-à-vis 2012 and 2050 agricultural resource demand at national, district and local scales, as a test case for Sub-Saharan Africa. The analysis identifies where the competing WLE resource constraints are and the variations from local (sub-county), regional, to national scale so that potential policy interventions can be appropriately targeted. The approach involves a combination of geo-spatial analysis, calorific-demand analysis and Source-to-Service resource transformation modelling. The results are visualised using coupled Sankey diagrams and resource stress maps. The analysis reveals the current competing demands and constraints at different scales, and helps to identify key resource intervention areas to resolve resource stress in Uganda’s food system. The inferences highlight variations in the significance of resource stress at different analytical resolutions and constraints at different locations for the WLE resources. Overall, the analysis helps to inform food security policy and the resource context for the present and future management of Uganda’s food system.