Many studies examine the correlation between the use of resources such as water, energy and land, and the production of food. These nexus studies focus predominantly on large scale systems, often considering the social dimensions only in terms of access to resources and participation in the decision-making process, rather than individual attitudes and behaviours with respect to resource use. Such a concept of the nexus is relevant to urban agriculture (UA), but it requires customisation to the particular characteristics of growing food in cities, which is practiced mainly at a small scale and produces not only food but also considerable social, economic, and environmental co-benefits. To this end, this paper proposes a new conceptual basis for a UA Nexus, together with an assessment methodology that explicitly includes social dimensions in addition to food, energy and water. The conceptual basis introduces People, together with Food, Energy and Water, as a fundamental factor of the UA Nexus. On this basis, a methodology is developed measuring not only resource efficiency and food production but also motivations and health benefits. It comprises a combination of methods such as diaries of everyday UA practices, a database of UA activities, life cycle assessment (LCA), and material flow analysis to connect investigations developed at a garden scale to the city scale. A case study shows an application of the methodology.

Over the next few years, Tunisia will face a growing scarcity of water. The concept of a food consumption water footprint has been recently applied to expand knowledge about water management and to respond to problems of food insecurity. In this study, following the Water Footprint Network (WFN) method, we assessed and analysed the food consumption water footprint of Tunisian households by geographical location and by group of food products. We used results from national food surveys to collect the quantities of food consumed and the WFN database containing water footprints of food products specific to Tunisia. We found that the average water footprint for the main consumed food groups has increased by 31% during recent decades, from 1208 m³/capita/year in 1985 to 1586 m³/capita/year in 2010. Despite the decline in cereal consumption in Tunisia, the food water footprint has continued to rise as a result of increased consumption of animal source products. This increase is associated with regional variations in food choices that imply large differences in water footprints. Urban diets present higher water footprints than rural diets proportionally to higher standards of living. This study provides a new perspective on the water footprint of food consumption in Tunisia by using dietary data at the household level and demonstrated significant variability in water footprints due to different food consumption modes, and socio-economic and geographic characteristics. Future food consumption trends will likely create more pressure on water resources, especially in Tunis city and coastal areas of Tunisia. Special measures related to price policies, sensitization of consumers, and changes in production systems may have to be taken by policy makers to reduce the water footprint in order to improve food security strategies and water management in Tunisia.

Evaluations of food, energy and water (FEW) linkages are rapidly emerging in contemporary nexus studies. This paper demonstrates, from a food consumption perspective, the potential of life cycle thinking in understanding the complex and often “hidden” linkages between FEW systems. Our study evaluates the upstream virtual water and embodied energy in food consumption in the Tamar catchment, South West England, distinguishing between domestic production and imports origin. The study also evaluates key inputs, including virtual nutrients and animal feed, when tracking supply chain of food products. Based on current dietary patterns and food products selection, the catchment consumes annually 834 TJ, 17 hm³ and 244 hm³ of energy, blue water and green water, respectively. Tamar is not self-sufficient in terms of food and requires imports of food products, as well as imports of virtual nutrients and animal feed for local production. Consequently, 51% of the embodied energy and 88% blue and 45% green virtual water in food consumed within the catchment are imported. Most of the embodied energy (58%) and green virtual water (90%) are because of animal feed production, where nearly half of embodied energy (48%) and green virtual water (42%) come from imports. 92% of blue virtual water is used for irrigation and primarily happens elsewhere due to imports. Irrigation is the process that demands the largest amount of energy for the crop-based products, with 38% of their total energy demand, followed by fertilisers production (24%). Our study illustrates water and energy hotspots in the food life cycle and highlights potential FEW risks and trade-offs through trade. This is useful considering potential unexpected changes in trade under recent global socio-political trends. Currently available databases and software make LCA a key tool for integrated FEW nexus assessments.

The objective of this study is to describe a target water–energy–food (WEF) nexus domain world including causal linkages and trade-off relationships between WEF resources and their stakeholders, and to develop a WEF nexus system map as an interdisciplinary tool used for understanding the subsequent complexity of WEF nexus systems. An ontology engineering method, which is a qualitative method, was applied for the replicability of the WEF nexus domain ontology and the map, because ontology engineering is a method of semantic web development for enhancing the compatibility of qualitative descriptions logically or objectively. The WEF nexus system map has three underlying concepts: (1) systems thinking, (2) holistic thinking, and (3) an integrated approach at an operational level, according to the hypothesis that the chains of changes in linkages between water, energy, and food resources holistically and systemically affect the WEF nexus system, including natural and social systems, both temporally and spatially. This study is significant because it allows us to (1) develop the WEF nexus domain ontology database, including defining the concepts and sub-concepts of trade-offs relating to WEF for the replicability of this study; (2) integrate the qualitative ontology method and quantitative network analysis method to identify key concepts serving as linkage hubs in the WEF nexus domain ontology; and (3) visualize human–nature interactions such as linkages between water, energy, and food resources and their stakeholders in social and natural systems. This paper also discusses future challenges in the application of the map for a science–policy–society interface.

Papers on mycobacteria in food, feed and water, published between 1945 and 2010 and indexed in the database Web of Science (Thomson Reuters), were ranked according to authors, institutions, countries and source titles. The total number of papers on mycobacteria and food, and mycobacteria and water were 1,486 and 1,419, respectively. More than 40% of papers have been published in the last five years. In addition to publications in peer reviewed journals the archives of ProMED-mail and the Rapid Alert System for Food and Feed of the European Union were also searched. It is evident that much attention is being paid to mycobacteria in food, feed and water as they likely pose a public health risk.

Exploring the environmental impact of dietary consumption has become increasingly important to understand the carbon-water-food nexus, vital to achieving UN sustainable development goals. However, the research on diet-based nexus assessment is still lacking. Here, we developed an Environmentally Extended Multi-Regional Input-Output (EE-MRIO) model with compiling a global MRIO table based on the latest Global Trade Analysis Project (GTAP) 10 database, where we specifically constructed a water withdrawal account and matched it to each economy at the sectoral level. The regional heterogeneity and synergy of carbon-water nexus affected by dietary patterns in nine countries was explored. The results show that: (1) Dietary consumption is the main use of water withdrawal for each country; Japan, the US, South Korea, and India have a high per capita dietary water footprint. Mainly due to consumption of processed rice, Japan has the highest per capita value of 488 M³/year, accounting for 63.4% of the total water footprint. (2) The total dietary carbon footprints in China, India, and the US are high, which is mainly caused by the high consumption of animal products (including dairy) either due to the large population (China, India) or animal-based diet (the US). Americans have the highest per capita dietary carbon footprint, reaching 755.4 kg/year, 2.76 times that of the global average. (3) Generally, imported/foreign footprints account for a greater share in dietary water and carbon footprints of developed countries with an animal-based diet. (4) In the nexus analysis, the US, Japan, and South Korea are key-nexus countries, vegetables, fruit and nuts, tobacco and beverages, and other food products are selected as key-nexus sectors with relatively high dietary water and carbon footprint. Furthermore, dietary consumption choices lead to different environmental impacts. It is particularly important to find a sustainable dietary route adapted to each country considering that heterogeneity and synergism exist in key-nexus sectors to achieve the relevant Sustainable Development Goals.

Integration of the food, energy, and water (FEW) nexus thinking is expected to enhance cross-sectoral discussion during the process of policy development. This process can be improved with comprehensive assessment tools to provide quantitative information regarding the interdependence of the FEW nexus. A comprehensive framework of the regional FEW nexus quantitative assessment was proposed in this study. Life cycle assessment (LCA) was the core method used to evaluate the FEW inter-linkages. Land use data which can further imply the resources consumption or requirement was introduced to estimate potential changes in the nexus in future time periods. In order to display the practicality of the FEW nexus approach, a user-friendly nexus platform, a GIS-based Regional Environmental Assessment Tool for Food-Energy-Water nexus (GREAT for FEW) (http://greatforfew.enve.ntu.edu.tw/FEW/), was developed with a solid conceptual model, a database, and calculation methods. The usability of the tool was demonstrated using a Taiwanese case study. The results of the Taiwanese case showed that Scenario 1 (non-nuclear homeland policy) caused the lowest environmental impacts as compared to both Scenario 0 (baseline) and Scenario 2 (non-nuclear homeland policy with National Spatial Plan) due to better energy structures and maintenance of agricultural lands. These outcomes indicate that the selection of indicators does affect the results. Therefore, it is suggested that additional indicators should be designed based on the characteristics of the case study area and concerns of stakeholders.

This article uses the WaterWorld Policy Support System, coupled with a global database for commodity flows, to examine the impacts of AR4 SRES climate change scenarios on Africa's drylands and the commodity flows that originate from them. It shows that changes to precipitation and, to a lesser extent, temperature in Africa's drylands can significantly affect the potential to supply water-for-food locally and internationally. By comparing the geographical distribution of climate change with the supply chain–connected distribution of climate change, it shows how food-water impacts of climate change may affect local dryland populations but also those dependent on these flows from afar.