Water security is a powerful concept that is still in its early days in the field of nutrition. Given the prevalence and severity of water issues and the many interconnections between water and nutrition, we argue that water security deserves attention commensurate with its importance to human nutrition and health. To this end, we first give a brief introduction to water insecurity and discuss its conceptualization in terms of availability, access, use, and stability. We then lay out the empirical grounding for its assessment. Parallels to the food-security literature are drawn throughout, both because the concepts are analogous and food security is familiar to the nutrition community. Specifically, we review the evolution of scales to measure water and food security and compare select characteristics. We then review the burgeoning evidence for the causes and consequences of water insecurity and conclude with 4 recommendations: 1) collect more water-insecurity data (i.e., on prevalence, causes, consequences, and intervention impacts); 2) collect better data on water insecurity (i.e., measure it concurrently with food security and other nutritional indicators, measure intrahousehold variation, and establish baseline indicators of both water and nutrition before interventions are implemented); 3) consider food and water issues jointly in policy and practice (e.g., establish linkages and possibilities for joint interventions, recognize the environmental footprint of nutritional guidelines, strengthen the nutrition sensitivity of water-management practices, and use experience-based scales for improving governance and regulation across food and water systems); and 4) make findings easily available so that they can be used by the media, community organizations, and other scientists for advocacy and in governance (e.g., tracking progress towards development goals and holding implementers accountable). As recognition of the importance of water security grows, we hope that so too will the prioritization of water in nutrition research, funding, and policy.

Strategies for reducing food waste and developing sustainable diets require information about the impacts of consumption behavior and waste generation on climatic, water, and land resources. We quantified the carbon, water, and ecological footprints of 17,110 family members of Chinese households, covering 1935 types of foods, by combining survey data with available life-cycle assessment data sets. We also summarized the patterns of both food consumption and waste generation and analyzed the factors influencing the observed trends. The average person wasted (consumed) 16 (415) kg of food at home annually, equivalent to 40 (1080) kg CO2e, 18 (673) m3, and 173 (4956) gm2 for the carbon, water and ecological footprints, respectively. The generation of food waste was highly correlated with consumption for various food groups. For example, vegetables, rice, and wheat were consumed the most and accounted for the most waste. In addition to the three plant-derived food groups, pork and aquatic products also contributed greatly to embedded footprints. The data obtained in this study could be used for assessing national food security or the carrying capacity of resources.

Although many African countries have made significant progress towards universal access to water, energy, and food resources (WEF), assessing the ecological response to the increasing productivity of these resources is not well researched, which carries the risk of ecological deficit, resource degradation, and inefficient policy responses to resource management. This study seeks to assess the ecological sustainability response to the high increase demand for WEF resources in well-developed African countries. The study developed new measurement metrics for the WEF production system, including three indicators of ecological footprint (EF), ecological biocapacity (EBC), and eco-balance. The overall analysis considers data from four distinct types of water and energy use activities, and eight distinct types of food consumption, in nine African countries with the highest WEF nexus performance. An evaluation tool for the Water, Energy, Food and Ecological Balance (WEFEB) nexus index is proposed as one of the study's outcomes. Despite having 100% access to WEF resources related to the SDG targets. The results reveal the significant levels of imbalance and large ecological deficits existing in many of the concerned countries, especially North Africa, Mauritius, and South Africa, which need to rethink their economic models. Projecting a sustained increase in resource demand so that each country achieves at least 1700 m³/capita/year as the minimum amount of water needed, most countries would suffer from a steady increase in ecological imbalance. According to the results, managing the ecological imbalances with increasing demand for WEF resources in well-developed African countries may require well-designed policies to effectively reduce certain types of human demand that have a large ecological footprint.

Water, energy, and food are the most basic and essential sectors for human welfare. However, an inextricable nexus and competition exists among these sectors. Production of molasses-based bioethanol is an interesting case resulting in the production of different food and energy materials while consuming water, energy, land, and other raw materials, throughout its life cycle. This paper briefly describes the nexus among water, energy, and food for bioethanol in Pakistan and its environmental implications. A life cycle approach has been used for evaluating four footprint categories including the carbon, ecological, water scarcity, and energy footprints along with an energy analysis of bioethanol. In comparison to conventional gasoline, bioethanol would have benefits in terms of lesser greenhouse gas emissions, better use of productive land, and superior energy performance, but, this will be at the expense of higher impacts in terms of water scarcity. Therefore, considering only a single aspect could result in inadvertent trade-offs that may go unnoticed. The quantified values would help accomplish integrated resource management along with their utilization within limits so as to be available for other uses. This study could help in developing strategies for optimal management of resources to maximize the synergies and minimize the possible trade-offs.

This study examines a green building retrofit plan through a system dynamics model (SDM) creating symbiosis embedded in a building-scale food-energy-water (FEW) nexus. An indicator approach was employed to exploit cross-domain seams via the use of carbon, water, and ecological footprints for sustainability, as well as food security and energy supply reliability ratio for resilience. The SDM was formulated to demonstrate a continuous stormwater treatment outflow model for rooftop farming with stormwater reuse for irrigation, nutrient cycling via the use of green sorption media, and green energy harvesting in support of rooftop farming. We prove that green energy use, stormwater reuse, and rooftop farming can lower carbon, water, and ecological footprints, avoid CO₂ emissions via carbon sequestration in rooftop farming, and improve energy supply reliability and food security. Case 1 (Base Case) includes no retrofit (current condition), Case 2 includes rooftop farming and stormwater reuse, and Case 3 incorporates additional green energy harvesting for sustaining rooftop farming. All three scenarios were assessed using a life cycle assessment (LCA) to generate water and carbon footprints. Case 3 exhibited a 2.24% reduction of total building energy demand from the utility grid due to renewable energy harvesting, while the preservation of nitrogen and phosphorus via the use of green sorption media for crop growth promoted nutrient cycling by maintaining 82% of nitrogen and 42% of phosphorus on site. The ecological footprints for the three case studies were 0.134 ha, 0.542 ha, 6.50 ha, respectively. Case 3 was selected as the best green building retrofit option through a multicriteria decision analysis.

With the acceleration of urbanization, the demand for water, energy and food (WEF) keeps increasing. However, the infrastructure construction leads to a sharp decline of cultivated land, water area and forest land, so the importance of ecological space management should be recognized. Based on ecological footprint theory, this paper proposes the WEF footprint and first attempts to explicitly examine the relationship between economic growth and WEF footprint by investigating the existence of an Environmental Kuznets Curve (EKC). GLS regression and the LOWESS model are used to explore the economic growth and WEF footprint nexus in the eight economic zones and the three regions of China. The results indicate that besides the traditional EKC shapes, an M-shape exists, and the proportion of the M-shape curve (12.5%) is lower than the traditional EKC (87.5%). The results showed that the LOWESS model may be more conducive to reflect the real relationship between economic growth and WEF footprint. According to the analysis, the policy suggestions are put forward to promote the sustainable development of the water-energy-food system. In addition, the study can provide some ideas for solving the contradiction of land use. HIGHLIGHTS Using ecological footprint measurement to study water-energy-food system.; EKC hypothesis is used to investigate the relationship between the WEF footprint and economic growth, and policy suggestions are further put forward.; LOWESS model and GLS regression are both introduced to test the EKC hypothesis.;

The concept of the water-food-energy nexus has been widely studied in the past decade. In this paper we expand on this concept to include environmental, economic, and social aspects as well as life cycle assessment based thinking. We proposed a set of Environmental Footprint Assessment, Life Cycle Assessment, and Socio-Economic Assessment indicators and calculated them using a developed System Dynamic Model for Water-Land-Food-Energy-Environment-Economic-Social Nexus (SD-WLF3ESN). The developed model was applied to predict the WLF3ESN of the corn crop in the Western Lake Erie Basin (WLEB)-USA for the period 2016-2030. The prediction was based on scenarios for population, land, yield, crop use, and crop production costs and returns at the county level of WLEB. A matrix for WLF3ESN of the corn crop in WLEB was developed. This matrix can help in developing policies and strategies for managing the nexus in the basin.