The water-energy-food (WEF) nexus is a complex system operating at many scales, the importance of which is increasingly recognized in academia and policy. There are calls to expand the nexus to include land and climate (WEFLC) as well as to narrow the science-policy divide, implying conducting assessments at policy-relevant scales to assess the impacts of policy objectives. This paper presents a national-scale WEFLC nexus system dynamics modelling assessment for Latvia. Qualitative and quantitative assessment was performed with local stakeholders to validate model structure, data, results, and to gather information on Latvian policy objectives and implement them in the model as potential future policies. Under baseline conditions (i.e. without implementing goal-specific policies under shared socio-economic pathway 2), results indicate a levelling off of consumption by 2050 while production of food products and energy is expected to increase. Nitrogen losses and climate emissions increase, going against policy targets. Implementation of indicative policies has desired impacts within their given sector, but may lead to trade-offs in others. Implementing multiple policies simultaneously may augment or hinder progress towards objectives due to system interconnectedness. Therefore, when choosing which policies to implement, cross-sectoral implications must be carefully considered. This work offers insight for policy and decision making in Latvia, hinting at policy options to pursue, and highlighting those to avoid. This study offers suggestions for closing the science-policy divide including the use of visual serious game environments for results interpretation, the use of selected indicators for nexus performance assessment, and close stakeholder engagement throughout a project.

We propose a hybrid Trustworthy Human–Machine collective decision-making framework to manage Food–Energy–Water (FEW) resources. Decisions for managing such resources impact not only the environment but also influence the economic productivity of FEW sectors and the well-being of society. Therefore, while algorithms can be used to develop optimal solutions under various criteria, it is essential to explain such solutions to the community. More importantly, the community should accept such solutions to be able realistically to apply them. In our collaborative computational framework for decision support, machines and humans interact to converge on the best solutions accepted by the community. In this framework, trust among human actors during decision making is measured and managed using a novel trust management framework. Furthermore, such trust is used to encourage human actors, depending on their trust sensitivity, to choose among the solutions generated by algorithms that satisfy the community’s preferred trade-offs among various objectives. In this paper, we show different scenarios of decision making with continuous and discrete solutions. Then, we propose a game-theory approach where actors maximize their payoff regarding their share and trust weighted by their trust sensitivity. We run simulations for decision-making scenarios with actors having different distributions of trust sensitivities. Results showed that when actors have high trust sensitivity, a consensus is reached 52% faster than scenarios with low trust sensitivity. The utilization of ratings of ratings increased the solution trustworthiness by 50%. Also, the same level of solution trustworthiness is reached 2.7 times faster when ratings of ratings included.

Food, energy, and water (FEW) systems have been recognized as an issue of critical global importance. Understanding the mechanisms that govern the FEW nexus is essential to develop solutions and avoid humanitarian crises of displacement, famine, and disease. The U.S. and China are the world’s leading economies. Although the two nations are shaped by fundamentally different political and economic systems, they share FEW trajectories in several complementary ways. These realities place the U.S. and China in unique positions to engage in problem definition, dialogue, actions, and transdisciplinary convergence of research to achieve productive solutions addressing FEW challenges. By comparing the nexus and functions of the FEW systems in the two nations, this perspective aims to facilitate collaborative innovations that reduce disciplinary silos, mitigate FEW challenges, and enhance environmental sustainability. The review of experiences and challenges facing the U.S. and China also offers valuable insights for other nations seeking to achieve sustainable development goals.

The use of sensors in critical areas for human development such as water, food, and health has increased in recent decades. When the sensor uses biological recognition, it is known as a biosensor. Nowadays, the development of biosensors has been increased due to the need for reliable, fast, and sensitive techniques for the detection of multiple analytes. In recent years, with the advancement in nanotechnology within biocatalysis, enzyme-based biosensors have been emerging as reliable, sensitive, and selectively tools. A wide variety of enzyme biosensors has been developed by detecting multiple analytes. In this way, together with technological advances in areas such as biotechnology and materials sciences, different modalities of biosensors have been developed, such as bi-enzymatic biosensors and nanozyme biosensors. Furthermore, the use of more than one enzyme within the same detection system leads to bi-enzymatic biosensors or multi-enzyme sensors. The development and synthesis of new materials with enzyme-like properties have been growing, giving rise to nanozymes, considered a promising tool in the biosensor field due to their multiple advantages. In this review, general views and a comparison describing the advantages and disadvantages of each enzyme-based biosensor modality, their possible trends and the principal reported applications will be presented.

Extreme climate change, rapid population growth and economic development drive a growing demand for resources, which lead to energy, food, water and their intertwined nexus becoming increasingly important. Agricultural decisions considering the interconnections among water, energy, and food are critical. The consumption of large amounts groundwater and non-renewable energy by the predominant traditional wheat-maize cropping system has caused a serious water shortage in the North China Plain (NCP), which is a large food production region in China. This situation has strained the relationship between water/energy consumption and food production. It is important to seek synergy in the water-energy-food nexus. This paper proposed a relative index of water-energy-food (WEFRI) based on different values of resource consumption and use efficiency between treatment systems and control system to analyze the synergy between water utilization, energy consumption and food supply in different cropping systems at the field scale. The goal is to seek a sustainable cropping system to balance crop production while reducing energy consumption and water depletion. In this case, different systems including monocropped maize (Zea mays) (MM), intercropped maize and soybean (Glycine max) (MS), relay cropped of maize with pea (Pisum sativum) (MP) and potato (Solanum tuberosum) (MO), rotation of maize with spinach (Spinacia oleracea) (MI) and ryegrass (Secale cereale) (MR), and using traditional wheat-maize (Triticum aestivum) (MW) as a control. MM, MS, MP and MO were the best systems within a particular range of food supply reduction. The WEFRI of the MM/MS system was the highest (2.96/2.78). Compared to the MW system, the groundwater consumption of MM/MS was reduced by 73.84%/73.84%, and non-renewable energy inputs were reduced by 48.01%/48.30%; however, the food supply decreased by 48.05%/51.70%. The WEFRI of the MP system was 1.98. In comparison with the MW system, the groundwater consumption of the MP system was reduced by 28.46%, and the non-renewable energy inputs were reduced by 42.68%. However, the food supply decreased by 37.13%. The WEFRI of MO system was 1.92. Compared to the MW system, the groundwater consumption of MO was reduced by 11.47%, non-renewable energy inputs were reduced by 32.14%, and the food supply only decreased by 26.27%. In conclusion, we theoretically proposed the following references for cropping systems in the NCP: MM and MS are implemented when the areas has extreme water shortages, MO is implemented when a less than 30% reduction in the food supply capacity is acceptable, and MP is recommended if a 30%–40% reduction in the food supply is acceptable.

Integrated adaptation strategies are needed to achieve the highly interlinked Sustainable Development Goals (SDGs) for water, food- and energy security in the Indus basin. However, detailed quantitative scenarios for the plausible dimensions of future resource security requirements under socio-economic development are lacking. Here we define three quantitative and spatially downscaled scenarios for future water, food and energy requirements in the Indus basin and we assess the implications of socio-economic development for the integrated resource security challenge. High-resolution gridded scenarios for resource security requirements are developed by combining three regionalised and spatialised Shared Socioeconomic Pathways (SSPs) with quantitative regional water, food and energy security thresholds. The results demonstrate that by 2080 basin level water- and energy security requirements are likely to at least double and potentially triple compared to the current situation. Food requirements could increase only marginally and double at most. Migration and urbanisation additionally drive the growing requirements to spatially converge around the largest cities of the basin. This demonstrates that socio-economic development increases the complexity of the water-food-energy security challenge by increasing its magnitude and spatial concentration. Future research and policymaking should anticipate for this heterogeneous growth of resource security challenges when developing adaptation strategies.

Extreme climate change, rapid population growth and economic development drive a growing demand for resources, which lead to energy, food, water and their intertwined nexus becoming increasingly important. Agricultural decisions considering the interconnections among water, energy, and food are critical. The consumption of large amounts groundwater and non-renewable energy by the predominant traditional wheat-maize cropping system has caused a serious water shortage in the North China Plain (NCP), which is a large food production region in China. This situation has strained the relationship between water/energy consumption and food production. It is important to seek synergy in the water-energy-food nexus. This paper proposed a relative index of water-energy-food (WEFRI) based on different values of resource consumption and use efficiency between treatment systems and control system to analyze the synergy between water utilization, energy consumption and food supply in different cropping systems at the field scale. The goal is to seek a sustainable cropping system to balance crop production while reducing energy consumption and water depletion. In this case, different systems including monocropped maize (Zea mays) (MM), intercropped maize and soybean (Glycine max) (MS), relay cropped of maize with pea (Pisum sativum) (MP) and potato (Solanum tuberosum) (MO), rotation of maize with spinach (Spinacia oleracea) (MI) and ryegrass (Secale cereale) (MR), and using traditional wheat-maize (Triticum aestivum) (MW) as a control. MM, MS, MP and MO were the best systems within a particular range of food supply reduction. The WEFRI of the MM/MS system was the highest (2.96/2.78). Compared to the MW system, the groundwater consumption of MM/MS was reduced by 73.84%/73.84%, and non-renewable energy inputs were reduced by 48.01%/48.30%; however, the food supply decreased by 48.05%/51.70%. The WEFRI of the MP system was 1.98. In comparison with the MW system, the groundwater consumption of the MP system was reduced by 28.46%, and the non-renewable energy inputs were reduced by 42.68%. However, the food supply decreased by 37.13%. The WEFRI of MO system was 1.92. Compared to the MW system, the groundwater consumption of MO was reduced by 11.47%, non-renewable energy inputs were reduced by 32.14%, and the food supply only decreased by 26.27%. In conclusion, we theoretically proposed the following references for cropping systems in the NCP: MM and MS are implemented when the areas has extreme water shortages, MO is implemented when a less than 30% reduction in the food supply capacity is acceptable, and MP is recommended if a 30%–40% reduction in the food supply is acceptable.

The Water-Energy-Food (WEF) nexus is a dynamic and complex system, in which the resources of water, energy, and food are inextricably linked. The system faces a number of threats including man-made hazards, e.g. overpopulation, urbanisation, ageing population, terrorism and geopolitical upheaval, and natural hazards such as climate change and extreme weather events. General indicators for the WEF nexus provide information on current access and availability of water, energy and food to a population. However, in industrialised nations such as the UK, such information is often masked by the consistently high access and availability of WEF resources. This paper proposes a composite WEF resilience index formed by aggregating two sets of indicators: one representing the availability level of WEF resources in terms of three WEF sectors; and the other representing population access to the resources at the household level. The WEF availability and the household accessibility indicators were calculated separately within the water, energy, food, and household sectors. Within each sector, an Analytical Hierarchical Process (AHP) was used for weighting sub-indicators based on experts’ evaluation of the relative importance among the sub-indicators. This allowed us to synthesize individual opinions using expertise level in a group decision-making framework. A pilot study was performed on the UK WEF nexus to measure resilience in recent times. This prototype composite index can be used for exploring the resilience of the WEF systems to shocks and changes in the presence of high WEF access and availability.

For the sustainable communities, there is a strong need to address the United Nations' sustainable development goals for communities, cities and countries. In this paper, we develop a unique hybrid energy system for cleaner productions of energy, fuel, food and water for an indigenous community by addressing the following goals, namely: zero hunger; clean water; affordable and clean energy; industry, innovation and infrastructure; sustainable cities and communities; and climate action. Also, the present sustainable system is investigated thermodynamically by considering energy and exergy criteria and evaluated through energy and exergy efficiencies. As a case study, the Saugeen First Nation indigenous community in the Bruce Peninsula in Ontario, Canada, is selected for meeting the demands of useful commodities where an integration of a newly developed multigenerational system with an existing nuclear reactor is achieved in order to provide food security, supply the freshwater for drinking purposes, and meet the community's electricity and heat demands. Moreover, to exploit the existing thermophysical properties of fluids in the nuclear system, a hydrogen generation unit is proposed. The novel integration is enhanced the current nuclear system and increased the variety of useful outputs. The overall system is analyzed according to the first and second laws of thermodynamics. A transient (time-dependent) analysis is carried out via hourly simulations with software packages and hourly sensitive meteorological data. The overall system performance results are obtained as 65.8% for energy efficiency and 40.1% exergy efficiency at average ambient conditions for a 126.04 mol/s hydrogen production rate.

The Water-Energy-Food (WEF) nexus is a dynamic and complex system, in which the resources of water, energy, and food are inextricably linked. The system faces a number of threats including man-made hazards, e.g. overpopulation, urbanisation, ageing population, terrorism and geopolitical upheaval, and natural hazards such as climate change and extreme weather events. General indicators for the WEF nexus provide information on current access and availability of water, energy and food to a population. However, in industrialised nations such as the UK, such information is often masked by the consistently high access and availability of WEF resources. This paper proposes a composite WEF resilience index formed by aggregating two sets of indicators: one representing the availability level of WEF resources in terms of three WEF sectors; and the other representing population access to the resources at the household level. The WEF availability and the household accessibility indicators were calculated separately within the water, energy, food, and household sectors. Within each sector, an Analytical Hierarchical Process was used for weighting sub-indicators based on experts’ evaluation of the relative importance among the sub-indicators. This allowed us to synthesize individual opinions using expertise level in a group decision-making framework. A pilot study was performed on the UK WEF nexus to measure resilience in recent times. This prototype composite index can be used for exploring the resilience of the WEF systems to shocks and changes in the presence of high WEF access and availability.