Resumen Objetivo: Proporcionar un marco conceptual de la esquematización del nexo agua-alimentos-comercio internacional utilizando el modelo actancial, basado en el análisis cualitativo de las relaciones que se presentan entre sus participantes con un enfoque integrador. Diseño metodológico: Se explica bajo la lógica del modelo actancial centrado en la descripción y clasificación de personajes, o bien, llamados actantes. El análisis se basó en la revisión de artículos que exponen el contexto y debate de los elementos del modelo actancial, que permitieran identificar las principales características que explican al actante y sus interrelaciones a través de la esquematización en el nexo de estudio. Resultados: Permiten comprender de manera esquemática y cualitativa las relaciones que subyacen entre los elementos que componen el nexo agua-alimentoscomercio internacional con una visión novedosa, argumentando el rol que desempeñan cada uno de los componentes de los actantes y los ejes del nexo. Esto es relevante debido a que la comercialización de agua virtual, puede conducir a serios problemas de dependencia hidro-alimentaria, por lo que se necesita de la formulación de políticas públicas estratégicas y efectivas en el corto y largo plazo. Limitaciones de la investigación: Se sugiere complementar esta investigación con un análisis cuantitativo bajo una perspectiva de la complejidad de redes que pueda valorar los efectos de estas interrelaciones desde una postura teórica y práctica e incorporar otros agentes que determinan la política hídrica y comercial de manera estratégica hacia una menor dependencia hidroalimentaria. Hallazgos: Estas interrelaciones son diversas e intensivas, destacando la importancia y compresión del nexo a escala global y nacional.

The deep sea is amongst the most food-limited habitats on Earth, as only a small fraction (<4%) of the surface primary production is exported below 200 m water depth. Here, cold-water coral (CWC) reefs form oases of life: their biodiversity compares with tropical coral reefs, their biomass and metabolic activity exceed other deep-sea ecosystems by far. We critically assess the paradox of thriving CWC reefs in the food-limited deep sea, by reviewing the literature and open-access data on CWC habitats. This review shows firstly that CWCs typically occur in areas where the food supply is not constantly low, but undergoes pronounced temporal variation. High currents, downwelling and/or vertically migrating zooplankton temporally boost the export of surface organic matter to the seabed, creating ‘feast’ conditions, interspersed with ‘famine’ periods during the non-productive season. Secondly, CWCs, particularly the most common reef-builder Desmophyllum pertusum (formerly known as Lophelia pertusa), are well adapted to these fluctuations in food availability. Laboratory and in situ measurements revealed their dietary flexibility, tissue reserves, and temporal variation in growth and energy allocation. Thirdly, the high structural and functional diversity of CWC reefs increases resource retention: acting as giant filters and sustaining complex food webs with diverse recycling pathways, the reefs optimise resource gains over losses. Anthropogenic pressures, including climate change and ocean acidification, threaten this fragile equilibrium through decreased resource supply, increased energy costs, and dissolution of the calcium-carbonate reef framework. Based on this review, we suggest additional criteria to judge the health of CWC reefs and their chance to persist in the future. | publishedVersion

Like most northern settlements, Kluane Lake Research Station (KLRS) in Yukon Territory, Canada, is an islanded microgrid dependent on diesel generation and subject to high fuel costs. To reduce diesel costs, the station has a 48 kW solar photovoltaic (PV) array alongside a 27 kW/171 kWh lead-acid battery system to store solar energy for nighttime use, primarily during summer. However, substantial solar energy is often curtailed when the battery becomes full due to prior charging with diesel-generated electricity. The goal of this analysis is to determine how to best operate the diesel generator to maximize solar PV generation, and thus minimize diesel costs. On a monthly basis, solar PV plus batteries can meet 96% of load during June, but only 3% during December, and 67% year-round. This study also analyzes how demand-side management of new food and water infrastructure can aid this objective while providing a constant source of electricity, locally-grown food, and clean water. Findings demonstrate that optimizing the KLRS diesel generator, battery management, and solar energy conversion may reduce diesel generation by up to 100% during June, 31% during the field season (mid-April to early October), and approximately 31% year-round (due to limited solar PV generation during the winter), compared with past operational data.

The increasing global population, rapid urbanization, and climate change are putting unprecedented pressure on limited water and energy resources for food production. It requires integrated management of the key resources to achieve economic and environmental sustainability. The water-energy-food (WEF) nexus, in conjunction with circular bioeconomy (CBE) principles, offer a promising approach to achieve sustainable agriculture. It provides the integration between interconnectedness and interdependencies of the resources through closing bio-resource loops. Using bio-based materials, renewable energy resources, and implementing energy-efficient practices and technologies can maximize synergistic among the resources and promote sustainable agriculture while minimizing negative environmental impacts. However, there are challenges and limitations, such as economic conditions, proper infrastructure and technology, policy and governance support, public awareness, and potential trade-offs and conflicts. Moreover, it also faces various social and cultural challenges in implementing this approach. Therefore, to overcome these challenges and limitations, the need for innovative and sustainable technologies, significant investments in research and development, infrastructure and training, environmental campaign, innovative financing mechanisms and policies that incentivize sustainable practices, and support from stakeholders and the public are essential.

This study introduces the foundational principles behind the water footprint in water and food security for evaluating the managerial strategies of agricultural water management in arid areas. The role of green, grey, blue and white water footprints in yield production has been critically investigated to analyze the climate and economic risks. Therefore, a nonlinear hydro-economic framework, which integrates soil water content, food production and economics has been used for the semi-arid regions of China. Non-dimensional form of net benefit per drop was formulated to analyze the uncertainty of economic parameters. Root zone moisture was simulated to estimate crop yield, transpiration, evaporation, water required for irrigation and increase water quality. Five plants of potato, onion, tomato, eggplant and carrot were selected due to similarity in the plant growth season and market criteria. The results showed that the average effective rainfall contributed less than 15% to food production. The impact of the risk of economic fluctuations in achieving the expected net profit has been more than water. HIGHLIGHTS The impact of the water footprint on food security was considered to improve agricultural water management in arid areas.; A hydro-economic framework, which integrates soil water content, food production and economics has been used.; Non-dimensional form of net benefit per drop was formulated to analyze the uncertainty of economic parameters.;

Water, food, and energy are considered necessary segments to achieve the sustainable development goals. Urbanization, population growth, international trade, economic development and climate change will significantly increase the need for these three segments, which is why it is necessary to focus on equal access to water, food and energy, while adhering to the principles of the circular economy. Water is used along the entire agri-food chain, while the generated energy is needed for the production, transport and distribution of food, as well as for the extraction, pumping, lifting, collection, transport, and treatment of water. Urbanization, industrial development, and the general population of citizens also require gradually more water, as well as land for food production and expansion, which entails the need for more and more energy resources. This results in environmental degradation and impairment of environmental sustainability, which leads to the scarcity of resources and impairment of the health of living organisms. Given the importance of the topic related to the knowledge of biowaste and its management, a survey was conducted to gain insight into whether the general population of citizens is aware that by throwing food, other resources represented in the "water-energy" chain also get wasted, which leads to the disturbance of ecological stability. As expected, the results showed that our society needs further education to be able to manage waste in a sustainable way.

Using water-energy-food-environment (WEFE) nexus as the prism, this review explores evolution of groundwater governance in Iran, Saudi Arabia, Mexico, China, Bangladesh and India – which together account for two-thirds of the global groundwater-irrigated area. Global discourse has blamed widespread water scarcity squarely on supply-side policymaking and advocated a broader template of water governance instruments. Integrated Water Resources Management (IWRM) presented just such a template – with pricing, participation, rights and entitlements, laws, regulations, and river basin organizations – as additional water governance tools. However, the IWRM template faced disillusionment and pushback in many emerging economies. WEFE nexus, the new paradigm, prioritizes system-level optima over sectoral maxima by harnessing synergies and optimizing trade-offs between food, water, energy, soil, and eco-system sustainability within planetary boundaries. Realizing this vision presents a complex challenge in groundwater governance. Global groundwater economy comprises three sub-economies: (a) diesel-powered unregulated, as in Nepal terai, eastern India, Bangladesh, Pakistan Punjab and Sind, and much of Sub-Saharan Africa, where use-specific energy subsidies are impractical; (b) electricity-powered regulated, as in North America and Europe, where tubewells are authorized, metered and subject to consumption-linked energy charges; and (c) electricity-powered unregulated, as in geographies covered by our review – barring China, Bengal and Bangladesh – where unmeasured electricity subsidies have created a bloated groundwater economy. This last sub-economy represents the heartland of global groundwater malgovernance, least equipped to meet the sustainability challenge. It has an estimated 300 million horsepower of grid-connected electric pumps that are either unauthorized and/or unmetered and/or use free or heavily subsidized or pilfered power for irrigating 50–52 million hectares, nearly half of global groundwater-irrigated area. In (a) and (b), groundwater scarcity inspires water-energy saving behavior via increased energy cost of pumping. In sub-economy (c), users are immune to energy costs and impervious to groundwater depletion. Here, the WEFE nexus has remained blind to the irrigation realpolitik that catalyzes or constrains policy action. We explore why the political costs of rationalizing subsidies are prohibitive and exemplify how a smart transition from fossil to solar energy for pumping may offer an opportunity to turn the perverse WEFE nexus into a virtuous one.