Water Energy Food Research Articles

The water–energy–food–ecosystem nexus in North Africa dryland farming: a multi-criteria analysis of climate-resilient innovations in Morocco

Smallholder farmers, who mostly engage in low-value agriculture in the drylands of Northern Africa, were the first to have felt the effects of climate change, with threats to their livelihoods and food security. The increasing costs of agricultural production, poor water and energy infrastructure, loss of agricultural land due to urban expansion, fragmented resource management, and unsustainable management practices all contribute to this vulnerability to climate change. This highlights the urgent need for innovative practices in farming systems. Within the framework of the water–energy–food–ecosystem nexus, this paper explores innovative practices in dryland farming systems, by assessing their impact on water, energy, food, and ecosystem through stakeholder perception. In this work, we aim to present a systems approach for assessing the resilience of the water–energy–food–ecosystem nexus in arid and semiarid regions. By using a multi-criteria analysis (MCA) approach, the study—which focuses on the Fès–Meknès region in Morocco—involves local actors to help researchers identify the key variables in order to assist farmers in their adaptation to climate change. The findings revealed different priorities between farmers and other stakeholders regarding the adoption of agricultural innovations. Farmers prioritize innovations that guarantee higher profitability and more market opportunities, such as integrating olive trees with cereal crops, by highlighting the importance of sustainable income sources. Meanwhile, stakeholders, such as researchers, engineers, government officials, and agribusiness entrepreneurs, prioritize innovations that emphasize high water use efficiency, which is crucial for the resilience of dryland farming areas: for instance, rainwater harvesting or the use of drought-resistant crop varieties that directly address the need for water conservation. But in doing so they are overlooking broader aspects within the water–energy–food–ecosystem nexus.

Role of women in the water–energy–food (WEF) nexus—challenges and opportunities

AbstractWater, food and energy are crucial for human survival and sustainable development, being interconnected through the water–energy–food (WEF) nexus. Despite extensive research, the significant roles women play in these sectors are often underappreciated. Women are vital in water management, enhancing resource management, water quality and access, particularly in rural areas. In agriculture, they make up a large proportion of the workforce, boosting productivity, promoting sustainable farming practices and ensuring food security. Their deep knowledge of traditional food systems, coupled with their caregiving roles, contributes to providing nutritious and culturally appropriate diets. In the energy sector, women are key advocates for sustainable solutions and grassroots adoption of renewable energy technologies. Recognizing gender equality and empowering women are essential for maximizing their potential in the WEF nexus. Implementing gender‐responsive policies, inclusive decision‐making processes, and investing in education and skills training can significantly enhance women's roles in sustainable management. Empowered women drive innovation and transformative change, leading to more resilient and inclusive governance structures. This article emphasizes the importance of recognizing and supporting women's contributions within the WEF nexus, as this leads to more sustainable and equitable outcomes for all.

A bibliometric analysis of water footprint in China and abroad: research hotspots and frontiers

ABSTRACT The water footprint (WF) serves as a vital tool for quantifying human water resource consumption and is extensively utilized for water allocation analysis and management. This study employs CiteSpace to visualize literature from the Web of Science and the China National Knowledge Infrastructure from 2000 to 2023. Initially, quantitative analysis identified the characteristics of WF. Keyword analysis then elucidated the similarities, differences, and temporal-spatial changes in domestic and international research hot spots. Additionally, co-cited literature networks systematically explored research frontiers in the WF field. China and foreign countries share common research themes while maintaining distinct characteristics. Specifically, the research results show that: (1) Chinese researchers keep up with the pace of international research, and the research results in the field of WF are updated quickly; (2) environmental impact, water–food–energy nexus, and gray WF have attracted attention globally. The international research focus is on the renewal of WF methodology. In contrast, Chinese researchers are more inclined to use methods on water-saving strategies and driving factors. (3) The research frontier mainly focuses on the updating of WF assessment methods and sustainable water use.

A material flow or life cycle analysis perspective for the Water-Energy-Food nexus assessment of organisations? A comparative study

Nowadays, food production systems play a relevant role as the steady increase of global population and food demand. The water-energy-food (WEF) nexus is a suitable approach to tackle resources management associated with these three pillars recognizing synergies and trade-offs. Different approaches have been used in the literature to measure the WEF nexus, being material flow analysis (MFA) and life cycle assessment (LCA), two of the most proven methodologies. The MFA approach is based on the amount of resources consumed, while using the LCA perspective considers all flows of the system (LCA footprints approach) or considering only the flows associated with water, energy, and food pillars as the inventory data (WEF-LCA approach). This manuscript compares the three mentioned approaches to identify their strengths and weaknesses. To do this, a sample of 100 Spanish dairy farms is analysed, where a single WEF nexus index (WEFni) is obtained using Data Envelopment Analysis. Results show that only four farms achieved a WEFni equal to 100 in all approaches, while the main difference between them is the number and type of resources considered for calculating the WEF nexus, which could imply a partial identification of hotspots of food systems.

Water–Energy–Food Nexus in the Yellow River Basin of China under the Influence of Multiple Policies

The water–energy–food (WEF) nexus constitutes a pivotal aspect of regional ecological protection and high-quality development. The exertion of multiple WEF-related policies would engender both synergies and trade-offs within the WEF nexus. However, a quantified framework that integrates the impact of multiple WEF-related policies with conventional WEF nexus assessments and simulations is currently lacking. This study quantified the WEF nexus in the Yellow River basin (YRB) of China under the influence of multiple policies, calculated the current and future WEF scores under different policy combination scenarios using the improved entropy weight method, the auto-regressive integrated moving average (ARIMA) model, and the linear optimization method. The results revealed the following: (1) From 2000 to 2020, WEF overall scores and subsystem scores were substantially increased with spatial heterogeneity. (2) Scenario analysis indicated that policy implementation would generally accelerate WEF score improvements in each city, yet embracing all policies simultaneously was not optimal for each city. (3) The spatial heterogeneity in policy impacts was also found in the YRB, with higher trade-offs in the upper reaches of cities, and higher synergies in the middle and lower reaches of cities. To attain high-quality development within the YRB, the related policies’ implementation should consider the regional disparities and enhance the optimization of resource allocation across the regions.

Optimizing water-energy-food nexus index, CO2 emissions, and chemical pollutants under irrigation water salinity scenarios

The escalation of crises related to water quantity of quality, energy, food, and the environment has posed numerous challenges to sustainable development in the agricultural sector. This study seeks to establish an optimal and sustainable framework within the agricultural sector by meeting the objectives of the WEF (Water-Energy-Food) nexus index and environmental. For this, we individually optimized the objectives: maximizing the WEFN index (O1), minimizing CO2 emissions (O2), reducing chemical fertilizer consumption (O3), minimizing chemical pesticide usage (O4), and maximizing gross margin (O5) under various electrical conductivity (EC) scenarios (optimistic, moderate, and pessimistic) within the irrigation network of the Jiroft plain in Iran. In the second stage, we employed a Multi-Objective Programming (MOP) Model to attain these objectives using a weighted sum approach simultaneously. The results of the first stage revealed that under moderate and pessimistic EC irrigation water scenarios, significant alterations in the crop selection within the optimized models for O1 and O5 objectives occurred compared to the baseline scenario, which did not consider EC irrigation water. Specifically, in the pessimistic scenario with an EC irrigation water level of 2.25 ds/m, crops such as onions, tomatoes, and potatoes were replaced within the optimal cropping pattern by wheat, barley, and green-maize, leading to a notable decline in program efficiency. The results from the MOP optimization model indicated that in the pessimistic EC irrigation water scenario, the WEFN index, CO2 emissions, fertilizer consumption, pesticide consumption, and gross margin would change by approximately +12%, −48%, −28%, −8%, and −74%, respectively, compared to the baseline scenario. Consequently, an increase in EC irrigation water, despite improving environmental conditions, would substantially diminish economic profit. Thus, overlooking the impact of EC irrigation water in the WEF nexus analysis could result in misleading conclusions.

FEW questions, many answers: using machine learning to assess how students connect food–energy–water (FEW) concepts

There is growing support and interest in postsecondary interdisciplinary environmental education, which integrates concepts and disciplines in addition to providing varied perspectives. There is a need to assess student learning in these programs as well as rigorous evaluation of educational practices, especially of complex synthesis concepts. This work tests a text classification machine learning model as a tool to assess student systems thinking capabilities using two questions anchored by the Food-Energy-Water (FEW) Nexus phenomena by answering two questions (1) Can machine learning models be used to identify instructor-determined important concepts in student responses? (2) What do college students know about the interconnections between food, energy, and water, and how have students assimilated systems thinking into their constructed responses about FEW? Reported here is a broad range of model performances across 26 text classification models associated with two different assessment items, with model accuracy ranging from 0.755 to 0.992. Expert-like responses were infrequent in our dataset compared to responses providing simpler, incomplete explanations of the systems presented in the question. For those students moving from describing individual effects to multiple effects, their reasoning about the mechanism behind the system indicates advanced systems thinking ability. Specifically, students exhibit higher expertise in explaining changing water usage than discussing trade-offs for such changing usage. This research represents one of the first attempts to assess the links between foundational, discipline-specific concepts and systems thinking ability. These text classification approaches to scoring student FEW Nexus Constructed Responses (CR) indicate how these approaches can be used, in addition to several future research priorities for interdisciplinary, practice-based education research. Development of further complex question items using machine learning would allow evaluation of the relationship between foundational concept understanding and integration of those concepts as well as a more nuanced understanding of student comprehension of complex interdisciplinary concepts.

Tracking the Dynamics and Uncertainties of Soil Organic Carbon in Agricultural Soils Based on a Novel Robust Meta-Model Framework Using Multisource Data

Monitoring and estimating spatially resolved changes in soil organic carbon (SOC) stocks are necessary for supporting national and international policies aimed at assisting land degradation neutrality and climate change mitigation, improving soil fertility and food production, maintaining water quality, and enhancing renewable energy and ecosystem services. In this work, we report on the development and application of a data-driven, quantile regression machine learning model to estimate and predict annual SOC stocks at plow depth under the variability of climate. The model enables the analysis of SOC content levels and respective probabilities of their occurrence as a function of exogenous parameters such as monthly temperature and precipitation and endogenous, decision-dependent parameters, which can be altered by land use practices. The estimated quantiles and their trends indicate the uncertainty ranges and the respective likelihoods of plausible SOC content. The model can be used as a reduced-form scenario generator of stochastic SOC scenarios. It can be integrated as a submodel in Integrated Assessment models with detailed land use sectors such as GLOBIOM to analyze costs and find optimal land management practices to sequester SOC and fulfill food–water–energy–-environmental NEXUS security goals.

A proposal for an academy to deliver capacity building in agricultural water management with particular reference to irrigation

AbstractThe paper proposes a capacity‐building programme (CBP) on water for food/agricultural water management in sub‐Saharan Africa contained within an academy on the water–energy–food (WEF) nexus. The paper is informed by a study funded by the International Water Management Institute and supported by the Water Research Commission of South Africa. It also reports on a stakeholder consultation workshop on 26 April 2023 in Pretoria, South Africa. It identifies key components of capacity‐building design and delivery, including six teaching and learning pathways. These are managed ad hoc self‐directed learning; continuing professional development; short‐course training; vocational college training; part‐time online postgraduate training; and full‐time in‐person postgraduate training. The accompanying budget analysis is speculative based on the size of the student cohorts per year for each of the six CBP pathways. The total budget of the academy is estimated at approximately US$60 million for a 10‐year programme training 2,800 individuals. This works out at an average per‐student cost of US$21,600. One question, debated at the stakeholder workshop but unresolved, was the emphasis on irrigation versus the agricultural water management continuum including rainfed agriculture.

Framing water–energy–food–ecosystem (WEFE) nexus interactions in the Tana-Beles Sub-basin of Ethiopia

The water–energy–food–ecosystems (WEFE) provide vital resources that are essential to human existence. Exploring synergies and trade-offs in these systems has been of interest in recent years to increase economic gain while sustaining the environment. The Tana-Beles Sub-basin of Ethiopia is challenged by population density, climate change, and ecosystem degradation that requires a WEFE Nexus thinking. To understand the current WEFE nexus interactions in the basin, a systematic review of 102 scientific research articles published from 1991 to 2021 was undertaken. Additionally, the systematic review is complemented by spatial data analysis to identify synergies and trade-offs among the WEFE nexus indicators. The analysis revealed the dominance of food–water–ecosystem interdependencies in WEFE nexus research for the Tana-Beles Sub-basin. This dominance is driven by extensive food production activities, which lead to substantial water abstraction and hydrological alterations to meet the intensive water demands of crop cultivation. Simultaneously, the energy-ecosystem interactions are critical due to excessive biomass utilization that exceeds the biomass production potential of the area. Furthermore, the available vegetation cover of the area is very limited to supplement the growing fuel wood demands, which is exerting extreme land degradation and threatening the ecosystem in the sub-basin. This study identifies gaps in WEFE understanding, highlights specific challenges and opportunities within the basin, and calls for coordinated stakeholder action for sustainable resource management through a Nexus approach.

Integrating the water-energy-food nexus and LCA + DEA methodology for sustainable fisheries management: A case study of Cantabrian fishing fleets

The fishing sector constitutes an important source of economic revenue in northern Spain. In this context, various research studies have focused on the application of the five-step Life Cycle Assessment (LCA) and Data Envelopment Analysis (DEA) methodology to quantify environmental impacts of fishing systems. However, some of them have used environmental indicators that focus on individual environmental issues, hindering the goal of achieving integrated resource management. Therefore, in this study, the Water-Energy-Food (WEF) Nexus is employed as an integrative perspective that considers the synergies and trade-offs between carbon footprint, energy requirements, and water demand.The main objective of this study is to evaluate the operational efficiency and environmental impacts of Cantabrian fishing fleets. To this end, the combined use of LCA and DEA, along with the WEF Nexus, was applied to the Cantabrian purse seine fleet. DEA matrices were generated using the LCA-derived WEF nexus values as inputs to calculate efficiency scores for each vessel. Subsequently, based on the efficiency projections provided by the DEA model, a new impact assessment was performed to understand the eco-efficiency and potential environmental benefits of operating at higher levels of efficiency within this fleet.The average efficiency of the fleet was above 60 %. Inefficient units demonstrated a greater potential to reduce their environmental impacts (up to 65 %) by operating according to efficiency projections. Furthermore, the results revealed a strong dependence of environmental impacts on one of the operational inputs, i.e., fuel consumption. These findings highlight the significance of embracing holistic approaches that combine technical, economic, and social factors to achieve a sustainable balance in fisheries systems. In this regard, the five-step LCA + DEA method applied in conjunction with the WEF Nexus emerged as a suitable tool for measuring operational and environmental objectives.

The contribution of water-energy-food nexus governance to sustainability: A case study of Singapore

The water-energy-food (WEF) nexus has been promoted as an approach to integrated governance that can increase system sustainability. However, there have been limited empirical studies that demonstrate how WEF nexus governance leads towards sustainability. Therefore, the study investigates how collaborative governance of the WEF nexus connects to sustainability in Singapore, considered one of the most sustainable cities in the world. The objective is to understand the structure of WEF nexus governance in Singapore and explore how this structure contributes towards sustainability. This study uses a case study approach with qualitative text analysis on multiple data types to address this research objective. The results show two key findings. First, the findings show that WEF nexus governance in Singapore has a collaborative governance approach at the national level but is less integrated at lower levels of governance. Second, the results show that while governance integration, including WEF nexus connections, contributes to sustainability, there are also factors beyond WEF nexus governance that contribute towards sustainability in Singapore. The study concludes that WEF nexus governance provides an opportunity for improved sustainability within the system, but WEF nexus governance alone may not be sufficient for sustainability to be realized.

Analysis of the Aquaponic System Sustainability via System Dynamics Modelling – FEW Nexus Approach

AbstractAquaponic systems integrate aquaculture and hydroponics, recycling nutrient-enriched water from fish tanks to grow plants, significantly reducing carbon emissions, water use and production costs compared to other methods. It is considered a sustainable solution for food production, addressing issues such as climate change and eutrophication. Particularly valuable in family farming, it increases the diversity and quality of food, while reducing its environmental impact. However, despite its potential, aquaponics lacks recognition in public policies, making its widespread adoption difficult. Quantifying its benefits is crucial for strategic planning and the formulation of policies to support family farming and the transition to sustainability, in line with global objectives. Therefore, there is a need to comprehensively quantify the benefits of aquaponics, particularly in terms of the Food-Energy-Water (FEW) nexus, to support decision-making and policy formulation for sustainable agriculture. The nexus concept encompasses highly complex systems requiring robust tools capable of analysing the interrelationships between multiple components. Aiming to analyse the degree of sustainability of aquaponics systems on family property in the FEW nexus context, a System Dynamics Modelling (SDM) coupling Socio-economic and environmental indicators was developed. The results obtained demonstrated the efficiency of using SDM as an analysis and support tool for decision-making. Additionally, they prove the environmental viability of food production via aquaponic systems.

Why Do Farmers Not Irrigate All the Areas Equipped for Irrigation? Lessons from Southern Africa

The reliance on rainfed agriculture exposes southern Africa to low agricultural productivity and food and nutritional insecurity; yet, the region is endowed with vast irrigation potential. Extreme weather events including drought, floods, and heatwaves exacerbate the existing challenges, underscoring the need to improve agricultural water management as a climate change adaptation strategy. This mixed-methods review followed the Search, Appraisal, Synthesis, and Analysis (SALSA) framework to explore the irrigation opportunities and challenges in southern Africa by critically analysing the drivers and constraints of irrigation systems in southern Africa. The premise is to understand the reasons behind the abandonment of some of the areas equipped for irrigation. In cases where irrigation systems are present, the study assesses whether such technologies are effectively being used to generate the expected agricultural productivity gains, and what factors, in cases where that is not the case, constrain farmers from fully using the existing infrastructure. The review further discusses the enabling environment supporting irrigated agriculture and the role of gender in irrigation development. An assessment of the role of women in agriculture on the share of land equipped for irrigation to total cultivated land area, as well as on the proportion of the area equipped for irrigation versus the area that is actually irrigated is conducted. The review found a divergence between countries’ land areas equipped for irrigation and actually irrigated areas. Specific to irrigation expansion, the review rebuts the notion that increasing the irrigated area increases crop production and ensures food security. This may not always be true as irrigation development needs to consider the impacts on other closely linked water and energy sectors through transformative approaches like the water–energy–food (WEF) nexus and scenario planning. If well-planned and implemented, sustainable irrigated agriculture could be catalytic to transforming southern Africa’s food system to be inclusive, equitable, socially just, and resilient, benefiting people and the planet.

Towards a Sustainable Structure of an Urban Water–Energy–Food Nexus: Based on Network and Hierarchy Analysis

Water, energy, and food (WEF) are critical resources to sustain urban development, which requires a sustainable structure of the urban WEF nexus to address trade-offs and achieve synergies. Although interactions in the WEF nexus are widely explored, its sustainable structure has largely been ignored. This study constructs a framework of WEF nexus sustainability factors. Based on a literature review and expert opinions, 21 factors influencing urban WEF nexus sustainability were extracted and their interrelationships determined. We used social network analysis (SNA) and interpretive structural modeling (ISM) to analyze the structure of the urban WEF network. The results indicate that technological investment and industrial added-value energy consumption are the most critical and fundamental factors for promoting the sustainable development of the urban WEF nexus. Additionally, the balance of water supply and demand and the comprehensive management of waste pollutants are also driving and supporting factors for the sustainability of the urban WEF nexus. The results of this study complement the interaction mechanism research of the urban WEF nexus and provide practical references for sustainable decision-making in urban WEF nexus practices.

A Review of Grease Trap Waste Management in the US and the Upcycle as Feedstocks for Alternative Diesel Fuels

As byproducts generated by commercial and domestic food-related processes, FOGs (fats, oils, and grease) are the leading cause of sewer pipe blockages in the US and around the world. Grease trap waste (GTW) is a subcategory of FOG currently disposed of as waste, resulting in an economic burden for GTW generators and handlers. This presents a global need for both resource conservation and carbon footprint reduction, particularly through increased waste upcycling. Therefore, it is critical to better understand current GTW handling practices in the context of the urban food–energy–water cycle. This can be accomplished with firsthand data collection, such as onsite visits, phone discussions, and targeted questionnaires. GTW disposal methods were found to be regional and correspond to key geographical locations, with landfill operations mostly practiced in the Midwest regions, incineration mainly in the Northeast and Mid-Atlantic regions, and digestion mainly in the West of the US. Select GTW samples were analyzed to evaluate their potential reuse as low-cost feedstocks for biodiesel or renewable diesel, which are alternatives to petroleum diesel fuels. Various GTW lipid extraction technologies have been reviewed, and more studies were found on converting GTW into biodiesel rather than renewable diesel. The challenges for these two pathways are the high sulfur content in biodiesel and the metal contents in renewable diesel, respectively. GTW lipid extraction technologies should overcome these issues while producing minimum-viable products with higher market values.

A Systematic Review of Socio-Technical Systems in the Water–Energy–Food Nexus: Building a Framework for Infrastructure Justice

A Systematic Review of Socio-Technical Systems in the Water–Energy–Food Nexus: Building a Framework for Infrastructure Justice

Does policy integration promote water–energy–food coordination? A quasi-natural experiment in the Yangtze River Delta Urban Agglomeration

Does policy integration promote water–energy–food coordination? A quasi-natural experiment in the Yangtze River Delta Urban Agglomeration

Development of a method to assess synergy and competition for water use among water-energy-food nexus in the Yellow River basin: Water quantity-quality dimensions

Water, as an indispensable component of the water-energy-food (WEF) nexus, plays a pivotal role in shaping its stability and safety. The competition for water between the food and energy systems is accentuated in the concept of the nexus. However, existing quantitative frameworks and assessment mechanisms have limitations as they often neglect to consider water quality in water competition within the WEF nexus. Therefore, a WEF nexus synergy and competition assessment method was proposed by coupling water footprint theory and the Lotka-Volterra model in this paper. This method establishes two scenarios based on the water footprint perspective, namely, water quantity and water quality-quantity. It effectively addresses the deficiencies in quantitative analysis of WEF system trade-offs and synergies. To illustrate the application of the method, this study conducted a case study in the Yellow River Basin (YRB) of China, evaluating the complex competitive and synergistic mechanisms of water use in the energy and food industries. Compared to the water quantity scenario, the results reveals that the inclusion of gray water footprint intensifies the competition for water in the food and energy industries in the YRB from 2000 to 2020, particularly in resource-based and economically developed cities. The spatial distribution characteristics of water resource competition and synergy in the YRB’s WEF system align with WEF endowment and economic technology levels. To address water conflicts in the WEF nexus and enhance nexus security, this study proposes a regulatory pathway for WEF system synergistic security based on two aspects (water competition and synergy characteristics and resource endowment). It contributes to a more comprehensive understanding of water competition and synergy in the WEF nexus and provides valuable insights for resource management.

Recycling food waste to agriculture through hydrothermal carbonization sustains food-energy-water nexus

Recycling underutilized resources from food waste (FW) to agriculture through hydrothermal carbonization (HTC) has been proposed to promote a circular economy (CE) in food-energy-water (FEW) nexus. However, most HTC studies on FW were conducted at laboratory scale, and little is known on the efficacy and feasibility of field application of HTC products from FW, i.e. the aqueous phrase (AP) and solid hydrochar (HC), to support agriculture production. An integrated pilot-scale HTC system was established to investigate practical HTC reaction conditions treating FW. A peak temperature of 180 °C at a residence time of 60 min with 3 times AP recirculation were recommended as optimal HTC conditions to achieve efficient recovery of nutrients, and desirable AP and HC properties for agriculture application. Dilution of the raw AP and composting of the fresh HC are necessary as post-treatments to eliminate potential phytotoxicity. Applying properly diluted AP and the composted HC significantly improved plant growth and nutrient availability in both greenhouse and field trials, which were comparable to commercial chemical fertilizer and soil amendment. The HTC of FW followed with agricultural application of the products yielded net negative carbon emission of −0.28 t CO2e t−1, which was much lower than the other alternatives of FW treatments. Economic profit could be potentially achieved by valorization of the AP as liquid fertilizer and HC as soil amendment. Our study provides solid evidences demonstrating the technical and economic feasibility of recycling FW to agriculture through HTC as a promising CE strategy to sustain the FEW nexus.