An integrative analytical model for the water-energy-food nexus: South Africa case study

A bibliometric analysis assessing the water-energy-food nexus in South Africa

The Water-Energy-Food (WEF) nexus is a paradigm that emphasises the interconnectedness and collaborative effects of water, energy, and food systems. This study presents a bibliometric analysis of South Africa's WEF nexus research landscape between 2011 and 2024 using the Scopus database. The article highlights the interconnectedness of sustainable development, resource management, sustainability challenges, and resilience strategies in the WEF Nexus in South Africa. The study also identifies critical research gaps in addressing socio-economic dimensions, policy and governance aspects, technological innovation, and human resource development within the WEF Nexus framework. The article reveals the transformative potential of blockchain technology in revolutionising resource management in South Africa. By leveraging blockchain's decentralised and transparent nature, the country can enhance efficiency, transparency, and sustainability in resource allocation and distribution.

Developing meaningful water-energy-food-environment (WEFE) nexus indicators with stakeholders: An Upper White Nile case study

The Upper White Nile (UWN) basin plays a critical role in supporting essential ecosystem services and the livelihoods of millions of people in East Africa. The basin has been exposed to tremendous environmental pressures following high population growth, urbanisation, and land use change, all of which are compounded by the threats posed by climate change and insufficient financial and human resources. The water-energy-food-environment (WEFE) nexus provides a framework to assess solution options towards sustainable development by minimising the trade-offs between water, energy, and food resources. However, the majority of existing WEFE nexus indicators and tools tend to be developed without consideration of practitioners at the local level, thus constraining the practical application within real-world contexts. To try to address this gap and operationalise the WEFE nexus, we examined how local stakeholders frame the most pressing WEFE nexus challenges within the UWN basin, how these can be represented as indicators, and how existing WEFE nexus modelling tools could address this. The findings highlight the importance of declining water quality and aquatic ecosystem health as a result of deforestation and increasing agricultural intensity, with stakeholders expressing concerns for the uncertain impacts from climate change. Furthermore, a review of current WEFE nexus modelling tools reveals how they tend to be insufficient in addressing the most pressing environmental challenges within the basin, with a significant gap regarding the inclusion of water quality and aquatic ecosystem indicators. Subsequently, these findings are combined in order to guide the development of WEFE nexus indicators that have the potential to spatially model the trade-offs within the WEFE nexus in the UWN basin under climate change scenarios. This work provides an example of how incorporating local stakeholder's values and concerns can contribute to the development of meaningful indicators, that are fit-for-purpose and respond to the actual local needs.

Rapid environmental flow assessment for sustainable water resource management in Tanzania's Lower Rufiji River Basin: A scoping review

The use of Environmental flow (e-Flow) assessment is a widely adopted approach to facilitate informed decision-making concerning sustainable management and utilization of water resources in river systems. The Lower Rufiji River Basin faces various developmental pressures from several sectors, including hydropower, mining, agriculture, livestock, fishing, and tourism, necessitating effective management of the sub-catchment area to prevent significant environmental impacts. Consequently, it is essential to acquire a comprehensive comprehension of the catchment's attributes, encompassing both climatic and non-climatic factors. Supported by e-Flow batch analysis of the available data at Stiegler's Gorge using the global environmental flow calculator, a scoping review was conducted to determine the status of environmental flow in the lower Rufiji River basin. The findings suggest that, while there has been progress in understanding eFlow estimation, limited data and ecohydrological processes' poor comprehension still present challenges. Hydrological and holistic methodologies are commonly employed in Tanzania; however, uncertainties remain, raising questions concerning trust between decision-making tools and water resource utilization by the public. Climate variability influences e-Flow in the Rufiji River Basin, and the projections under various scenarios indicate an increased temperature, varying rainfall, and humidity levels. Further, the area has been identified as a vulnerable "hotspot" where communities face greater climate stressor risks. With the existing and planned developmental projects in the basin, including hydroelectric dams, mining, agriculture, livestock, and fisheries, it is critical to assess e-Flow in the Lower Rufiji River basin to ensure resource sustainability. Advocating for preserving a dynamic environmental flow regime in rivers is recommended, considering the Rufiji River Basin's habitat connectivity. The future research direction should be quantifying the contribution of base flow to the surface flow, and salinity dynamics in the Lower Rufiji River Basin, which can affect the Delta's biodiversity.

An African perspective on the Water-Energy-Food nexus

There is a need to address resource security and distributional justice in developing countries. People need water, energy, and food to sustain their livelihoods, grow economies, and achieve sustainable development. The interactions between these resource sectors form the crux of water-energy-food (WEF) nexus assessments. In this study, we have utilised the WEF Nexus Index to analyse the WEF nexus of 54 African nations. The results from the analysis were used to illustrate the opportunities and constraints for future development. Generally, African countries are performing sub-optimally in the WEF Nexus Index due to the insecurity of water, energy and/or food. The performance of countries varies with context, highlighting the need for contextual analysis in identifying challenges and potential solutions. Implementation of interventions for achieving WEF security needs to be planned from an integrated perspective to optimise synergies and minimize trade-offs. Implementation of the WEF nexus approach towards simultaneous security of WEF resources has potential to improve the WEF nexus. For example and for many African countries, policies that undergird investments in energy supply projects are needed to unlock available freshwater resources and meet food requirements-energy is shown to be a critical enabler of development. Such projects can be utilised to enhance the ability of farmers to manage water through drought-proofing rainfed agriculture, an increase in irrigation development, or both. WEF nexus-based studies, policies, and projects must be focused on the direct and indirect achievement of SDGs 1, 2, 6, 7, and 13, both in terms of access and availability, to ensure distributional justice, especially in the African context. Such actions, combined with broad public participation, can have a ripple effect on other SDGs such as SDGs 5, 10, and 17, thereby reducing inequalities and building partnerships to attain these aspirational goals. The assessment of Africa's relatively low scores in terms of the WEF Nexus Index does not represent a negative narrative. Instead, it provides an entry point to identifying hotspots and understanding the underlying challenges, through which more detailed analyses can lead to identified solutions and policies. Many African countries are trapped in an environment that could be termed a 'poverty-unemployment-inequality nexus' (due to the interlinkages that exist between these 'wicked' problems). The WEF Nexus Index provides high-level insights into these opportunities.

Progress in modeling dynamic systems for sustainable development

This Perspective evaluates recent progress in modeling nature-society systems to inform sustainable development. We argue that recent work has begun to address longstanding and often-cited challenges in bringing modeling to bear on problems of sustainable development. For each of four stages of modeling practice-defining purpose, selecting components, analyzing interactions, and assessing interventions-we highlight examples of dynamical modeling methods and advances in their application that have improved understanding and begun to inform action. Because many of these methods and associated advances have focused on particular sectors and places, their potential to inform key open questions in the field of sustainability science is often underappreciated. We discuss how application of such methods helps researchers interested in harnessing insights into specific sectors and locations to address human well-being, focus on sustainability-relevant timescales, and attend to power differentials among actors. In parallel, application of these modeling methods is helping to advance theory of nature-society systems by enhancing the uptake and utility of frameworks, clarifying key concepts through more rigorous definitions, and informing development of archetypes that can assist hypothesis development and testing. We conclude by suggesting ways to further leverage emerging modeling methods in the context of sustainability science.

Barriers to conducting independent quantitative research in low-income countries: A cross-sectional study of public health graduate students in Liberia

INTRODUCTION

During recent disease outbreaks, quantitative research has been used to investigate intervention scenarios while accounting for local epidemiological, social, and clinical context. Despite the value of such work, few documented research efforts have been observed to originate from low-income countries. This study aimed to assess barriers that may be limiting the awareness and conduct of quantitative research among Liberian public health graduate students.

METHODS

A semi-structured questionnaire was administered September-November 2021 to Master's in Public Health (MPH) students in Liberia. Potential barriers around technology access, understanding of quantitative science, and availability of mentorship were interrogated. Associations between barriers and self-reported likelihood of conducting quantitative research within six months of the investigation period were evaluated using ordinal logistic regression.

RESULTS

Among 120 participating MPH students, 86% reported owning a personal computer, but 18.4% and 39.4% had machines with malfunctioning hardware and/or with battery power lasting ≤2 hours, respectively. On average, students reported having poor internet network 3.4 days weekly. 47% reported never using any computer software for analysis, and 46% reported no specific knowledge on statistical analysis. Students indicated spending a median 30 minutes per week reading scientific articles. Moreover, 50% had no access to quantitative research mentors. Despite barriers, 59% indicated they were very likely to undertake quantitative research in the next 6 months; only 7% indicated they were not at all likely. Computer ownership was found to be statistically significantly associated with higher likelihood of conducting quantitative research in the multivariable analysis (aOR: 4.90,95% CI: 1.54-16.3).

CONCLUSION

The high likelihood of conducting quantitative research among MPH students contrasts with limitations around computing capacity, awareness of research tools/methods, and access to mentorship. To promote rigorous analytical research in Liberia, there is a need for systematic measures to enhance capacity for diverse quantitative methods through efforts sensitive to the local research environment.

Sustainable irrigation technologies: a water-energy-food (WEF) nexus perspective towards achieving more crop per drop per joule per hectare

Sustainable agricultural intensification requires irrigation methods and strategies to minimize yield penalties while optimizing water, land and energy use efficiencies. We assessed, from a silo-based and integrated water-energy-food (WEF) nexus perspective, the performance of irrigation technologies in different agro-climatic regions. Secondary to this, we assessed the impact of adopting systematic approaches such as the WEF nexus on improving efficiency in irrigated agriculture through irrigation modernization. The evidence-based perspectives of silo-based performances individually considered the metrics of yield (Y), water use efficiency (WUE), and energy productivity (EP). The WEF nexus approach applied sustainability polygons to integrate the three metrics into a nexus index representing the holistic performance of the irrigation technologies. Silo-based performance in temperate regions suggests net gains for WUE (+1.10 kg m-3) and Y (+6.29 ton ha-1) when transitioning from furrow to sprinkler irrigation, with a net loss in EP (-3.82 ton MJ-1). There is potential for a net loss on EP (-3.33 ton MJ-1) when transitioning from furrow to drip system in temperate regions. The best performance of irrigation technologies in dry regions in water, energy and food silos was achieved by sprinkler, drip and furrow irrigation systems, respectively. Thus, appraising irrigation technologies from a silos perspective promotes individual silos, which renders an unsustainable picture of the performance of irrigation systems. The integrative WEF nexus approach successfully highlighted the trade-offs and synergies in the nexus of water, energy and food in irrigated agriculture. Drip irrigation led all irrigation technologies in WEF nexus performance in dry (21.44 unit2), tropical (23.98 unit2), and temperate regions (47.28 unit2). Overall, the irrigation modernization pathway to drip technology from either furrow or sprinkler systems improves irrigated agriculture's WEF nexus performance in all three regions for more crop per drop per joule per hectare under climate change. This can promote inclusive and sustainable irrigation development within the planetary boundaries.

Securing Land and Water for Food Production through Sustainable Land Reform: A Nexus Planning Perspective

Land and water are vital resources for sustaining rural livelihoods and are critical for rural development as they form the basis of agriculture, the main economic activity for rural communities. Nevertheless, in most developing countries, land and water resources are unevenly distributed due to historical and socio-economic imbalances, hence the need for land reform policies to address these disparities. However, redistributing land without considering the interconnectedness of land and socio-ecological systems can compound existing food and water insecurity challenges. This study used a mixed research method, integrating both quantitative and qualitative data, to develop a framework to guide policy and decision-makers to formulate coherent strategies towards sustainable land redistribution programmes and achieve the desired outcomes. The approach was vital for integrating the broad and intricate interlinkages between water, land, and environmental resources. Therefore, the framework is based on transformative and circular models for informing strategic policy decisions towards sustainable land redistribution. The focus was on South Africa’s land redistribution plans and the implications on water and food security and rural development. The developed framework is designed to ensure the sustainability of agrarian reform and rural economic development. It is framed to address land and water accessibility inequalities, promote water and food security, and enhance rural development. A sustainable land redistribution increases the adaptive capacity of rural communities to climate change, enhances their resilience, and provides pathways towards Sustainable Development Goals (SDGs).

A New Low-Cost Technology Based on Pump as Turbines for Energy Recovery in Peripheral Water Networks Branches

The recovery of excess energy in water supply networks has been a topic of paramount importance in recent literature. In pressurized systems, a pump used in inverse mode (Pump As Turbine, PAT) demonstrated to be a very economical and reliable solution, compared to traditional energy production devices (EPDs). Due to the large variability of flow rate and head drop within water distribution networks, the operation of PATs could be performed by a series-parallel regulation system based on an electronic or a hydraulic principle. Despite the low cost of the PATs and of regulation and control systems, a great barrier to the diffusion of a small hydro power plant in water distribution is represented by the necessity of additional civil works to host the whole plant. Based on laboratory and numerical experiments, the present paper proposes a new low-cost technology, overcoming most of the limitations of the present technologies when low energy is available and high discharge variation occurs. The operating conditions of the plant are properly optimized with reference to the working conditions of a case study. Despite the laboratory prototype having exhibited a significantly low efficiency (i.e., 16%), due to the use of small centrifugal pumps suitable for the analyzed case study, in larger power plants relying on more efficient semi-axial submersed pumps, the energy conversion ratio can increase up to 40%. The results of this research could be useful for network managers and technicians interested in increasing the energy efficiency of the network and in recovering energy in the peripheral branches of the network were a large variability of small flow rates are present.

Co-creating sustainability indicators for the local water-energy-food nexus

Sustainability indicators have become essential tools to deal with compartmentalized resources planning and management in cities. The development of water, energy, and food nexus (WEF nexus) indicators is a prominent goal of current research, but the focus is mainly on economic issues and material flows. Attention to the local scale and context, social aspects, and the inclusion of non-academic actors is mostly lacking. To address these gaps, this paper reports and reflects on the co-creation of sustainability indicators related to the WEF nexus in the city of São Paulo, Brazil. With a transdisciplinary approach, non-academic actors were included in the different stages of the process using the Urban Living Lab methodology, to improve the usability of the produced indicators' set. The case of São Paulo concerned on-going actions in the peri-urban and rural areas of the city which seek to improve environmental protection by stimulating more sustainable forms of agriculture. Thirty-four indicators were developed through a sequence of interactive activities, such as workshops, meetings, and field trips. The presented process aims to strongly enhance usability by actively involving users from the start, connecting the nexus approach to previous knowledge and familiar frameworks, paying attention to the local scale and context, and to social aspects, and by anticipating future use in various ways.

Multi-Level Prioritization Analysis of Water Governance Components to Improve Agricultural Water-Saving Policy: A Case Study from Korea

The challenge of unstainable agricultural water usage in Korea has continued interminably despite persisting climate change impacts; thus, necessitating urgent actions to forestall future water crises. However, achieving this goal requires the involvement of stakeholders to develop an effective governance policy concerning water saving. This study investigates the components of water governance following existing water policy gaps. A multi-level Delphi-AHP technique was used to identify and prioritize the essential components of agricultural water governance that can specifically enhance water-saving policy in Korea. The analysis of twenty-nine formulated components (six main and twenty-three sub-components) based on the OECD water policy gaps was conducted. A Delphi-AHP technique with process evaluation of the agricultural water experts’ opinions under pairwise comparisons was used to arrive at the relative order of importance of the components. The order of main components based on the consolidated weight follows core actors (0.316), law, policies, and systems (0.069), budget support (0.135), information sharing and communication (0.099), mutual learning (0.142), and external experts (0.239), while village representatives (0.353), legislation (0.358), central government (0.311), policy committee (0.309), education course (0.374), and facilitator (0.402) were considered as priorities, respectively, for the sub-components of water governance. The findings indicate that strengthening the informal institution could address the water governance gaps in the agricultural sector to achieve water-saving policies. This study recommends a bottom-up approach to water governance that could promote the active participation of core actors such as farmers and villagers in the design of policy and management of agricultural water resources.

Assessing the Nexus on Local Perspective: A Quali-Quantitative Framework for Water-Energy-Food Security Evaluation in Neglected Territories

There is limited focus on the water-energy-food (WEF) nexus approach at the local scale, particularly considering the social contexts of neglected territories. To contribute to this debate, we propose a framework to address this topic in an area in Angra dos Reis, Rio de Janeiro State, Brazil, as a case study. A survey was conducted regarding residents’ perceptions, choices, practices and access to water, energy, and food. The interviews highlighted important topics on the WEF nexus. As a result, a set of 12 indicators with data available on official datasets was proposed, reflecting residents’ perceptions of WEF safety. For each indicator, thresholds were established based mainly on the goals defined by Brazilian policies across different spheres—federal, state, or municipal. Thus, each indicator is multi-scale and integrative, since it comprises a local perspective (from the interview results), an official perspective (from the official databases), and a threshold. The results showed problems with energy and water supply, and the presence of home cropping, contrasting with residents who do not have access to basic food and experience extreme poverty. All these elements drew attention to the possibility of applying the WEF nexus approach, searching for feasible solutions which can support better decisions and governance in neglected territories.

Water, Energy and Food Nexus: Policy Relevance and Challenges

Connections between water, food, and energy are at the center of long-term economic and environmental development and protection. Water, energy and food are the keys to economic input and a necessary component of economic progress. The adoption of water management policies and techniques that support the sustainable use of resources while promoting economic growth is becoming an important concern, particularly in countries where water and food scarcity are critical or problematic. This study aimed at evaluating Water, Energy and Food Nexus (WEF), and as well as challenges of its implementation. This study looked at the articles that were published on WEF nexus between 2015 and 2021 acquired from the Scopus database, focusing on gaps and implementations. I searched for relevant key terms in the database and the search found hundreds of articles on WEF, of which 28 articles were relevant to the scope of the study and these articles were downloaded as BibTeX file for the analysis and the analysis was done using R programming. A number of insights and implications were identified based on the analyses of the findings of the reviewed research in order to increase the policy relevance and overall implementation of the WEF nexus by public policy and decision-making institutions. To boost uptake of the findings, the study gives an outline of the primary constraints and challenges that restrict the policy relevance of the WEF nexus.

Going beyond Global Indicators—Policy Relevant Indicators for SDG 6 Targets in the Context of Austria

Bringing forward sustainable transformation as envisioned within the Agenda 2030 requires comprehensive monitoring of the 17 Sustainable Development Goals (SDGs) formulated therein. To monitor and report progress on goal 6 on clean water and sanitation and its eight pertinent targets, 11 indicators were stipulated in an elaborated process. Yet, through continuous scientific and public scrutiny and debate several gaps and weaknesses were identified. Amongst others, these globally defined indicators are found to reflect weakly the diversity of national realities, capacities and levels of development. To translate the targets into national contexts and fully cover all aspects of the SDG 6 targets, the utilization of complementary indicators is recommended. Within this paper, following a critical appraisal of the SDG 6 indicators, possible complementary indicators are collected from literature and screened based on their quality, relevance for the national context and data availability. A deepened status quo of the SDG 6 targets and corresponding problem areas are outlined for the context of Austria, where water and sanitation infrastructure as well as regulation and governance of water bodies are widely established. Despite increasing the monitoring effort, it is concluded that complementary indicators are practicable to support coherent policy-making and ultimately contribute to the Agenda 2030’s aspiration that all countries take action.

Governance using the water-food-energy nexus and human-factor measures

Household water food and energy (WFE) expenditures, reflect respective survival needs for which their resources and social welfare are inter-related. We developed a policy driven quantitative decision-making strategy (DMS) to address the domain geospatial entities’ (nodes or administrative districts) of the WFE nexus, assumed to be information linked across the domain nodal-network. As investment in one of the inter-dependent nexus components may cause unexpected shock to the others, we refer to the WFE normalized expenditures product (Volume) as representing the nexus holistic measure. Volume rate conforms to Boltzman entropy suggesting directed information from high to low Volume nodes. Our hypothesis of causality-driven directional information is exemplified by a sharp price increase in wheat and rice, for U.S. and Thailand respectively, that manifests its impact on the temporal trend of Israel’s administrative districts of the WFE expenditures. Welfare mass (WM) represents the node’s Volume combined with its income and population density. Formulation is suggested for the nodal-network WM temporal balance where each node is scaled by a human-factor (HF) for subjective attitude and a superimposed nodal source/sink term manifesting policy decision. Our management tool is based on two sequential governance processes: one starting with historical data mapping the mean temporal nodal Volumes to single out extremes, and the second is followed by WM balance simulation predicting nodal-network outcome of policy driven targeting. In view of the proof of concept by model simulations in in our previous research, here HF extends the model and attention is devoted to emphasize how the current developed decision-making approach categorically differs from existing nexus related methods. The first governance process is exemplified demonstrating illustrations for Israel’s districts. Findings show higher expenditures for water and lower for energy, and maps pointing to extremes in districts’ mean temporal Volume. Illustrations of domain surfaces for that period enable assessment of relative inclination trends of the normalized Water, Food and Energy directions continuum assembled from time stations, and evolution trends for each of the WFE components.

Resilience and Sustainability of the Water Sector during the COVID-19 Pandemic

The COVID-19 pandemic brought unprecedented socio-economic changes, ushering in a “new (ab)normal” way of living and human interaction. The water sector was not spared from the effects of the pandemic, a period in which the sector had to adapt rapidly and continue providing innovative water and sanitation solutions. This study unpacks and interrogates approaches, products, and services adopted by the water sector in response to the unprecedented lockdowns, heralding novel terrains, and fundamental paradigm shifts, both at the community and the workplace. The study highlights the wider societal perspective regarding the water and sanitation challenges that grappled society before, during, after, and beyond the pandemic. The premise is to provide plausible transitional pathways towards a new (ab)normal in adopting new models, as evidenced by the dismantling of the normal way of conducting business at the workplace and human interaction in an era inundated with social media, virtual communication, and disruptive technologies, which have transitioned absolutely everything into a virtual way of life. As such, the novel approaches have fast-tracked a transition into the 4th Industrial Revolution (4IR), with significant trade-offs to traditional business models and human interactions.

Artificial Intelligence in the Water–Energy–Food Model: A Holistic Approach towards Sustainable Development Goals

This study aims to analyze the role of artificial intelligence (AI) in the Water–Energy–Food (WEF) nexus under the lens of institutional, stakeholder, and innovation theories. Specifically, this study focuses on AI as the technology adopted by companies to promote Sustainable Development Goals (SDGs). A structured literature review has been conducted on 94 articles published from 1990 to 2021 in ISI Web of Science, Scopus, and Google Scholar. This study develops an in-depth review of the literature on the main articles arguing about these issues. The findings highlight the increasing relevance of AI in the water, energy, and food industries individually considered, but the study of AI as a connector between water, energy, and food to achieve SDGs is still under investigation. Research on AI for WEF nexus management has adopted mostly a technical perspective, neglecting the relevance of management tools and the business model concept. Most of the articles did not adopt a specific theoretical lens, but scholars recognize the need to adopt a multi-stakeholder approach and the important role played by AI and other digital technologies to address the WEF nexus challenge. This study proposes an integrated approach for managing the nexus through AI technologies to meet sustainable and responsible business models. The gap between research and policy making could be filled by combining scientific data and policy needs with inclusive tools that are technically viable for sustainable resource utilization.

Informing Equitable Water and Food Policies through Accurate Spatial Information on Irrigated Areas in Smallholder Farming Systems

Accurate information on irrigated areas' spatial distribution and extent are crucial in enhancing agricultural water productivity, water resources management, and formulating strategic policies that enhance water and food security and ecologically sustainable development. However, data are typically limited for smallholder irrigated areas, which is key to achieving social equity and equal distribution of financial resources. This study addressed this gap by delineating disaggregated smallholder and commercial irrigated areas through the random forest algorithm, a non-parametric machine learning classifier. Location within or outside former apartheid "homelands" was taken as a proxy for smallholder, and commercial irrigation. Being in a medium rainfall area, the huge irrigation potential of the Inkomati-Usuthu Water Management Area (UWMA) is already well developed for commercial crop production outside former homelands. However, information about the spatial distribution and extent of irrigated areas within former homelands, which is largely informal, was missing. Therefore, we first classified cultivated lands in 2019 and 2020 as a baseline, from where the Normalised Difference Vegetation Index (NDVI) was used to distinguish irrigated from rainfed, focusing on the dry winter period when crops are predominately irrigated. The mapping accuracy of 84.9% improved the efficacy in defining the actual spatial extent of current irrigated areas at both smallholder and commercial spatial scales. The proportion of irrigated areas was high for both commercial (92.5%) and smallholder (96.2%) irrigation. Moreover, smallholder irrigation increased by over 19% between 2019 and 2020, compared to slightly over 7% in the commercial sector. Such information is critical for policy formulation regarding equitable and inclusive water allocation, irrigation expansion, land reform, and food and water security in smallholder farming systems.

Operationalising the water-energy-food nexus through the theory of change

The water-energy-food (WEF) nexus facilitates understanding of the intricate and dynamic interlinkages among the three resources. Its implementation can enhance resource securities and sustainable development. Despite its potential, full adoption of the approach has been hindered by a lack of actionable strategies to guide its practical application. This is attributed to (i) poor data (ii) lack of empirical evidence, (iii) inadequate analytical tools, and (iv) lack of clarity on applicable spatial scale. This study undertook a literature review, coupled with systemic analyses of a WEF nexus analytical model, whose outputs were used as a basis to develop a Theory of Change, an iterative outline for operationalising the approach in the context of southern Africa. The consultative and iterative Theory of Change culminated with the formulation of pathways to (i) overcome the barriers impeding WEF nexus operationalisation, (ii) mitigation of trade-offs while enhancing synergies towards attaining simultaneous resource securities, (iii) poverty alleviation and reduction of inequalities, and (iv) reconciling policy with implementation scale. The WEF nexus operationalisation outcomes are linked to Sustainable Development Goals 2 (zero hunger), 6 (clean water and sanitation), and 7 (affordable and clean energy), with synergies to SDGs 1 (no poverty), 5 (gender equality), 8 (decent work and economic growth), 12 (responsible consumption and production), 13 (climate action), 14 (life below water), and 15 (life on land). Operationalising the WEF nexus through an interactive process can inform sustainable pathways towards resource security, job and wealth creation, improved livelihoods and well-being, and regional integration.

Towards a Water-Energy-Food (WEF) nexus index: A review of nutrient profile models as a fundamental pillar of food and nutrition security

The Water-Energy-Food (WEF) nexus approach should be promoted as a tool for sustainable management of resources through the interconnection of these three fundamental pillars. Particularly, food security must ensure healthy and balanced diets for everyone, but selecting individual indicators to assess all slants covered by this element is not an easy task. Hence, the objective of this paper is two-fold, to review nutrient profiling (NP) models that allow to categorize foods and evaluate diets based on their nutritional quality, and to choose the most appropriate model to be used within a WEF nexus index. To address this issue, a total of 159 documents were assessed, appraising the geographic distribution, and time evolution of the publications, as well as the characteristics and potential applications of the NP systems. The review concludes that the NRF9.3. model is the most liable option to be used in a WEF nexus index, presenting the best characteristics by means of the definition of scores and thresholds, and the use of an 'across-the-board' criteria and a reference quantity of 100 kcal, alongside offering higher ability to assess diets and foods than the other competitive model (HEI) through the evaluation of nutrients to encourage instead of foods. A secondary outcome of the review is the identification of the NP models as a useful tool to enable institutions with information to establish policies in the field of public health and facilitating the decision-making process according to the current healthy claims.

Transitional Pathways towards Achieving a Circular Economy in the Water, Energy, and Food Sectors

Achieving sustainable socio-economic development requires approaches that enhance resource use efficiencies and can address current cross-sectoral challenges in an integrated manner. Existing evidence suggests an urgent need for polycentric and transformative approaches, as global and local systems have come under strain. This study conducted a systematic literature review at the global level to assess the progress made towards achieving a circular economy between 2010 and 2020, a period covering the formulation of the Sustainable Development Goals (SDGs) and the initial five years of their implementation. The focus was on the potential of improved water and energy use efficiency, linking them to food production within the context of a circular economy. Identifying successes, opportunities, challenges, and pathways towards a circular economy from the literature review facilitated developing a conceptual framework to guide strategic policy formulations towards a more sustainable economy. A combination of transformative approaches is analysed in an integrated way in response to the 2030 global agenda on sustainable development. Thus, the study is informed by the initiatives to attain SDGs and mitigating negative environmental impacts due to waste and pollution. The premise is to enhance transformational change as a catalyst for employment creation and the attainment of a green economy while reducing waste. Transformative approaches have been identified to provide pathways towards global climate targets and protection of the environment from further degradation. They are a catalyst to achieve SDG 12 on ensuring sustainable consumption and production patterns.

Urban nexus and transformative pathways towards resilient cities: A case of the Gauteng City-Region, South Africa

Challenges emanating from rapid urbanisation require innovative strategies to transform cities into global climate action and adaptation centres. We provide an analysis of the impacts of rapid urbanisation in the Gauteng City-Region, South Africa, highlighting major challenges related to (i) land use management, (ii) service delivery (water, energy, food, and waste and sanitation), and (iii) social cohesion. Geospatial techniques were used to assess spatio-temporal changes in the urban landscapes, including variations in land surface temperatures. Massive impervious surfaces, rising temperatures, flooding and heatwaves are exacerbating the challenges associated with rapid urbanisation. An outline of the response pathways towards sustainable and resilient cities is given as a lens to formulate informed and coherent adaptation urban planning strategies. The assessment facilitated developing a contextualised conceptual framework, focusing on demographic, climatic, and environmental changes, and the risks associated with rapid urbanisation. If not well managed in an integrated manner, rapid urbanisation poses a huge environmental and human health risk and could retard progress towards sustainable cities by 2030. Nexus planning provides the lens and basis to achieve urban resilience, by integrating complex, but interlinked sectors, by considering both ecological and built infrastructures, in a balanced manner, as key to resilience and adaptation strategies.

Environmental Services: A New Approach Toward Addressing Sustainable Development Goals in Sub-Saharan Africa

The physical environment provides resources and specific types of environmental services relevant to the maintenance of human livelihoods globally and with specific reference to sub-Saharan Africa, including soils, food, and water systems. Previous studies on the shared nexus of such resources commonly view these as self-contained systems operating independent of their physical contexts provided by landscape-scale geomorphology and its related processes. This study critically examines the viewpoints adopted by such nexus studies with specific reference to sub-Saharan Africa, arguing that these studies are reductive, considering only the shared disciplinary overlap (nexus) and not their wider contexts, and are based on only a limited understanding of the workings of physical systems. This study argues that considering the attributes of the physical landscape and its provision of environmental services provides a broader and scientifically-informed context for understanding of interlinked issues such as relationships between soil–food–water systems. Framing such “nexus” studies in this wider context can derive a better understanding of the connections between different elements such as soil, food, and water, amongst others, and with respect to the United Nations' Sustainable Development Goals. The concept of environmental services is therefore a more powerful tool to examine both the connections between physical and human environmental processes and properties in sub-Saharan Africa, and to address overarching environmental issues such as land degradation, soil erosion loss, water scarcity, and impacts of climate change.

System dynamics modelling to explore the impacts of policies on the water-energy-food-land-climate nexus in Latvia

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.

Insights on Water and Climate Change in the Greater Horn of Africa: Connecting Virtual Water and Water-Energy-Food-Biodiversity-Health Nexus

Water is the key limiting factor in socioeconomic and ecological development, but it is adversely affected by climate change. The novel virtual water (VW) concept and water, energy, food, biodiversity, and human health (WEFBH) nexus approach are powerful tools to assess the sustainability of a region through the lens of climate change. Climate change-related challenges and water are complex and intertwined. This paper analyzed the significant WEFBH sectors using the multicriteria decision-making (MCDM) and analytic hierarchy process (AHP) model. The AHP model demonstrated quantitative relationships among WEFBH nexus sustainability indicators in the Greater Horn of Africa countries. Besides, the net VW imports and water footprints of major staple crops were assessed. The composite WEFBH nexus indices varied from 0.10 to 0.14. The water footprint of crops is increasing period by period. The results also revealed that most countries in the study area are facing WEFBH domains unsustainability due to weak planning or improper management strategies. The strong policy constancy among the WEFBH sector is vital for dissociating the high-water consumption from crop production, energy, environmental, and human health system. Thus, this study enhances insights into the interdependencies, interconnectedness, and interactions of sectors thereby strengthening the coordination, complementarities, and synergies among them. To attain sustainable development, we urgently call all public and private entities to value the amount of VW used in their daily activities and design better policies on the complex WEFBH nexus and future climate change.

Assessing Progress towards Sustainable Development Goals through Nexus Planning

Sustainable Development Goals (SDGs) acknowledge the inter-linkages between human wellbeing, economic prosperity, and a healthy environment and, hence, are associated with a wide range of topical issues that include the securities of water, energy and food resources, poverty eradication, economic development, climate change, health, among others. As SDGs are assessed through targets to be achieved by 2030 and monitored through measurable indicators, this study applied the nexus planning model to monitor and evaluate progress towards SDGs using South Africa as a case study. The study highlighted pathways to ensure socio-ecological sustainability and environmental health by establishing the connectivity between SDGs and nexus approaches. The linkages between SDGs and nexus planning facilitated the sustainable management of resources in an integrated manner. They addressed the cross-sectoral synergies, value-addition, and trade-offs within interlinked sectors. The connectedness of current challenges facing humankind (climate change, rapid urbanisation, migration, and the emergence of novel infectious diseases) require transformative approaches that address these cross-cutting challenges holistically. Managing the intricate relationships between distinct but interconnected sectors through nexus planning has provided decision support tools to formulate coherent strategies that drive resilience and sustainability. The established linkages between nexus planning and SDGs have strengthened cross-sectoral collaboration and unpacked measures for cooperative governance and management through evidence-based interventions. As food production, water provision, and energy accessibility are the major socio-economic and environmental issues currently attracting global attention; the methodology promotes attaining sustainability by 2030.

The Water–Energy–Food Nexus Discovery Map: Linking Geographic Information Systems, Academic Collaboration, and Large-Scale Data Visualization

The Water–Energy–Food (WEF) Nexus framework for holistic sustainable development has spawned independent and academic communities around the globe that utilize the framework in research, implementation, policy development, and technological advancement. These communities, however, are geographically and topically segmented and lack large-scale databasing that clearly catalogs and classifies their work. Recognizing this need, the WEF Nexus Strategic Initiative program at The Pennsylvania State University has developed the WEF Nexus Discovery Map utilizing the Arc Geographic Information Systems’ (GIS) Online Dashboard creation toolkit. In real time, users are able to select from 5040 different combinations of filters with the ease of a few button pushes and see projects pop up or disappear from the map located on the dashboard. Projects can then be clicked on to view their specific information, such as the institution that produced the work, local collaborators, relevant web page, and point of contact. The WEF Nexus Discovery Map demonstrates the early new-age of data resource management with the intersection of visuals, advanced search with built-in filters, and community-driven data collection to provide users with exact needs and connections to better facilitate and deploy the holistic sustainability framework of the WEF Nexus.

Application of the Random Forest Classifier to Map Irrigated Areas Using Google Earth Engine

Improvements in irrigated areas' classification accuracy are critical to enhance agricultural water management and inform policy and decision-making on irrigation expansion and land use planning. This is particularly relevant in water-scarce regions where there are plans to increase the land under irrigation to enhance food security, yet the actual spatial extent of current irrigation areas is unknown. This study applied a non-parametric machine learning algorithm, the random forest, to process and classify irrigated areas using images acquired by the Landsat and Sentinel satellites, for Mpumalanga Province in Africa. The classification process was automated on a big-data management platform, the Google Earth Engine (GEE), and the R-programming was used for post-processing. The normalised difference vegetation index (NDVI) was subsequently used to distinguish between irrigated and rainfed areas during 2018/19 and 2019/20 winter growing seasons. High NDVI values on cultivated land during the dry season are an indication of irrigation. The classification of cultivated areas was for 2020, but 2019 irrigated areas were also classified to assess the impact of the Covid-19 pandemic on agriculture. The comparison in irrigated areas between 2019 and 2020 facilitated an assessment of changes in irrigated areas in smallholder farming areas. The approach enhanced the classification accuracy of irrigated areas using ground-based training samples and very high-resolution images (VHRI) and fusion with existing datasets and the use of expert and local knowledge of the study area. The overall classification accuracy was 88%.

Improving Policy Coordination Across the Water, Energy, and Food, Sectors in South Asia: A Framework

Land, water, and energy resources are coming under unprecedented pressure owing to growing populations, urbanization, industrialization, and changing lifestyles, food habits, and climate. Generally, sectoral approaches are taken to address these challenges that overlook the close linkages between the water, energy and food sectors and resultant cross-sectoral implications. The result is an uncoordinated and unsustainable use of resources that increasingly threatens water, energy, and food securities in many parts of the world. To enhance sustainability in resource use, the use of water-energy-food nexus (WEF) approach has been advocated in recent years. Despite its conceptual appeals, the practical application of this approach in government planning and decision making has remained limited in part due to lack of an appropriate framework to operationalize the concept as a planning and decision-making tool. This paper suggests a framework for operationalizing the nexus concept in planning and decision-making, using South Asia as an example. The framework outlines four steps to evaluate and prioritize nexus issues to improve cross-sectoral planning and coordination using three broad criteria to assess the impact of actions in one sector on another: synergies (co-benefits), trade-offs (externalities), and neutrality. A cross-sectoral coordination body provides the institutional mechanism for ensuring coordination of policy and action. The four steps are: (a) harmonizing policy goals, (b) identifying interactions and critical connections between these sectors in an integrated manner, (c) assessing compatibility of nexus objectives and policy instruments, and (d) screening programs, projects, and investments against nexus goals. The framework is expected to help governments in coordinating the actions of diverse actors across the water, energy and food sectors and designing policies and programs that address trade-offs, while increasing production sustainably, conserving natural resources, and enhancing -water-energy-food nexus outcomes.

Water-Energy-Food Nexus: Critical Review, Practical Applications, and Prospects for Future Research

This paper presents knowledge gaps and critiques on the water–energy–food (WEF) nexus that have emerged since the concept of the WEF nexus was proposed by the World Economic Forum and the Bonn 2011 Conference. Furthermore, this study analyses current innovations on the WEF nexus concept, applications, and impacts during the period of 2012–2020. This begins by reviewing ten WEF nexus frameworks developed by international organizations and researchers. On this basis, several gaps and omissions in nexus frameworks are obvious in almost all developed frameworks. Studies that start to address some of these gaps are analysed, but they are relatively few and do not address all gaps. Several proposed improvements to nexus frameworks are identified to narrow the gaps and put the concept into practical implementation in WEF resources management and governance. Four principles and the perspective of “from local to global” for future WEF nexus framework development and analysis are suggested to ensure that the security of water, energy, and food resources can be achieved sustainably in local communities. This will improve the impact of national and global ambitions on WEF security.

A Review of the Water–Energy–Food Nexus Research in Africa

Notwithstanding the dispersed nature of the water, energy and food (WEF) nexus scholarship in the African continent, its strategic importance to the African agenda has gained widespread attention in research and planning circles. In this regard, the bibliometric science mapping and content analysis of the WEF nexus scientific publication trends, the conceptual, intellectual and social structures, as well as the inherent paradigmatic shifts in the WEF nexus body of knowledge in the African continent have been undertaken, using the nexus body of literature accessed from the Web of Science and Scopus core collection databases. The review results confirmed that, whilst the WEF nexus scholarship has expanded since 2013, there is also evidence of growth in the conceptual, intellectual and social structures of the WEF nexus in the African continent. These shifts have resulted in the emergence of hot topics (subfields) including modelling and optimization, climate variability and change, environmental ecosystem services sustainability, and sustainable development and livelihoods. The review further determined that these structures have evolved along two main perspectives of WEF nexus research development, i.e., the interdisciplinary and transdisciplinary domains. In support of the interpretation of the visual analytics of the intellectual structure and changing patterns of the WEF nexus research, the shifts in positivist, interpretivist and pragmatic paradigmatic perspectives (these are underpinned by the ontology, epistemology, and methodology and methods) are considered when explaining WEF nexus research shifts: (a) From the unconnected silo paradigms that focus on water, energy and food (security concerns) to interconnected (and sometimes interdependent or nested) linkages or systems incorporating environmental, social-economic and political drivers (also viewed as subfields) in a bid to holistically support the Sustainable Development Goals (SDGs) across the African continent; and (b) in the evaluation of the WEF nexus scholarship based on novel analytical approaches. We contend that whilst the theories of science change underpin this apparent expansion, the macro-economic theory will find use in explaining how the WEF nexus research agenda is negotiated and the Integrative Environmental Governance (IEG) is the duly suited governance theory to bridge the inherent disconnect between WEF nexus output and governance processes uncovered in the literature. Overall, operational challenges and opportunities of the WEF nexus abound, transitioning the WEF nexus research to practice in Africa, motivating the need to take advantage of the scholar–practitioner research underpinnings, as contemplated in the transdisciplinary research approach, which is characterised by the dual quest for new knowledge and considerations of use. Yet, there is need for more coordinated and collaborative research to achieve impact and transition from WEF nexus thinking to WEF nexus practice.

The Relationship between Coordination Degree of the Water–Energy–Food System and Regional Economic Development

The sustainable development of the water–energy–food (WEF) system has gained global attention as a result of limited land resources, inadequate energy supply and growing water stress. Coordination degree is an important indicator to measure the sustainable development of the WEF system. Improving the coordination degree contributes to the sustainable development of the WEF system and affects regional economic development. The extended Cobb–Douglas function is applied to examine the relationship between coordination degree of the WEF system and regional economic development in 31 provinces of China during the period of 2007–2018. By using the system generalized method of moments (GMM) estimation, empirical results indicate that in the regions with low coordination degree, improved coordination degree of the WEF system will hinder regional economic growth. In the regions with high coordination degree, it will promote regional economic growth. The results indicate that there is a lag period for the influence of improved coordination degree on regional economic growth. When making resources management policies, shortening the lag period is conducive to achieving sustainable development and promoting regional economic development. Governments of various regions should formulate different resource management policies based on the conditions of each region and the different relationships between coordination degree of the WEF system and regional economic development.

Nexus planning as a pathway towards sustainable environmental and human health post Covid-19

The Covid-19 pandemic has exposed the fragility of linear and monocentric approaches in addressing today's complex, cross-cutting, and interconnected challenges. Experiences from the Covid-19 have shown that focusing on one sector during a crisis only aggravates the stresses in other sectors as decision-makers often view the world from a linear perspective, with the thought that a click of a button would get the economy and society back on track. This study argues that linearity forgets the interconnectedness of systems and how their systemic properties shape their interactions, interdependencies, and interrelationships, whereas nexus planning integrates and simplifies socio-ecological systems, indicates priority areas for intervention, and reduces risk and vulnerability. The lockdowns implemented during the peak of the Covid-19 pandemic resulted in job losses, company closures, and economic recessions, demonstrating that linear approaches often over-emphasise on a limited set of attributes of a system, notably efficiency, at the expense of other aspects. While linear approaches have been beneficial to some extent for long, the Covid-19 pandemic exposed how they transfer stresses to other sectors, and compromise resilience-building initiatives, allowing failure to cascade from one sector to the other. Nexus planning emphasises on cross-sectoral sustainability and enhances socio-economic resilience against future shocks.

The Water-Energy-Food Nexus as an Adaptation Strategy for Achieving Sustainable Livelihoods at a Local Level

The imbalance between resource availability and population increase requires transformative approaches to inform policy, decision-making and practice on coherent adaptation strategies for improved livelihoods and resilient communities. Nexus approaches are built on an understanding that natural processes do not operate in isolation within a system; hence, an emergent challenge in one unit obviously disturbs the whole system. This study applied an integrated water-energy-food (WEF) nexus analytical model to holistically assess resource availability, distribution, use and management at a local level in Sakhisizwe Local Municipality, South Africa. The aim was to inform strategies and guidelines on improving livelihoods of resource-poor rural communities. The calculated municipal composite index of 0.185, coupled with a deformed spider graph, represents a marginally sustainable resource management result. The analysis simplified the relationship between the intricately interlinked socio-ecological components and facilitated the identification of priority areas for intervention. The process provides pathways that steer resource use efficiencies and attainment of Sustainable Development Goals (SDGs). Unlike current linear approaches, integrated and transformative approaches like the WEF nexus provide a multidisciplinary platform for stakeholder engagement to sustainably enhance cross-sectoral coordination of resource management and harmonisation of policies and strategies. The WEF nexus approach is useful for informing decisions on improving livelihoods, enhancing resource securities, identifying priority areas for intervention and providing transformative pathways towards sustainable development.

Migration under Climate Change in Southern Africa: A Nexus Planning Perspective

Population increase is exacerbating resource insecurities due to increased demand for already depleted resources. Coupled with climate change, they are the main drivers of both intra-(rural-urban and urban-urban) and inter-migration (from one country to the other). We carried out a systematic review of literature, focusing on available options to ensure water and food security, as well as improve the socio-economic environment, highlighting the drivers of migration in southern Africa. The aim was to develop informed adaptation strategies and build resilience in the advent of accelerated migration. We developed a migration conceptual framework based on the nexus between water, food and socio-economic interlinkages. Urban areas in southern Africa are under immense pressure to accommodate climate refugees from resource stressed rural areas, a situation that is impacting on agricultural production. Most urban areas are exceeding their ecological thresholds to support the built environment, causing some socio-ecological challenges. Nexus planning can inform adaptation planning on permissible migration that are aligned with regional goals such as regional integration, poverty reduction and improved livelihoods. This would also contribute to the region's achievements of the Sustainable Development Goals. Furthermore, through the identification of synergies and trade-offs, nexus planning can inform regional adaptation strategies for positively managing migration leading to sustainable outcomes.