How does the water-energy-food nexus work in developing countries? An empirical study of China

Minimizing energy footprint of seawater desalination system via wind power generation in coastal areas

Wind power has become an essential direction for transforming energy structures in energy-intensive seawater desalination under the dual goals of carbon peaking and carbon neutrality. In this study, the energy footprint of the case project is analyzed by combining the hybrid life cycle analysis and environmentally extended input-output modeling, which is compared with the traditional thermal desalination processes from the whole life cycle perspective. The analysis revealed that the total energy consumption of the seawater desalination driven by wind power generation can be reduced by 79.77% compared with the traditional thermal drive mode under the same water production scale. Although the energy consumption in the construction phase accounts for 24.97% of the total, the energy consumption per unit of water production can be reduced by about 80% after adopting wind power technologies. The payback period is 7.2 years, that is, the energy consumption can be balanced after around 7 years during the operation phase. The results showed that the wind-driven seawater desalination system can significantly decrease the energy consumption of the project, which attempts to provide implications for the upgrading of energy-intensive seawater desalination in coastal areas towards low-carbon transition.

Analysis of the factors influencing the water-energy-food system stress in China

Water, energy and food security are at the heart of the UN 2030 Agenda for Sustainable Development. Maintaining water-energy-food (WEF) system security is critical to sustainable socio-economic development. To clarify the trends in China's WEF system stress, this paper analyses the spatial and temporal heterogeneity of WEF system stress using panel data for 30 Chinese provinces from 2002 to 2020. Using an extended STIRPAT model, we discuss the influencing factors of WEF system stress and forecast the WEF system stress index (WEF_SI) for 2021-2030. We find that China's WEF_SI has a significant positive spatial autocorrelation, with energy stress being the dominant stress in China's WEF system. Second, GDP per capita, urban population density, education level per capita, technology level and effective irrigated area have spatial and temporal heterogeneity in their effects on WEF system stress. Third, the prediction results show that China's WEF system stress will decrease in 2021-2030 but to a lesser extent. The government should coordinate the relationship between water, energy and food based on the evolutionary characteristics and projected trends of each element and formulate differentiated policies according to the resource endowment of each region to promote the coordinated development of the WEF system.

Water rights trading planning and its application in water resources management: A water-ecology-food nexus perspective

Nexus approach provides an effective perspective for implementing synergetic management of water resources. In this study, an interval two-stage chance-constrained water rights trading planning model under water-ecology-food nexus perspective (ITCWR-WEF) is proposed to analyze the interaction between water trading and water-ecology-food (WEF) nexus, which fills in the water resources management gaps from a novel nexus perspective. ITCWR-WEF incorporates hydrological simulation with soil and water assessment tool (SWAT), water rights configuration with interval two-stage chance-constrained programming (ITCP), and multi-criterion analysis with Technique for Order Preference by Similarity to an Ideal Solution (TOPSIS). The developed ITCWR-WEF is applied to a real case of Daguhe watershed, which has characteristics of water scarcity, food producing areas and fragile ecosystem. Initial water rights allocation is addressed before the trading. Mechanisms analysis is designed to reveal mutual effect of water rights trading and WEF nexus. Optimal water management scenario is identified through multi-criterion analysis. Results reveal that the mechanism of water rights trading with WEF nexus under low constraint-violation risk level of water availability and environment capacity is recommended to promote the rational water resources allocation to balance the economic goals, water environment and water supply security, as well as ecological and food water demand guarantees.

Synergistic evolution of water-energy-food system resilience and efficiency in urban agglomerations

With increasing internal and external risks to the WEF system, a single emphasis on efficiency or a lopsided pursuit of resilience can lead to difficulties in adapting to complex changes and resource redundancy. Revealing the synergistic evolutionary characteristics between efficiency and resilience of the WEF system is an effective method to deal with systemic internal and external risks. However, the current study of the WEF system lacks a synergistic perspective on resilience and efficiency. Thus, taking Chengdu-Chongqing Economic Circle (CCEC) as the research object and its geospatial boundary as the system boundary, this paper adopted the entropy-topsis model to evaluate the WEF resilience, and applied the super-efficient SBM model to measure the WEF efficiency accurately, which fully considered the non-expected outputs in the process of resource utilization. Then, applying the development coordination degree model, the synergistic relationship between the two was measured. The results indicated that: the average value of WEF resilience in CCEC increased from 0.414 to 0.485 and showed spatial characteristics of west＞east＞central. The WEF efficiency interval was 0.79-0.93, and cities with average WEF efficiency reaching the effective production frontier accounted for only 37.5%. The clustered distribution of the synergy levels intensified. The number of cities with primary, medium, more advanced, and advanced levels was 6, 6, 1, and 3, respectively, with primary and medium synergy levels dominating. The findings suggest that cities should strengthen regional exchanges and formulate targeted measures based on their own situations. In addition, CCEC should possess a comprehensive understanding of the interdependencies and conflicts that arise between resilience and efficiency throughout the decision-making procedure.

The water-energy-food nexus: a systematic bibliometric analysis

Adequate water, electricity, and food are essential for sustainable development. Regional conflicts intensified by global water, energy, and food shortages necessitate a rethinking of the security and interdependence of these resources. However, most earlier scholars concentrated on the subsystems of the water-energy-food nexus (WEF nexus), lacking holistic studies. Therefore, to understand the history and current state of research on the WEF nexus and predict future research directions, this study analyzed 1313 journal articles from the Web of Science database between 2007 and 2022 using the bibliometric analysis and Citespace software. The findings in this study indicate that (1) the progress of the WEF nexus research can be classified into three stages between 2007 and 2022: the early stage (2007-2010), the fast-developing stage (2011-2015), and the steady and in-depth stage (2016-2022). The WEF nexus has become a hot zone for academic research. (2) Map of the network of countries, institutions, and author collaborations implies tight academic collaboration among countries, institutions, and writers. (3) Climate change, integrated WEF nexus, sustainable development, and security are research hotspots in this field. Meanwhile, energy security, circular economy, and resource allocation are advanced subjects in this field. These key findings can provide managers and researchers with valuable information for decision-making.

Optimization of Regional Water-Energy-Food Systems Based on Interval Number Multi-Objective Programming: A Case Study of Ordos, China

Water, energy, and food are the most important basic resources for economic and social development. In the context of global population growth, environmental degradation, and resource shortages, the interrelationship between the water, energy, and food has become increasingly important. In this paper, the city of Ordos in China was selected as a study area. Firstly, this paper sorted out relevant research literature and fully understood the concept of water-energy-food (WEF) nexus. Then, an optimization model of WEF system was constructed based on interval number multi-objective programming, which took the comprehensive coordination deviation degree of the WEF system security and carbon dioxide emission minimization as the target. At the same time, the optimization model was constructed with full consideration of constraints such as economic benefit, water resource consumption, energy production, food production and environmental pollution emission. The results showed that the production of coal, thermal power, hydropower, wind power, and food all show an upward trend. Among them, the production of hydropower has the largest change, and the food production has the smallest change. In terms of water resource utilization, food production has the largest allocation of water resources accounting for nearly 80%, followed by coal production, thermal power generation and hydropower generation. The smallest allocation is natural gas. In particular, the allocation of water for coal production and hydroelectric power generation has increased significantly. Finally, the policy recommendations were put forward to promote the sustainable development of WEF system in Ordos. The optimization research on the WEF system can help to ensure the WEF system security in Ordos and promote the sustainable development of WEF system, which also can provide reference for other regions.