This article examines the dynamics of the Water-Energy-Food nexus in two transboundary basins between Ecuador and Colombia, from a political ecology perspective that prioritizes experiences and perspectives of local communities. Through in-depth interviews, emerging categories are identified: territory, community, extractivism and conflict. Communities experience extractive activities as a threat to their territory, culture and ways of life. Water pollution, decreased availability and climate changes negatively impact agriculture and food security. The proposed approach reveals the struggles for environmental justice and power inequalities in the region. The most affected communities are indigenous, Afro-descendant and peasant communities. The recovery of traditional culture and food sovereignty are presented as key strategies to resist and adapt to the negative effects of extractivism and the climate crisis. | El presente artículo examina las dinámicas del nexo agua-energía-alimentos en dos cuencas transfronterizas entre Ecuador y Colombia, desde una perspectiva de ecología política, la cual prioriza las experiencias y perspectivas de las comunidades locales. A través de entrevistas a profundidad, se identifican las categorías emergentes de análisis: territorio, comunidad, extractivismo y conflicto. Los resultados muestran que las comunidades experimentan las actividades extractivas como una amenaza a su territorio, cultura y formas de vida. La contaminación del agua, la disminución de su disponibilidad y los cambios climáticos impactan negativamente en la agricultura y la seguridad alimentaria. El enfoque propuesto revela las luchas por la justicia ambiental y las desigualdades de poder en la región. Las comunidades más afectadas son las indígenas, afrodescendientes y campesinas. La recuperación de la cultura tradicional y la soberanía alimentaria se presentan como estrategias clave para resistir y adaptarse a los efectos negativos del extractivismo y la crisis climática.

Reliable food production relies on consistent water availability. The last two decades have provided a deeper understanding of the role of trees and forests in ensuring this water supply. In this chapter, I highlight the links between trees and water security, an indispensable element of food security. We now know that, in many contexts, trees can improve water access and reliability. Achieving the right densities of the right trees in the right places can increase soil water recharge and maintain dependable baseflow. On a larger scale, atmospheric processes are key, and expanding tree cover can render regions wetter and more productive, yielding more predictable rainfall through enhanced atmospheric moisture import and recycling. Opportunities and implications vary with local circumstances. While new insights raise new questions and research remains essential, existing knowledge can guide land-use policy, planning and practices. The large-scale relationships between tree cover and water cause significant threats if tree cover declines but offer substantial opportunities when forests are preserved and extended. Although forests and trees provide many valuable goods and services to local communities, economies and the planet, any alterations in tree cover can effect water availability, directly impacting food production. Can we boost water security and maximise the wider benefits of tree cover while increasing food production? This chapter emphasises that trees are neither a luxury consideration nor a minor footnote when we consider food security but rather a foundation for achieving it.

Motivation: Breaking through the constraints of water scarcity is a crucial factor for the efficient and sustainable production of food in China. Objective: To explore a new strategy to alleviate the water resource pressure in food production in China, based on the theory of resource flow, this study empirically explores the relationship between food imports and the water pressure in food production in China from the perspective of virtual water trade. Data and Method: This study collects panel data from 30 provincial-level administrative regions in China from 2003 to 2020 and employs methods such as the two-way fixed effects model, instrumental variable approach, and spatial Durbin model for empirical analysis. Results: (1) China’s net food imports surged from −0.000397 billion tons (Bt) in 2003 to 0.118325 Bt in 2020, with a rapid annual growth rate of about 9.37%. Changes in net imports are accompanied by virtual water flows. Between 2003 and 2020, the virtual water content of China’s net food imports increased from 31.7086 Bt to 187.7511 Bt, a yearly increase of 10.39%. (2) Virtual water for food imports has a mitigating effect on the water pressure in food production. Every 0.100 Bt of virtual water imported will reduce the water pressure in food production index by 0.026. The impact has a spatial spillover effect. Moreover, as there is high pressure on water resources in food production in northern regions and major grain-producing areas, the mitigating effect of food imports on the pressure of water resources in food production is also enhanced. The quantile regression found that as the water pressure in food production increases, the mitigating effect of virtual water for food imports on the water pressure in food production gradually increases. Implications: This study examines the relevance of resource flow theory within the context of food trade, thereby broadening the scope of research on virtual water trade in food. Additionally, this study offers valuable insights for the development of strategies aimed at mitigating the pressure on water resources associated with food production in China.

Motivation: Breaking through the constraints of water scarcity is a crucial factor for the efficient and sustainable production of food in China. Objective: To explore a new strategy to alleviate the water resource pressure in food production in China, based on the theory of resource flow, this study empirically explores the relationship between food imports and the water pressure in food production in China from the perspective of virtual water trade. Data and Method: This study collects panel data from 30 provincial-level administrative regions in China from 2003 to 2020 and employs methods such as the two-way fixed effects model, instrumental variable approach, and spatial Durbin model for empirical analysis. Results: (1) China&rsquo:s net food imports surged from &minus:0.000397 billion tons (Bt) in 2003 to 0.118325 Bt in 2020, with a rapid annual growth rate of about 9.37%. Changes in net imports are accompanied by virtual water flows. Between 2003 and 2020, the virtual water content of China&rsquo:s net food imports increased from 31.7086 Bt to 187.7511 Bt, a yearly increase of 10.39%. (2) Virtual water for food imports has a mitigating effect on the water pressure in food production. Every 0.100 Bt of virtual water imported will reduce the water pressure in food production index by 0.026. The impact has a spatial spillover effect. Moreover, as there is high pressure on water resources in food production in northern regions and major grain-producing areas, the mitigating effect of food imports on the pressure of water resources in food production is also enhanced. The quantile regression found that as the water pressure in food production increases, the mitigating effect of virtual water for food imports on the water pressure in food production gradually increases. Implications: This study examines the relevance of resource flow theory within the context of food trade, thereby broadening the scope of research on virtual water trade in food. Additionally, this study offers valuable insights for the development of strategies aimed at mitigating the pressure on water resources associated with food production in China.

The interrelationship among water, energy, food, and carbon emissions has emerged as a critical factor influencing agricultural sustainability. However, existing studies on food crop planting structure (FCPS) optimization primarily focus on the water–food relationship, overlooking the complex and dynamic interactions within the water–energy–food–carbon emissions nexus (WEFCN). Additionally, the concept of harmony provides a quantitative framework for assessing system stability and coordination. Previous research has largely overlooked the influence of the WEFCN harmony degree on optimizing food crop planting structure. In response, this study proposes a novel FCPS optimization method that integrates the WEFCN and incorporates harmony degree constraints, aiming to address two key scientific challenges: (1) integrating the WEFCN into FCPS optimization research, and (2) quantitatively evaluating and constraining system harmony degree to enhance overall system stability and coordination. The results indicate that, compared to approaches focusing solely on single or localized relationships, the proposed method effectively reduces water and energy consumption, mitigates water pollution, and significantly decreases agricultural carbon emissions. Relative to methods without harmony degree constraints, it achieves reductions of 4.591 × 10⁸ m³ in blue water, 3.325 × 10⁸ m³ in grey water, 8.527 × 10⁸ m³ in total water footprint, 6.04 × 107 kgce in energy consumption, and 1.09 × 106 tCO₂eq in carbon emissions, while improving the system harmony degree from 3.411 to 3.434. This study addresses the limitations of conventional research that focuses primarily on the water–food relationship, which often results in suboptimal outcomes insufficient for advancing green agricultural development. It enhances the stability, balance, and coordination of the WEFCN, offers a reference for addressing its internal imbalances, and contributes to the promotion of sustainable agricultural development.

Studying the water-emissions-food nexus (WEF Nexus) is crucial for the sustainability of agricultural economic systems. The multi-regional input–output (MRIO) model provides insights for water-emissions-food integrated collaborative management. This study develops a detailed agriculture-oriented MRIO model based on the RAS method, which disaggregates the agricultural sector into 12 sub-sectors. The water consumption and greenhouse gas (GHG) emissions are allocated to the entire supply chain to identify the key regions and routes of the WEF Nexus in China for 2017. Then the environmental output level of the agricultural sector and its sub-sectors is analyzed using productivity indicators. Results demonstrate that the agricultural sector exhibits a strongly connected WEF Nexus (coefficient of 0.87), particularly in Coastal and Southwest regions. The synergistic relationship between water and emissions suggests significant opportunities for implementing integrated management strategies. 73.3% of virtual water and 71.7% of embodied emissions are concentrated in downstream non-agricultural sectors of supply chains, highlighting the substantial impact of trade transmission on the environment. The water and emissions productivity in the agricultural sector are spatially aligned except in the Central and Southwest regions. As significant agricultural output regions, Northeast and Central regions have lower water or emissions productivity, making sustainable agricultural development more challenging. Therefore, practical measures should focus on promoting technological innovation and its adoption to enhance water use efficiency and reduce GHG emissions in agricultural production.

Irrigated agriculture is an important contributor to African food security, both for farmers directly and for the urban population and wider economy. This chapter argues that the irrigated area in Africa is much larger than generally thought, but still much smaller than it could be. We also explore the concept of irrigation potential and show that it is not a static number, but depends on economic context and people’s abilities to develop irrigation. It is important to also consider that irrigation can be partial or for protection against droughts. The potential of irrigation to contribute to Africa’s food security depends not only on developing water resources, but even more so on an approach that focuses on inclusion and optimization to get the most benefits for most people. The concluding section presents five areas where work can be done radically differently to support a much faster development of water-based agricultural intensification.

Abstract Water scarcity is one of the most urgent food security issues facing countries of arid and semiarid climate like Iran. This study examines the impact of water scarcity on food security in an era of climate change. Using the Iranian Statistics Center (ISC) data on food production, climate change variables, energy consumption, population growth and water use coupled with a simultaneous equations (3SLS) modelling approach, the impacts of water scarcity, are analyzed. The results show that water scarcity in Iran is a regional issue, mainly in eastern and central areas. This is reflected in the limited and uneven distribution of water resources, decline of surface water resources, depletion of groundwater resources, degradation of water quality and increasing water demand. Climate change has further aggravated water scarcity in several river basins in central Iran, resulting in the food security shortage due to fall in food production. The need for more research on improving water-limited crop production is highlighted, and emphasis is placed on interdisciplinary approaches to gain the insight needed to achieve new breakthroughs that would help in tackling this complex problem.