The Yangtze River Basin is a resource axis represented by hydropower resources, bulk agricultural products, and mining resources. However, with rapid socio-economy development, the balance between water, energy, and food elements in the region has become more fragile. As the core element of the water-energy-food nexus, it is necessary to study water resources security and give effective pre-warning of possible water safety problems from the perspective of water-energy-food symbiosis. In this paper, we introduce the “symbiosis theory” to build a regional water-energy-food nexus symbiosis framework. Then, we establish a Lotka–Volterra symbiotic evolution model to calculate the symbiotic security index. Finally, we judge the water security state and pre-warning level and analyze the causes of water security problems by the inverse decoupling of the indicator-index. The results show that the spatial differentiation of water security in the Yangtze River Basin is obvious from the perspective of water-energy-food symbiosis. The state of water security in the middle and upper reaches of the Yangtze River Basin is better than that in the lower reaches. Specifically, the water resources security levels in the upstream hydropower energy enrichment regions are generally low. By contrast, the water systems of some downstream socio-economically developed provinces have certain risks. Therefore, each province needs to find out the key factors that hinder the healthy development of the water resources system based on combining the evolution mechanism and symbiotic state of water-energy-food so that water security can be managed in a targeted manner.

The Yangtze River Basin is a resource axis represented by hydropower resources, bulk agricultural products, and mining resources. However, with rapid socio-economy development, the balance between water, energy, and food elements in the region has become more fragile. As the core element of the water-energy-food nexus, it is necessary to study water resources security and give effective pre-warning of possible water safety problems from the perspective of water-energy-food symbiosis. In this paper, we introduce the “symbiosis theory” to build a regional water-energy-food nexus symbiosis framework. Then, we establish a Lotka–Volterra symbiotic evolution model to calculate the symbiotic security index. Finally, we judge the water security state and pre-warning level and analyze the causes of water security problems by the inverse decoupling of the indicator-index. The results show that the spatial differentiation of water security in the Yangtze River Basin is obvious from the perspective of water-energy-food symbiosis. The state of water security in the middle and upper reaches of the Yangtze River Basin is better than that in the lower reaches. Specifically, the water resources security levels in the upstream hydropower energy enrichment regions are generally low. By contrast, the water systems of some downstream socio-economically developed provinces have certain risks. Therefore, each province needs to find out the key factors that hinder the healthy development of the water resources system based on combining the evolution mechanism and symbiotic state of water-energy-food so that water security can be managed in a targeted manner.

The Yangtze River Basin is a resource axis represented by hydropower resources, bulk agricultural products, and mining resources. However, with rapid socio-economy development, the balance between water, energy, and food elements in the region has become more fragile. As the core element of the water-energy-food nexus, it is necessary to study water resources security and give effective pre-warning of possible water safety problems from the perspective of water-energy-food symbiosis. In this paper, we introduce the “symbiosis theory” to build a regional water-energy-food nexus symbiosis framework. Then, we establish a Lotka–Volterra symbiotic evolution model to calculate the symbiotic security index. Finally, we judge the water security state and pre-warning level and analyze the causes of water security problems by the inverse decoupling of the indicator-index. The results show that the spatial differentiation of water security in the Yangtze River Basin is obvious from the perspective of water-energy-food symbiosis. The state of water security in the middle and upper reaches of the Yangtze River Basin is better than that in the lower reaches. Specifically, the water resources security levels in the upstream hydropower energy enrichment regions are generally low. By contrast, the water systems of some downstream socio-economically developed provinces have certain risks. Therefore, each province needs to find out the key factors that hinder the healthy development of the water resources system based on combining the evolution mechanism and symbiotic state of water-energy-food so that water security can be managed in a targeted manner.

This study presents an evaluation of the food-energy-water nexus (FEWn), complemented by a thorough life cycle assessment (LCA), of four young cacao production systems: two full-sun monocultures and two agroforestry systems under conventional and organic management. Land footprint (LF) for food production, non-renewable cumulative energy demand (NR CED) for energy, total water footprint (TWF) for water, and three efficiency indicators for the FEWn were all analysed. In addition, ten LCA impact categories were evaluated in relation to two functional units (kilograms of cacao output and kilograms of total crop output, i.e., cacao + other crops). The integrated analysis of the FEWn and the LCA framework reveals how agroforestry systems and organic management report better environmental performances for almost all indicators and impact categories considered, except for the TWF. However, given that the systems analysed have no irrigation, between 96.3% and 99.8% of the TWF corresponds to green water, i.e., soil moisture from precipitation. Green water has lower environmental impacts and opportunity costs than the water used to manufacture inputs (WFᵢₙₚᵤₜ). Accordingly, when the efficiency of the nexus is measured in relation to the WFᵢₙₚᵤₜ, organically managed systems produce more food/energy per unit of water used. Our results show how production diversification and organic and cultural management practices can improve energy efficiency and reduce the use of water associated with the inputs and, consequently, improve the nexus, as well as the rest of the environmental impacts analysed. The design of agricultural policies focused on sustainability should strongly favour the establishment of agroforestry systems, particularly those that are organically managed.

This study presents an evaluation of the food-energy-water nexus (FEWn), complemented by a thorough life cycle assessment (LCA), of four young cacao production systems: two full-sun monocultures and two agroforestry systems under conventional and organic management. Land footprint (LF) for food production, non-renewable cumulative energy demand (NR CED) for energy, total water footprint (TWF) for water, and three efficiency indicators for the FEWn were all analysed. In addition, ten LCA impact categories were evaluated in relation to two functional units (kilograms of cacao output and kilograms of total crop output, i.e., cacao þ other crops). The integrated analysis of the FEWn and the LCA framework reveals how agroforestry systems and organic management report better environmental performances for almost all indicators and impact categories considered, except for the TWF. However, given that the systems analysed have no irrigation, between 96.3% and 99.8% of the TWF corresponds to green water, i.e., soil moisture from precipitation. Green water has lower environmental impacts and opportunity costs than the water used to manufacture inputs (WFinput). Accordingly, when the efficiency of the nexus is measured in relation to the WFinput, organically managed systems produce more food/energy per unit of water used. Our results show how production diversification and organic and cultural management practices can improve energy efficiency and reduce the use of water associated with the inputs and, consequently, improve the nexus, as well as the rest of the environmental impacts analysed. The design of agricultural policies focused on sustainability should strongly favour the establishment of agroforestry systems, particularly those that are organically managed.

International audience | The implementation of sustainable water management practices, through the recycling and reuse of water, is essential in terms of minimizing production costs and the environmental impact of the food industry. This problem goes beyond the classical audit and housekeeping practices through developing a systemic water-using reduction strategy. The implementation of such an approach needs R&D development, especially for the food industry, where there is a lack of knowledge on: (a) process integration and (b) data on the pollutant indicators or (c) volumes of water used and discharged at specific steps of the food processing line. Since energy pinch analysis emerged, different variations of pinch methods have been developed. As a variation of pinch, Water pinch analysis is a global and systematic approach to minimize water consumption and discharges, especially for the most energy-intensive and water-consuming factories. Based on the nature of the food industry, the real systems are complex, multi-source multi-contaminant systems, the problem should be well formulated, including mathematical constraints (inequalities thresholds). Current work has reviewed comprehensive literature about different variations of pinch analysis. In continue, water pinch method deeply discussed and some relevant data concerning the water using process and pollutant indicators have been reviewed with emphasis on the food industry sector.

International audience | The implementation of sustainable water management practices, through the recycling and reuse of water, is essential in terms of minimizing production costs and the environmental impact of the food industry. This problem goes beyond the classical audit and housekeeping practices through developing a systemic water-using reduction strategy. The implementation of such an approach needs R&D development, especially for the food industry, where there is a lack of knowledge on: (a) process integration and (b) data on the pollutant indicators or (c) volumes of water used and discharged at specific steps of the food processing line. Since energy pinch analysis emerged, different variations of pinch methods have been developed. As a variation of pinch, Water pinch analysis is a global and systematic approach to minimize water consumption and discharges, especially for the most energy-intensive and water-consuming factories. Based on the nature of the food industry, the real systems are complex, multi-source multi-contaminant systems, the problem should be well formulated, including mathematical constraints (inequalities thresholds). Current work has reviewed comprehensive literature about different variations of pinch analysis. In continue, water pinch method deeply discussed and some relevant data concerning the water using process and pollutant indicators have been reviewed with emphasis on the food industry sector.