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.

The water-energy-food (WEF) Nexus encompasses complex and interdependent relations and its examination requires content-specific concepts and approaches. Managing, conserving and maximizing the potential of each component is a major global concern considering the many challenges to be faced in the 21st century. The aim of this study was to identify, in the literature, recommendations for public policy, research and development, and practices for the WEF Nexus, aimed at promoting sustainable development considering stochastic and risk elements. In this regard, this paper presents a literature review of the contribution scientific studies have made toward better understanding the importance of the WEF Nexus in the context of sustainable development. Research indicates that the WEF Nexus cannot be discussed as independent sectors, highlighting the need for integrated policies and inter-sectoral and international cooperation to promote sustainable development. Therefore, the effective management of the WEF Nexus requires science-based data using risk and stochastic elements to assist policy and decision-making. Thus, in a situation of rapid global changes, decision-making processes for this Nexus must be assisted by multidisciplinary, multi-stakeholder and cross-sectoral approaches, aimed at avoiding the unintended effects of a single sector approach (e.g., energy policies stimulating hydroelectricity production need to consider factors affecting conservation and food production). With regard to the effects of climate change on the WEF Nexus, risk and stochastic elements must be considered when developing a science-based model for the sustainable management of WEF resources.

As the basis for virtually any form of nitrogen fertilizers, ammonia plays a vital role in agriculture; in addition, there has been an increased interest in its use as a carbon-free energy carrier. However, ammonia is also associated with two major environmental concerns: CO₂ emissions from the conventional production process and nitrogen pollution from the excessive use of ammonia-based fertilizers. To mitigate these environmental impacts, we develop an optimization framework for the design of a sustainable ammonia-based agricultural system that synergistically integrates the production of ammonia from renewable resources and effective measures for nitrogen management. The proposed model captures the effect of intermittency by incorporating both design and detailed operational decisions. By applying a multiscale time representation that reduces the problem size and a tailored surrogate model that accurately approximates model nonlinearity, we are able to achieve optimal solutions within reasonable computation times. A computational case study is conducted using real-world data from a local farm in Morris, Minnesota, and the results indicate the trade-off between cost and nitrogen loss. Importantly, we show that practicing effective nitrogen management can significantly reduce the nitrogen loss with only a small increase in net present cost.

Society's increasing demand for resources creates an urgent need of resource allocation strategies. This research analyzed how alternative renewable-based energy plans affect a sustainability index related to the Water-Energy-Food nexus in a region highly dependent on desalted water. 50 water bodies of the island of Gran Canaria were analyzed for evaluating a pumping hydro energy storage strategy to support a renewable energy plan. The storage uses water from desalination plants which allowed to increase water and energy in the system. With the restrictions imposed, the Spanish island of Gran Canaria could store from 11.44 GWh/mcm to 30.76 GWh/mcm. Results showed that, depending on the specific renewable energy plan and on the factor of operation in the desalination plant, the stress in the water subsystem would be reduced from 8 mcm to 20 mcm. A system analysis strategy to control the water index was proposed to support the decision-making strategies.

With the economic and social development and population growth, as three basic interconnected resources, water, energy and food are gradually deficient and inharmonious. This research selected 31 provinces of China as the study area and collected data of 16 years’ time series. The temporal and spatial synergetic change of water, energy and food was quantitatively described by wavelet analysis and MK test methods. The results show that water consumption for energy in 2001–2016 has the first main period of 12 years and the temporal synergetic change of water and energy would not be obvious in the future. According to the results, the resources consumption of water energy and food can be optimized to implement the sustainable utilization. Also, this paper proposed the adjustment strategy for the country.

The integrative approach of water, energy, and food nexus (WEF nexus) is now widely accepted to offer better planning, development, and operation of these resources. This study presents a first attempt towards understanding the WEF nexus of urban environments in the Nile River Basin under conditions of hydrological droughts and fluvial floods. A case study was conducted for the capital of Sudan, Khartoum, at the confluence of the White Nile and the Blue Nile for illustration. The results were based on analyses of river flow and water turbidity data, field observations, a printed questionnaire and an interview of farmers practicing irrigated agriculture, and hydropower modeling. The study analyzes indicators for the association of the river water resources environment (intra-annual regime, quantity, and quality), the status of urban irrigated agriculture, water treatment for domestic use, and hydropower generation under hydrological extremes, i.e. droughts and fluvial floods. It additionally examines the consequent interactions between the impacts on three sectors. The present study shows how floods and droughts impose impacts on seasonal river water quality and quantity, water treatment for domestic use, irrigated agriculture, and hydro-energy supply in an urban environment. The results demonstrate how the two hydrological phenomena determine the state of hydropower generation from dams, i.e. high energy production during floods and vice versa during droughts. Hydropower dams, in turn, could induce cons in the form of low fertile soils in the downstream due to sediment retention by the reservoir. Finally, present and potential options to minimize the above risks are discussed. This study is hoped to offer good support for integrated decision making to increase the resource use efficiency over the urban environment within the Nile Basin.

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.

Background: With millions of people experiencing malnutrition and inadequate water access, FI and WI remain topics of vital importance to global health. Existing unidimensional FI and WI metrics do not all capture similar multidimensional aspects, thus restricting our ability to assess and address food- and water-related issues. Methods: Using the Sanitation, Hygiene and Infant Nutrition Efficacy (SHINE) trial data, our study conceptualizes household FI (N = 3551) and WI (N = 3311) separately in a way that captures their key dimensions. We developed measures of FI and WI for rural Zimbabwean households based on multiple correspondence analysis (MCA) for categorical data. Results: Three FI dimensions were retained: ‘poor food access’, ‘household shocks’ and ‘low food quality and availability’, as were three WI dimensions: ‘poor water access’, ‘poor water quality’, and ‘low water reliability’. Internal validity of the multidimensional models was assessed using confirmatory factor analysis (CFA) with test samples at baseline and 18 months. The dimension scores were associated with a group of exogenous variables (SES, HIV-status, season, depression, perceived health, food aid, water collection), additionally indicating predictive, convergent and discriminant validities. Conclusions: FI and WI dimensions are sufficiently distinct to be characterized via separate indicators. These indicators are critical for identifying specific problematic insecurity aspects and for finding new targets to improve health and nutrition interventions.

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.