The availability of freshwater is one of the biggest limitations and challenges of food production, as freshwater is an increasingly scarce and overexploited resource in many parts of the world. Therefore, the concept of water footprint (WF) has gained increasing interest, in the same way that the generation of food loss and waste (FLW) in food production and consumption has become a social and political concern. Along this line, the number of studies on the WF of the food production sector is currently increasing all over the world, analyzing water scarcity and water degradation as a single WF indicator or as a so-called WF profile. In Spain, there is no study assessing the influence of FLW generation along the whole food supply chain nor is there a study assessing the different FLW management options regarding the food supply chain’s WF. This study aimed to assess the spatially differentiated WF profile for 17 Spanish regions over time, analyzing the potential linkages of FLW management and water scarcity and water degradation. The assessment considered compliance and non-compliance with the Paris Agreement targets and was based on the life cycle assessment approach. Results are highlighted in a compliance framework; the scenarios found that anaerobic digestion and aerobic composting (to a lesser extent) had the lowest burdens, while scenarios with thermal treatment had the highest impact. Additionally, the regions in the north of Spain and the islands were less influenced by the type of FLW management and by compliance with the Paris Agreement targets. | This study has been conducted thanks to the financial support of the Project Ceres-Procom: Food production and consumption strategies for climate change mitigation (CTM2016-76176-C2-1-R) (AEI/FEDER, UE), financed by the Ministry of Economy and Competitiveness of the Government of Spain. Daniel Hoehn thanks the Ministry of Economy and Competitiveness of the Spanish Government for their financial support via the research fellowship BES-2017-080296. Thanks are also due to the FCT/MCTES for the contracts granted to Paula Quinteiro (CEECIND/00143/2017) and for the financial support to CESAM (UIDB/50017/2020+UIDP/50017/2020) by means of national funds.

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.

This document aims to outline the importance and advantages of the WEFE Nexus as an approach and methodology in EU development cooperation aimed at integrating governance and management across water, energy, and food security while attempting to balance different uses of ecosystem resources and services. The document makes special reference to the EU policy framework for development cooperation, particularly the “New European Consensus on Development”, to the relevant SDGs, as well as to the main conclusions of the WEFE Nexus specific workshop held in Brussels 25-26 January 2018 and jointly organised by JRC and DEVCO. This workshop was oriented towards implementing and operationalising the Nexus approach with the objective of improving the sustainability of the intervention projects and programmes involving water–energy–food security based on the experience of the NEXUS experts who attended the workshop. The reader will be able to see the evaluation of the implementation of NEXUS practices in a variety of projects and regions. | JRC.D.2 - Ocean and Water

A ‘nexus’ approach, comprising interrelated systems components of energy, water, and food, has been suggested to accelerate progress towards achieving sustainable development goals on food waste and related issues, like climate change. The current body of literature usually focuses on food security, especially in relation to production and waste management in the supply chain. The food service sector (FSS), a major consumer-facing component of the food system, has often been overlooked or neglected. There exists, then, an opportunity to better understand the interlinkages between food waste, energy, water, and emissions – the FEWE Nexus – to assist this sector in developing more sustainable operations, such as kitchen equipment management and menu development. To fill this gap, we introduce a novel FEWE Nexus Framework, to understand the flow of nexus components associated with receiving, storing, preparing, cooking, cleaning, and serving menu items. A key aspect of the methodological approach for FEWE evaluation is life cycle assessment (LCA). This is embodied in a comprehensive nexus audit tool comprising several indicators to monitor and quantify energy and water consumption, emissions from cooking, food waste generated, and type and efficiency of equipment used. Further, a stakeholder engagement survey is integrated, allowing for stakeholder feedback on applications of the audit tool, and to assess the impacts and acceptance of potential interventions. Finally, we describe how an iterative nexus approach can enable decision makers in the FSS to robustly estimate nexus components and establish a baseline to track their progress towards minimizing wastages and maximize efficiency.

Understanding the complexity and feedbacks among food, energy, and water (FEW) systems is key to making informed decisions about sustainable development. This paper presents qualitative representation and quantitative system dynamics simulation of the water resources system in the Qazvin Plain, Iran, taking into account the energy intensity of water supply and interconnected water use sectors (e.g., urban, industrial, and agricultural). Qazvin Plain faces water resources challenges that are common to arid/semi-arid areas, including frequent droughts, declining surface water and groundwater, and increased urban and agricultural water demand. A system dynamics model is developed using historical data (2006–2016) to investigate the effects of anticipated dynamics of integrated water and energy sectors in the next two decades. The results of policy scenarios (2020–2039) demonstrate that the continuation of the existing management policies will cause severe damage to the water and energy sectors, pushing the system towards water resources limits to growth. An annual groundwater table decline of nearly 1 m is anticipated, indicating significant overshoot of the plain's natural recharge capacity, which may lead to the depletion of recoverable groundwater in the plain within the next three decades. The groundwater table decline will cause energy consumption of water supply to increase by about 32% (i.e., 380 GWh) to maintain irrigated agriculture. It is critical to implement a combination of water demand and supply management policies (e.g., net agricultural water savings and recycling treated wastewater) to delay the problem of water limits to growth in the region.

Singapore is a city-island-state in the transition towards a circular economy. The country has already implemented policies and adopted several approaches that contribute to closing loops for e-waste, packaging waste, and food waste. However, other areas that also contribute to a circular economy have not been fully explored in Singapore. One of these areas is resource recovery from wastewater streams. In this report, we review state-of-the-art technologies to recover valuable components from domestic wastewater and sludge. These technologies are analyzed based on technological maturity and applicability for the recovery of phosphate, and organic compounds such as volatile fatty acids, bioplastics, and biomass. The report covers the current status of the recovery of these compounds in the Singaporean context and identifies factors that can promote or prevent the application of the recovery processes.

According to the Brazilian National Water Resources Policy, water is a limited public good, and its management involves the participation of public authorities, users, and communities. This paper analyzes data on groundwater concession and uses in five Brazilian municipalities, located in the northeastern region of the Paraíba do Sul River Basin. Data were analyzed to associate aquifer systems and groundwater use with electricity consumption of the water supply systems and food production, in the perspective of the water-food-energy nexus. This analysis aimed to quantify the exploited water flows and if it is adequate with the capacity of the aquifers. For data analysis and interpretation, statistical techniques were used, which allowed structuring, organizing, and associating the information. The results indicate that, among the regional aquifer systems, the Caçapava System is the most explored in terms of groundwater abstraction, with an average of 9769 m³/h, of which only 1331 m³/h is used for public supply and 8456 m³/h for private use. One finding of this research was to verify that just one of the municipalities studied makes public the use of groundwater abstraction, with consequences in public policy and alerting to the need for adequate inspection in the areas of underground well-drilling for non-contamination and better maintenance of aquifer systems. The results highlight the water-food-energy nexus in the study area, indicating that municipalities with large rice cultivation areas use or store most of the water resources for agricultural use. Promoting new sustainable actions and achieving the Sustainable Development Goals requires integrated management outside the traditional sectors and water-food-energy nexus approach.

The objective of this study was evaluate the efficiency in water and food use in sheep production, using two new traits (residual water intake - RWI; residual feed and residual water intake - RFRWI). For this purpose, we evaluated the relationships between the traits total water intake, RWI and RFRWI with water measures, productive performance and carcass traits (ultrasound). We used 32 lambs with age of 3 months: 16 Santa Ines breed (8 males and 8 females) and 16 crossbred 7/8 Dorper x Santa Ines (8 males and 8 females). They were fed at an automated feed and water station (Intergado®), where the food and water intake by each animal was measured automatically. Residual water intake (RWI), residual feed intake (RFI) and residual body weight gain (RWG) were calculated using the MIXED procedure in SAS®. Correlation coefficients between total water intake (TWI), RWI and all traits (water measures, performance and carcass traits) were calculated using the CORR procedure (P ≤ 0.05). Total water intake showed mean 3.15 L/day during the study and the RWI ranged from 0.66 L to -0.89 L, which represents a difference of 1.55 L between the most and least efficient animal. There was positive correlation between less efficient animals in water consumption (positive RWI) and water intake (r = 0.31); total water intake in relation to dry matter intake (r = 0.36); total water intake in relation to mid-trial metabolic body weight (r = 0.26); residual feed and residual water intake (r = 0.99) and gain/feed ratio (r = 0.44). There was negative correlation between less efficient animal and dry matter intake in relation to body weight (r= -0.33) and feed conversion ratio (r= -0.44). The evaluation of the new variables, RWI and RFRWI, proved effective in identifying the most efficient animals in water use. Moreover, these findings open the possibility of considering the traits RWI and RFRWI in sheep selection, because performance and carcass traits are not adversely affected by selecting for these new traits.