This study proposes a novel monitoring tool based on Satellite Remote Sensing (SRS) data to examine the status of water distribution and Water Use Efficiency (WUE) under changing water policies in large-scale and complex irrigation schemes. The aim is to improve our understanding of the water-food nexus in such schemes. With a special reference to the Gezira Irrigation Scheme (GeIS) in Sudan during the period 2000–2014, the tool devised herein is well suited for cases where validation data are absent. First, it introduces an index, referred to as the Crop Water Consumption Index (CWCI), to assess the efficiency of water policies. The index is defined as the ratio of actual evapotranspiration (ETa) over agricultural areas to total ETa for the whole scheme where ETa is estimated using the Simplified Surface Energy Balance model (SSEB). Second, the tool uses integrated Normalized Difference Vegetation Index (iNDVI), as a proxy for crop productivity, and ETa to assess the WUE. Third, the tool uses SSEB ETa and NDVI in an attempt to detect wastage of water. Four key results emerged from this research as follows: 1) the WUE has not improved despite the changing agricultural and water policies, 2) the seasonal ETa can be used to detect the drier areas of GeIS, i.e. areas with poor irrigation water supply, 3) the decreasing trends of CWCI, slope of iNDVI-ETa linear regression and iNDVI are indicative of inefficient utilization of irrigation water in the scheme, and 4) it is possible to use SSEB ETa and NDVI to identify channels with spillover problems and detect wastage of rainwater that is not used as a source for irrigation. In conclusion, the innovative tool developed herein has provided important information on the efficiency of a large-scale irrigation scheme to help rationalize laborious water management processes and increase productivity.

The sustainability of food production systems is inherently linked with energy, water and food (EWF) resources directly and in-directly throughout their lifecycle. The understanding of the interdependencies between the three resource sectors in the context of food production can provide a measurable account for resource requirements, while meeting food security objectives. The energy, water and food Nexus tool developed by the authors has been designed to model the inter-dependency between energy, water and food resources, whilst conducting an environmental assessment of product systems. With emphasis on the inter-linkages between EWF resources, the tool quantifies material flows, natural resource and energy consumption at component unit process level. This work integrates greenhouse gas control and waste to power technologies within the energy, water and food Nexus tool and evaluates the environmental impact of a hypothetical food product system designed to deliver a perceived level of food self-sufficiency (40%) for the State of Qatar. Multiple system configurations, representative of different pathways for the delivery of consistent food products are evaluated, transforming a once linear product system into a circular design. The sub-systems added consist of a biomass integrated gasification combined cycle which recycles solid waste into useful forms of energy that can be re-used within the nexus. In addition, a carbon capture sub-system is integrated to capture and recycle CO2 from both the fossil fuel powered and the biomass integrated gasification combined cycle energy sub-systems. The integration of carbon capture with the biomass integrated gasification combined cycle transforms the carbon neutral biomass integrated gasification combined cycle process to a negative greenhouse gas emission technology known as bio-energy with carbon capture and storage. For the different scenarios and sub-system configurations considered, the global warming potential can be theoretically balanced (reduced by ∼98%) through the integration of photovoltaics, biomass integrated gasification combined cycle and carbon capture technologies. The peak global warming potential, i.e. a fully fossil fuel dependent system, is recorded at 1.73 × 10⁹ kg CO2 eq./year whilst the lowest achievable global warming potential is 2.18 × 10⁷ kg CO2 eq./year when utilising a combination of photovoltaics, carbon capture integrated with combined cycle gas turbine in addition to the integrated negative emission achieving system. The natural gas consumption is reduced by 7.8 × 10⁷ kg/year in the best case configuration, achieving a credit. In the same scenario, the photovoltaics land footprint required is calculated to a maximum of 660 ha. The maximum theoretically achievable negative emission is 1.09 × 10⁹ kg CO2/year.

The water-energy-food nexus has become a popular concept in environmental change research and policy debates. Proponents suggest that a nexus approach promotes policy coherence through identifying optimal policy mixes and governance arrangements across the water, energy and food sectors. Although the nexus literature identifies some barriers to achieving coherence it does not clearly explain why the barriers are present, what influences them, and how they can be acted upon. These gaps disconnect the nexus literature from the governance processes it ultimately seeks to influence. This paper examines how the integrative environmental governance literature can help to close these gaps. It extracts insights from seven streams of research literature and discusses their relevance for the nexus literature. We argue that connecting the nexus to decision-making processes requires: i) rethinking the boundaries of nexus analysis vis-à-vis other sectors and levels; ii) elaboration of shared principles that can guide decision-making towards policy coherence − or an appropriate form of fragmentation − in different contexts; iii) viewing policy coherence as a continuous process of changing values and perception rather than as an outcome.

The institutional reform of the State established in Ecuador during the last decade has aimed at regaining control of specific sectors such as the consumptive use of water. Since 2014, regulation, consumption, and use of water, especially in agriculture, have been analyzed through policies and fiscal instruments. This research presents itself in the context of the simulation of scenarios using positive mathematical programming, to analyze the economic impact of pricing policies on agro-food farms. Policies of fixed costs, water blocks, and volumetric prices are evaluated. The results show that the existing fixed costs do not reduce water consumption. In contrast, the scenarios of water blocks and volumetric prices impact on the behavior of farmers. The tendency of water consumption to the application of volumetric prices demonstrates that banana farms have a greater tolerance to the increase of water costs. On the other hand, the response to an increase in cost in the case of cacao, sugar cane, and rice depends on the productivity of farmers. The negative effects can lead to the abandonment of agriculture. Thus, volumetric policies are more efficient in reducing water consumption as well as in recovering the costs of the irrigation system.

International audience

This study was carried out to evaluate the effects of power ultrasound (US) on the molecular weight and rheological properties of a food polysaccharide, konjac glucomannan (KGM). Upon the exposure of KGM solution (1% w/v in water) to US at a relatively high power intensity (50 W/cm2), the apparent viscosity decreased rapidly from about 50 Pa s to a negligible level within 10–20 min. The intrinsic viscosity ([η]) of KGM solution decreased gradually during the US exposure with a time course closely fitted to the first-order polymer degradation kinetics (random chain scission). The US treatment also caused a significant reduction of particle size (Zavg) of KGM aggregates and changes in the rheological properties including the decrease of storage modulus (G′) and loss modulus (G″), and the increase in phase angle (tan δ = G″/G′). Nevertheless, no change in primary structure was detected by Fourier transformation infrared (FT-IR) analysis. The results suggested that high intensity US was an effective means for KGM degradation without significant structural destruction.

This study explores the connectivity of upland farmers and downstream fishers through interlinkages of water, energy and food within the Dampalit sub-watershed of Laguna Lake, Philippines.The aim of the study is to yield policy relevant results to improve the status of the water resources and food products and to reduce possible user conflicts. Surveying 176 households mainly in the mid- and downstream areas elements and interlinkages of the local Water-Energy-Food Nexus (WEF-Nexus) were identified by the five capitals of the sustainable livelihood approach through a socio-ecological network analysis.Besides the innovative methodology, this research adds to the underserved local perspective in the WEF-Nexus research. The survey shows different livelihood profiles for the two groups and a lack of direct social links between them in the WEF-Nexus context. Also indirect links through consumption of the other group’s food products could not be identified. However, a large fraction of the population share the use of char coal for cooking, the Makiling groundwater for drinking and various household purposes and the Central Market in Los Banos for their food supply.

The paper analyzed the important role of water saving in protecting the food safety, introduced the present development of agricultural water-saving technique, pointed out the potential risks of water resources, and proposed the future development of water-saving irrigation.

The world is facing a more water constrained future as a result of urbanisation, population growth, industrialisation and the emergence of climate change. This has direct impacts on the resilience and performance of the energy and food industries, as water plays a key role in electricity generation processes and agriculture production. Water, energy and food dependencies are more evident in transboundary river basins where several countries share the same source of water for irrigation demand and energy production. From the perspective of the upstream users, it would be ideal to store the water for hydropower generation and the agriculture sector while protecting the environment, whereas the downstream users need the supply of water for their agricultural growth and municipal requirements. We aim to develop a system thinking study by focusing on the transboundary Blue Nile River basin where the Ethiopian government investment in the Grand Renaissance dam has led to opposition by downstream users due to potential reduction of water resource availability downstream. We propose a system thinking approach for analysing different water management practices that considers all the available resources and the requirements set by all the users. To simulate this interaction, we use system dynamics to model the linkage between food production, water abstraction and energy generation. We link the simulation model to an optimisation engine to achieve effective management of the reservoir’s operation. The study provides a platform to investigate how the reservoir operating policies can improve an understanding of the value of water in its alternative uses, and shows how different optimal reservoir release rules generate different optimal solutions inherently involved in upstream and downstream users’ requirements. The proposed methodology is an attempt to enable Nile riparian countries to make more informed decisions on water resources policy and management.

Sustainable agriculture encompasses economic, environmental, and social aspects of the food system. Members of the Academy of Nutrition and Dietetics (Academy) play an important role in promoting sustainable agriculture because they work in areas where they can influence the food purchasing decisions of foodservice operations and the public.To investigate behavior of registered dietitian nutritionists (RDNs) toward incorporating sustainable agriculture principles into professional practice using the Theory of Planned Behavior.This cross-sectional study surveyed RDNs nationwide about their perspectives on incorporating sustainable agriculture issues into practice. The survey questions were based on a survey originally administered to Minnesota RDNs during 2002.The sample (N=626) was drawn from a randomly selected, national sample of Academy members.Data were analyzed using descriptive statistics, independent t tests, Pearson correlations, and stepwise regression.The sample was mostly white, female, and the average age was 45.4±12.2 years. Almost half of Academy RDNs (47%) reported incorporating environmental issues into their practice. All four Theory of Planned Behavior variables (intention, attitude, perceived behavior control, and subjective norm) were predictive of behavior to include sustainable agriculture issues into practice. Barriers to incorporating this topic into practice included lack of knowledge, ability, time, and employer support.This study found that most of the RDN respondents had heard of sustainable agriculture and nearly half reported including this topic in their professional practice. To integrate this topic into practice more consistently, RDNs need more knowledge, time, and employer support.