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Given the need for water use to be a crucial consideration in sustainable development, an adequate water allocation system across economic sectors is essential, especially in the face of increasing seasonal and perennial water scarcity. In an attempt to facilitate a socially and economically efficient adaptation to the climate emergency, we propose a set of eleven socio-economic indicators to analyze the current water management. This set of indicators could help to quantify the interrelationship between water use and its economic perspective, as well as its social perspective through its impact on employment. Any demand for water not only includes the direct use of water but also its indirect use, referred to as virtual water. This is the water indirectly used through the other inputs in the production process (input–output methodology). These indicators are evaluated in the South-West Europe territory where, in light of increasing water scarcity, there is a need to orientate water allocation toward employment with less intensive water use, to more water productivity and to less environmental impacts. The results at river basin scales show that water use is more productive in the tertiary than in the secondary and primary sectors.

I Halmstad kommun har kunskapsnivån kring virtuellt vatten hos privatpersoner och/eller yrkesverksamma undersökts. En enkätundersökning har genomförts där 85 stycken respondenter har medverkat. Respondenterna har fått ange kön, ålder och utbildningsnivå för att kunna identifiera möjliga skillnader i förmågan att skatta virtuellt vatten. Enkäten innehöll även frågor om kommunikation som var ämnade att fastställa hur respondenterna föredrog att få ämnet virtuellt vatten kommunicerat till sig. Studien har visat att i Halmstad kommun finns där en tendens att underskatta mängden virtuellt vatten i produkter. Även den dagliga vattenförbrukningen nationellt och internationellt underskattas. Genom de utförda Chi2-testerna i kategorierna kön, ålder och utbildningsnivå har det visats att en fråga hade korrelation mellan kön och skattningsförmåga, medan resterande frågor inte visade på något samband. Det här skiljer sig gentemot tidigare forskning som gjorts kring privatpersoners förmåga att skatta sin vattenanvändning, där kategorierna högre ålder, att vara man och högre utbildning tydligt har varit korrelerat till en bättre skattningsförmåga. Vidare har produktmärkning, TV och sociala medier varit de föredragna kommunikationsmedierna i den här undersökningen, sett till respondenternas svar. För att öka kännedomen om virtuellt vatten har även förslag på en kommunikationsinsats kring virtuellt vatten utformats där sex kommunikationsmål och två slutmål har tagits fram för kommunikation om ämnet. Den här studien ger också en inblick i varför virtuellt vatten är en viktig aspekt för att uppnå Agenda 2030 samt hur en kommunikationsinsats kring virtuellt vatten kan vara en del av att uppnå en mer hållbar vattenhantering., The knowledge about virtual water among private individuals and/or professionals have been researched in Halmstad municipality. A questionnaire survey has been conducted where 85 respondents participated. The respondents were asked to state their gender, age, and educational level so that differences concerning the perception of virtual water could be identified. The questionnaire also contained questions regarding how the respondent’s wanted information about their water usage communicated. This survey concluded that there is a tendency to underestimate the volume of virtual water in products in Halmstad municipality, as well as the daily virtual water usage both on a national and international scale. Through the performed Chi2-tests it has been shown that one question had a correlation between gender and the perception of virtual water, whilst the remaining questions related to their respective categories, gender, age, and education level, did not. This contrasts with previously conducted research about perception of water usage, where the categories higher age, being a male and higher educational level were related to a more correct water perception. Preferred ways to receive information about water usage have been shown to be through product labeling, TV, and social media. Efforts to communicate virtual water have been designed in this study in the form of six communication goals and two end goals to increase knowledge regarding the topic. It has been identified that virtual water is an important aspect to achieve Agenda 2030 as well as how communicational efforts regarding virtual water can be a part of achieving a more sustainable water management.

Iraq depends on its water resources from the water of the Tigris and Euphrates Rivers and their tributaries. Now, the flow of these rivers is decreasing, and Iraq is experiencing a water shortage problem. The situation is expected to be graver in the future if no action is considered. It is expected that the population will be about 70 million in 2050 and about 90 million in 2070. In such a case, thus, the quantities of water available in the future will not besufficient to produce most of the requirements of food security, whether that be from agricultural or animal products. To overcome this problem, water management planning should be based on scientific background to overcome the present and expected problems. One of the main factors to be considered should be based on scientific studies of the virtual water footprint of different food crops to provide the largest possible amount of virtual water and avoid the acute shortage of its national water from surface and ground irrigation water (blue water) and rainwater (green water), in addition to working hard to provide the largest possible amount of desalinated water and refined sewage (gray water). In addition, any strategic plan for sustainable development in the country must be comprehensive so that it is not satisfied with improving the situation in the field of food security related to water security, but rather among its other elements is community development that directly affects food security, including setting policies to reduce consumption by reducing the steady increase in population where the population rate is 2.97% now. Collective awareness and guidance programs in all the fields of water and food security are very important to be adopted, so that everyone knows that the issue of food security and what derives from it are an existential issue related to the survival of Iraq as a state and people. In this research, facts are stated so that action is to be considered to minimize the water shortage prob, Godkänd;2023;Nivå 0;2023-07-20 (sofila)

Globally, agriculture is the primary water consumption sector. This study used water footprint (WF) as a bottom-up tool and satellite imagery as a top-down tool to estimate the internal water use (WU) in the agricultural sector in an innovative way to show the effects of water-intensive use in agriculture in an arid country. The WF of Iran has been quantified for 19 main crops and for related agricultural products exported from Iran to partner countries. Using a bottom-up approach, Iran's total yearly agriculture net water consumption is estimated to be 42.43 billion cubic meters (BCM) per year. Out of 42.43 BCM total net internal water use, only 1.61 BCM is virtual-water export related to these 19 products, and the remaining 40.82 BCM is for internal use. Our results using satellite imagery show that in case of using all possible lands for agriculture, it would require 77.4 BCM. However, not all these lands are within human reach, and the maximum available water is way lower than this amount. Using satellite imagery, the total evaporation from agricultural lands shows 55.27 BCM for 2020, which agrees with national reports during 2005–2014. This study shows that agricultural water consumption tends to use internal water resources at a maximum level for export and national use, significantly impacting renewable and non-renewable water resource availability, especially in groundwater.

The price paid by producers for water is not enough to recover operation and maintenance costs. A pricing policy can contribute to efficient water use, to improvements in irrigation technology and to the reconversion of higher value crops. The objective was to determine the water rate per dam3 to produce one ton of alfalfa, grain corn and forage oats in the different modules of irrigation district 003 Tula, Hidalgo. The methodology approach was quantitative based on data from the current irrigation quota, crop yield and irrigation lamina. The results suggest that the calculated water rate is different for each crop and for each irrigation module; on average, it was higher for forage oats, followed by grain corn and alfalfa. Increasing irrigation fees as water demand increases represents a brake on those increases. However, increasing fees in irrigation district 003 would not result in crop reconversion because water contamination prevents them from planting crops that require better water quality., El precio que pagan los productores por el agua no alcanza para recuperar los costos de operación y mantenimiento. Una política de precios puede contribuir a uso eficiente del agua, a mejoras en la tecnificación de riego y a la reconversión de cultivos de mayor valor. El objetivo fue determinar la tarifa del agua por dam3 para producir una tonelada de alfalfa, maíz grano y avena forrajera, en los diferentes módulos del distrito de riego 003 Tula, Hidalgo. El enfoque de la metodología fue cuantitativo a partir de datos de la cuota actual de riego, el rendimiento del cultivo y la lámina de riego. Los resultados sugieren que la tarifa calculada del agua es diferente para cada cultivo y para cada módulo de riego; en promedio, fue mayor para la avena forrajera, seguido del maíz grano y la alfalfa. Incrementar las cuotas de riego a medida que aumenta la demanda de agua representa un freno a esos incrementos. Sin embargo, incrementar las tarifas en el distrito de riego 003 no resultaría en una reconversión de cultivos debido a que la contaminación del agua les impide sembrar cultivos que requieren mejor calidad de agua.

Producción Científica, Poorer countries often face a severe trade-off: the need to improve socio-economic conditions is hard to balance with the maintenance of key ecological processes. As a case study, we select Colombia, a Latin American country with almost 10% of its inhabitants living in extreme poverty. We elaborate a water–food–labour (WFL) nexus grounded on a sub-national Environmentally Extended Input–Output (EEIO) analysis to assess the virtual water trade (VWT) and virtual informal labour (VIL) flows across administrative departments and economic sectors related to domestic trade. The main results are the following: high cross-departmental resource interdependence both in terms of VWT and VIL, rich departments highly depend on the resources of their neighbouring trading partners, extreme poverty conditions shown by economically isolated departments, and considerable income inequality in the food production sectors. Moreover, departments that are net exporters of virtual water suffer from water stress that might be exacerbated by future high rainfall variability due to climate change. These results suggest that strategies to attain sustainable development goals (SDGs) must deal with the biophysical constraints and the economic and political feasibility of the proposed solutions. In this vein, we argue that a holistic framework, grounded on quantitative analyses, is necessary to support informed policy decisions for the simultaneous achievement of multiple (possibly contrasting) goals. Moreover, severe spatial imbalances call for local policy responses coordinated at the national level., The authors are grateful for the comments received from four anonymous reviewers. T.D. acknowledges the “Low-carbon society: an enhanced modelling tool for the transition to sustainability (LOCOMOTION)” H2020 project (no. 821105) and the PRA project (2020-52) titled “Shaky capitalism: How business and finance respond to global threats”.

Previous research papers on urban water resources accounting were confined to the perspectives of production and consumption, ignoring the perspective of income. This paper proposes a systems framework to analyze the income, production, and consumption-based water uses and underlying driving forces of a city based on the methods of multi-scale input-output analysis and structural decomposition analysis. A case study is performed for Shanghai as a megacity. The results show that the income, production and consumption-based water uses of Shanghai had decreased from 5.70 billion m3, 10.85 billion m3 and 28.45 billion m3 in 2007 to 2.80 billion m3, 6.20 billion m3 and 24.10 billion m3 in 2017, respectively. Domestic imported primary inputs had emerged as an important virtual water supplier of Shanghai and its share of total supply-side water use had increased from 23.92% in 2007 to 42.95% in 2017. Meanwhile, about 46% and 40% of Shanghai's total consumption-based water use had been imported from other Chinese regions and foreign countries in 2017, respectively. It is revealed that trade played an important role in relieving water use pressure in Shanghai. The factors that had increased the uses of water resources in Shanghai include population, per capita value-added, per capita output, final consumption structure, and per capita final consumption. The factors that had reduced the water uses in Shanghai include technology, value added mix, output structure, value added structure, domestic import, commodity mix, and foreign import. It is suggested that in addition to curbing urban water use from the production side, more targeted water-saving measures should be devised from the supply (e.g., restricting loan to heavy water-consuming enterprises) and consumption sides (e.g., encouraging residents to buy low-water products).

This article aims to show that virtual water has historically been an adaptation strategy that enabled some arid regions to develop a prosperous economy without putting pressure on their scarce water resources. Virtual water is referred to as the total amount of water that is consumed to produce goods and services. As an example, in arid central Iran, the deficiency in agricultural revenues was offset by more investment in local industries that enjoyed a perennial capacity to employ more workers. The revenues of local industries weaned the population from irrigated agriculture, since most of their raw materials and also food stuff were imported from other regions, bringing a remarkable amount of virtual water. This virtual water not only sustained the region’s inhabitants, but also set the stage for a powerful polity in the face of a rapid population growth between the 13th and 15th centuries AD. The resultant surplus products entailed a vast and safe network of roads, provided by both entrepreneurs and government. Therefore, it became possible to import more feedstock such as cocoons from water-abundant regions and then export silk textiles with considerable value-added. This article concludes that a similar model of virtual water can remedy the ongoing water crisis in central Iran, where groundwater reserves are overexploited, and many rural and urban centers are teetering on the edge of socio-ecological collapse. History holds an urgent lesson on sustainability for our today’s policy that stubbornly peruses agriculture and other high-water-demand sectors in an arid region whose development has always been dependent on virtual water.

Ensuring access to water is one of the United Nations' Sustainable Development Goals. Water demand management, which has emerged as an important approach to secure water supply, should be underpinned by a good understanding of how the public perceive their use of water. In this study, we investigated public perceptions of physical and virtual water in China through online surveys using the multi-level regression models (two-level models). Based on 3262 responses, we found that overall, participants underestimated water uses and differences between water uses (daily potable water of an adult, shower, toilet flushing, etc.). Most participants did not possess the knowledge of virtual water embedded in their daily consumed products. Individuals showed rather different perceptions in water use, which were affected by gender, age, education, resource and environmental attitude, water saving behaviors, water price and residential water source. In combination with previous findings in the United States, we concluded that despite different natural water endowment and socio-economic and cultural conditions, underestimation of water use is commonly shared by Chinese and Americans. This highlights a need of strengthening public knowledge of water use. The results are useful in informing policies to enhance the public's awareness of water use towards improved water demand management.

The amounts of clean waters on our planet are limited by global climate change,growing population, and pollutant rates. Therefore it is important to use more effectivewater management strategies. The methodology of water footprint (WF) analyzes,directly and indirectly, the blue, green and gray components of water (consumed andpolluted). It is also possible to calculate the virtual water contents (VWC) behind theproducts. In terms of the sustainability and efficiency of freshwater resources,particularly in water-scarce regions, the approach to WF contributes towards watermanagement studies and the analysis of the total water used in the import and exportproducts supply chain. The VWC approach provided new insights into internationalwater transfers that give water an economic value. The objective of this research is tohelp to build the national water management and sustainable development strategy. Inthis sense, it was measured separately the WF of the imported quantities of wheat.Virtual water flow was identified in the most important countries. Savings and lossesarising from wheat trading on national and global water were also noted and addressed.It was found that in 2019, the wheat WF was 1876 m3/ton of water, WF of productionwas 8,147,468,000 m3/year and for import was 1,184,007,630 m3/year. From importingwheat, Iraq saved 46,672,673 m3 of water but there is no global water saving., Godkänd;2020;Nivå 0;2020-11-18 (johcin);Konferensartikel i tidskrift

[ES] California es el estado con mayores ingresos por exportación de productos agrícolas en Estados Unidos. En la definición de agua exportada se contabiliza el agua contenida físicamente en los productos agrícolas cultivados y transportados fuera de una frontera geográfica, adicionalmente se incluye la evapotranspiración inducida por el riego del cultivo. Como consecuencia de las condiciones climáticas, el agua evapotranspirada se pierde y no está disponible en el ciclo hidrológico local. En el presente estudio, para la estimación del agua exportada se utilizaron datos de los 50 productos agrícolas más exportados desde California (período 2000-2012). Los resultados muestran que, en promedio, el agua exportada en productos agrícolas corresponde a 2.88×1010 m3 año-1, lo que equivale al 68.3% del agua utilizada en riego del cultivo. La mayor parte del agua exportada (67.7%) está representada en la evapotranspiración inducida por el riego del cultivo. El agua contenida físicamente en los productos agrícolas exportados se calculó en 2.32×108 m3 año-1, esto representa menos del 1% del total anual de agua utilizada en California para riego., [EN] California is the state with the highest income from export of agricultural products in the United States. The total exported water is defined as the physical water contained in crops transported outside a geographic border plus the water lost as induced evapotranspiration as a result of crop irrigation. As a consequence of environmental conditions, the evapotranspiration water is no longer available inside the local hydrologic cycle. In this research, a data set for California’s 50 most exported agricultural commodities (in the period 2000-2012), has been used to quantify exported water. The results show that, on average, the overall exported water in California’s agricultural products was 2.88×1010 m3 yr –1, equivalent to 68.3% of the total water used in agricultural irrigation. The majority of the exported water is in the form of induced evapotranspiration, totaling 67.7% of the annual total water used in irrigation. The physical water content contained in crops was approximately 2.32×108 m3 yr –1, representing less than 1% of the total water used in irrigation and of the induced evapotranspiration.

Due to globalization, increasing amounts of water are traded across borders as virtual water embodied in traded products. The thesis traces global water trade patterns at different levels of income between 1990 and 2015 in order to test whether developed countries outsource their water-intensive production to less developed countries increasing global water use in the process. The research problem is approached by means of an environmentally extended multiregional input-output analysis using the Eora26 database to identify the balance of water embodied in trade of high, upper-middle, lower-middle and low income countries. This methodology is supplemented with a new accounting technique from the field of carbon emission research taking technological differences between countries at different income levels into consideration and assessing the contribution of the trade specialization and the monetary trade balance to the technology-adjusted balance of water embodied in trade. The thesis finds that high income countries outsourced water-intensive production to lower-middle income and low income countries between 1990 and 2015 whereas the virtual water trade balance of upper-middle income countries changed over time. The results support the displacement and pollution haven hypotheses and suggest that structural change processes of economic development lead to these unequal terms of trade.

This paper commemorates the influence of Arjen Y. Hoekstra on water footprint research of the United States. It is part of the Special Issue “In Memory of Prof. Arjen Y. Hoekstra”. Arjen Y. Hoekstra both inspired and enabled a community of scholars to work on understanding the water footprint of the United States. He did this by comprehensively establishing the terminology and methodology that serves as the foundation for water footprint research. His work on the water footprint of humanity at the global scale highlighted the key role of a few nations in the global water footprint of production, consumption, and virtual water trade. This research inspired water scholars to focus on the United States by highlighting its key role amongst world nations. Importantly, he enabled the research of many others by making water footprint estimates freely available. We review the state of the literature on water footprints of the United States, including its water footprint of production, consumption, and virtual water flows. Additionally, we highlight metrics that have been developed to assess the vulnerability, resiliency, sustainability, and equity of sub-national water footprints and domestic virtual water flows. We highlight opportunities for future research.

Jedan od najznačajnijih prirodnih resursa je voda. Od prvih početaka života na planeti, voda se neprestano koristi i postepeno kontaminira biljnim, životinjskim i humanim otpadom i debrijem. Razvoj urbanih područja izazvao je značajno povećanje količine organskog otpada u vodenim tokovima, prevazilazeći autopurifikacioni kapacitet same vode. Zbog kompleksne prirode korištenja i visokog značaja za održavanje života na Zemlji, integralna zaštita voda je prioritetni zadatak. Virtuelna voda predstavlja vodu koja je sastavni deo proizvoda, onu koja je utrošena u procesu njegove proizvodnje i koja je tim procesom zagađena. Ova količina varira u zavisnosti od tipa proizvoda. Ovaj koncept na jedinstven i logičan način, povezuje trgovinu i vodu, kako površinsku, tako i podzemnnu i vodu sadržanu u porama zemljišta. Vodno najzahtevnija tehnološka oblast je proizvodnja hrane. Sa aspekta međunarodne trgovine, država koja uvozi/izvozi pšenicu, takođe izvozi i vodu koja je u njoj sadržana i koja je utrošena za njenu proizvodnju, i to u odnosu od 1159 kubnih metara vode po svakoj toni proizvoda. U radu je analiziran vodni potencijal Republike Srbije i njegovo korištenje u poljoprivrednoj i industrijskoj proizvodnji, sa aspekta zelene, plave i sive vode, a u cilju ekonomske i ekološke održivosti, zaštite životne sredine i obezbeđivanja vonde samoodrživsti zemlje. Rad ukazuje na nepostojanje pravne regulative, kojom bi se definisala vrednost virtuelne vode, a samim tim ne kao i sistema monitoringa njenog režima, te na neophodnost izrade strateških programa, koji bi definisali osnovna načela i mere upravljanja ovim resursom u Republici Srbiji., One of the most important natural resources is water. Since the first beginnings of life on the planet, water is continuously used and gradually contaminated by plant, animal and human waste and debriefing. The development of urban areas caused a significant increase in the amount of organic waste in watercourses, exceeding the autopurification capacity of the water itself. Due to the complex nature of the use and the high importance of maintaining life on Earth, integral water protection is a priority task. Virtual water is water that is an integral part of the product, the one consumed in the process of its production and which is contaminated with the process. This quantity varies depending on the type of product. This concept in a unique and logical way connects trade and water, both surface, as well as underground and water contained in the pores of the land. The most demanding technological area is food production. From the aspect of international trade, the state that imports / exports wheat also exports the water contained in it and which is spent on its production, in relation to 1159 cubic meters of water per ton of products. The paper analyzes the water potential of the Republic of Serbia and its use in agricultural and industrial production, from the aspect of green, blue and gray water, with the aim of economic and ecological sustainability, environmental protection and securing the country's voodoo sustainability. The paper points out that there is no legal regulation that would define the value of virtual water, and therefore not as a system of monitoring its regime, and the necessity of drafting strategic programs that would define the basic principles and measures of managing this resource in the Republic of Serbia.

China and India's miraculous economic growth has undoubtedly improved the livelihoods of millions of people, but it has also increased demand for already scarce water resources in the region. The hydro-political relationship between the two countries is particularly interesting due to China’s hold of the Tibetan Plateau which houses the heads of most major rivers in the region. China’s general unwillingness to cooperate with their downstream neighbors has become cause for concern, especially for India’s growing economy and population. This study analyzes the quantitative economic and resource consumption changes of China and India since 1980 to demonstrate the sharp changes linked to export-oriented economic development. These data are supported by a holistic analysis of key domestic policy changes as well as current domestic water-related issues in order to fully grasp the current circumstances and hypothesize the potential for escalation to conflict. Using Feron’s rationalist framework, I analyze the key sources of conflict as credibility problems, incomplete information and the indivisible nature of water. These three issues work cyclically and feed into one another, any solution for the issue would have to acknowledge all three elements. This study suggests that domestic water efficiency improvements such as increased water-recycling and smarter irrigation infrastructure coupled with bilateral solutions like joint hydraulic projects on the Brahmaputra and codified data sharing agreements can foment cooperation between the nations. This thesis ultimately establishes a link between the globalization-led development in the region and India and China’s changing hydraulic needs in order to determine the actions necessary to avoid international conflict and ensure long-term water and energy security for both states.

This paper proposes the use of water-resources inter-regional input-output (WRIRIO) table as a tool to evaluate virtual water trade between Shikoku Island, one of the severe areas in water shortages, and other regions. The WRIRIO table meets the challenge of evaluating water demand to support to various economic activities such as (1) agriculture, (2) manufacturing, and (3) service sector in all regions of Japan. This approach, which combines input-output tables and water demand analysis, overcomes the shortcoming of traditional input-output tables which do not resolve the challenge of evaluating demand of natural resources to meet economic development in each region. Regional virtual water or trade of services of water is enumerated by combining a Shikoku inter-regional input-output table and water demand analysis in same industry product. The calculated results show inter-regional trade of money and water use to support each industry. The application methodology is illustrated through the case of year 2005. The paper indicates that “water-resources inter-regional input-output table” provides a tool that allows decision makers to accurately value regional trade with consideration not only of money circulations, but also of water uses.

Water scarcity has direct implications for food security in arid regions. Egypt faces an escalating situation of water scarcity, as its renewable fresh water resources are fixed and the population is growing rapidly. The per capita supply of fresh water is already dangerously low and predicted to plummet even further by the year 2025. This paper critically analyzes three different approaches to the water scarcity problem in Egypt: importing virtual water, using Nile water more efficiently, and creating new sources of fresh water with desalination. The advantages and disadvantages of each approach are reviewed. This exposes a number of fundamental trade-offs that must be resolved. Discussion and recommendations are made as to which solution is most viable.

Virtual water, that is the water used to produce exported products from agriculture and other commodity sectors like mining, has produced multiple effects on the socio-economic and environmental conditions of the producer regions and their populations. Export-related growth and increase of revenue have come together with resource-depletion, socio-environmental conflict and geo-political claims of local and/or national resource-ownership. While trade agreements and multi-scale environmental regulation try to address some of these issues, though in controversial ways, there is still a long way to go through in the construction of water governance arrangements that ensure sustainable water use. Our presentation illustrates this argument with cases of export agriculture and large scale mining in the Mediterranean and South American regions.

The question this study sought out to answer was: What is the possible correlation between high and low imports of virtual water and degree of securitization in Egypt and Israel? Virtual water, e.g. the water embedded in goods and services, can be imported to water scarce countries to mitigate the domestic water use. For the years 1996-2005 Israel imported a great amount of virtual water compared to Egypt. We have done a comparative qualitative discourse analyses for the years 2007-2010 for the mentioned states to identify a general trend in the discourse held by political elites in accordance with the securitization theory developed by Buzan et al. Another theory used to identify the correlation between the analyzed variables is the resource scarcity thesis, developed by Homer-Dixon and the Toronto group. We found out that Egypt’s political elite frames the water issue in a more securitized manner than the political elite of Israel and the final conclusion is that a correlation between high import of virtual water and a low degree of securitization can be argued for on several levels. Although this is a preliminary conclusion based on a limited study it can be used as a base for further studies aimed to fusion security studies with a typically economic matter such as a virtual water import.

Introduction: The broiler chicken is the most consumed protein source in Lima - Peru, reason why its demand and consumption of water for its production, is increasing every year. According to the Peruvian Poultry Association (2016) in Lima, 76.4 kilograms per inhabitant per year are consumed and at the Latin American level chicken consumption in Peru is one of the highest in the region (Evans, 2016). Also, the World Wildlife Foundation (2014) indicates that food production is responsible for 70% of the water used by man on the planet, so it is everyone's responsibility to make good water resource management. Objective: In this context, the present work estimates the water footprint of the broiler chicken benefited. Materials and methods: The identification of the processes of broiler chicken production was carried out by means of direct observation, interviews and review of information, while for the estimation of the water footprint measurements were taken during the period from June 2016 to November 2016, water consumption, volumes of wastewater treated and kilograms of chicken benefited. Result: The incubation, breeding and profit processes were identified, the virtual water ratios of each process were calculated and based on this, the water footprint of the broiler chicken benefited was obtained according to the guidelines of the "The Water Footprint Assessment Manual: Setting The Global Standard "(Hoekstra, et.al, 2011). Conclusions: The result of the evaluation reports that the water footprint of the broiler chicken benefited is 2059.76 liters of water per kilogram of chicken, of which 85.28% corresponds to the indirect green water of imported agricultural inputs (corn and soybean) that are used in the production of balanced feed for chicken., Resumo Introdução: O frango de corte é uma fonte proteica de maior consumo em Lima-Peru, pela a sua demanda, e - consequentemente pelo consumo de agua para a sua produção - vem se incrementando cada ano. Segundo A Associação Peruana de Avicultura (2016), em Lima consumam-se 76,4 quilogramas de frango por habitante, o que põe ao Peru entre os maiores consumidores da região (Evans, 2016). Além, a World Wildlife Foundation (2014) indica que a produção de alimentos é a responsável do 70% da água utilizada pelo homem no planeta, por isso, é responsabilidade de todos fazer uma boa gestão do recurso hídrico. Objetivo: Neste contexto, no presente trabalho estima-se a pegada hídrica do frango de corte beneficiado. Materiais e métodos: A identificação dos processos da produção do frango de corte realizou-se mediante observação direta, entrevistas e revisão de informação existente, no entanto que para a estimativa da pegada hídrica realizaram-se medições -durante o período de junho a novembro 2016- de consumo de água, volumes de descargas de água residual tratada e de quilogramas de frango beneficiado. Resultados: Identificaram-se los processos de incubação, criança e beneficio, calcularam-se os ratios de água virtual de cada processo e, baseado, obtive-se a pegada hídrica do frango beneficiado de acordo aos lineamentos da manual The Water Footprint Assessment Manual: Setting The Global Standard (Hoekstra et al., 2011). Conclusão: O resultado da Avaliação informa que a pegada hídrica do frango de corte beneficiado é 2059,76 litros de água por quilograma de frango, dos quais o 85,28% corresponde à água verde indireta dos fornecimentos agrícolas importados (milho e soja) que são utilizados na produção do alimento balanceado para o frango., Resumen Introducción: El pollo de engorde es la fuente proteica de mayor consumo en Lima -Perú, por lo que su demanda -y, consecuentemente, el consumo de agua para su producción- se viene incrementando cada año. Según La Asociación Peruana de Avicultura (2016), en Lima se consumen 76,4 kilogramos de pollo por habitante, lo que pone a Perú entre los mayores consumidores de la región (Evans, 2016). Además, la World Wildlife Foundation (2014) indica que la producción de alimentos es la responsable del 70% del agua utilizada por el hombre en el planeta, por tanto, es responsabilidad de todos hacer una buena gestión del recurso hídrico. Objetivo: En ese contexto, en el presente trabajo se estima la huella hídrica del pollo de engorde beneficiado. Materiales y métodos: La identificación de los procesos de la producción del pollo de engorde se realizó mediante observación directa, entrevistas y revisión de información existe, en tanto que para la estimación de la huella hídrica se realizaron mediciones -durante el periodo de junio a noviembre 2016- de consumo de agua, volúmenes de vertimiento de agua residual tratada y de kilogramos de pollo beneficiado. Resultados: Se identificaron los procesos de incubación, crianza y beneficio, se calcularon los ratios de agua virtual de cada proceso y, en base a ello, se obtuvo la huella hídrica del pollo beneficiado de acuerdo a los lineamientos de la guía The Water Footprint Assessment Manual: Setting The Global Standard (Hoekstra et al., 2011). Conclusiones: El resultado de la evaluación reporta que la huella hídrica del pollo de engorde beneficiado es 2059,76 litros de agua por kilogramo de pollo, de los cuales el 85,28% corresponde al agua verde indirecta de insumos agrícolas importados (maíz y soya) que son utilizados en la producción del alimento balanceado para pollo.

The Belt and Road is an initiative of cooperation and development that was proposed by China. Moreover, most of the spanning countries faced water shortages and agriculture consumed a lot of water. Virtual water links water, food and trade and is an effective tool to ease water shortages. Therefore, this paper aims to understand the Belt and Road from the new perspective of virtual water trade of agricultural products. We considered agricultural products trade from 2001 to 2015. On the whole, the results indicated that China was in virtual water trade surplus with the countries along the Belt and Road. However, in terms of each country, >40 spanning countries were in virtual water trade surplus with China and eased water shortages. Russia had the largest net imported virtual water from China. Furthermore, the proportion of the grey water footprint that China exported to the spanning countries was much higher than that imported, no matter from the whole or different geographical regions. Moreover, more than half of the countries' virtual water trade with China conformed to the virtual water strategy, which helped to ease water crises. Furthermore, the products that they exported to China were mainly advantageous products that each spanning countries have. Virtual water trade is a new perspective to explore the Belt and Road. Agricultural products trade with China definitely benefits both the countries along the Belt and Road and China from the perspective of virtual water. The findings are beneficial for the water management of the countries along the Belt and Road and China, alleviating water shortages, encouraging the rational allocation of water resources in the various departments. They can provide references for optimizing trade structures as well. (c) 2017 Elsevier B.V. All rights reserved.

An analysis of virtual crop water export through international trade is conducted for Greece, downscaled to the River Basin District (RBD) level, in order to identify critical “hotspots” of localized water shortage in the country. A computable general equilibrium model (MAGNET) was used to obtain the export shares of crops and associated irrigation water was calculated for all major crops in Greece. A distinction between virtual crop water locally consumed and traded internationally was made for all Greek RBDs. Cotton was identified as a large water consumer and virtual water exporter, while GR08 and GR10 were identified as the RBDs mostly impacted. The value of virtual water exported was calculated for all crop types and fruits and vegetables were identified as the crop most beneficial, since they consume the least water for the obtained value.

Water scarcity is a limiting factor for agriculture. As the competition for this resource intensifies; the agricultural sector must make a more efficient use. This work estimated the production of water in beans (Phaseolus vulgaris L.) produced in Calera and Villa de Cos, Zacatecas based on the methodology established by Ríos et al., (2015). The physical productivity was 0.118 kg m-3, namely; 8, 442 L kg-1 of bean for Rural Development District 189 Zacatecas. The price of the cubic meter for irrigation was $ 0.48 m-3 and gross profit MN$1.88m-3. It is concluded that the agricultural production of water in beans was low, so the production of beans in pumping is unsustainable, La escasez de agua es un factor limitante para la agricultura. Conforme la competencia por este recurso se intensifica, el sector agrícola debe hacer un uso más eficiente. Se estima la productividad del agua en frijol (Phaseolus vulgaris L.) producido en Calera y Villa de Cos, Zacatecas, con base en la metodología establecida por Ríos et al. (2015). La productividad física fue 0.118 kg m-3, es decir, 8 442 L kg-1 de frijol para el Distrito de Desarrollo Rural 189 Zacatecas. El precio del metro cúbico para riego fue $0.48 m-3 y utilidad bruta MN$1.88m-3. Se concluye que la productividad agrícola del agua en frijol fue baja, por lo que la producción de frijol en bombeo es insostenible.

The aridity of the area between the Persian Gulf and the Nile, combined with rapid economic and population growth, and a disorder produced by inter- and intra-state conflicts, results in the country experiencing a wide range of challenges. Water security. The Nile River is the longest transboundary artery in the world and has become a major challenge for nations that share their waters. The distribution of Nile waters has been a source of controversy and tense relations for many decades. Military threats have almost disappeared, but have given way to new threats to political, economic, societal and environmental security. All these threats are present in the Nile Valley. But solutions are still possible in a cooperative way, La aridez del área comprendida entre el golfo Pérsico y el Nilo, combinada con un rápido crecimiento económico y de la población y un desorden producido por conflictos inter e intraestatales, da lugar a que la misma experimente una amplia gama de retos a la seguridad hídrica. El río Nilo es la arteria transfronteriza más larga del mundo y se ha convertido en un desafío importante para las naciones que comparten sus aguas. La distribución de las aguas del Nilo ha sido una fuente de controversia y tensas relaciones durante muchas décadas. Las amenazas militares casi han desaparecido, pero han dado paso a nuevas amenazas contra la seguridad política, económica, social y ambiental. Todas estas amenazas se encuentran presentes en el valle del Nilo. Pero aún son posibles las soluciones negociadas de forma cooperativa.

The milk production impact on water natural mechanism was evaluated, by estimating the Water Footprint (WFP) in this productive system. The Water Footprint Network approach was used in 28 Tunja City (Boyacá, Colombia) farms, through a discretionary none probabilistic sampling. The green WFP was calculated using the CROPWAT program; to identify the blue WFP was taken into account the water consumed, the loss by transpiration and the other one incorporated to the product. The gray WFP was focused on the contamination by Nitrogen. The estimated WFP was 2,007.8 l/kg, being almost double above the global average (790 to 1,087 l/kg milk); with high impact of the green WFP (99.3 % of the total WFP), represented in the forage use as a staple food and the high-water pressure index in the area. The blue WFP of 7.0 l/kg milk has no significant impact. Although gray WFP of 6.7 l/kg milk represents a total minimum percentage, it has a great impact since it produces water resource contamination. In relation to the productive process, it was found that the animal load and the milking cows percentage account for 31 % and 36 %, respectively, of the total WFP variations., Se evaluó el impacto de la producción lechera sobre el agua, estimando la Huella Hídrica (HH) en este sistema productivo. Se empleó el enfoque de la Water Footprint Network en 28 fincas del municipio de Tunja (Boyacá), mediante un muestreo no probabilístico discrecional. La HH verde se calculó utilizando el programa CROPWAT; para identificar la HH azul se tuvo en cuenta el agua consumida, la pérdida por transpiración y la incorporada al producto; la HH gris se enfocó en la contaminación por nitrógeno. La HH estimada fue de 2.007,8 l/kg, que se encuentra por encima de la media global (790 a 1.087 l/kg leche); con alto impacto de la HH verde (99,3 % de la HH total), representada en el uso de forraje como alimento básico y en el alto índice de presión hídrica en la zona. La HH azul (7,0 l/kg leche) no tiene impacto significativo. Aunque la HH gris (6,7 l/kg leche) representa un porcentaje mínimo del total, tiene gran impacto, ya que produce contaminación del recurso hídrico. En relación con el proceso productivo, se encontró que la carga animal y el porcentaje de vacas en ordeño explican el 31 % y el 36 %, respectivamente, de las variaciones en la HH total.

This article is a fairly new theme, is the conceptualization and economic importance of the Virtual water analysis, into the natural capital sustainability academic discussion, and as we know water is a natural resource of vital so much importance as an input is the main production processes, as well as also essential to sustain life, therefore should be considered one of the main components of the natural capital of a nation, and we must analyze its rational use, its replacement and maintenance to ensure the sustainability of the economic structure. Therefore content is focused on conceptual aspects for understanding that we refer to as heard on Virtual water, what is the relationship and difference between this concept and the water footprint? As we can quantify it, and because it is important to do so. Here is presented a little exercise on the basis that is required of water to produce some products which occupy a considerable place in the productive structure, allowing us to sit down and consider that we are doing to ensure the use of the resources today and in the future., El presente artículo trata un tema bastante novedoso, es la conceptualización e importancia económica del análisis del Agua Virtual, para introducir en la discusión académica la sostenibilidad del capital natural, y como sabemos El Agua es un recurso natural de vital importancia tanto como un insumo es los principales procesos productivos, así como también elemento esencial para mantener la vida, por tanto debe ser considerado uno de los principales componentes del capital natural de una nación, y debemos analizar su uso racional, su reposición y conservación para garantizar la sostenibilidad de la estructura económica. Por tanto su contenido está enfocado en aspectos conceptuales para comprender a que nos referimos cuanto escuchamos sobre el Agua Virtual, cuál es la relación y diferencia entre este concepto y la huella hídrica?. Como podemos cuantificarla y porque es importante hacerlo. Aquí se presente un pequeño ejercicio sobre la base lo que se requiere de agua para producir algunos rubros que ocupan un lugar considerable dentro de la estructura productiva, que nos permite sentarnos a reflexionar sobre que estamos haciendo para garantizar el uso de los recursos hoy y en el futuro.

The water footprint and economic productivity of water, capital and labor force were determined in pecan (Carya illinoiensis) cultivation in Francisco I. Madero (FIM), Coahuila, Mexico, and data gathered compared to that derived from Water District - 017 (WD-017) Comarca Lagunera, Mexico. They were used the mathematical models of Ríos et. al., (2015, 2016, 2016a). Results indicate that water production in physical terms; when comparing FIM with WD- 017 was 0,064 kg m-3 vs 0,075 kg m-3, show that FIM was 16% less productive in water use. Likewise, FIM pecans used 15,73 m3 kg-1, while WD-017 utilized 13,25 m3 kg-1. Equal water volume, 1 hm3 produced in FIM 10.921 USD profits and 17 work spaces, and USD 86.178 USD and 14,70 jobs in WD-017. Producers water cost was extremely low: 0,0006 vs 0,0096 USD. The cost-benefit analysis in FIM and WD-017 was 1,097 and 2,138 respectively. Soil productivity was 0,94 ton ha-1 in FIM and 1,28 ton ha-1 in WD-017, while the gain ha-1 was 161 USD in FIM and 1.462 USD in WD-017. One million USD capital investment generated 151 work spaces in FIM and 194 in WD-017. One labor hour yielded 1,62 kg nuts in FIM and 2,23 kg at WD-017, as well as 0,28 and 2,55 USD profit for FIM and WD-017, respectively., Se determino la huella hídrica y la productividad económica del agua, el capital y la fuerza laboral en el cultivo de nogal pecanero (Carya illinoiensis) en Francisco I. Madero (FIM), Coahuila, México, y se comparó con los obtenidos a nivel Distrito de Riego 017 (DR017), Comarca Lagunera, México. Se utilizaron los modelos matemáticos de Ríos et. al., (2015, 2016, 2016a). Los resultados, al comparar FIM con el DR017, indican que la productividad del agua en términos físicos fue de 0,064 kg m-3 vs 0,075 kg m-3, indicando que FIM fue 16% menos productivo en el uso del agua. Asimismo el nogal empleó 15,73 m3 kg-1 vs 13,25 m3 kg-1 respectivamente. Un hm3, produjo USD 10.921 de ganancia y 17,00 empleos vs USD 86.178 y 14,70. El costo del agua al productor fue en extremo bajo: USD 0,0006 vs USD 0,0096. La Relación Beneficio/Costo fue 1,097 vs 2,138. La productividad del suelo fue de 0,94 ton ha-1 vs1,28 ton ha-1, mientras la ganancia por hectárea fue USD 161 vs USD 1.462. Un millón de USD de inversión de capital generó 151 empleos vs 194 empleos. Una hora de trabajo produjo 1,62 kg de nuez vs 2,23 kg de nuez, así como USD 0,28 y USD 2,55 de ganancia respectivamente, para todos los indicadores, en FIM y el DR017.

Brazil plays a major role in the global biofuel economy as the world’s second largest producer and consumer and the largest exporter of ethanol. Its demand is expected to significantly increase in coming years, largely driven by national and international carbon mitigation targets. However, biofuel crops require significant amounts of water and land resources that could otherwise be used for the production of food, urban water supply, or energy generation. Given Brazil’s uneven spatial distribution of water resources among regions, a potential expansion of ethanol production will need to take into account regional or local water availability, as an increased water demand for irrigation would put further pressure on already water-scarce regions and compete with other users. By applying an environmentally extended multiregional input-output (MRIO) approach, we uncover the scarce water footprint and the interregional virtual water flows associated with sugarcane-derived biofuel production driven by domestic final consumption and international exports in 27 states in Brazil. Our results show that bio-ethanol is responsible for about one third of the total sugarcane water footprint besides sugar and other processed food production. We found that richer states such as São Paulo benefit by accruing a higher share of economic value added from exporting ethanol as part of global value chains while increasing water stress in poorer states through interregional trade. We also found that, in comparison with other crops, sugarcane has a comparative advantage when rainfed while showing a comparative disadvantage as an irrigated crop; a tradeoff to be considered when planning irrigation infrastructure and bioethanol production expansion.

Water is an important factor for the sustainable development of tourism. We constructed a comprehensive model of the tourism water footprint (TWF), including tourism sewage and water for management, and used the world heritage Mount Huangshan as an example. The results showed that the total TWF, which included green, blue and grey water of Mount Huangshan in 2012, was about 10.19 million m(3)/year, approximately per tourist 3.39m(3)/day or 3387L/day. Tourism sewage and food were the main factors of water consumption. The spatial transfer of TWF led the spillover of tourism environmental impact, not only affecting Mount Huangshan but the Huangshan City and even nationwide. Tourist flow and temperature had a highly significant positive correlation with the TWF. Quantifying the TWF can reflect the pressure of tourists on water resources, and provide an effective decision-making basis for rational use of water resources.

At global scale, the majority of world water withdrawal is for the agricultural sector, with differences among countries depending on the relevance of agri-food sector in the economy. Virtual water and water footprint could be useful to express the impact on the water resources of each production process and good with the objective to lead to a sustainable use of water at a global level. International trade could be connected to the virtual water flows, in fact through commodities importation, water poor countries can save their own water resources. The present paper focuses on the bilateral virtual water flows connected to the top ten agri-food products traded between Italy and China. Comparing the virtual water flow related to the top 10 agri-food products, the virtual water flow from Italy to China is bigger than the water flow in the opposite direction. Moreover, the composition of virtual water flows is different; Italy imports significant amounts of grey water from China, depending on the different environmental strategies adopted by the two selected countries. This difference could be also related to the fact that traded commodities are very different; the 91% of virtual water imported by Italy is connected to crops products, while the 95% of virtual water imported by China is related to the animal products. Considering national water saving and global water saving, appears that Italy imports virtual water from China while China exerts pressure on its water resources to supply the exports to Italy. This result at global scale implies a global water loss of 129.29 million m3 because, in general, the agri-food products are traded from the area with lower water productivity to the area with the higher water productivity.

In recent years there has been a surge in land investments, primarily in the African continent, but also in Asia and Latin America. This increase in land investment was driven by the food pricing crisis of 2007-2008. Land investors can be identified from a variety of sectors, with actors ranging from hedge funds to national companies. Many water-scarce countries in the Middle East and North Africa (MENA) are among these financiers, and primarily invest in Africa. Recognizing the potential for "outsourcing" their food security (and thereby also partly their water security), Middle Eastern countries such as Jordan, Qatar and the United Arab Emirates have invested in land for food production in Africa. The extent to which this is happening is still unclear, as many contracts are not yet official and the extent of the leases is vague. This paper investigates the land investments and acquisitions by Middle Eastern countries. It also seeks to analyse what effect, if any, these investments can have on the potential for conflict reduction and subsequent peacebuilding in the Middle East region as the activity removes pressure from transboundary water resources.

How much could farm water management interventions increase global crop production? This is the central question posed in a global modelling study by Jägermeyr et al (2016 Environ. Res. Lett. 11 025002). They define the biophysical realm of possibility for future gains in crop production related to agricultural water practices—enhancing water availability to crops and expanding irrigation by reducing non-productive water consumption. The findings of Jägermeyr et al offer crucial insight on the potential for crop water management to sustainably intensify agriculture, but they also provide a benchmark to consider the broader role of sustainable intensification targets in the global food system. Here, we reflect on how the global crop water management simulations of Jägermeyr et al could interact with: (1) farm size at more local scales, (2) downstream water users at the river basin scale, as well as (3) food trade and (4) demand-side food system strategies at the global scale. Incorporating such cross-scale linkages in future research could highlight the diverse pathways needed to harness the potential of farm-level crop water management for a more productive and sustainable global food system.

How much could farm water management interventions increase global crop production? This is the central question posed in a global modelling study by J�germeyr et al (2016 Environ. Res. Lett. 11 025002). They define the biophysical realm of possibility for future gains in crop production related to agricultural water practices - enhancing water availability to crops and expanding irrigation by reducing non-productive water consumption. The findings of J�germeyr et al offer crucial insight on the potential for crop water management to sustainably intensify agriculture, but they also provide a benchmark to consider the broader role of sustainable intensification targets in the global food system. Here, we reflect on how the global crop water management simulations of J�germeyr et al could interact with: (1) farm size at more local scales, (2) downstream water users at the river basin scale, as well as (3) food trade and (4) demand-side food system strategies at the global scale. Incorporating such cross-scale linkages in future research could highlight the diverse pathways needed to harness the potential of farm-level crop water management for a more productive and sustainable global food system.

Growing trade in virtual water – the water used to produce exported products from agriculture and mining sectors – affects local communities and the environment, and transforms hydrosocial territories. National and international water regulations reshape communities’ hydrosocial territories by changing water governance structures to favour export commodity sectors, often inducing strong contestation from local communities. Transnational companies formulate and enforce global water governance arrangements oriented toward strengthening export production chains, often through asymmetrical relationships with local groups in water-export regions. These arrangements compromise political representation and water security for both local communities and companies.

Global consumption of farming commodities is an important driver of water demand in regions of production. This is the case in Brazil, which has emerged as one of the main producers of globally traded farming commodities. Traditional methods to assess environmental implications of this demand rely on international trade material flows at country resolution; we argue for the need of finer scales that capture spatial heterogeneity in environmental variables in the regions of production, and that account for differential sourcing within the borders of a country of production. To illustrate this, we obtain virtual water flows from Brazilian municipalities to countries of consumption, by allocating high-resolution water footprints of sugarcane and soy production to spatially-explicit material trade flows. We found that this approach results in differences of virtual water use estimations of over 20% when compared to approaches that disregard spatial heterogeneity in sourcing patterns, for three of the main consumers of the analysed crops. This discrepancy against methods using national resolution in trade flows is determined by national heterogeneity in water resources, and differential sourcing. To illustrate the practical implications of this approach, we relate virtual water flows to water stress, identifying where global demand for water coincides with high levels of water stress. For instance, the virtual water flows for Brazilian sugarcane sourced by China were disproportionally less associated to areas with higher water stress when compared to those of the EU, due to EU's much higher reliance on sugarcane from water scarce areas in Northeast Brazil. Our findings indicate that the policy relevance of current assessments of virtual water flows that rely on trade data aggregated at the national level may be hampered, as they do not capture the spatial heterogeneity in water resources, water use and water management options.

The global distributions of water availability and population density are uneven and therefore inequality exists in human access to freshwater resources. Is this inequality unjust or only regrettable? To examine this question we formulated and evaluated elementary principles of water ethics relative to human rights for water, and the need for global trade to improve societal access to water by transferring 'virtual water' embedded in plant and animal commodities. We defined human welfare benchmarks and evaluated patterns of water use with and without trade over a 25-year period to identify the influence of trade and inequality on equitability of water use. We found that trade improves mean water use and wellbeing, relative to human welfare benchmarks, suggesting that inequality is regrettable but not necessarily unjust. However, trade has not significantly contributed to redressing inequality. Hence, directed trade decisions can improve future conditions of water and food scarcity through reduced inequality.

The global distributions of water availability and population density are uneven and therefore inequality exists in human access to freshwater resources. Is this inequality unjust or only regrettable? To examine this question we formulated and evaluated elementary principles of water ethics relative to human rights for water, and the need for global trade to improve societal access to water by transferring 'virtual water' embedded in plant and animal commodities. We defined human welfare benchmarks and evaluated patterns of water use with and without trade over a 25-year period to identify the influence of trade and inequality on equitability of water use. We found that trade improves mean water use and wellbeing, relative to human welfare benchmarks, suggesting that inequality is regrettable but not necessarily unjust. However, trade has not significantly contributed to redressing inequality. Hence, directed trade decisions can improve future conditions of water and food scarcity through reduced inequality.

This dissertation presents three studies on California’s water footprint, which is defined as the amount of water required to produce everyday goods and services demanded by California consumers on a yearly basis. Such a consumption-based indicator of water use is novel, and I introduce water footprint science as an expanded reading of water that adds value to conventional approaches to understanding society’s relationship with water resources. California, as a water-limited state, presents a useful case study for examining how demands on water resources have shifted within and outside of the region through its water footprint. The Introduction section discusses the history of water use in California from a conventional perspective as well as what water footprint assessment, as an evolving science, might offer in terms of an expanded reading of water for sustainability decision making. The first study (Chapter 2) shows that scaling water footprint assessment to the state level both illuminates California’s unique arrangement with respect to internal and external water resources and provides a basis for policy consideration at a relevant decision-making level. The second study (Chapter 3) focuses on the water footprint of California’s energy system in order to show how environmental policymaking, particularly climate mitigation policies in the energy sector, can result in maladaptation with respect to water systems and that water footprint assessment provides a useful tool for avoiding redistribution of water impacts. The third study (Chapter 4) presents a time-series of California’s overall water footprint, indicating an externalization of water footprint demands in recent decades and a decreasing of dependence on internal water resources for instate consumption of everyday goods.The Conclusion section reflects on what water footprint assessment has thus far provided in terms of an expanded reading of water for California, and how that information might support sust

The objective was to determine a model to obtain the water footprint of main agricultural products from the Peru’s central highlands which are sold in the Lima markets, so a conceptual model that determines the crops water requirement was developed also with the respective yields both have established the virtual water content of each agricultural product expressed in l/kg; with this result and the sold product amount, the virtual water (AV) was determined transferred to the Lima market, corresponding to fourteen agricultural products. Values which indicate that virtual water volumes between the products vary by the commercialized amounts according to the production which depends on factors such as weather, consumer demand and the technology used in production were obtained. Thus, consumption of a potato kg in Lima involves the transfer of 300,71 liters of “virtual water” from the Junin region where the product is produced. The product which transfer as much virtual water is the potato with 78 069 926,37 m3, followed by green peas with 16 889 273,96 m3, and the product which transfer as little virtual water is the onion with 10 336,59 m3, whereas the total volume of transferred virtual water is 165 595 592,28 m3., El objetivo ha sido determinar un modelo para obtener la huella hídrica de los principales productos agrícolas de la sierra central del Perú que son comercializados en los mercados de la ciudad de Lima, para ello se desarrolló un modelo conceptual que determine el requerimiento de agua de los cultivos que junto a los respectivos rendimientos han permitido establecer el contenido de agua virtual de cada producto agrícola expresado en l/kg; con este resultado y la cantidad de producto comercializado, se han determinado el agua virtual (AV) transferida hacia el mercado de Lima, correspondiente a los catorce productos agrícolas considerados. Se obtuvieron valores que indican que los volúmenes de agua virtual entre los productos varían por las cantidades comercializadas y están en función de la producción que a su vez depende de factores como el clima, la demanda del consumidor y de la tecnología empleada en la producción. Así, el consumo de un kg de papa en la ciudad de Lima implica la transferencia de 300,71 litros de “agua virtual” desde la región Junín, donde se produce el producto. El producto que transfiere la mayor cantidad de agua virtual es la papa con 78 069 926,37 m3, seguido de la arveja verde con 16 889 273,96 m3, y el producto que transfiere la menor cantidad es la cebolla con 10 336,59 m3, en tanto que el volumen total de agua virtual transferida es de 165 595 592,28 m3.

Tourism is increasingly recognized as a significant water-consuming sector on local, regional and global scales. As a consequence, the efficient use of water resources is now considered a key sustainability challenge for the tourism industry. To date, most research has focused on direct (on site) water consumption, with tourism water management based almost exclusively on direct water use benchmarks. This paper argues that such an approach overlooks the complexity of 'local' and 'global' water use, with local water use affecting sustainable water use in the destination and global water use representing the sustainability of water embodied in goods produced elsewhere, including fuels and food. Focussing on tourism accommodation as the locus of tourism water consumption, conventional water indicators are reviewed and discussed, and knowledge gaps identified. New data accounting for food consumption are then presented for a case study of resort hotels in Rhodes, Greece. The results are used to develop a novel set of performance indicators suitable for resort hotels and other accommodation, considering water availability, planning and operation, as well as complexities of direct vis-a-vis indirect water consumption. The findings suggest a significant potential for water and related cost savings, indicating that holistic water management should be an operational imperative. (C) 2014 Elsevier Ltd. All rights reserved.

Ever since the food price crisis of 2007/8, concerns about global food supply interruptions have mounted. However, while exports from Brazil, the world’s leading soy exporter, are currently under threat, this is not due to geopolitical concerns, but due to resource mismanagement. As a consequence, the country with the most water availability per person is mired in an enduring water crisis, impacting on its major water transport routes. Brazil’s development model is based on an oligopolistic public-private, primary-sector conglomerate, fueled by the federal investment bank, BNDES. This article argues that Brazil has embarked on an unsustainable model of development and is exporting that model as part of its ‘South-South Cooperation’ (SSC) drive. Like the other BRICS, Brazil is using SSC to present itself as non-ideological and anti-imperialist but, in fact, uses the cooperation strategy for diplomatic and self-interested economic purposes. The Middle East is specifically targeted as a region with ‘complementary’ interests: rich in fossil fuels, poor in land and water and plenty of petrodollars to buy food security. The current water crisis shows limits to this complementarity, in the process undermining the assumption that ‘virtual-water exports’ promoted by competitive specialization are salutary to the global water balance.

In his dissertation Brian Dermody sought explanations for how the climate has changed in the last 10,000 years. Specifically, he used statistical methods to obtain a composite spatial and temporal image of climate change. He was also interested in how these climate changes have influenced past societies. He therefore developed a virtual water network of the Roman world based on grain production and transportation during the Roman period. In this way he could begin to unravel how Roman trade and agriculture influenced their resilience to climate change.

Agriculture is the main user of limited fresh water resources in the world. Optimisation of agricultural water resources and their use can be obtained by both agronomical and political incentives. Important options are: reduction of the loss of irrigation water in conveyance before it reaches the farm; selection of water-efficient irrigation methods such as drip and micro-irrigation saving 30–40 % water compared to furrow irrigation; improvement of irrigation scheduling using plant and soil sensors and remote sensing-based models; deficit irrigation (DI) raising the water productivity in the range of 10–50 %; use of saline and wastewater for which modelling tools lately have been developed; introduction of drought and salt-tolerant crops eases the use of DI and use of saline water; improvement of cropping systems with development of conservation agriculture. Further options are: use of the ‘virtual water’ principles so that water-rich regions secure food supply to dry regions; reduction in waste of food, feed and biofuel from post-harvest to the end consumer; changing of food composition to less water-consuming products; regulating amount of irrigation water by rationing, subsidies or water pricing to support water-saving measures such as use of drip, irrigation scheduling and DI. The potential for water saving for different measures is discussed and estimated. Reduction in waste of food and loss of irrigation water from conveyance source to farm both has a great potential for water saving compared to other measures. How to choose the measures will depend on the local situation, which is ultimately a political choice., Agriculture is the main user of limited fresh water resources in the world. Optimisation of agricultural water resources and their use can be obtained by both agronomical and political incentives. Important options are: reduction of the loss of irrigation water in conveyance before it reaches the farm; selection of water-efficient irrigation methods such as drip and micro-irrigation saving 30-40 % water compared to furrow irrigation; improvement of irrigation scheduling using plant and soil sensors and remote sensing-based models; deficit irrigation (DI) raising the water productivity in the range of 10-50 %; use of saline and wastewater for which modelling tools lately have been developed; introduction of drought and salt-tolerant crops eases the use of DI and use of saline water; improvement of cropping systems with development of conservation agriculture. Further options are: use of the 'virtual water' principles so that water-rich regions secure food supply to dry regions; reduction in waste of food, feed and biofuel from post-harvest to the end consumer; changing of food composition to less water-consuming products; regulating amount of irrigation water by rationing, subsidies or water pricing to support water-saving measures such as use of drip, irrigation scheduling and DI. The potential for water saving for different measures is discussed and estimated. Reduction in waste of food and loss of irrigation water from conveyance source to farm both has a great potential for water saving compared to other measures. How to choose the measures will depend on the local situation, which is ultimately a political choice.

This dissertation consists of three essays on different aspects of water management. The first essay focuses on the sustainability of freshwater use by introducing the notion that altruistic parents do bequeath economic assets for their offspring. Constructing a two-period, over-lapping generational model, an optimal ratio of consumption and pollution for old and young generations in each period is determined. Optimal levels of water consumption and pollution change according to different parameters, such as, altruistic degree, natural recharge rate, and population growth. The second essay concerns water sharing between countries in the case of trans-boundary river basins. The paper recognizes that side payments fail to forge water-sharing agreement among the international community and that downstream countries have weak bargaining power. An interconnected game approach is developed by linking the water allocation issue with other non-water issues such as trade or border security problems, creating symmetry between countries in bargaining power. An interconnected game forces two countries to at least partially cooperate under some circumstances. The third essay introduces the concept of virtual water (VW) into a traditional international trade model in order to estimate water savings for a water scarce country. A two country, two products and two factors trade model is developed, which includes not only consumers and producer’s surplus, but also environmental externality of water use. The model shows that VW trade saves water and increases global and local welfare. This study should help policy makers to design appropriate subsidy or tax policy to promote water savings especially in water scarce countries.

Virtual water, the amount of water used along a good’s value chain, has come under discussion. Fairness and efficiency problems are seen to arise in the reallocation of access to water resources through the means of international trade. Moral issues are attached to both imports and exports, and even to a country’s own consumption of virtual water. Global institutional arrangements have therefore been suggested to regulate virtual water trade both efficiently and ‘fairly’. With this paper we will provide a short overview of the concept’s history and findings, and an analysis from the perspective of economic trade theory, bringing up the old debate about the economic and environmental merits of free trade. The contribution of this paper will be to examine the performance of virtual water concepts in advising business or policy decisions in the form of global governance arrangements. It must be concluded that the virtual water concept is limited in terms of its usefulness in providing policy advice. The usually applied normative criteria are inconsistent, implying governance schemes that improve neither efficiency nor sustainability. Water-related problems should be solved in the respective arenas and not by global governance schemes or trade barriers.

In our globalizing world, the geographical locations of food production and consumption are becoming increasingly disconnected, which increases reliance on external resources and their trade. We quantified to what extent water and land constraints limit countries' capacities, at present and by 2050, to produce on their own territory the crop products that they currently import from other countries. Scenarios of increased crop productivity and water use, cropland expansion (excluding areas prioritized for other uses) and population change are accounted for. We found that currently 16% of the world population use the opportunities of international trade to cover their demand for agricultural products. Population change may strongly increase the number of people depending on ex situ land and water resources up to about 5.2 billion (51% of world population) in the SRES A2r scenario. International trade will thus have to intensify if population growth is not accompanied by dietary change towards less resource-intensive products, by cropland expansion, or by productivity improvements, mainly in Africa and the Middle East. Up to 1.3 billion people may be at risk of food insecurity in 2050 in present low-income economies (mainly in Africa), if their economic development does not allow them to afford productivity increases, cropland expansion and/or imports from other countries., Peer Reviewed