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The Water Footprint Network (WFN) methodology has emerged as a major framework of/for policy analysis as water problems increase. Being addressed by a growing body of literature, water footprint (WF) accounting has advanced substantially in recent years, whereas its sustainability assessment has lagged behind. For this and other reasons, the suitability of WF in guiding water management and planning has been criticised. Simultaneously, water efficiency has gone through much discussion and a new framework called 'sefficiency' (sustainable efficiency) has been presented. It uses a universal law (water balance) to develop systemic and comprehensive performance indicators, integrating water quantity, pollution and value to reveal their trade-offs in multi-level governance with climate descriptors and stakeholder enablers. This article revisits WF criticisms in six categories and advances the sustainability assessment phase of the WFN framework via sefficiency. Starting from, and critically reviewing, a two-country example presented by Dennis Wichelns, we illustrate, through nine (3x3) scenarios, real possibilities of integrating WF and sefficiency. The results reveal that economic and/or WF perspectives alone are insufficient to improve water decision-making processes, not necessarily guaranteeing an increase in the performance of the full system. Consequently, policy makers should be doubly careful about, for example, WF reductions, if sefficiency also decreases. [ABSTRACT FROM AUTHOR]

While agriculture places the greatest demand on water resources, increasing agricultural production is worsening a global water shortage. Reducing the cultivation of water-consuming crops may be the most effective way to reduce agricultural water use. However, when also taking food demand into consideration, sustaining the balance between regional water and food securities is a growing challenge. This paper addresses this task for regions where water is unsustainable for food production (Beijing-Tianjin-Hebei Region for example) by: (i) assessing the different effects of wheat and maize on water use; (ii) analyzing virtual water and virtual land flows associated with food imports and exports between Beijing-Tianjin-Hebei and elsewhere in China; (iii) identifying sub-regions where grain is produced using scarce water resources but exported to other regions; and (iv) analyzing the potentiality for mitigating water shortage via Land-Water-Food Nexus. In the Beijing-Tianjin-Hebei Region, the study reveals that 29.76 bn m 3 of virtual water (10.81 bn m 3 of blue virtual water) are used by wheat and maize production and 8.77 bn m 3 of virtual water used in nearly 2 million ha of cropland to overproduce 12 million ton of maize for external food consumption. As an importing-based sub-region with high population density, Beijing & Tianjin imported mostly grain (wheat and maize) from Shandong Province. Then, Hebei Province, as an exporting-based sub-region with severe water shortage, overproduced too much grain for other regions, which aggravated the water crisis. To achieve an integrated and sustainable development of the Beijing-Tianjin-Hebei Region, Hebei Province should stop undertaking the breadbasket role for Beijing & Tianjin and pay more attention to groundwater depletion. The analysis of the Land-Water-Food Nexus indicates how shifts in cultivated crops can potentially solve the overuse of water resources without adverse effects on food supply. It also provides meaningful information to support policy decisions about regional cropping strategies. [ABSTRACT FROM AUTHOR]

This paper examines the determinants of virtual water trade - embodied in agricultural products - and tests the relationship between property rights and the export of water-intensive products. Using two different measures of property rights protection, I show that countries with weaker property rights have an apparent comparative advantage in the export of water-intensive products. After controlling for economic size, natural resource endowments and bilateral trade determinants, the trade flow of virtual water is negatively and significantly correlated with the property rights index of the exporting country. The results are robust across different estimation methods. [ABSTRACT FROM AUTHOR]

Chongming Island is a distinct developing area in Shanghai and is currently being transformed as an international eco-island. The area is located in the Yangtze River estuary and secures the crop supply in Shanghai because of its unique geographical position and abundant water resource. Chongming is an agriculture-dominated district in an industrial city and is characterized by balanced utilization and natural preservation. In this study, the water footprint in Chongming Island from 2011 to 2014 was calculated and the water shortage was analyzed using virtual water as a criterion. Result shows that agricultural water footprint accounted for a major proportion of the total water footprint in Chongming Island. Water footprint from the manufacture of consumer products or services for residents was within the local water resource capacity, indicating that the self-sufficiency rate of water resource in Chongming Island was high. Nevertheless, this rate had been decreasing because of large imports that transfer water burden to other areas to optimize sustainable water consumption. However, Chongming Island had a higher water scarcity than other cities near Shanghai. Agricultural water footprint was categorized to assess the water utilization structure in Chongming’s agriculture. On the basis of the data from 2005 to 2014, four different scenarios were analyzed to predict the water footprint by 2040. The influence of the agricultural structure adjustment on the water resources of Chongming Island was assessed. Water consumption could be obviously reduced by 11.5% when the agricultural structure was changed. This situation should not be ignored by policy makers. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Agricultural Sciences, Belgrade is the property of University of Belgrade, Faculty of Agriculture and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

This study provides an innovative application of virtual water trade in the traditional allocation of physical water resources in water scarce regions. A multi-objective optimization model was developed to optimize the allocation of physical water and virtual water resources to different water users in Beijing, China, considering the trade-offs between economic benefit and environmental impacts of water consumption. Surface water, groundwater, transferred water and reclaimed water constituted the physical resource of water supply side, while virtual water flow associated with the trade of five major crops (barley, corn, rice, soy and wheat) and three livestock products (beef, pork and poultry) in agricultural sector (calculated by the trade quantities of products and their virtual water contents). Urban (daily activities and public facilities), industry, environment and agriculture (products growing) were considered in water demand side. As for the traditional allocation of physical water resources, the results showed that agriculture and urban were the two predominant water users (accounting 54% and 28%, respectively), while groundwater and surface water satisfied around 70% water demands of different users (accounting 36% and 34%, respectively). When considered the virtual water trade of eight agricultural products in water allocation procedure, the proportion of agricultural consumption decreased to 45% in total water demand, while the groundwater consumption decreased to 24% in total water supply. Virtual water trade overturned the traditional components of water supplied from different sources for agricultural consumption, and became the largest water source in Beijing. Additionally, it was also found that environmental demand took a similar percentage of water consumption in each water source. Reclaimed water was the main water source for industrial and environmental users. The results suggest that physical water resources would mainly satisfy the consumption of urban and environment, and the unbalance between water supply and demand could be filled by virtual water import in water scarce regions. [ABSTRACT FROM AUTHOR]

The pattern of virtual water trade within a region or region has a certain complexity. This paper uses multi-regional input-output models, local and tele-coupling theory, and geographical detectors to analyze the short-range and remote spatial pattern, change trends, and influencing factors of China's virtual water trade, which has essential research significance for the sustainable development and utilization of water resources. The results are as follows: (1) The water footprint and virtual water trade of each province in China are more likely to occur between the provinces close to each other, the local distance average distance is below 500 km, and the remote average distance is between 1100 km and 2000 km; (2) China's short-range inflow and outflow water footprint has always been the main dependent part of China's consumption and production end water resources, especially the local water footprint. The contribution of the remote water footprint has gradually been "replaced" by the short-range water footprint, and water resources only form a "small cycle" between the local and surrounding areas, becoming the main pattern of sustainable utilization of water resources in China; (3) The flow pattern of water resources in China still has a spatial imbalance and agglomeration effects. Regions with abundant water resources are net inflow and net import regions in both short-range and remote, and the net inflow and net outflow values in remote are higher than those in short-range; (4) The virtual water trade in all provinces of China tends to be close to each other. The "flow" in the trade network is mainly concentrated in the link path below 800 km. The interaction of various "flows" in short-range and remote virtual water trade results in fewer "flows" on one side and more on the other side in the industrial link path. Local virtual water trade has become an important guarantee and foundation for the utilization of water resources in all provinces and an important auxiliary to the total import virtual water trade; (5) The correlation of socio-economic factors to China's short-range and remote virtual water trade is higher than that of natural factors and scientific and technological factors. The interaction of factors contribution of a single factor more thoroughly and even far exceeds the sum of the contribution of two single factors, which can better explain the formation and change of near and long-distance virtual water trade patterns and flow on the link path. [ABSTRACT FROM AUTHOR]

Climate change is leading to increased water scarcity and drought in many parts of the world. This has implications for the European Union (EU) because a lot of the water intensive goods consumed or used there are produced abroad. This makes the EU’s economy dependent on water resources well beyond its borders since when a country imports water intensive goods, indirectly it also imports virtual water (water needed to produce the imported goods). This study maps the EU’s global dependency on water resources outside its borders in terms of virtual water imports and assesses how water scarcity and drought may disrupt supplies of key food crops that it imports. The EU uses approximately 668 km3 of water for all of the goods it produces, consumes and exports, annually. Around 38% of that water comes from outside its borders, which means that the EU’s economy is highly dependent on the availability of water in other parts of the world. In the near future, supplies of certain crops to the EU could be disrupted due to water scarcity in other parts of the world; a large portion of the water used in producing soybeans, rice, sugarcane, cotton, almonds, pistachios and grapes for import to the EU comes from areas with significant or severe levels of water scarcity. Although the immediate risks to the EU’s economy are due to current water scarcity levels, any disruption to rainfall patterns that occur in the future, due to the effects of climate change in the countries of origin of key crops, could have a far greater impact. This is because as much as 92% of the EU’s total external water demand from agriculture is attributed to green water use, availability of which has relatively higher vulnerability to drought.

This study investigates the Water Footprint (WF) resulting from the agricultural imports of the European Union (EU-28). Import trade statistics were compiled and linked with crop- and country-specific water consumption data and water scarcity factors. Within the study, the virtual water imports of 104 agricultural commodities for the baseline year 2015 were assessed and product and country hotspots were evaluated. It was shown that (a) Europe imported 100 million tons of agricultural goods and 11 km3 of associated virtual irrigation water; (b) the highest impacts of water consumption do not necessarily result from high import amounts, but from water-intensive goods produced in water scarce countries; (c) the largest external EU-28 water footprint occurred due to the product categories cotton, nuts and rice; and (d) the highest share of the EU external water footprint took place in the United States (US), Pakistan, Turkey, Egypt and India.

We quantify the impact of food consumption on local and foreign water resources through an indicator of the environmental value of the riverine water. This indicator takes into account both the local environmental relevance of the fluvial area where water is withdrawn (biodiversity richness, riparian vegetation, sediment transport, etc) and the downstream effects of water withdrawals. In the 1986–2013 period, food consumption has more than doubled its impact on foreign riverine environments, but still the international trade reduces the pressure of food consumption on global river system by 11%, as compared to an ideal situation where all food is produced locally. We also show the geography of country (or individual) responsibility on the environmental changes of world rivers. Hotspots of food-related river-environment degradation are found in Australia, Pakistan, South Africa, and Spain.

The increasing global demand for farmland products is placing unprecedented pressure on the global agricultural system and its water resources. Many regions of the world, that are affected by a chronic water scarcity relative to their population, strongly depend on the import of agricultural commodities and associated embodied (or virtual ) water. The globalization of water through virtual water trade (VWT) is leading to a displacement of water use and a disconnection between human populations and the water resources they rely on. Despite the recognized importance of these phenomena in reshaping the patterns of water dependence through teleconnections between consumers and producers, their effect on global and regional water resources has just started to be quantified. This review investigates the global spatiotemporal dynamics, drivers, and impacts of VWT through an integrated analysis of surface water, groundwater, and root-zone soil moisture consumption for agricultural production; it evaluates how virtual water flows compare to the major ‘physical water fluxes’ in the Earth System; and provides a new reconceptualization of the hydrologic cycle to account also for the role of water redistribution by the hidden ‘virtual water cycle’.

Recent studies have highlighted the reliance of global food production on unsustainable irrigation practices, which deplete freshwater stocks and environmental flows, and consequently impair aquatic ecosystems. Unsustainable irrigation is driven by domestic and international demand for agricultural products. Research on the environmental consequences of trade has often concentrated on the global displacement of pollution and land use, while the effect of trade on water sustainability and the drying of over-depleted watercourses has seldom been recognized and quantified. Here we evaluate unsustainable irrigation water consumption (UWC) associated with global crop production and determine the share of UWC embedded in international trade. We find that, while about 52% of global irrigation is unsustainable, 15% of it is virtually exported, with an average 18% increase between year 2000 and 2015. About 60% of global virtual transfers of UWC are driven by exports of cotton, sugar cane, fruits, and vegetables. One third of UWC in Mexico, Spain, Turkmenistan, South Africa, Morocco, and Australia is associated with demand from the export markets. The globalization of water through trade contributes to running rivers dry, an environmental externality commonly overlooked by trade policies. By identifying the producing and consuming countries that are responsible for unsustainable irrigation embedded in virtual water trade, this study highlights trade links in which policies are needed to achieve sustainable water and food security goals in the coming decades.

In the international trade network, links express the (temporary) presence of a commercial exchange of goods between any two countries. Given the dynamical behaviour of the trade network, where links are created and dismissed every year, predicting the link activation/deactivation is an open research question. Through the international trade network of agricultural goods, water resources are ‘virtually’ transferred from the country of production to the country of consumption. We propose a novel methodology for link prediction applied to the network of virtual water trade. Starting from the assumption of having links between any two countries, we estimate the associated virtual water flows by means of a gravity-law model using country and link characteristics as drivers. We consider the links with estimated flows higher than 1000 m 3 /year as active links, while the others as non-active links. Flows traded along estimated active links are then re-estimated using a similar but differently-calibrated gravity-law model. We were able to correctly model 84% of the existing links and 93% of the non-existing links in year 2011. It is worth to note that the predicted active links carry 99% of the global virtual water flow; hence, missed links are mainly those where a minimum volume of virtual water is exchanged. Results indicate that, over the period from 1986 to 2011, population, geographical distances between countries, and agricultural efficiency (through fertilizers use) are the major factors driving the link activation and deactivation. As opposed to other (network-based) models for link prediction, the proposed method is able to reconstruct the network architecture without any prior knowledge of the network topology, using only the nodes and links attributes; it thus represents a general method that can be applied to other networks such as food or value trade networks. [ABSTRACT FROM AUTHOR]

The paper investigates how the topological features of the virtual water (VW) network and the size of the associated VW flows are likely to change over time, under different socio-economic and climate scenarios. We combine two alternative models of network formation –a stochastic and a fitness model, used to describe the structure of VW flows- with a gravity model of trade to predict the intensity of each bilateral flow. This combined approach is superior to existing methodologies in its ability to replicate the observed features of VW trade. The insights from the models are used to forecast future VW flows in 2020 and 2050, under different climatic scenarios, and compare them with future water availability. Results suggest that the current trend of VW exports is not sustainable for all countries. Moreover, our approach highlights that some VW importers might be exposed to “imported water stress” as they rely heavily on imports from countries whose water use is unsustainable. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Water & Land Development is the property of Polish Academy of Sciences and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this paper we consider some of the economic implications of climate change scenarios as described in the Shared Socioeconomic Pathways (SSPs). By comparing potential water demand with estimates of (sustainable) water availability in different regions, we identify regions that are likely to be constrained in their future economic growth potential by the scarcity of water resources. We assess the macroeconomic impact of water scarcity under alternative allocation rules finding that, by assigning more water to sectors in which it has a higher value, shifting production to less water intensive sectors, and importing more water intensive goods, constrained regions can effectively neutralize these water related climate risks and adapt to a changing water environment. However, this adaptation effort is likely to imply some radical changes in water management policies. [ABSTRACT FROM AUTHOR]

Iran's focus on food self-sufficiency has led to an emphasis on increasing water volumes available for irrigation with little attention to water use efficiency, and no attention at all to the role of consumption and trade. To better understand the development of water consumption in relation to food production, consumption, and trade, we carried out the first comprehensive water footprint assessment (WFA) for Iran, for the period 1980-2010, and estimated the water saving per province associated with interprovincial and international crop trade. Based on the AquaCrop model, we estimated the green and blue water footprint (WF) related to both the production and consumption of 26 crops, per year and on a daily basis, for 30 provinces of Iran. We find that, in the period 1980-2010, crop production increased by 175%, the total WF of crop production by 122%, and the blue WF by 20%. The national population grew by 92%, and the crop consumption per capita by 20%, resulting in a 130% increase in total food consumption and a 110% increase in the total WF of national crop consumption. In 2010, 26% of the total water consumption in the semi-arid region served the production of crops for export to other regions within Iran (mainly cereals) or abroad (mainly fruits and nuts). Iran's interprovincial virtual water trade grew by a factor of 1.6, which was mainly due to increased interprovincial trade in cereals, nuts, and fruits. Current Iranian food and water policy could be enriched by reducing the WFs of crop production to certain benchmark levels per crop and climatic region and aligning cropping patterns to spatial differences in water availability and productivities, and by paying due attention to the increasing food consumption per capita in Iran. [ABSTRACT FROM AUTHOR]

Indirect trade of water (virtual water) through export of crop and livestock products may pose a risk to water resources in the exporting country. Management strategies can be framed by identifying the partner countries and the current status of water resources in these countries. This study for the first time analyses the virtual water trade of India considering the specific virtual water contents of crop and livestock products from all partner countries from 1986 to 2013 (28 years). Average virtual water export of India is 59 Bm 3 /y and virtual water import is 32.6 Bm 3 /y. Net virtual water import (−26.4 Bm 3 /y) indicates India is a major exporter. Oil, cereals, industrial products (cotton, jute, hides etc.) and semi-luxury goods contribute to 79% of virtual water export. Oil and nuts contribute to 71% of virtual water import. Decline in virtual water trade due to slow economic growth and impact of floods are reflected in the inter-annual variation. Highest virtual water trade from India is to countries in Asia (74% as virtual water export and 59% as virtual water import). Virtual water import to India are mainly through palm oil, cashew nuts, soybean, sunflower oil, wheat, rubber, cotton and pulses. Water footprint of India has increased by 1.3 times in 28 years. Strategies for sustainable management of water resources in India and the partner countries should aim at reducing the import of water-intensive goods from water-scarce countries and increasing import of water-intensive goods from water-abundant countries. [ABSTRACT FROM AUTHOR]

The aim of this study was to evaluate virtual water export through five crops (barley, rice, maize, soybeans, and wheat) in terms of the external virtual water rate, within and outside of Asia from 2000 to 2012, and in comparison with that within and outside the European Union (EU). The external virtual water rate indicates the proportion of virtual water export outside of a boundary. Approximately 46.9% of the green water exports and 40.9% of the blue water exports were discharged from Asia to non-Asian countries. For example, Thailand, which is the main exporter in Asia, exported 55.5% of the total virtual water exported to non-Asian countries, and Kazakhstan exported 63.8% of the total virtual water exported to European countries. In comparison, the external virtual water rate for the EU was 30.2% (green water) and 25.2% (blue water). The virtual water trade is also important to the main importers in Asia. We evaluated the virtual water dependency on exporters in East Asia of Japan, Korea, and Taiwan. These three countries have a high dependency on virtual water imported from only a few exporters; thus, they should extend their virtual water trade boundary to include additional exporters. These results provide information necessary for the development of an integrated water strategy in Asia, and could convince the main Asian importers of the risks of serious dependency on foreign water resources. [ABSTRACT FROM AUTHOR]

The development of approaches to tackle the European Union (EU) water-related challenges and shift towards sustainable water management and use is one of the main objectives of Horizon 2020, the EU strategy to lead a smart, sustainable and inclusive growth. The EU is an increasingly water challenged area and is a major agricultural trader. As agricultural trade entails an exchange of water embodied in goods as a factor of production, this study investigates the region's water–food–trade nexus by analysing intra-regional virtual water trade (VWT) in agricultural products. The analysed period (1993–2011) comprises the enactment of the Water Framework Directive (WFD) in the year 2000. Aspects of the VWT that are relevant for the WFD are explored. The EU is a net importer of virtual water (VW) from the rest of the world, but intra-regional VWT represents 46% of total imports and 75% of total exports. Five countries account for 60% of total VW imports (Germany, France, Italy, The Netherlands, Belgium) and 65% of total VW exports (The Netherlands, France, Germany, Belgium and Spain). Intra-EU VWT more than doubled over the period considered, while trade with extra-EU countries did not show such a marked trend. In the same period, blue VWT increased significantly within the region and net import from the rest of the world slightly decreased. Water scarce countries, such as Spain and Italy, are major exporters of blue water in the region. The traded volumes of VW have been increasing almost monotonically over the years, and with a substantial increase after 2000. The overall trend in changes in VWT does not seem to be in accordance with the WFD goals. This study demonstrated that VWT analyses can help evaluate intertwining effects of water, agriculture and trade policies which are often made separately in respective sectors. [ABSTRACT FROM AUTHOR]

This special issue is a collection of recent papers in the field of Water Footprint Assessment (WFA), an emerging area of research focused on the analysis of freshwater use, scarcity, and pollution in relation to consumption, production, and trade. As increasing freshwater scarcity forms a major risk to the global economy, sustainable management of water resources is a prerequisite to development. We introduce the papers in this special issue by relating them to Sustainable Development Goal (SDG) number 6 of the United Nations, the goal on water. We will particularly articulate how each paper drives the understanding needed to achieve target 6.3 on water quality and pollution and target 6.4 on water-use efficiency and water scarcity. Regarding SDG 6, we conclude that it lacks any target on using green water more efficiently, and while addressing efficiency and sustainability of water use, it lacks a target on equitable sharing of water. The latter issue is receiving limited attention in research as well. By primarily focusing on water-use efficiency in farming and industries at the local level, to a lesser extent to using water sustainably at the level of total water systems (like drainage basins, aquifers), and largely ignoring issues around equitable water use, understanding of our water problems and proposed solutions will likely remain unbalanced. [ABSTRACT FROM AUTHOR]

Since the concept of virtual water was put forward, there has been an increasing number of papers on the topic, as a result of which virtual water is now being mainstreamed in the water policy world. Unfortunately, virtual water trade strategy as a solution to water shortages is wrong and fallacious. Although the virtual water trade theory is considered a descendant of the comparative advantage theory of economics, it is in fact an over-simplification, going from the truth to fallacy. To make decisions of virtual water trade based on only one production factor, water, though there are many other production factors that influence the allocation of resources at the same time, is misleading theoretically and practically. [ABSTRACT FROM AUTHOR]

The Trans-Pacific Partnership Agreement (TPPA) is one of the most important multilateral free trade and investment agreements in recent years. Although as a major economic power in the Asia-Pacific region, China has yet to join the TPPA. Existing research on China and TPPA countries has mainly been conducted from political and economic perspectives. This paper first reports the relationship between China and TPPA countries from the perspective of virtual water trade of agricultural products and completes a diachronic analysis from 2001 to 2014. The results indicate that China was in virtual water trade surplus with TPPA countries for agricultural products and that the surplus had an expansion trend. The exported virtual water totalled 7.47 billion m 3 /y, whereas 63.45 billion m 3 /y was embedded in imported products. Malaysia was the biggest virtual water surplus partner of China and Japan was the biggest virtual water deficit partner. Additionally, the proportion of the grey water footprint of agricultural products that China exported to TPPA countries was about five times higher than that imported from TPPA countries. It reflected the difference of agricultural science and technology. Moreover, the products structure of China's virtual water trade was not reasonable and was excessively focused on several products. Finally, with respect to environmental and water allocation ethics, TPPA countries were classified into four types in terms of net import and water abundance: mutual benefit countries (Australia, Canada, New Zealand, the United States, Malaysia and Chile); unilateral benefit countries (Peru and Brunei); supported countries (Japan and Singapore); and double pressure countries (Mexico and Vietnam). With respect to the virtual water trade of agricultural products, there is a close relationship between China and TPPA countries. The virtual water trade promotes the sustainability of water resources and the findings are conducive to the adjustment of trade structure to achieve optimal state of ecology, economy and politics. [ABSTRACT FROM AUTHOR]

The observed and predicted changes in climate, as well as the growth in urban population, are creating severe stress on existing water resources in South Korea. By the importation of agricultural products from more water-rich countries through the virtual water concept, a country could save local water resources for other important uses. However, these imports from other countries could lead to certain vulnerabilities in the importing country derived from climate change. Therefore, through the application of the virtual water concept and the climate vulnerability index ((CVI) - measure of a country's vulnerability to indirect climate impacts), this study assessed the implication of virtual water imports and climate change through food trade, on the water, land and food security status of South Korea over the period of 2000–2017. The results showed that significant amounts of national water and land was saved through the importation of major upland crops. Virtual water imports increased significantly over time, rising from 16.2 Bm3 in 2000 to 16.5, 17.4, and 20.7 Bm3 in 2005, 2011, and 2017 respectively, with the USA, China, Australia, Brazil and Canada being the major exporters to South Korea. The study also revealed high CVI values for the oils and grains category of imported food, implying the high vulnerability of South Korea to climate change effects resulting from the import of these crops. The quantitative impacts and structural changes in virtual water trade, as well as the link between climate change, food security, international trade, and domestic water consumption could be evaluated for the sustainable management and allocation of resources. This study successfully identified and quantified the status of food trade and its environmental implications in the study area, providing insight into a better allocation of locally available resources. • South Korea's food trade is analyzed using the virtual water concept and climate vulnerability index. • Significant amounts of national water and land was saved through the importation of major upland crops. • Virtual water imports increased significantly between 2000 and 2017. • South Korea is more exposed to climate change effects from the imports of oils and grains. • The study can aid the development of effective policies that curb water stress. [ABSTRACT FROM AUTHOR]

Trade of commodities can lead to virtual water flows between trading partners. When commodities flow from regions of high water productivity to regions of low water productivity, the trade has the potential to generate water saving. However, this accounting of water saving does not account for the water scarcity status in different regions. It could be that the water saving generated from this trade occurs at the expense of the intensified water scarcity in the exporting region, and exerts limited effect on water stress alleviation in importing regions. In this paper, we propose an approach to measure the scarce water saving associated with virtual water trade (measuring in water withdrawal/use). The scarce water is quantified by multiplying the water use in production with the water stress index (WSI). We assessed the scarce water saving/loss through interprovincial trade within China using a multi-region input-output table from 2010. The results show that interprovincial trade resulted in 14.2 km ^3 of water loss without considering water stress, but only 0.4 km ^3 scarce water loss using the scarce water concept. Among the 435 total connections of virtual water flows, 254 connections contributed to 20.2 km ^3 of scarce water saving. Most of these connections are virtual water flows from provinces with lower WSI to that with higher WSI. Conversely, 175 connections contributed to 20.6 km ^3 of scarce water loss. The virtual water flow connections between Xinjiang and other provinces stood out as the biggest contributors, accounting for 66% of total scarce water loss. The results show the importance of assessing water savings generated from trade with consideration of both water scarcity status and water productivity across regions. Identifying key connections of scarce water saving is useful in guiding interregional economic restructuring towards water stress alleviation, a major goal of China’s sustainable development strategy.

[Display omitted] • Urbanisation was a core driver of staple crop WFSS in water scarce provinces. • Population and social urbanisation enhanced China's staple crop WFSS. • Economic and spatial urbanisation reduced crop WFSS. • This work challenged the conventionally urbanisation-water relationship. Rapid urbanisation in developing countries has exerted ever-increasing pressure on food and water resource systems. Existing studies mostly focus on impacts of population urbanisation on agricultural water use, disregarding the multidimensional characteristics of urbanisation. Accounting for four dimensions of urbanisation: population, economy, spatial distribution, and society, we assessed the impact of multidimensional urbanisation on the water footprint self-sufficiency rate (WFSS) of three staple crops, that is, the ratio of the water footprint (WF) of crop production to the WF of crop-related consumption, through the case for China over 2000–2017. The socio-economic driving factors and spatial heterogeneity of crop WFSS were further tested. Results show that <30% of high-crop WFSS provinces supplied more than 70% of low-crop WFSS provinces. Social urbanisation and economic urbanisation were the governing positive and negative driving factors of the rice WFSS, respectively. Population urbanisation was the dominant factor attenuating wheat WFSS during the study period, while playing a reverse role in maize WFSS. Impacts of different dimensions of urbanisation on crop WFSS were heterogeneous and even contradictory depending on the crop type, the different processes of urbanisation, and the water endowment and economic level of the provinces. The quantile regression results further indicate that population urbanisation, spatial urbanisation and social urbanisation had greater impact on the higher WFSS (i.e., resulted in virtual water export) of rice and wheat. The current analysis challenges the conventionally monotonous urbanisation-water relationships, and suggests that additional dimensions of urbanisation should be considered when assessing the effects of urbanisation on agricultural water use. [ABSTRACT FROM AUTHOR]

Copyright of Irrigation & Drainage is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The study assesses green and blue water footprints (WFs) and virtual water (VW) trade in China under alternative scenarios for 2030 and 2050, with a focus on crop production, consumption and trade. We consider five driving factors of change: climate, harvested crop area, technology, diet, and population. Four scenarios (S1–S4) are constructed by making use of three of IPCC's shared socio-economic pathways (SSP1–SSP3) and two of IPCC's representative concentration pathways (RCP 2.6 and RCP 8.5) and taking 2005 as the baseline year. Results show that, across the four scenarios and for most crops, the green and blue WFs per tonne will decrease compared to the baseline year, due to the projected crop yield increase, which is driven by the higher precipitation and CO 2 concentration under the two RCPs and the foreseen uptake of better technology. The WF per capita related to food consumption decreases in all scenarios. Changing to the less-meat diet can generate a reduction in the WF of food consumption of 44% by 2050. In all scenarios, as a result of the projected increase in crop yields and thus overall growth in crop production, China will reverse its role from net VW importer to net VW exporter. However, China will remain a big net VW importer related to soybean, which accounts for 5% of the WF of Chinese food consumption (in S1) by 2050. All scenarios show that China could attain a high degree of food self-sufficiency while simultaneously reducing water consumption in agriculture. However, the premise of realizing the presented scenarios is smart water and cropland management, effective and coherent policies on water, agriculture and infrastructure, and, as in scenario S1, a shift to a diet containing less meat. [ABSTRACT FROM AUTHOR]

This study develops water footprint scenarios for Europe for 2050, at the country level, based on projections regarding population and economic growth, production and trade patterns, consumption patterns (diets and bioenergy use) and technological development. The objective is to estimate possible future changes in the green, blue and grey water footprint (WF) of production and consumption, to analyze the main drivers of projected changes and to assess Europe's future dependence on water resources elsewhere in the world. We develop four scenarios, considering globalization versus regional self-sufficiency, and development driven by economic objectives versus development driven by social and environmental objectives. The study shows that the most critical driver of change affecting Europe's future WF is the consumption pattern. The WFs of both production and consumption in Western Europe increase under scenarios with high meat consumption and decrease with low-meat scenarios. Besides, additional water demands from increasing biofuel needs will put further pressure on European water resources. The European countries with a large ratio of external to total WF of consumption in 2000 decrease their dependencies on foreign water resources in 2050. [ABSTRACT FROM AUTHOR]

We quantify the potential impacts of global food production on freshwater availability (water scarcity footprint; WSF) by applying the water unavailability factor (fwua) as a characterization factor and a global water resource model based on life cycle impact assessment (LCIA). Each water source, including rainfall, surface water, and groundwater, has a distinct fwua that is estimated based on the renewability rate of each geographical water cycle. The aggregated consumptive water use level for food production (water footprint inventory; WI) was found to be 4344 km³/year, and the calculated global total WSF was 18,031 km3 H²Oeq/year, when considering the difference in water sources. According to the fwua concept, which is based on the land area required to obtain a unit volume of water from each source, the calculated annual impact can also be represented as 98.5 × 106 km². This value implies that current agricultural activities requires a land area that is over six times larger than global total cropland. We also present the net import of the WI and WSF, highlighting the importance of quantitative assessments for utilizing global water resources to achieve sustainable water use globally. [ABSTRACT FROM AUTHOR]

Copyright of Tecnología y Ciencias del Agua is the property of Instituto Mexicano de Tecnologia del Agua (IMTA) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The globalization process of the last half century entailed a growing trade in agricultural and food products. As a result, water has been transferred among countries, embodied in these goods. This paper studies the evolution of virtual water flows over the long term, analyzing the main driving factors through Decomposition Analysis. It contributes to the existing literature by offering a dynamic and economic interpretation of the historical changes in virtual water trade flows. In particular, this study points to a gradual increase in virtual water exchange, related to the upsurge of agricultural and food products trade in the world from 1965 to 2010. Although the origins and destinations of virtual water have changed, North America stands out as the primary net exporter of virtual water. Europe and Asia, on the other hand, with a high dependency on foreign water resources, appear as net importers of virtual water. Despite improvements in agricultural yields and the reallocation of production, the virtual water trade continues to increase globally via these significant commercial exchanges. [ABSTRACT FROM AUTHOR]

The aim of the paper is to investigate the main determinants of the bilateral virtual water (water used in the production of a commodity or service) flows associated with international trade in agricultural goods across the Mediterranean basin. We consider the bilateral gross flows of virtual water in the area and study what export-specific and import-specific factors are significantly associated with virtual water flows. We follow a sequential approach. Through a gravity model of trade, we obtain a “refined” version of the variable we aim to explain, one that is free of the amount of flows due to pair-specific factors affecting bilateral trade flows and that fully reflects the impact of country-specific determinants of virtual water trade. A number of country-specific potential explanatory variables, ranging from water endowments to trade barriers, from per capita GDP to irrigation prices, is presented and tested. To identify the variables that help to explain the bilateral flows of virtual water, we adopt a model selection procedure based on model averaging. Our findings confirm one of the main controversial results in the literature: larger water endowments do not necessarily lead to a larger ‘export’ of virtual water, as one could expect. We also find some evidence that higher water irrigation prices reduce (increase) virtual water ‘exports’ (‘imports’). [ABSTRACT FROM AUTHOR]

Although water is rarely traded over long distances by itself, the total weight of the water consumed to produce traded commodities exceeds the weight of any other commodity traded in the world. This concept is known as virtual water trade. Although space-/time-/commodity-based quantification has been conducted extensively, the underlying causes of this peculiar feature have thus far received little exploration. Here, we use estimates of water consumption from a global hydrological model and statistical data related to food trade to elucidate three facts that explain the fundamental nature of virtual water trade with respect to alleviating water scarcity. First, we quantitatively illustrate the unique position of water among commodities based on its unit price and quantity of sales. Water has an extremely low unit price, and a tremendous volume of water is consumed per person each day. Second, we show that rich but water-scarce countries tend to reduce local water consumption by importing virtual water. Third, we demonstrate that nations characterized by net virtual water exports have higher water resources and income per capita and that no countries fall below a certain threshold with respect to both GDP and water resources. These points suggest that the virtual water trade is explained by economic characteristics of water and that sustainable development depends on promoting the co-development of poverty alleviation and water resource development.