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Purpose: Low water resource utilization rate, water environment pollution, and water ecology deterioration are unfavorable factors restricting the high-quality development of the Yellow River basin and the coordinated development of the region, and industrial linkage is an important mechanism to promote the regional "pole-diffusion" effect. Currently, the water resource constraints of the Yellow River basin are close to the upper limit; in this context, how to enhance the industrial linkage between regions, promote the coordinated development of resources and economy in the Yellow River basin, and construct new "growth poles" of high-quality development has become an important proposition. Methods: By analyzing the mechanism of water resource constraints affecting industrial linkage and constructing a mediation effect model, we investigate the transmission mechanism of water resource constraints affecting industrial linkage through virtual water trade and optimization of industrial structure. Results: The results show that water resource constraints significantly inhibit the development of industrial linkage in the whole basin, but enhance the development of industrial linkage through the promotion of virtual water trade and optimization of industrial structure; in terms of subregions, there are differences in the mediation effect in the Yellow River basin in the regions with advantages in agriculture and animal husbandry, in the regions with advantages in the energy industry, and in the regions with advantages in the emerging industry and advanced manufacturing industry. Inspiration: This study has several aims: first, the rational use of the virtual water trade model of the Yellow River basin; second, use of the basin as a whole to promote the upgrading of industrial structure; third, the development of water resource rigid constraints in accordance with local conditions to promote the sustainable development of the economy; and fourth, promotion of the construction of the industrial community of the whole basin to realize the synergistic high-quality development of the Yellow River basin. Marginal contribution: In the study of high-quality development in the Yellow River basin, the existing literature focuses on the optimization of the industrial layout and industrial structure based on the theory of resource advantage and industrial division of labor. Based on this, this article analyzes the impact of water resource constraints on the industrial linkage of regions with advantages in agriculture and animal husbandry, energy industry, and emerging industry and advanced manufacturing industry from the perspective of the adaptability of water resources to the layout of productive forces and puts forward the proposal of coordinating the linkage development of industries in the whole river basin, which promotes the research on the relationship between water resources and industries. [ABSTRACT FROM AUTHOR]

Cotton, the world's most widely cultivated fiber crop, is associated with a multitude of environmental impacts, particularly the intensive use of water resources. While previous studies have assessed cotton's water usage through the water footprint concept, they largely focused on spatial variability, leaving temporal dynamics and the issue of unsustainable water use underexplored. This global study addressed these gaps by examining both the spatial and temporal variability of cotton's water footprint and assessing the unsustainable water footprint over time. Additionally, it explored the potential of flax as a water-efficient alternative for fiber production. Using a global gridded crop model, the study simulated yield and water use of flax and cotton from 1972 to 2018 at 30 arcmin resolution. The results showed that the global average blue, green, and total water footprint of cotton decreased by 37%, 48%, and 43%, respectively, due to yield improvements driven by improved crop cultivars, fertilizers, and better water management practices, with climate playing a minor role in these reductions. Despite this, the total water footprint of cotton production increased by 5%, with the blue water footprint rising by 17%. Additionally, unsustainable blue water usage in cotton cultivation increased from 59.3 km³/y to 70.9 km³/y between 1972-1976 and 2014–2018, with 71.1% of the unsustainable water traded virtually. USA, Pakistan, and India accounted for over 60% of this unsustainable virtual water trade. Flax, with its substantially lower water footprint, emerged as a promising alternative to reduce water consumption in fiber production. These findings offer critical insights for formulating strategies to mitigate unsustainable water use in global fiber production.

Argentina stands as the leading producer and exporter of olive products in the Americas, with the province of La Rioja as its main productive area. Since the 1990s, the olive grove cultivated area and related agro-industry in La Rioja have expanded. However, the resulting wastewater has generally been neglected. The water footprint (WF) provides information about the water volume consumed and polluted by a production process. Since the 1990s, agricultural and agro-industrial activities in La Rioja have experienced substantial growth. This study aims to analyze the generation, quality, and management of Oil Mill Wastewater (OMWW) using the grey WF of chloride and nitrate as an indicator and focusing on two olive mills (OM) in La Rioja. Additionally, it seeks to examine the relationship between the international trade of provincial olive oil and the estimated grey WF. For the diagnosis of OMWW generation, a description of the production process was made coupled with flow and physico-chemical characterization. The total grey WF was 8.69 and 45.5 L water/L olive oil for OM 1 and OM 2, respectively. Nitrate was identified as the critical pollutant. The grey virtual water export related to the export of olive oil was 5569 m3 for OM 1 and 28,000 m3 for OM 2. The provincial grey virtual water export related to olive oil was 161,955 m3 with major trade destinations including Spain, the United States, and Brazil. The article analyses for the first time the grey WF of olive oil industries and assess the related grey virtual water exports. This research represents a step forward in the knowledge of wastewater management in the olive oil sector and facilitates the search for solutions to minimize negative environmental impacts while promoting cleaner production. [ABSTRACT FROM AUTHOR]

China faces severe water resource shortages due to the uneven distribution of water resources and ever-increasing water demand driven by rapid industrialization and urbanization. The virtual water trade (VWT) is a potential solution to conserve water resources by transferring water from water-abundant/water-productive regions to water-scarce/less water-productive regions. Based on the inter-provincial input-output model, the provincial VWT of China was estimated at the sectoral level. The relationship of VWT with water resources in 30 provinces was analyzed in relation to the water stress index (WSI). It was found that (1) total inter-provincial VW trade showed a downward trend during the study period, with 363.91 km3 in 2002, 283.72 km3 in 2007, and 285.23 km3 in 2012. Overall, the primary industry dominated the VWT for most provinces. (2) China's virtual water flowed from the relatively underdeveloped central and western regions to the east with a relatively developed economy from the inter-provincial level. This trend became increasingly prominent. (3) In many instances, VW was transferred from water-poor to water-rich areas. These results imply that China needs to improve its water use efficiency and optimize its regional industrial structure. Additionally, establishing an ecological compensation mechanism is considered a valuable measure for China to alleviate regional water resource pressure. [ABSTRACT FROM AUTHOR]

Qatar is a severely water-stressed country. Despite Qatar's aridity and its lack of freshwater resources, its per capita water consumption is one of the highest in the world, and it is expected to increase in the coming decades. Therefore, understanding water consumption and use through space and time becomes paramount. By employing water footprint assessment (WF) and analysis of virtual water trade (VWT), this research comprehensively examines Qatar's water consumption patterns both domestically and internationally on a sectorial level (agricultural, industrial and urban sectors) between 2010 and 2021. The findings show that, internally, the urban sector contributed the most to the WF, followed by the industrial and the agricultural sectors with an annual average WF of 3250, 1650, and 50 million m3/y, respectively. Although Qatar exports large amounts of VW (1450 million m3/y), its VW imports (7530 million m3/y) are very high, reflecting the country's agricultural demand, making Qatar a net VW importing country. Qatar exhibits a national WF of consumption of 11,900 million m3/y, with a water dependency index of 56% and a self-sufficiency index of 44%. Additionally, Qatar has a significant water export fraction of 20%, while only 3% of its water consumption relies on its natural resources. This study pinpoints sectors and areas where WFs can be reduced; the outcomes serve as a foundation for strategic planning, enabling Qatar to make informed decisions to optimize its water resources, enhance water use efficiency, and secure a sustainable water future in the face of escalating water stress. This study's methodology and findings not only pave the way for more efficient water resource management in Qatar, but also offer a replicable framework for other arid and semi-arid countries to assess and optimize their water footprint and virtual water trade, contributing significantly to global efforts in sustainable water use. [ABSTRACT FROM AUTHOR]

Water scarcity has received global attention in the last decade as it challenges food security in arid and semi-arid regions. This study employs water scarcity indices to assess water resources in the agricultural sector of Iran's Jazmourian watershed. Overall, we find that the watershed is experiencing a “very high stress” water situation. This is primarily due to intensive water usage for diverse crops, which has resulted in a negative net virtual water balance and contributed to a rise in water stress and poverty levels. The water stress index is 0.88, and the agricultural water stress is 1.25. The agricultural water footprint is 2,018.53 million cubic meters (MCM), with the share of blue, green and gray water footprints being 80.21, 6.08, and 13.72%, respectively. The region possesses 3,210 MCM of available water for crops, with 17.1% sourced from green waters and 82.9% from blue waters. Despite low annual rainfall and limited water resources, the region excessively exploits water for diverse crops. The net virtual water balance is negative, indicating high virtual water export (1,112–1,605 MCM) compared to imports (58–265 MCM). With declining water availability and increasing crop production, the region experiences rising water stress. The spatial analysis of sub-watersheds reveals diverse patterns of water stress and poverty, as detailed in the study. HIGHLIGHTS Water scarcity indices were quantified using water resource availability and the water footprint in the watershed scale.; The agricultural Water Stress Index was estimated based on agricultural water footprint and agricultural water resources.; The AWSI and blue water scarcity increased from 2008 to 2019 in the agricultural production of the Jazmurian watershed.;

This study delves into the intricate dynamics of South Korea's grain production and trade, specifically scrutinizing water resource management and sustainability trends from 1991 to 2022. The primary objective was to assess the temporal evolution of South Korea's agricultural virtual water trade in maize, soybeans and wheat. Employing the virtual water flows assessment method, water stress index, and an unsustainable import fraction (UIF) analysis, this research aimed to uncover key patterns and dynamics within the agricultural grain trade landscape. Utilizing comprehensive datasets encompassing grain trade, as well as water and land footprint data, this study assessed the intricate interplay between agricultural production, trade, and resource utilization. Results showed a reduction in local production for soybeans and a slight increase in domestic wheat production over the study period. In addition, the study revealed an overall increase in the virtual water imports associated with grain crops, with maize exhibiting the steepest upward trend in comparison with the other grains (wheat and soybeans). Furthermore, the study demonstrated that the import of maize contributed the highest amount of water and land savings, implying that this grain crop had the most significant impact on conserving local water and land resources. Environmental impact assessments, including water stress indices and the unsustainable import fractions, contributed to a comprehensive understanding of grain trade sustainability with concrete result values and insights, highlighting the intricate interplay of international grain trade and local water resource conservation in South Korea. By scrutinizing the virtual land and water dimensions of grain trade, this research offers valuable insights for policymakers and researchers striving to navigate the nexus of agriculture, trade, and resource management. The findings hold significance in the context of ensuring food security, optimizing resource allocation, and fostering sustainable agricultural practices in a dynamically evolving global landscape. [ABSTRACT FROM AUTHOR]

Due to international agriculture crops trade, significant virtual water flows are transferred between nations, known as virtual water trade. Virtual water trade affects the sustainability of freshwater resources worldwide. However, there is presently no sustainable virtual water usage classification that might serve as the basis for global virtual water management. This study's primary objective is to address this research gap. This work attempts to develop a novel virtual water trade classification to achieve freshwater resources' global sustainability. To classify VWT, the research presents a global analysis of the global trade of wheat virtual water. Our findings show that the global trade of wheat annually translocated an average of 268.5 billion m3 of virtual water among the nations, of which 89.33% was green water, 2.65% was blue water, and 8.02% was gray water. A classification of global virtual water trade based on this work is divided into three sustainability states: "strong sustainability," "balanced sustainability," and "fragile sustainability," as well as four unsustainable states, including "critical unsustainability," "high unsustainability," "moderate unsustainability" and "low unsustainability." [ABSTRACT FROM AUTHOR]

Cross-regional water allocation within the river basin, coupled with the development of specialized industries based on comparative advantages, can effectively mediate overall water use efficiency. The uneven distribution of water resources and structural contradictions in water usage hinder the sustainable development of water resources in the Yangtze River Economic Belt (YEB). This study aims to address these issues from the perspective of virtual water trade, to facilitate cross-regional water resource allocation and guide structural adjustments in industrial water use, ensuring water security. In this study, we developed a dynamic multi-regional input–output model (MRIO) to explore dynamic change of virtual water trade pattern in the YEB that evolves over time. This model sheds light on evolving virtual water transfer patterns and the nuances of water resource pressure transmission. Additionally, it quantifies sectoral water use variations, pinpointing the cornerstone industries across different regions. The findings are as follows: (1) The pattern of virtual water transfer predominantly towards the developed downstream regions remains unchanged, but regional disparities are gradually diminishing. (2) The upstream regions of the YEB transfer more water resource pressures externally, while the downstream regions do not experience excessive external transfers of water resource pressures. (3) The pattern of Agriculture-driven virtual water transfers is gradually being disrupted. While the upstream regions continue to rely on Agriculture as their pillar industries, the downstream regions are progressively shifting towards tertiary industries such as Service. These results indicate that economic development is the primary driver of changes in the the pattern of virtual water transfer, and economic disparities are a key factor in shaping the latest virtual water transfer. Based on existing policies, there is a need for comprehensive coordination of water resource allocation and strengthening of virtual water trade exchanges between regions to address the uneven distribution of water resources. Additionally, it is necessary to resolve structural water use conflicts by developing specialized economic strengths based on the main industries for virtual water in each region.

Freshwater is fundamental for all aspects of human well-being and sustainable development. The supply of freshwater resource largely depends on the natural water cycle, leading to extremely unequal distribution over the world. This uneven distribution and increasing freshwater demand results in spatial and temporal physical freshwater shortage. By discussing the limitations of desalination techniques and the shortcomings of existing pathways for freshwater transfer including water transfer projects, bottled water market, and virtual water trade, we suggest that international freshwater trade as an additional pathway is necessary. The analysis of the cost structure of freshwater production and transportation and the hypothetical examples between potential exporting and importing countries show the feasibility of international freshwater trade. The establishment of a global freshwater market is confronted with six challenges, namely, natural sustainability, ecological safety, opinions of stakeholders, market access mechanism, pricing mechanism, and infrastructure system. We conclude that a global freshwater market is expected to make contributions to achieving SDG 6 by mitigating spatial and temporal freshwater scarcity and by resolving transboundary freshwater conflicts and managing local freshwater consumptions. [ABSTRACT FROM AUTHOR]

As a semi-arid/arid country located in the northwest of Africa, Morocco is facing serious water scarcity driven by the dual stresses of decreasing availability of water resources and increasing water demands. Virtual water trade could be an effective tool to alleviate water scarcity. The paper presents an analysis of the relationships between agrarian productions, foreign trade, and the water sector in Morocco by deriving a comprehensive estimate of virtual water export and import in Morocco's foreign trade of 40 crop products during the period from 2000 to 2017. Our objectives include determining the intensity of water consumption of exported and imported crop products and quantifying the water consumed and saved, respectively, by locally producing and importing these products. To this end, FAO's Penman-Monteith climate model was used to estimate crop water requirements based on data on meteorological factors. The results show that Morocco was a net virtual water importer during the study period. The deficit was 595.74 Gm3. The tendency of total virtual water export was on a rising trend, while the total virtual water import was on a downward trend. The main exported virtual water was from vegetables (68.87 Gm3, 72.47%) and the main imported virtual water was from cereals (679.68 Gm3, 98.4%). Regarding crop product's water intensity, we found that the exported crop products were excessively concentrated on water-intensive products such as mandarins and clementines, figs, oranges, apricots, plums, citrus fruits, olives, tomatoes, asparagus, peas, and artichokes. On the other hand, the agricultural policy of 2009–2020 increased the production of water-intensive products. This finding seems to be going against the virtual water trade theory, which states that water-poor countries should import water-intensive products and produce local products with lower water requirements. [ABSTRACT FROM AUTHOR]

Irrigated agriculture is the highest water user in Sri Lanka. Therefore, when there is an increasing demand of other sectors such as drinking, industries, environment etc., it is required to reallocate water from the irrigated agriculture sector to meet this increased demand. However, this needs to be done while ensuring the food security of the nation using the virtual water concept, which is defined as the embedded water in a product. Therefore, this study is conducted with the objective of assessing the, i) virtual water of agricultural production, ii) virtual water of food imports and exports, iii) virtual water trade and iv) water footprint of the nation. The data on crop water requirements, extent cultivated, imported, and exported agricultural products were collected from secondary sources and the analysis was made according to the globally accepted methodology. The annual virtual water value of domestic production is found to be 8.13 Gm³ of which paddy contributes 54.7%. The average virtual water value of paddy in Maha season is less than that in the Yala season whilst the virtual water value of paddy in minor schemes are higher than that in the major schemes in both seasons implying that more water is required to produce 1kg of paddy in minor schemes. The net import of Virtual water is 3.8 Gm³ per year. The water footprint of Sri Lanka is 12.0 Gm³ per year with a per capita water footprint of 535.22 m3 per year. The water required for domestic production is about 15.8% of the surface runoff of the country indicating the possibility of meeting the food demand with the available water resources. [ABSTRACT FROM AUTHOR]

International trade can spur economic growth, but it can also deplete the water resources needed to produce traded goods. This is crucial for Egypt as a lower-middle income country where boosting agricultural exports is encouraged to promote the sustainable agriculture development strategy. The objective of this paper was to quantify Egypt's virtual water flows contributing to agricultural trade with one of its main trading partners, the European Union. We considered calculating virtual water of exports since 2001 as it represents Egypt-EU's implementation of the association agreement. We focused on the five governorates of the Nile Delta. These governorates are major producers of the five major crops exported to the European Union. This study used long-term trade trends, and changes in crop composition to analyze the implications for virtual water outflows and economic water use efficiency. By decomposing the virtual water of exports, we were able to identify the trend of virtual water outflows and the factors affecting this trend. From both an economic and water perspective, our results suggest that adopting a policy aimed at saving water resources at the national level and focusing on high-yield exports at the international level will promote the development agenda of Egypt. [ABSTRACT FROM AUTHOR]

Limited and declining water resources, increasing demand of water resources from different sectors, has posed a major challenge for maintaining water sustainability and thus overall sustainability for a populous and water-scarce country like India. Over extraction and changing climate have put additional pressure to maintain water sustainability. Therefore, there is a need for proper planning of utilization and management of water resources. Recently, virtual water trade has received much attention and become an important tool for balancing the water budget. On the other hand, virtual water trade may also adversely affect the water balance of the exporter's country as well as the economy. Analysis of the virtual water trade with its implications for water resources is missing; hence, there is a need for such analysis that will help in management of water resources. In this study an attempt is made to present a quantitative analysis of the virtual water trade and its implications for water sustainability. For this study, the rice crop is considered only due to its characteristics as rice is a major water consumer crop and water exporter crop from India. HIGHLIGHTS Total water required for production of rice is 318 billion m3, 16.67% of total water available.; Virtual water export is about 32 billion m3, while the virtual water import is negligible.; The net virtual water content export is about 4.8 billion m3 which is irreversible in the system and leads to loss of water sustainability.; The net export of virtual water is about 32 billion m3, a large volume of water export.;

Water resources are under increasing pressure from population growth, socio-economic development, and climate change. The main user of freshwater is the agriculture sector, accounting for 70–80% of global water use. Consequently, increasing water productivity and reducing water use in this sector are vital for alleviating water scarcity. It has been alleged that domestic or international trade of water-consumed products from wet-provinces or countries to arid and semi-arid provinces or countries is one possible path to mitigate water shortage. In this regard, virtual water flows and their determinants in Iran are investigated in this paper. This study examines the main determinants of bilateral virtual water flows associated with international trade in agricultural goods among Iran and other countries using a gravity model of trade. The impacts of climate change and socio-economic change scenarios on the virtual water trade are simulated. The result of the gravity model indicated that bilateral virtual water trade flows are influenced by the classical determinants and all the mass-related variables (gross domestic product and population) are significant with expected signs. Finally, the result obtained from the simulation of climate and socio-economic change scenarios showed that under the pessimistic scenario of climate change and population growth rate of 0.98 and 0.44%, VW trade between Iran and other countries would increase by 41 and 66% in the periods of 2016–2045 and 2070–2099, respectively. As a consequence, identifying the appropriate countries for business interactions and adopting effective trade policies are very important and need attention soon. HIGHLIGHTS Bilateral virtual water trade flows are influenced by the classical determinants and all the mass-related variables (gross domestic product and population).; The size of the future virtual water flows was predicted under the climate and population change scenarios.; The average annual temperature and the population of Iran, as the determinants of virtual water flows, have a positive and significant effect on the net virtual water flows.;

The original intention of virtual water trade (VWT) is to help water-scarce areas adjust the crop trade structure to alleviate the water shortage problem. However, China's existing virtual water trade (VWT) must effectively alleviate the problem. This paper's structural features and stability of the VWT network (VWTN) in China's major crop trade between 2000 and 2017 were characterized using complex network theory. The results in terms of time scale showed that the total content of VW in China's major crops increased by ~23.6% for 18 years. Trade relations among most regions remained stable, whereas a few areas changed: Jilin, Henan, and Heilongjiang played essential roles in the output network, and so did Guangdong, Shanghai, and Fujian in the input network. Attributed to policy adjustment, Henan and Jilin became more prominent in the output network with the gradual decline of Jiangsu's position. Regarding spatial scale, the cumulative distribution of degrees consistent with the power–law relationship showed high variability and vulnerability of China's VWTN, especially when nodes were weighted. Since areas with more VWT partners/content provided connectivity to those with fewer partners/content, it is worthwhile to focus on developing protection policies for critical areas. The virtual water trade from North China (water-poor) to South China (water-rich) is contrary to the distribution of water resources. A similar situation showed in a global world that the long-term supply relationship would aggravate the water resources shortage and food security. Furthermore, we suggest combining network theory and VWT to lay the foundation for the invulnerability research of VWTN and the optimal regulation of crops. [ABSTRACT FROM AUTHOR]

The world's sustainable growth is being severely hampered by the inefficient use of water resources. Despite the widely acknowledged importance of trade in global and regional water and food security, societal reliance on local production, as well as international trade, remains inadequately assessed. Therefore, using South Korea as a case study, this study fills in this research gap by applying the virtual water concept, the logarithmic mean divisia index (LMDI) method, and the Tapio decoupling model. The virtual water concept was used to estimate South Korea's net virtual water trade for major grain crops from 1992 to 2017. Then, the LMDI method was utilized to assess the driving factors causing changes in net virtual water trade. Lastly, the Tapio decoupling model was used to investigate the decoupling relationships between economic growth and the driving factors of net virtual water trade. The results showed that South Korea remains a net importer of virtual water flows with respect to grain crops, with an average import of 16,559.24 million m3 over the study period. In addition, the change in net virtual water trade could be attributed to the water intensity effect, product structure effect, economic effect, and population effect. However, water intensity and economic effects were the major decisive factors for decreases and increases in net virtual water trade, respectively, while the population and product structure effects had minor positive influences on the net virtual water trade. Furthermore, water intensity and economic growth showed a strong decoupling in most periods, while the decoupling state between product structure and economic growth was observed as expansive negative decoupling. Likewise, population size and economic growth showed a weak decoupling in most periods. The results reveal South Korea's status as it concerns the virtual water trade of grain crops, thus providing valuable insights into the sustainability of trade activities for the management of local water resources. [ABSTRACT FROM AUTHOR]

This study reviews groundwater status and management based on the existing literature regarding its resource endowment, hydrogeology, challenges and issues of management and policy suggestions for India. Efficient management requires decoupling groundwater rights from land-ownership rights, changes in electricity pricing and metering, aquifer-based plans for storage and replenishment, and empowerment of participatory irrigation management for local management. Issues of water-food-energy nexus, climate change, carbon footprint of groundwater extraction and virtual water trade are also important for ensuring sustainable management of groundwater resources. [ABSTRACT FROM AUTHOR]

Attention to water resources and consumption in Iran's industrial sector is important due to the existence of severe tensions in the country's water resources. Therefore, the purpose of this study is to evaluate the virtual water trade in the oil industry of Iran. For this purpose, the technical-basic approach has been used to measure virtual water and the special water demand and virtual water trade of Iran's oil sector has been calculated from 1978 to 2019. The results show that due to the high volume of oil exports, Iran is a net exporter of virtual water. The amount of water consumed in the oil industry and the process of extraction and production of crude oil in the years under review averaged 594 million cubic meters per year and the amount of virtual water that left the country following the export of crude oil in these years averaged 356 million cubic meters per year. Also, the export value of virtual water in the oil sector has a value of 1838 thousand Rials per cubic meter. To manage the country's water resources and the leading crises in this sector of the industry, it is possible to greatly increase water efficiency in this sector by modifying production processes and updating equipment, facilities, and methods used to optimally consume water in this sector. .

With water scarcity increasingly becoming a growing global risk, it is prevalent to explore water supply-demand interaction within and beyond national borders driven by global virtual water trade and its effects on water sustainability. However, there is little study on system integration of differential environmental impacts of various types of trade. Based on metacoupling framework highlighting human-nature interactions across space- within a place (intracoupling), between adjacent places (pericoupling), and between distant places (telecoupling), this study quantified the linkages and intensities of three kinds of coupling processes during global virtual water trade for the first time. Correspondingly, water stress changes under a set of trade scenarios were evaluated based on the indicator of UN SDG 6.4.2 to distinguish the influence of trade taking place on different spatial scales. Results show that during 2005–2015, local water resources supported 80% of global water consumption. Distant virtual water import was about 5 times in volume as large as adjacent virtual water import, alleviating 99.8% of global average water stress. Virtual water trade reduced water stress in 86% of developed countries and increased that in 71% of developing countries in 2005. Owing to trade, water stress in many countries with poor water resources endowment declined while that of many with relatively good endowment went up from 2005 to 2015. Our findings can help to systematically understand the influence of virtual water trade on water stress change and provide scientific guidance for sustainable water management and regional regulations.

A dynamic multi-region computable general equilibrium (CGE) model is used to analyze virtual water and its effect in the Huaihe River basin, which includes Jiangsu, Anhui, Shandong and Henan provinces. The baseline scenario was first constructed to describe the trade situation and virtual water among different regions and sectors from 2009–2020. Then two hypothetical policy scenarios were set to analyze the economic, water consumption and virtual water trade impacts under different policy shocks. The results show that (1) the Huaihe River basin was a net virtual water outflow region, with 13.977 × 109 m3 virtual water transferred outside the river basin in 2009, and 26.653 × 109 m3 VW transferred to outside in 2020. Jiangsu is the largest virtual water outflow province (mainly flows to outside), followed by Anhui. Anhui suffers from severe water shortage, but provides a net virtual water outflow to Henan, Jiangsu and Shandong and outside; (2) reducing Anhui's agricultural output (S1 scenario) and Anhui's agricultural virtual water outflow (S2 scenario) can not only reduce virtual water trade but also save water, but S1 scenario reduced net virtual water outflow by more, and saved more water. S1 had a positive effect on gross domestic product (GDP), but reduced the employment rate. HIGHLIGHTS Role of VWT analyzed using a CGE.; CGE based on 12 years of data (2009–2020).; VW study not only focused on agriculture, but also included industry and service sectors.; Two hypothetical scenarios were set to analyze the economic, water consumption and VWT impact.; Assessment of VW will change water usage and trade in different upstream and downstream regions of the Huaihe watershed.;

As a semi-arid/arid country located in the northwest of Africa, Morocco is facing serious water scarcity driven by the dual stresses of decreasing availability of water resources and increasing water demands. Virtual water trade could be an effective tool to alleviate water scarcity. The paper presents an analysis of the relationships between agrarian productions, foreign trade, and the water sector in Morocco by deriving a comprehensive estimate of virtual water export and import in Morocco’s foreign trade of 40 crop products during the period from 2000 to 2017. Our objectives include determining the intensity of water consumption of exported and imported crop products and quantifying the water consumed and saved, respectively, by locally producing and importing these products. To this end, FAO’s Penman-Monteith climate model was used to estimate crop water requirements based on data on meteorological factors. The results show that Morocco was a net virtual water importer during the study period. The deficit was 595.74 Gm3. The tendency of total virtual water export was on a rising trend, while the total virtual water import was on a downward trend. The main exported virtual water was from vegetables (68.87 Gm3, 72.47%) and the main imported virtual water was from cereals (679.68 Gm3, 98.4%). Regarding crop product’s water intensity, we found that the exported crop products were excessively concentrated on water-intensive products such as mandarins and clementines, figs, oranges, apricots, plums, citrus fruits, olives, tomatoes, asparagus, peas, and artichokes. On the other hand, the agricultural policy of 2009–2020 increased the production of water-intensive products. This finding seems to be going against the virtual water trade theory, which states that water-poor countries should import water-intensive products and produce local products with lower water requirements.

Study region: The Yellow River Basin (a water-deficient region) in China. Study focus: To establish whether the virtual water trade (VWT) is beneficial for water-deficient regions we conducted an integrated assessment of the local and distant VWT of the Yellow River Basin (YRB). We adopted a modified input–output analysis model and applied multiregional input–output tables of 31 provinces in China (2017) to estimate the dependence of the YRB on water from other regions and to determine the VWT status. We calculated the total water consumption coefficient of 29 sectors in the YRB, investigated the water-use intensity of various sectors, and analyzed the water footprint and per capita usage of each province. Furthermore, we revealed the VWT among downstream, midstream, and upstream regions of the YRB. New hydrological insights for the region: This study revealed that virtual water flow is unidirectional from downstream and midstream regions to upstream regions, and that the trade structures among these three regions of the YRB differ notably, which has rarely been addressed in previous literature. Furthermore, the VWT exacerbates water resource shortages in the YRB. The irrational industrial structure is the main reason for the need for transfer of water resources. This information could inform the development of effective policies both for alleviating regional water shortages and for developing a viable virtual water strategy for the YRB.

The world’s sustainable growth is being severely hampered by the inefficient use of water resources. Despite the widely acknowledged importance of trade in global and regional water and food security, societal reliance on local production, as well as international trade, remains inadequately assessed. Therefore, using South Korea as a case study, this study fills in this research gap by applying the virtual water concept, the logarithmic mean divisia index (LMDI) method, and the Tapio decoupling model. The virtual water concept was used to estimate South Korea’s net virtual water trade for major grain crops from 1992 to 2017. Then, the LMDI method was utilized to assess the driving factors causing changes in net virtual water trade. Lastly, the Tapio decoupling model was used to investigate the decoupling relationships between economic growth and the driving factors of net virtual water trade. The results showed that South Korea remains a net importer of virtual water flows with respect to grain crops, with an average import of 16,559.24 million m3 over the study period. In addition, the change in net virtual water trade could be attributed to the water intensity effect, product structure effect, economic effect, and population effect. However, water intensity and economic effects were the major decisive factors for decreases and increases in net virtual water trade, respectively, while the population and product structure effects had minor positive influences on the net virtual water trade. Furthermore, water intensity and economic growth showed a strong decoupling in most periods, while the decoupling state between product structure and economic growth was observed as expansive negative decoupling. Likewise, population size and economic growth showed a weak decoupling in most periods. The results reveal South Korea’s status as it concerns the virtual water trade of grain crops, thus providing valuable insights into the sustainability of trade activities for the management of local water resources.

Virtual water trade, which underlines the importance of inter-regional commodity transactions for enhancing water management, has often been recommended as an alternative to technological advancements in addressing water scarcity and increasing water savings in dry regions. Sectoral adjustment policies that focus on enhancing the productivity of specific sectors therefore should prioritize sectors with high growth impact potential but low virtual water demand. However, the diverse understanding of the concept and differing assessment techniques employed by various research communities complicate the debates surrounding the policy relevance of the virtual water trade. This study proposes a novel and integrated approach to evaluating virtual water content and flows endogenously, leveraging the advantages of Input-Output and Computable General Equilibrium (CGE) modeling methods. The quantification of the method is exemplified in the case of Uzbekistan (Central Asia), where water is a limited yet essential resource for sustainable economy and environmental systems. Specifically, this study examines the impacts of changes in economy-wide and sector-specific Total Factor Productivity (TFP) and water productivity on water uses, virtual water flows, and economic outcomes. The findings reveal that TFP improvements in livestock and fodder crop production and water productivity enhancements in gardening are recommendable options to constrain the net virtual water trade and enhance economic growth in Uzbekistan. The study also shows a high sensitivity of virtual water flows to technological changes, highlighting the importance of considering options for improving productivity when analyzing the potential of virtual water trade. [Display omitted] • SAM/Input-Output based method of virtual water flow assessment was integrated into a CGE modeling framework. • Water use intensity and virtual water flows were endogenously incorporated into the CGE model. • Virtual water trade is an outcome of technological change policies but not a policy itself. • Improved productivity in livestock and fodder crops production enhance water and income security. • Water productivity improvements in fruits and vegetables production reduce net virtual water exports. [ABSTRACT FROM AUTHOR]

The disclosure of global value chain (GVC) division and cooperation is essential for the rational allocation of water resources and the achievement of trade equality, particularly as the global division of labor becomes more pronounced. Currently, there are limited studies on the global value chain at the sub-national level, with most focusing on virtual water trade (VWT) characteristics between two trading partners, without integrating VWT into the global value chain and overlooking significant cooperation among participants. Here, we characterize the international division of GVC and VWT patterns covering 194 regions (31 regions in China and 163 countries) around the world in 2020, and then examine the inequality between virtual water (VW) and value-added (VA) transfer from both environmental and economic perspectives, focusing on the sub-national scale of China. Our results show that in terms of water consumption responsibilities, considerable heterogeneity can be seen in different regions across China. Furthermore, relying solely on the export of primary products for economic development will lead to inequality in trade between countries. In this study, we trace the characteristics of VWT, taking into account the participation and contribution of regions in numerous GVC linkages. In addition, to make our policy implications more targeted, we refine the study resolution to the sub-national scale. Our results suggest that countries should prioritize consumer responsibility in GVC, reduce the drawbacks of trade barriers, and dispassionately exploit the economic and environmental advantages of water resources. [ABSTRACT FROM AUTHOR]

• This paper constructs the MRIO of YEB. • This paper constructs the spatial–temporal pattern of virtual water trade in the YEB. • This paper discovers that the virtual water trade pattern is contrary to the virtual water strategy hypothesis because of productivity. Cross-regional water allocation within the river basin, coupled with the development of specialized industries based on comparative advantages, can effectively mediate overall water use efficiency. The uneven distribution of water resources and structural contradictions in water usage hinder the sustainable development of water resources in the Yangtze River Economic Belt (YEB). This study aims to address these issues from the perspective of virtual water trade, to facilitate cross-regional water resource allocation and guide structural adjustments in industrial water use, ensuring water security. In this study, we developed a dynamic multi-regional input–output model (MRIO) to explore dynamic change of virtual water trade pattern in the YEB that evolves over time. This model sheds light on evolving virtual water transfer patterns and the nuances of water resource pressure transmission. Additionally, it quantifies sectoral water use variations, pinpointing the cornerstone industries across different regions. The findings are as follows: (1) The pattern of virtual water transfer predominantly towards the developed downstream regions remains unchanged, but regional disparities are gradually diminishing. (2) The upstream regions of the YEB transfer more water resource pressures externally, while the downstream regions do not experience excessive external transfers of water resource pressures. (3) The pattern of Agriculture-driven virtual water transfers is gradually being disrupted. While the upstream regions continue to rely on Agriculture as their pillar industries, the downstream regions are progressively shifting towards tertiary industries such as Service. These results indicate that economic development is the primary driver of changes in the the pattern of virtual water transfer, and economic disparities are a key factor in shaping the latest virtual water transfer. Based on existing policies, there is a need for comprehensive coordination of water resource allocation and strengthening of virtual water trade exchanges between regions to address the uneven distribution of water resources. Additionally, it is necessary to resolve structural water use conflicts by developing specialized economic strengths based on the main industries for virtual water in each region. [ABSTRACT FROM AUTHOR]

Despite the recent droughts in Isfahan province, climatic changes and the rising trend of population growth, as well as development of industrial and agricultural activities, are exposed to the water crisis. Thus, in order to tackle this problem, the essential strategies should including exploring virtual water and water foot print for strategic crops in agricultural sector should be taken into consideration for the management of water supplies at risk. This study was aimed to examine virtual water and ecologic fingerprint of water for the wheat crop in Isfahan Province from the farming year 2006-7 through 2014-15. For this purpose, the quantity of virtual water was extracted using net irrigation demand by NETWAT software and the rate of irrigation efficiency was computed to be 48%. The results indicated that only in 2007, Isfahan province was an exporter of virtual water for the wheat crop, so this province exported about 0.15 billion cubic meters of virtual water to other provinces by wheat exportation, but Isfahan province was the only virtual water in the years (2008-15) and this was due to the annual population rise and the existing drought in this zone. During this period, the rate of the mean annual rate of ecological footprint of water was 5.87 billion cubic meters and Isfahan Province stored this volume of water from the given internal supplies annually, with the mean rate of 0.65 billion cubic meters of virtual water importation at that year.

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.

Limited water resources, an increase in water demand and a changing climate triggered the development of new concepts for assessment of water demand and water consumption locally and globally. The newest concepts that successfully tackle this issue are water footprint and virtual water trade. Aims of this study are: (1) to define specific water demand for the most important agricultural products in the international trade of the Republic of Serbia, (2) to assess possibilities of an increase in water productivity for those products, and (3) to assess sustainability of water resources in Serbia, based on the ratio of import/export during virtual water trade. Specific water demand for wheat, maize, sunflower, sugar beet and soya bean has been calculated and compared with specific water demand in other countries. Results prove that water productivity can be improved by, for example, using other varieties of crops or modifying cultivation technology. The ratio of imported/exported virtual water quantities for the periods 1995-1999 and 2010- 2013 in Serbia shows that more water was exported than imported. Sustainability of water resources in Serbia will not be endangered even if the export of agricultural products is increased.

Due to population growth, climatic change, and growing water usage, water scarcity is expected to be a more prevalent issue at the global level. The situation in Australia is even more serious because it is the driest continent and is characterized by larger water footprints in the domestic, agriculture and industrial sectors. Because the largest consumption of freshwater resources is in the agricultural sector (59%), this research undertakes a detailed investigation of the water footprints of agricultural practices in Australia. The analysis of the four highest water footprint crops in Australia revealed that the suitability of various crops is connected to the region and the irrigation efficiencies. A desirable crop in one region may be unsuitable in another. The investigation is further extended to analyze the overall virtual water trade of Australia. Australia's annual virtual water trade balance is adversely biased towards exporting a substantial quantity of water, amounting to 35 km3, per trade data of 2014. It is evident that there is significant potential to reduce water consumption and footprints, and increase the water usage efficiencies, in all sectors. Based on the investigations conducted, it is recommended that the water footprints at each state level be considered at the strategic level. Further detailed analyses are required to reduce the export of a substantial quantity of virtual water considering local demands, export requirements, and production capabilities of regions. [ABSTRACT FROM AUTHOR]

Growth in water use and threatened shortages of water have become increasingly important in the modern world system. Natural resources are exploited extensively by capitalist interests in industrially advanced nations, while the lower strata of the world system, the underdeveloped societies, are left with limited access to natural resources for their productive processes, particularly water resources. We contribute to socio-hydrological research by examining underlying socio-structural factors that play a part in the process of deteriorating conditions of global water resources. Drawing on a world-systems perspective, this study examines how socio-structural forces – world-system position, per capita beef consumption, per capita energy consumption, and urbanization – affect per capita water footprint, which includes an accounting of "virtual water" consumption. We find that per capita beef consumption and per capita energy consumption have significant positive direct effects, and the world-system position has a significant indirect and total effect on per capita water footprint. [ABSTRACT FROM AUTHOR]

The concept of virtual water, as a new approach for addressing water shortage and safety issues, can be applied to support sustainable development in water-scarce regions. Using the input-output method, the direct and the complete water use coefficients of industries categorized as primary, secondary, or tertiary, and the spatial flow patterns of the inter-provincial trade in the Gansu province region of China, were explored. The results show that in 2007, 2010, and 2012 the direct and complete water use coefficients of the primary industries were the greatest among the three industry categories, with direct water use coefficients of 1545.58, 882.28, and 762.16, respectively, and complete water use coefficients of 1692.22, 1005.38, and 873.44, respectively; whereas, the direct and complete water use coefficient values of the tertiary industry category were the lowest, with direct water use coefficients of 16.65, 7.74, and 66.89 for 2007, 2010, and 2012, respectively, and complete water use coefficients of 65.46, 66.89, and 72.81 for 2007, 2010, and 2012, respectively. In addition, study results suggest that the volume of virtual water supplied to Gasnu province's local industries has decreased annually, while virtual water exports from the province have increased annually, with the primary industry accounting for 95% of virtual water output. Overall, the virtual water of Gansu province in 2010 showed a net output trend, with a total output of 0.506 billion m³, while in 2007 and 2012 it showed a net input trend with a total input of 0.104 and 1.235 billion m³, respectively. Beijing, Shanghai, Guangdong, Ningxia and other water-scarce areas were the main input, or import source for Gansu's virtual water; during the years studied, these provinces imported more than 50 million m³ individually. Based on these results, it is clear that under the current structure, virtual water is mainly exported to the well-developed coastal areas and their adjacent provinces or other water-abundant regions. Therefore, Gansu province should (1) adjust the industrial structure and develop water-saving and high-tech industries; (2) adjust the current trade pattern to reduce virtual water output while increasing its input to achieve balanced economic development and water resource security. [ABSTRACT FROM AUTHOR]

As water scarcity intensifies worldwide, the equitable allocation of water resources has emerged as a critical challenge. This research investigates the intricate issue of allocating responsibility for virtual water, a concept that quantifies the water embedded in traded commodities. In pursuit of an effective allocation mechanism, we refine an innovative accounting scheme grounded in economic welfare gains arising from externalities. The results show that water-stressed areas in China, such as Xinjiang, significantly contribute to exporting virtual water and is responsible for 70%–85% of the virtual water outflow. Furthermore, more than 50% of virtual water imported from water-rich regions is attributed to these water-stressed areas while their trade partners bear the rest water responsibility. In contrast, southern China's abundant water resources reduce dependence on virtual water trade, leading to fewer responsibilities. Globally, the allocated responsibility for the new accounting mechanism reaches up to 7.5 times higher than for production-based accounting (PBA) and consumption-based accounting (CBA). Our study also reveals that the degree of dependency (price elasticities) plays a pivotal role in shaping the allocation outcomes. The implications of this research are significant for establishing a transparent and accountable framework for sustainable water resource management and facilitating seamless transitions toward sustainability. As global water scarcity intensifies, the redefined responsibility accounting according to the economic welfare is indispensable in addressing immediate and long-term water-related challenges. • We refine a mechanism to reallocate responsibility based on economic welfare gains. • Notable differences exist between results of the new mechanism and current production, consumption, and income-based methods. • Water-stressed areas bear higher proportions of virtual water responsibility. • Price elasticities play a crucial role in determining responsibility allocations. [ABSTRACT FROM AUTHOR]

Shortage of water is considered as one of the most important straits of agricultural development in Iran. The main purpose of this study is to determine virtual water used to pea and bean production and water use efficiency, select the best area for cultivating these two grains and find the virtual water budget for the aforementioned grains. The results showed that among the three provinces main producers of pea in Iran, the highest virtual water of pea belongs to Lorestan with 3534 dm3·kg−1 and the lowest belongs to West Azerbaijan with 2660 dm3·kg−1 in irrigated cultivation. Water use efficiency in irrigated cultivation in Kermanshah and West Azerbaijan are at the same level; however, Kermanshah has enjoyed much more level of virtual water. For beans, the highest amount of virtual water in irrigated cultivation belongs to Lorestan (3651 dm3·kg−1) and the lowest amount refers to Markazi (2725 dm3·kg−1) and also the highest level of water use efficiency for this product refers to Markazi. Also it was found that 160.15 mln m3 of water has been exported from the country water resources by these products so virtual water budget for studied crops were negative.

The water used in the production process of an agricultural or industrial product iscalled "virtual water". In Iran with low average annual precipitation also lack ofavailable water resources, concept of the virtual water and its trade is used as astrategy for optimal operation of water resources in many fields such as waterscarcity, drought and so on. This concept, also, could hold some interesting newopportunities for the field of sustainable consumption. Recently, in Iran, net virtualwater import reached to (15-20)*109 m3 per year and is one out of the top ten virtualimporting countries. In this research, after virtual water applicable conceptsexpressing, virtual water content in some of the agricultural products in the worldhave been compared with products existence in Iran. Additionally, we selectedsome strategic agricultural products, which export and import to the country, andused an algorithm called "Genetic Algorithm", to optimize virtual water usage andtrade according to demands, agricultural situation, production cost andenvironmental condition. Results showed which products how could help optimalwater resources operation and effect of virtual water usage in economic growth.

Water crisis is of utmost importance due to the growing demand and consumption of water, especially in developing countries where its production and food security are facing serious challenges. Virtual water trade has been proposed as one strategy to combat the water scarcity crisis in arid and semi-arid regions. The strategy is based on the import of food and water-intensive supplies from neighboring regions that enjoy adequate supplies of water. Given the fact that the industrial sector has been proposed to serve as the basis of development in Zanjan Province, the present study was conducted to investigate the virtual water trade by the industrial sector in this province. For the purposes of this study, data from the statistical period 2010-2011 were obtained from the Statistical Center of Iran on enterprises employing ten member staffs or above. The data were used to categorize the industries surveyed, their water demands, and products to estimate the quantities of water needed for their continued operation. It was found that the highest quantities of virtual water in Zanjan are allocated to coking and petroleum plants, paper and cellulosic industries, and food and beverage processing factories with average values of 32.70, 26.14, and 11.63 cubic meters per million Rials, respectively. In addition, the total amount of virtual water exported from the industrial units operating in Zanjan Province is estimated at about 3.10 MCM, 50% of which belongs to base metal production. Conclusion: Our findings show that the industrial sector in Zanjan Province is a net exporter of virtual water.

Many water footprint studies have been conducted on those water scarce regions to respond their water crisis, while water rich regions also face water sustainability challenges due to inadequate water management or being virtual water exporter. Therefore, this paper tries to clarify the water footprint and detail virtual water flow features of a water-rich province, namely Yunnan province in China, to pursuit for more enlightenment for water conservation of not only water scarce regions but also water abundant regions. Multi-regional input-output (MRIO) method was adopted for water footprint and virtual water flow calculation. Results showed that the total water footprint of Yunnan was 11.35 billion m3, with 7.98 billion m3 (70%) of internal water footprint, demonstrating that Yunnan was a high water self-sufficient province. Moreover, Yunnan was a net virtual water exporter with a value of 1.18 billion m3, which was not good for Yunnan but was good for water scarce provinces. As for the detailed virtual water flow trade, high water intensity Guangxi, Hunan, Xinjiang were the top three net importers of Yunnan, while low water intensity Guangdong, Shanghai and Zhejiang were the top three export provinces of Yunnan. This did not affect Yunnan, but was not a good phenomenon for water sustainability of whole China. Moreover, agricultural sector was found to be the dominant sector for both virtual water import and export, accounting for about 88% and 86%, respectively. To maintain sustainable water management of both Yunnan and China, policy insights on keeping Yunnan as a net virtual water exporter, making use of its advantage in green water, adjusting trade structure by considering provincial water intensity were proposed. [ABSTRACT FROM AUTHOR]

Water depletion and pollution caused by industrialization have become major environmental concerns worldwide, which are further complicated by the urbanization and globalization. China has become an industrial powerhouse for the world, and its industrial activities-induced water pressure is no longer negligible. This study investigates China's industrial water pressure from final consumption and international export based on water footprint (WF) and dynamic structure decomposition analysis (SDA). The industrial blue and gray WFs with respect to rural consumption, urban consumption, and export are accounted for 2002–2015, and an advanced dynamic SDA model is developed and applied to examining the evolving WFs with 9 socio-economic drivers quantified. Results show that China's water resources pressure is intensified due to the increase of total industrial blue WF (by 47.4%) for 2002–2015, whereas a mitigation of water environment pressure is suggested by the decreasing gray virtual water outflow and total internal gray WF (by 31.9% and 36.4%, respectively). The SDA demonstrates that export scale and urban consumption level are two major drivers of water situation deterioration, which accumulatively contribute 38.3% and 33.0% to the evolving blue and gray WFs, respectively. In contrast, technology development is the dominant contributor alleviating China's water pressure, with absolute contribution proportions of 38.9% and 56.5%, correspondingly. Based on these, export regulation, consumption pattern adjustment and technological innovation are recommended for water policy making. The methodology used in this study can be extended to diagnosing the water issues in other nations/regions as well. • China's industrial blue and gray WFs from rural consumption, urban consumption, and export are separately accounted. • The effects of nine drivers on the WFs are examined using an advanced dynamic structural decomposition analysis model. • Intensified water resources pressure and relieving water environment stress from industrialization are recognized. • Export scale and urban wealth level principally drive up China's industrial WFs. • Technology development dominantly alleviates the water pressure. [ABSTRACT FROM AUTHOR]

Grey water footprint (GWF) accounting has previously been conducted at the global level using a bottom-up approach but lacking detailed industrial information. Here we applied a multi-region input-output approach based on the World Input-Output Database (WIOD) to quantify global GWF of 40 countries/regions with 35 economic sectors. The GWF from both the production perspective (GWFP), and the consumption perspective (GWFC) are quantified. The results show that the global GWFP/GWFC was 1507.9 km3 in 2009. Except for the "Agriculture, Hunting, Forestry and Fishing" sector, the industrial sectors with the largest GWFC were "Food, Beverages and Tobacco", "Construction", "Chemicals and Chemical Products", and "Textiles and Textile Products". The BRIC countries (Brazil, Russia, India, China) had a larger GWFP than their GWFC, which accounted for over half of global GWFP (53.6%), and their GWFP was mainly generated from the production of domestic final demand. In contrast, the OECD29 and EU27 groups of countries i.e. the country groups consisting mainly of economically advanced nations, had larger GWFC than their GWFP. Overall, the OECD29 and EU27 outsourced 134.8 km3 and 64.4 km3 of their grey water respectively, mostly to large newly advanced economies such as the BRIC group of countries, which, in turn, were collectively outsourcing 112 km3 of grey water. Quantitative approaches are thus suggested for development, aimed at shared responsibility for water pollutant discharge among poor exporters and wealthy consumers. • Global Grey Water Footprint (GWF) was quantified from production and consumption perspectives. • Multi-region input-output approach was applied to account for GWF of 40 countries/regions. • Global GWF was 1507.9 km3 in 2009. • BRIC countries accounted for 53.6% of the global GWF from production perspective. • OECD29 and EU27 outsourced 134.8 and 64.4 km3 of their grey water, respectively. [ABSTRACT FROM AUTHOR]

International trade of soybeans has increased substantially over recent decades. Its environmental toll is routinely linked to deforestation and biodiversity loss. However, soybean trade also imposes a huge demand on water and land resources, in individual countries and globally. Such a burden, and its underlying sectoral drivers, is frequently overlooked within the current research and policy agenda around sustainable soybean supply chains. This study evaluates the Virtual Water Trade (VWT) and Virtual Land Trade (VLT) of global soybean trade and reveals which countries and sectors are responsible. Soybean-related VWT and VLT are estimated by combining physical import and export data and associated resource use information from 166 countries during the period 2000–2016. Over this period global virtual soybean-related virtual water and land trade grew by 298% and 250% respectively. In 2016, 812 Gm3 of water use and 41 Mha of land use was directly embodied in international soybean trade. This corresponds to one-third of water and land used to grow soybean globally. Soybean-related VWT and VLT was mainly driven by demand in China, the Netherlands and Mexico, for soybean grown in the US, Brazil and Argentina. Animal feed is responsible for around three-quarters of this resource use. A reduction in the consumption of animal products or switching to direct human consumption of soybeans would reduce the overall demand for soybean production and associated resource use. Although welcome, calls for deforestation-free soybean supply chains do not go far enough to reduce the large, global water and land demand of soybean trade. The research and policy agenda around soybean trade warrants a broader focus on water and land use and whether this represents an efficient, and logical, allocation of resources within the context of food provision and national resource security. [ABSTRACT FROM AUTHOR]

Despite the recent droughts in Isfahan province, climatic changes and the rising trend of population growth, as well as development of industrial and agricultural activities, are exposed to the water crisis. Thus, in order to tackle this problem, the essential strategies should including exploring virtual water and water foot print for strategic crops in agricultural sector should be taken into consideration for the management of water supplies at risk. This study was aimed to examine virtual water and ecologic fingerprint of water for the wheat crop in Isfahan Province from the farming year 2006-7 through 2014-15. For this purpose, the quantity of virtual water was extracted using net irrigation demand by NETWAT software and the rate of irrigation efficiency was computed to be 48%. The results indicated that only in 2007, Isfahan province was an exporter of virtual water for the wheat crop, so this province exported about 0.15 billion cubic meters of virtual water to other provinces by wheat exportation, but Isfahan province was the only virtual water in the years (2008-15) and this was due to the annual population rise and the existing drought in this zone. During this period, the rate of the mean annual rate of ecological footprint of water was 5.87 billion cubic meters and Isfahan Province stored this volume of water from the given internal supplies annually, with the mean rate of 0.65 billion cubic meters of virtual water importation at that year. [ABSTRACT FROM AUTHOR]

Abstract In the era of globalisation over the last half century, there has been an increase in the exchange of agricultural and food products. This internationalisation process has led to intense environmental pressures on a global level, which has been the case of water resources. This paper studies the determinants of global virtual water trade flows between 1965 and 2010. Using panel data techniques, we have evaluated and quantified the explanatory factors of bilateral virtual water transfers between 70 countries as a result of agri-food trade. We have used the well-known trade gravity equation to explain exchanges of water embodied in agricultural goods on the basis of economic, geographical, institutional and environmental factors. The analysis considers economic country heterogeneity in order to evaluate how trade impacts water resources depending on different development patterns. Our main findings indicate that the traditional economic, institutional and geographic factors played a key role as drivers of virtual water bilateral trade flows between 1965 and 2010. In addition, the natural endowments also exerted a notable influence on these trends. Highlights • The long term determinants of VWT are assessed using a gravity model. • Changes in the country and product composition of VWX and VWM happened from 1965. • Environmental endowments notably determine VWT trends. • Considering income heterogeneity reveals notable divergences in the drivers of VWT. • Dynamic analyses offer a broader framework to study impacts on water through trade. [ABSTRACT FROM AUTHOR]

Traditional methods of assessing virtual water (VW) trade usually overestimate the foreign VW used by a country as the imported VW can also be re-exported and used by the countries other than the initial importer. Due to its ability to provide better estimates of transboundary resource use, the global value chain (GVC) method can provide more precise guidelines for the global policy debate over sustainable resource use. Here, we use GVC analysis based on multi-regional input-output tables to quantify the embodied trade of virtual blue and green water for China in the major agricultural sectors and agro-based industries. We find that China is a net importer of blue VW (2.9 billion m ^3 ) and green VW (57.9 billion m ^3 ) through agricultural commodities. Our results reveal that a large portion of imported blue (37%) and green (17%) VW is re-exported by China and consumed in other countries, representing the overestimated parts of China’s VW import use. These ratios are even higher for individual commodities, including 44% for blue VW for cotton and 22% for green VW for grains. This work demonstrates the importance of improved accounting in VW trade to achieve the sustainable use of global water resources and equitably share responsibility between producers, intermediates, and end-users.

Future transformations in the electricity sector could entail major shifts in power sector technology mixes and electricity trade, with consequences for the trading of virtual water. Previous virtual water trade studies largely focus on historical timeframes. We explore, for the first time, future—through 2050—virtual water trade driven by electricity trade under a range of future electricity sector transformation scenarios using the United States as an example. Under a business-as-usual scenario, virtual water trading in 2050 decreases by 3% relative to 2015 levels. By contrast, virtual water trading increases respectively by 3%, 26%, and 32%, in scenarios characterized by higher socioeconomic growth, higher potential for transmission expansion, and low-carbon transitions. These increases are driven by electricity generation expansion in the western U.S., resulting in higher virtual water trade to the east. In addition, we find that as electricity generation shifts west, an increased amount of nonrenewable groundwater will be consumed to generate electricity that is supplied to the east. Independent of scenario, the US electricity grid largely relies on virtual water exports from only a few states. Our study highlights the need for integrated and national strategies to manage the water and electric systems.