Search

The environmental impacts of the fashion industry have been aroused wide concerns. The globalization and fragmentation of the textile and fashion system have led to the uneven distribution of environmental consequences. As denim is the fabric of jeans that is representative of fashion, this study assessed virtual carbon and water flows embodied in the global denim-product trade, and footprints of denim production were quantified by life-cycle assessment and water footprint assessment. Results indicated that virtual carbon embodied in the global denim trade increased obviously from 14.8 Mt CO2e in 2001 to 16.0 Mt CO2e in 2018, and the virtual water consumption dropped from 5.6 billion m3 to 4.7 billion m3 from 2001 to 2018. The denim fabric production and cotton fibre production respectively contribute the most of the carbon emissions and water consumption. Polyester blended denim has 5% larger carbon footprint and 72% lower water footprint than cotton denim, and contributes to increasing embodied carbon emissions (from 4% in 2001 to 43% in 2018). Increasing the utilization of polyester blended denim would save water but face more pressures on carbon emission reduction. In the past two decades, virtual carbon and water flows embodied in the global denim trade are relocating, main jean consumers (i.e., the USA, EU-15, and Japan) withdraw the denim manufacturing supply chain and developing countries (i.e., China, India, and Pakistan) with higher carbon and water footprint undertake main global denim production, facing increasing climate-related risks and water crisis. The South-South cooperation helps share successful experiences, save production cost, and lessen resource consumption and environmental emissions. The production and consumption of denim should be shifted to circular and sustainable ways and new business models are required. The analysis framework can provide the basis for exploring environmental flows of product-level trade, and results can offer a basis for environmental policies and control strategies of the fashion industry, and as well as the sustainable production and consumption of garment.

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.

As the headwaters region of many major Asian rivers and one of the most vulnerable ecosystems in the world, Tibet is an important strategic water resources and ecological conservation district in China. Although Tibet has developed increasing economic links with external regions, the virtual water (VW) interactions have rarely been discussed due to data unavailability. In this study, based on a newly released China multiple-regional input-output table in 2012, Tibet's local water use is analyzed by associating it with interregional-level trades in China. The structural decomposition analysis (SDA), which is conventionally applied to trace influencing factors for temporal changes of environmental variables, is adapted to examine socio-economic determinants of net VW trade in Tibet. The results indicate that Tibet is a net VW exporter, providing 577.5 million m 3 net VW to other provinces. The SDA results provide quantified effects of different factors. Tibet's low direct water use intensity and water intensive dominated export structure contribute 1048.6 and −738.9 million m 3 net VW exports, respectively. In contrast, the trade volume of commodities and production structure contribute to offsetting the net VW export 1140.7 and 69.4 million m 3 , respectively. Policies are informed towards sustainable water resources uses and management. Measures including resources use efficiency improvement, industry upgrade towards a less resource intensive production structure and material support from external regions are suggested, highlighting the importance of strengthening coordination between Tibet and downstream regions.

The Fifth Assessment Report (AR5) of the Intergovernmental Panel on Climate Change (IPCC) has concluded that climate change will have significant impacts on global water resources. The risk of production loss due to water scarcity can be transmitted through international trade to distant economies downstream the supply chain. In this research, how climate change may affect the global economy via reducing available water resources in some regions is investigated based on a multi-regional input output (MRIO) model that provides information on the current global economic structure. Key nation-sectors with the greatest virtual water scarcity risk (VWSR) exports are identified under two climate change scenarios, including the Agriculture sectors in Syria, Pakistan, Kazakhstan, India, Uzbekistan, Iran, and China. Improving water efficiency in these sectors is essential for increasing the resilience of the global economy against climate change-induced water scarcity. Nation-sectors with the largest VWSR imports are also identified under the two climate change scenarios, including Food & Beverages sectors, Textiles and Wearing Apparel sectors, and Petroleum, Chemical and Non-Metallic Mineral Products sectors in Saudi Arabia, the United States of America, Russia, Germany, Italy, and China. These are the most vulnerable nation-sectors facing the reduction in foreign water resources due to climate change. Additionally, through comparing the change of rankings of VWSR imports, VWSR exports, and LWSRs at country and sector level, the rankings of VWSR exports are relatively close to LWSRs, while the rankings of VWSR imports are quite different from LWSRs. The evaluation demonstrates that nations should cooperatively manage water resources and be aware of the transmission of virtual water scarcity risk through international trade under climate change. Moreover, nation-sectors with high VWSR imports may reduce the reliance on water-intensive products and diversify importing sources, and national governments can encourage residents to change consumption patterns.

China faces increasingly severe water stress from its limited, unevenly distributed water resources and rapid economic growth. Interregional trade of goods and services within China further leads to a redistribution of water resources through virtual water transfers. Such virtual transfers are subject to constant changes due to the temporal variabilities in driving factors such as production efficiency, consumption patterns and population. Here we use the most recent public data to measure the water footprints of 31 provincial-level regions in China and virtual water transfers among these regions in 2012. We find that virtual water transfer plays a significant role in regional water footprints and greatly changes the allocation of water resources towards regional consumptions. Already water-scarce north China regions benefit from virtual water transfer by outsourcing water-intensive products from other regions. However, the water-scarce Northwest China suffers from virtual water transfer by exporting water-intensive products. We suggest policy makers pay attention to demand-side measures to incentivize parties to improve water efficiency in their production and reduce the consumption of water-intensive goods. Policymaking should consider economic policy and water conservation policy together to alleviate regional water stress through virtual water transfers.

Physical water consumption (PW) in economic sectors are linked with virtual water consumption (VW) embodied in the supply chain of commodities. It is important to quantitatively assess PW and VW in economic sectors and understand interconnections between them for supporting water resources management. Here, we applied an IO framework to analyse how the PW is linked to the VW from both production and consumption perspectives. A water scarce region consisting of Ganzhou, Linze, and Gaotai counties (GLG) in the Heihe river basin in China is used as a case study. The agricultural sector is broken down into seven sub-sectors represented by individual major crops. From production perspective, the results show that the agricultural sector accounted for 98.1% of total PW, which can be divided into 79.0% of final demand driven water consumption and 21% of intermediate demand driven water consumption. From consumption perspective, the VW of all the sub-sectors in the agricultural sector was largely attributed to the direct VW. The sector “Food and tobacco processing” (the downstream of the agricultural sector) has the largest indirect VW among all the sectors. Most PW in GLG was used to produce the low value added primary agricultural products to fulfil the final demand (VW) outside GLG. The results suggest that the water resources management in arid regions should guide the restructuring of economy from increasing agricultural production to increasing the economic value of the embodied virtual water, and reducing the export of the virtual water from the low economic value products.

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.

Urbanization, industrialization and their associated water shortage pressures have brought great challenges to agricultural development and water security. Understanding the virtual water flow involved in the grain trade is critical to ensuring water security and agricultural production. However, there are few studies on the comprehensive benefits provided by virtual water flow in the grain trade. This paper proposes a linear optimization model to fill this gap. The model is used to estimate the virtual water flow via interregional grain trade within China in 2015 and corresponding benefits to resources, the economy, and the environment from both outflow and inflow comparative perspectives. Three results characterize the virtual water flow pattern of interprovincial grain trade in China in 2015: (1) In terms of resource benefit, 31. billion cubic meters of water resources were saved, accounting for approximately 39.7% of the total virtual water flow. (2) A positive economic benefit was realized, with an increase of 6.4 trillion yuan in industrial value added. (3) Certain regions with a high crop green water occupation index account for a considerable proportion of the green water of the local agricultural ecosystem. Simultaneously, massive output of virtual water would aggravate the destruction of terrestrial ecosystems. Finally, the results suggest that promoting the marketization of water resources, improving water productivity, exploring regional compensation mechanisms and improving green water conservation capacity should be considered for water security policies.

Previous studies had shown that the virtual water flows had intensified local water scarcity of China. There is an urgent need to identify the drivers of virtual water flows and provide the potential options to reduce the impact of virtual water flows on regional water scarcity. Based on the multi-regional input-output model and structural decomposition analysis, we evaluated the redistribution of water withdrawal within China in 2002, 2007 and 2012, and then revealed the hidden driving forces of the changes in virtual water flows. For a specific province, the drivers had been divided into local and the rest of China. Here we found that: (1) The share of virtual water flows in interregional trade to total water withdrawal had increased (from 20.1% to 40.5%) during the study period. (2) The direction of virtual water flows has reversed between some Chinese regions. Northwest and Northeast regions have become the major virtual water exporters. (3) The virtual water flows hidden in traded products of agriculture, electricity and the chemical industry accounted for more than 83% of total virtual water flows. (4) Local efficiency gains and consumption pattern changes in other provinces were the main drivers for changes in virtual water flows. The water-scarce Northwest and Northeast of China had further increased virtual water export to the water-rich provinces in southern China. This trend could be curbed by improving water use efficiency and restraining water-intensive consumption. Our results could pinpoint areas to invest in water use efficiency and provide guidance for areas to restrain water-intensive consumption.

Currently, agriculture uses about 70–80% of global water resources and, in the Mediterranean area, it accounts for the high pressure of freshwater demand. This study provides a useful framework for the meso-level assessment of the Water Footprint (WF) in agriculture. Particularly, the WF methodology is used to quantify the water consumption and pollution of olives, grapes and tomatoes, traditional crops widespread both in the Apulia region, in Southern Italy, and in the Mediterranean area. Hence, from a meso-level assessment of the Water Footprint of Apulian agriculture, a general level of evaluation of the use of Mediterranean water resources was provided, estimating the Virtual Water (VW) too. Furthermore the climate change effects on the Water Footprint of the traditional crops identified were predicted, proposing some scenarios useful to reduce the grey component, which values for olives were evaluated by a sensitivity analysis. The results highlight that olives present the highest value of the WF and that grapes are the most affected by the variations according to the climate change scenarios, increasing over 200% of the green component and 77% of the blue one. Finally, a Circular Economy proposal, based on the reuse of the wastewater from a meso-scale perspective, highlights saving up to 70% of the water resource. The research questions proposed displayed the novelty of this paper, particularly as concerns the use of the Water Footprint analysis on a meso-level evaluation. Particularly, the new insights of this research addressed the needs of stakeholders in areas suffering from drought, such as the Mediterranean, to integrate and systematize a data-set of indicators to rationalize and plan water resource usage and safety in agriculture.

With growing populations and climate change, more regions around the world are prone to unprecedented water scarcity. The concept of virtual water is introduced in the Middle East, where one of the strategy to solve water scarcity is to import grain instead of grow grain locally. However, some researchers have argued that such virtual water strategy as a solution to water scarcity is fallacious failing to take regional socio-economic and environmental suitability into account. In this study, an evaluation index system of virtual water strategy was constructed from an integrated water–ecosystem–economy system perspective. The evaluation index system can reflect the co-relationship among water, ecosystems and the economy and the status of system, which consists of resources, technology, economy, society, and environment. Using the improved entropy weighting and fuzzy synthetic evaluation methods, regional suitability of virtual water strategy was assessed and classified into the following five grades: excellent, good, average, fair, and poor. Using the Heihe River Basin (HRB) as the case study area, the evaluation index system was applied to examine the regional suitability of virtual water strategy for each county in the river basin. Results showed the suitability degree of approximately half of the counties was ‘excellent’, while the other half was ‘average’, except for Jinta County whose suitability of the virtual water strategy was ‘poor’. The results indicated that the suitability of the implementation of virtual water strategy is closely related to the economic development and ecological conditions. In addition, the study propels the evaluation of virtual water strategy, and enhances their persuasion in addressing water scarcity, identifying the feasibility in the arid and semi-arid regions worldwide.

China's “Developing a Water-saving Society” policy is an ambitious water conservation strategy. However, there has been little evidence of the policy's effectiveness in terms of saving water at a river basin level. In this paper, we used a basin-scale hydroeconomic input-output model to calculate the water consumption (WC) by producers and consumers (WCp and WCc), respectively in the first pilot area for implementation of this policy, the Heihe River Basin, which belongs to an arid area in inland China. The results show that, after implementation of the policy, WCc decreased sharply but WCp only decreased slightly. A structural decomposition analysis revealed that decreased water consumption intensity played an important role in reducing water consumption. However, this effect was largely offset by the increasing exports of virtual water in goods and services. Our results suggest that in arid river basins, measures in saving water must be accompanied with a cap on total water consumption which is set in accordance with the local water endowments and consideration of environmental water requirement.

As a typical region moving forward on green development demonstration belt, Yangtze River Economic Belt (YREB) is sensitive to profound conflict between coordination development and unbalanced water allocation. Uncovering water transfer network can help improving water resource coordination development from the perspective of water-trade nexus. An integrated framework by uniting the inter-regional input-output (IRIO) analysis and social network analysis (SNA) in this study can estimate not only the scale and structure of water trade pattern, but also the topological characteristic of water transfer network of YREB. Results show that the rank of production-based virtual water volume was roughly in the order of middle, lower and upper reaches except Jiangsu, while the rank of consumption-based virtual water volume was in the order of lower, middle and upper reaches. The provincial virtual water external dependence in YREB was not well consistent with the water resource endowment. Water transfer network was constructed on basis of the inter-provincial virtual water transfers between every two provinces inside YREB. Furthermore, the water transfer network assessment results illustrated the network structural form and revealed the network property and characteristics. Inside YREB, Shanghai, Jiangsu, Zhejiang, Anhui and Jiangxi were predominant in the water transfer network (from degree centrality), while Jiangxi, Hubei, Hunan and Anhui acted as the important medium and bridge (from betweenness centrality). The AFAF sector (Agriculture, Forestry, Animal husbandry and Fishery) and Industry sector of Jiangxi, and the Industry sector of Hubei and Jiangsu were the critical exporters in the network. Jiangsu received large amounts of virtual water from many good hubs and also transferred much to many good authorities when acted as bagmen in the network. Some provinces received large virtual water flow but provided few to others, such as Shanghai, and the AFAF sectors of most provinces transferred much to others. Thus, the research results would help understand the regional responsibility transfer in the hidden network linkages of interprovincial and intersectoral virtual water flows.

To reduce the water footprint of a cement plant is one of the most important clean production performance indicators of the manufacturer. This paper proposes a comprehensive model for evaluating water footprint of cement production based on the type of energy consumption, transportation and human effects using a system boundary analysis. A cement plant located on western Iran is analysed to demonstrate the application of the proposed model and a sensitivity analysis is conducted to show the effects of different parameters on the performance of the model. The paper shows that the total water footprint of the selected cement plant accounts for 3.614 × 106 m3 in 2016 with water consumption intensity of 2.126 m3 per each ton of cement production indicating the risk of surviving cement industry in dry regions. The paper also shows that in the selected cement plant virtual water consumption contributes to the 90 percent of the total water footprint value. In addition, the paper demonstrates that the majority of the virtual water consumption is related to the energy sources which is 9.3 times more than the direct water consumption of the case study plant. Furthermore, the paper shows that water footprint can be most effectively reduced by shifting to greater contributions of wind and solar energy. This paper will be of interest to academics and practitioners interested in cleaner production of cement plants. It provides an understanding of water consumption of the cement industry broader than is currently available.

The spatial mismatch between energy resources and water resources has been widely concerned. Electricity trade drives virtual water flows from electricity production sides to consumption sides, which can aggravate or alleviate regional water scarcity. Investigating the historical evolution of virtual water transmission and its impacts on water scarcity benefits the sustainable development of energy and water. To reduce data uncertainties, in this study, we built provincial water intensity of electricity generation inventory considering the impacts of factors such as electricity generation types, cooling technologies and generator units. Besides, to investigate how the direction and quantity of virtual water flows aggravate or alleviate the regional water scarcity, the impact assessment model was built, and the impact assessment index was defined. The results showed that the water consumption of electricity generation and interprovincial virtual water transfer increased by 2.61 times and 5.12 times during 2005–2015, respectively. Changes in the amount of electricity generation and the electricity transmission structure were the two main drivers of increases in virtual water flows, contributing to a total increase of 85.28%. A large amount of virtual water was transferred from the southwest and the northwest to the eastern coastal areas. There were many “positive flows” from the southwest to Jiangsu-Zhejiang-Shanghai, while “negative flows” were concentrated in Xinjiang-Henan, Gansu-Qinghai and Gan-Shaanxi. The nodes with the largest impact assessment index value were Hubei, Sichuan and Shanghai, while the lowest were Gansu, Xinjiang and Qinghai. This study can provide a basis for optimizing the electricity generation mix and electricity transmission structure, alleviating the growing tension between energy and water, and realizing the sustainable development of water resources.

The irrational grain virtual water flow caused by spatial mismatch in water and available arable land threatens grain security in China. However, systematic and quantitative assessment of grain virtual water flow on environmental impacts has rarely been conducted. This study analyzes the flow patterns of China's interprovincial and international grain virtual water and resulting environmental impacts during 2019–2020, with a focus on water-saving and environmental benefits. Results showed that the main importers and exporters of environmental impact flow were inconsistent with those of virtual water flow, and maize trade was the main contributor to these flows. China's grain virtual water flow resulted in approximately 2.21 Gm3 water loss and increased the impacts on water scarcity and human health by 1.61 Gm3deprived and 3.42 × 104 DALY, respectively. Nevertheless, the grain virtual water flow generated benefits in ecosystem quality by 1.20 × 10−3 species. yr, compared with the no-grain transfer scenario. Exporting maize from Shanxi, Inner Mongolia, Gansu, and Xinjiang provinces dominated water loss and environmental burdens, whereas exporting rice from Hubei, Hunan, Anhui, and Jiangxi provinces contributed mostly to water-saving and environmental benefits. Importing grains from abroad also contributed to water-saving and ecosystem quality impact reduction. Measures, including improving irrigation water productivity and developing a regional compensation mechanism for dominant maize exporters, strengthening green water management in dominant rice-exporting areas, achieving the diversified development of China's trade partners, and implementing strict tariff quota administration, are suggested to alleviate environmental impacts and ensure grain security.

Interregional trade not only contributes to economic growth but also causes a large amount of virtual water transfer. The virtual water transfer brings about two-way impact of environmental stress between regions. It is essential to examine the two-way impact mechanism to achieve water sustainability. Interregional virtual water transfer includes three aspects of effects: multiplier, spillover and feedback effects. Among them, multiplier effect is the interaction in a single region. Spillover effect generally refers to the one-way impact of former region's economic development on latter region, while the feedback effect refers to the economic change of latter region in turn has an impact on the former region on the basis of the spillover effect. However, most studies have been focusing only on the one-way impact of virtual water transfer, which are the multiplier and spillover effects. This paper introduces a new spillover-feedback effects model to measure the two-way impact of virtual water transfer in urban agglomerations, and takes the Beijing, Tianjin and Hebei capital agglomerations in China as a specific case. The results illustrate that the spillover-feedback effects had significant contributions to virtual water transfer. From the perspective of regional scale, Beijing was a net importer of virtual water, with a net import volume of 1.019 × 108 m3. Tianjin and Hebei were net exporters of virtual water, with net exports of 0.069 × 108 m3 and 0.950 × 108 m3 respectively. The values of the feedback effect were large and should not be ignored, which accounted for up to 40% of the spillover effect. Furthermore, at the sectoral scale, the sectors with large ratios of spillover-feedback effects to total effects in regions included mining, agriculture, manufacturing and transportation. In Beijing, this ratio of mining exceeded 50%. Additionally, the effect intensity patterns were different from the effect patterns, which prove that the regional ability to stimulate water consumption was not consistent with the actual impacts. Finally, regions should pay more attention to managing the industries and enterprises with high virtual water export, adjust the trade structure, strengthen inter-regional cooperation and clarify regional responsibilities for water-saving. In a word, understanding interregional two-way impact mechanism is essential for the sustainable and collaborative development of the economy and environment in urban agglomerations.

Here we identified and evaluated the strengths and spatio-temporal heterogeneities in 12 main socio-economic driving factors of water footprints and inter-provincial virtual water flows related to three staple crops (rice, wheat, and maize) within mainland China for 2000–2017, in consideration of the infrastructure related to irrigation, agricultural electricity and road for the first time. The irrigation, agricultural electricity, and road infrastructures in China expanded by 33.8, 4.5, and 2.4 folds, respectively, throughout the course of this study. The results show that irrigation infrastructure in water-scarce regions was the most critical driver for the effective reduction of the water footprint per unit mass of crops, particularly the blue water footprints (i.e. increasing water efficiency). As the irrigation infrastructure per unit area doubled for 2000–2008, blue water use efficiency and total blue water consumption decreased by 58% and 71%, respectively. However, the development of irrigation infrastructure has led to a larger total water footprint in crop production. Agricultural electricity and road infrastructures had increasing effects on provincial virtual water export, with varied corresponding driving strengths across spaces. The visible effects of agricultural infrastructure on regional water productivity, water consumption, and virtual water patterns should not be neglected. This analysis suggests that investments in agricultural infrastructure should consider the spatio-temporal heterogeneity of these infrastructures on local water productivity and water consumption in addition to the economic benefits.

In this study, a two-stage factorial-analysis-based input-output model (TFA-IOM) is advanced for virtual water assessment, which integrates techniques of factorial analysis (FA) and ecological network analysis (ENA) into input-output model (IOM). TFA-IOM can not only identify the crucial water transaction sectors and the associated integral utility relationships, but also investigate the individual and interactive effects of multiple factors on virtual water metabolic network (VWMN) through measuring water consumptions of different sectors. The developed TFA-IOM is applied to Kyrgyzstan in Central Asia to quantify its virtual water and identify its metabolic network, where agricultural and animal husbandry sectors are the main water consumers. Our major findings are: (i) Kyrgyzstan is a country relying on net virtual water import (reaching up to 3,242 × 106 m3); (ii) WHT (wheat) is the main virtual water supplier (with 349 × 106 m3 virtual water to others); (iii) WHT, VGF (vegetables, fruit, and nuts), PFB (plant-based fibers), CTL (bovine cattle) and RMK (raw milk) are the main sectors affecting the VWMN (e.g., utility relationship and integral virtual water recycling index). From a long-term and sustainable development point view, stimulating Kyrgyzstan’s domestic WHT and RMK productions and improving VGF, PFB and CTL water-use efficiencies can facilitate reducing net virtual water import and promoting the mutualism degree of the national VWMN.

A rapidly expanding economy and increasing water demand for agricultural and industrial production is placing enormous stress on water quantity and the aquatic environment in Northern China, especially the so-called Jing-Jin-Ji (Beijing-Tianjin-Hebei) urban agglomeration, home to over 110 million people producing 10% of China's overall GDP. Several studies have focused on energy consumption, air pollution, CO 2 emissions and regional blue water footprint (WF) following release of the Jing-Jin-Ji Integration Strategy by the China government in 2013. However, a comprehensive assessment distinguishing blue, green and grey WF amongst different industrial sectors, ascertaining how WF transfers internally and beyond the region and final demand consumption is not available. We consider this to be crucial in understanding and addressing the deteriorating water situation in the Jing-Jin-Ji. In this study, we quantified the WF and virtual water flow on a sectoral basis for the year 2010 through coupling the multi-regional input-output model (MRIO) with WF assessment. The results showed that Beijing and Tianjin are net importers of green, blue and grey water from Hebei and other China provinces to support their needs. Conversely, Hebei exports all WF colors to Beijing, Tianjin and other provinces in China, and more than 60% of WF is transferred as virtual water. For the overall Jing-Jin-Ji region a small amount of blue water (2086 million m 3 ) is exported, but huge amounts of green water (15,573 million m 3 ) and grey water (30,620 million m 3 ) are outsourced. A “Virtual Water Strategy” is one measure which could alleviate water stress at the regional scale, with consideration of financial compensation from water receiving regions made to water supplying regions in the context of achieving water management targets. We also found that physical water transfer to Jing-Jin-Ji could not balance virtual blue water exports, not to mention compensating for internal water consumption. Our research suggests that a continuation of an export-based economic development model will worsen Hebei's water stress. Reducing the dependency of Hebei's sectoral economy on export of water intensive and low value added agricultural products may be one strategy to reduce the pressure on regional water resources. In addition, the Beijing-Tianjin-Hebei Integration Strategy drives industrial transfer from Beijing to Hebei resulting in the transfer of enterprises with low water utilization efficiency and producing heavy pollution. As a result, the government should consider incentivizing corporations to adopt technologies that reduce water consumption and pollution.

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.

China is a country with a serious water shortage. Irrigation water accounts more than 60% of total water use. With the nation’s population forecasted to peak approximately 2030, the production of food for additional people will require more water resources, which exacerbates water shortages. North China is a typical case for studying water-food nexus because water shortage has become a primary factor in restricting food production. From the perspective of virtual water, the study calculates the changing trend of the virtual water (VW) flow related to grain transfer in China, for which three primary crops of China, including rice, wheat and maize, are considered. The results demonstrate the impact of changing the spatial patterns of grain production on water resource utilization is large, and water resources are redistributed related to grain trade. Northern China imports water-intensive products from southern China and exports water-extensive products, and the VW flow from North to South from 2004 to 2013 was approximately 42.6 billion m3 per year, about 10.2 billion m3 irrigation water was transferred per year which accounts for about 10% of the water consumption for crop production in the North. Although the South–North Water Diversion Project, a mega-engineering scheme constructed from the Yangtze River Basin to the Huang-Huai-Hai River Basins, alleviates water pressure on the North to a certain extent, it is insufficient for exporting to provinces, and water resources for meeting grain production in the North is problematic. Based on the results, this paper suggests that virtual water flow among provinces should be linked to water resource management. The next step in water management should focus on water demand management, rather than increasing crop trade from the North to the South, which is governed by governmental policies and economy.

In the globalised world greenhouse gas (GHG) emissions and water consumption are becoming increasingly important indicators for policy and decision making. Development of footprint assessment techniques over the last decade has provided a set of tools for monitoring CO2 emissions and water flows in the world. An overview of the virtual CO2 emissions and virtual water flow trends in the international trade based on consumption perspective is performed in the current work. The review of the recent literature indicates that: (1) Producers and consumers are located at various places in different parts of the world, and consequently they are significant differences in virtual GHG (Greenhouse gases) emissions. (2) The US and the EU have high absolute net CO2 imports. (3) China and some other fast developing countries as India, Brazil, and others are exporting countries and increasingly carry the load of exports of virtual GHG including CO2 emissions and virtual water that are triggered due to consumption of the related goods in the importing countries. (4) By importing products produced with lower carbon emission intensity and less water consumption than in the domestic industry, international trade can reduce global environmental pressure. Results from analysis indicate that future actions should be focused onto two main areas: (i) To steer regions towards self-sufficiency based on more efficient processes and by combining production of surrounding countries. (ii) To develop a mechanism with shared market of virtual carbon and virtual water between trading partners regionally and internationally.

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 m3/y, whereas 63.45 billion m3/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.

Facing the prospective conflict between fast economic growth and water-use challenges, it is desired to explore the relationship between industrial structure and virtual-water flow in a socio-economic system to support the formulation of water-resource management related legislation. In this study, a multi-hierarchy industrial virtual water network model (MIVWN) was developed for analyzing the status of varied industrial sectors in the virtual-water system. A special case study for Hubei Province, China, was conducted to demonstrate the potential profits of its use in the formulation of water-resource management related legislation. Specifically, multi-hierarchy scenarios for system identification were performed to get more insights on the complex interrelationships among various industrial sectors. It is found that the industrial sectors have low water-use efficiency; and the mutual connections of virtual water between various industrial sectors are limited in Hubei. For the substantial industrial sectors, it is of vital importance to upgrade the upstream and downstream supply chains. For the isolated sectors, the decision maker should commit to enhance their virtual water exchanges with other sectors. It is expected that the results will provide a solid basis for supporting the application of an effective water-resource management strategies for industrial sectors.

Water resources are strategically important for human production and life. However, water resources are unevenly distributed in time and space. Rational use of broad water resources such as water footprint is essential for promoting regional sustainable development. This study developed an approach that quantified water footprint of Beijing, China based on input-output data of local production and living sectors and defined an indicator system to assess the dependency and vulnerability of regional water footprint network. Results indicated that water footprint of Beijing decreased from 1.89×1010 m3 in 2007 to 1.61×1010 m3 in 2012, of which the imported virtual water accounted for 33.85% in 2007 and 26.39% in 2012, respectively. The primary industry had the smallest total water footprint but the largest proportion of imported virtual water. The secondary industry had the largest total water footprint and a moderate proportion of imported virtual water. The tertiary industry had a moderate proportion of total water footprint and the smallest proportion of imported virtual water. Regions with main virtual water export to Beijing include neighboring provinces and long distance provinces. These providers exerted indirect water stress on Beijing due to their own direct water stress and industrial structure. In order to reduce the vulnerability of the water footprint network, Beijing should import virtual water-related products and services from the areas with less water stress, and at the same time, it should improve the water use efficiency of its own production and consumption. The methodology suggested in this study towards decreasing the vulnerability of the water footprint network is instructive for other regions facing water scarcity like Beijing to promote rational water resources use.