Environment International 121 (2018)178-188Contents lists available at ScienceDirectEnvironment InternationalELSEVIERjournal homepage:www.elsevier.com/locate/envintEvolution of China's water footprint and virtual water trade:A global tradeassessmentXu Tian,Joseph Sarkis,Yong Geng,Yiying Qian",Cuixia Gao,Raimund Bleischwitz,ABSTRACTHandling Editor:Yong Guan ZhuWater embodied in traded commodities is important for water sustainability management.This study providesinsight into China's water footprint and virtual water trade using three specific water named Green,Blue andWater footprintGrey.A multi-region input-output analysis at national and sectoral analysis levels from the years 1995 to 2009 isGlobal supply chainconducted.The evolution and position of China's virtual water trade across a global supply chain are exploredCluster analysisthrough cluster analysis.The results show that China represented 11.2%of the global water footprint in 1995Virtual water tradeand 13.6%in 2009.The green virtual water is the largest of China's exports and imports.In general,China is anet exporter of virtual water during this time period.China mainly imports virtual water from the USA,India andBrazil,and mainly exports virtual water to the USA,Japan and Germany.The agriculture sector and the foodsector represent the sectors with both the largest import and export virtual water quantities.China's globalvirtual water trade network has been relatively stable from 1995 to 2009.China has especially close relation-ships with the USA,Indonesia,India,Canada,Mexico,Brazil and Australia.Trade relations,resource endowmentand supply-demand relationships may play key roles in China's global virtual water footprint network ratherthan geographical location.Finally,policy implications are proposed for China's long term sustainable watermanagement and for global supply chain management in general.1.IntroductionUnderlying international trade is the globalization of industrial supplychains,which should not go unrecognized in this discussion of inter-Water is a fundamental natural resource for human and environ-national trade flows.mental development (Dalin et al.,2012).Water availability variesWater embodied in traded commodities is called "virtual water"greatly across countries and global regions with uneven distribution.(VW),which is defined as the volume of water required for the pro-Water use also has different environmental impacts depending on theduction of one commodity (Allan,1997).The water footprint (WF)hasgeographic location.Additionally water related issues constrain thebeen introduced to further identify anthropogenic (human)pressure onsustainable development of countries or regions,with various socio-the natural environment.The WF is based on virtual water measures,itpolitical issues arising,such as the water war between Central Asiancan also be used to quantify water resource gross requirements forcountries (Ercin and Hoekstra,2014).In order to alleviate water crises,products and services consumed by an individual,business,town,cityinternational trade can play a significant role in water resources re-or country (Chapagain and Hoekstra,2002;Chapagain and Orr,2008;distribution.This global redistribution can occur through traded com-Hoekstra et al.,2011).WF across global supply chains at the interna-modities,which may contain large volumes of embodied upstreamtional level can be used to investigate water flows and the equity ofwater use across the supply chain (Hoekstra,2010;Zhang et al.,2016).water resources distribution across nations.The linkages betweenCorresponding authors.Correspondence to:Y.Geng,China Institute for Urban Governance,Shanghai Jiao Tong University,Shanghai 200240,China.E-mail addresses:tianxu@sjtu.edu.cn (X.Tian),jsarkis@wpi.edu (J.Sarkis),ygeng@sjtu.edu.cn (Y.Geng).https://dai.org/10.1016/j.ewit.2018.09.011Received 5 July 2018;Received in revised form 22 August 2018;Accepted 6 September 2018Available online 11 September 20180160-4120/@2018 Published by Elsevier LtdX Tian et al.consumption behaviors,trade activities,and anthropogenic water use2002;Ercin and Hoekstra,2014;Cazcarro et al.,2012;Yang et al.,can also be evaluated (Chen and Chen,2013:Chenoweth et al..2014:2013).Hoekstra and Mekonnen,2012).VW and WF can be jointly evaluated with trade transfer from globalWF flows for China is especially pertinent due to water and otherand regional perspectives.In China,water flows can be assessed fromresource shortages from its rapid economic development and growingdomestic or foreign trade perspectives.For China's domestic trade,population (Dong et al.,2014).China has been one of the top waterseveral studies identified imbalanced exchanges with water resourcesconsumption countries in the world for the past two decades (Chen andbetween China's provinces and basins (Chen et al.,2017;Deng et al.,Chen,2013).Limited water resources have severely restricted devel-2016;Dong et al.,2014;Jiang et al.,2015;Zhuo et al.,2016;Liu et al.,opment of its national economy (Chen et al.,2017).China,as the2017;Zhang and Anadon,2014;Feng et al.,2012).Other studies in-world's manufacturer',supports its export production by consuming itsvestigated VW or WF for single cities and provinces and the influence ofnatural resources and releasing vast amounts of pollutants (Geng et al.,trade on their water resources (Dong et al.,2013;Wang et al.,2013;2017;Z.Liu et al.,2015;J.Liu et al.,2015).China's resource-intensiveand export-oriented growth model has resulted in environmental de-The VW and WF of China's international trade has also been in-gradation.Previous published research outcomes show that China is avestigated.Agricultural international trade has been the primary focusnet virtual water,virtual land,and embodied emissions exportingof most published studies (Shi et al.,2014;Zhang et al.,2016,2017,2018).Several studies focused on China's import and export trade fromet al.,2018;Peters et al.,2011).In order to understand and managea national level.For instance,Chen and Chen (2013)calculated the WFsChina's and global water issues,China's water consumption across theof 112 countries (regions)and the VW trade using a multi-region I/Omodel with the Global Trade Analysis Project (GTAP)database.ResultsWith these issues in mind,the aims of this study are to:(1)holi-showed that India,the United States,and mainland China are thestically explore the trends and roles of China's water consumption froma global trade/supply chain perspective over a given time period;(2)from non-food trade.In addition,China's net import and export VWidentify the industrial sectors influencing China and its trade partners'were evaluated for its trade partners.However,that study only eval-virtual water flows;and (3)understanding China's dynamic trends ofuated a snapshot of a single year situation.Broader industry sectoralvirtual water trade across the global supply chain and glean insightstrade transfer between China and its partners was not considered.and policy directions.Although the goal of this study is to understandChina's VW export and import using I/O analysis from 2000 to 2012China's situation,the implications for other regions,policies,andwas also evaluated in a recent study based on China's national input-supply chains will also be made evident.output tables (Chen et al.,2018).This study found that China was a netThe remainder of this paper begins with Section 2 which gives aexporter of VW during this time period.VW exports were primarily tobrief review of virtual water and water footprint studies.Section 3 in-the USA,EU and Japan.China mainly imported VW from ASEANtroduces the basic method and data sources of this study.The results arecountries,Brazil,and Korea.Sector of Textile,Garment and Leatherpresented in Section 4.Finally,Section 5 discusses various policy,tradeProducts was China's main industrial export sector,while agricultureand supply chain implications,as well as limitations;Section 6 sum-was the main import sector.This study only applied a single region I/Omarizes this study and provides directions for future study.model of China.It did not consider the complex interaction across thebroader supply chain network;it investigated China's export and import2.Review of virtual water and water footprintV from a sectoral perspective only,without investigating interna-tional sectoral relationships.Virtual water (VW)and water footprints (WF)emerged in the 1990sChina's WF from production and consumption caused by foreignand 2000s,respectively (Allan,1997;Chapagain and Hoekstra,2002).trade in 2012 was investigated based on a European database (HanVW quantifies total water consumed by product or service.Agricultureet al.,2017).The results show that China was a net embodied waterproducts and VW transfer between regions and countries have been asupplier in both final consumption based trade relations and in inter-particular focus of most relevant studies.WF can be used to identifymediate production-based ones.This study shows Pakistan,Myanmarhuman pressure on the natural environment,quantifying water re-and India were China's largest embodied water suppliers.Hong Kong,source gross requirements for products and services consumed by anthe United States,and Japan were its largest net recipients.The elec-individual,business,town,city or country.trical and machinery sector and the agriculture sector were China'sThree types of water resources are valued in VW and WF.Theselargest export and import VW sectors,respectively.This study identi-three water resources are green,blue and grey water.Green water isfied the VW of China via international trade during a single year andprecipitation on land that does not run off or recharge the groundwater,did not distinguish relationships among the three specific VWs.but is stored in the soil or temporarily stays on the top of the soil orUnder such a circumstance,in our study we seek to address thevegetation.Blue water is fresh water drawn from surface water andlimitations and expand on existing studies relating to China's WF andgroundwater.Grey water is freshwater required to assimilate the loadof pollutants based on existing water quality standards.It is necessaryto know that grey water footprint is not an actual consumed quantitysupply chain and trade partners from 1995 to 2009 based on a multi-but a hypothetical amount to assimilate water pollution to certainregion I/O model with the World Input-Output Database (WIOD).Thispredefined levels,therefore,it is used to show the economic burden onstudy distinguishes between benchmarks for Blue,Green and Greywater use (Chapagain and Hoekstra,2003;Hoekstra and Chapagain,water consumption,respectively.VWs transfer between China and its2008).partners from a sectoral perspective are also identified.China's VWStudies on VW and WF have included global (Hoekstra andtrade flow evolution during this period is analyzed with the help ofMekonnen,2012),regional (Vanham et al.,2013),specific countriescluster analysis;a unique investigation not seen in other studies.The(Schyns and Hoekstra,2014),basin (Zhuo et al.,2014),city (Li et al.,main innovation is that it is a temporal study,covering sectoral per-2016),industry (Duarte et al.,2014),production (Rodriguez et al.,spectives.Also,this study investigates green,blue and grey water re-2015),and products perspectives (Schyns et al.,2017).Topics coveredsources so that more valuable policy insights can be obtained.In ad-by the literature include water consumption,scarcity,efficiency,sus-dition,cluster analysis is conducted to uncover the key features oftainable management and transfer.Bottom-up methods,also defined asChina's VW so that the detailed water interaction between China and itsa "production tree",and top-down Input-Output (1/O)analyses aretrade partners can be presented for preparing sustainable water po-widely used for quantifying V and WF (Chapagain and Hoekstra,licies.179