Virtual Water

Implications for Agriculture and Trade

Chittaranjan Ray, David McInnes, Matthew Sanderson

• Publisher: Routledge
• Year: 2020
• Print ISBN:
  9780367408077
• eBook ISBN:
  9781000732160
• Topic: Biological Sciences
• Subtopic: Ecology
• Index: Biological Sciences

Virtual Water explores the role of "virtual water" – the water embedded in a product – in ongoing conversations of agriculture, trade and sustainability in an increasingly inter-connected world.

A pervasive theme throughout the book is the general lack of knowledge of the use of water in producing and consuming food. The chapters, arising from a workshop supported by the OECD Co-operative Research Programme: Biological Resources Management for Sustainable Agricultural Systems, on virtual water, agriculture and trade at the University of Nebraska-Lincoln, consider questions of gaps in knowledge, why sustainability matters and the policy implications of virtual water trade. Contributors show how water is a lens through which to examine an array of vital issues facing humanity and the planet: human and animal health; food production; environmental management; resource consumption; climate change adaptation and mitigation; economic development, trade and competitiveness; and ethics and consumer trust.

Virtual Water will be of great interest to scholars of water, resource management and consumption, the environmental aspects of development, agriculture and food production.

It originally published as a special issue of Water International.

Open Access: The water footprint of the EU: quantification, sustainability and relevance

Davy Vanham

Introduction

This presentation was delivered on behalf of the European Commission’s Joint Research Centre (JRC) at the conference Virtual Water in Agricultural Products: Quantification, Limitations and Trade Policy at the University of Nebraska in Lincoln, Nebraska, USA, 14–16 September 2016, sponsored by the Organisation for Economic Co-operation and Development’s (OECD) Co-operative Research Programme. It provides an overview of the quantification, sustainability and relevance of the water footprint (WF) concept, for the case study of the European Union (EU), with a focus on agricultural products. The WF concept provides the opportunity to link the use of water resources to the consumption of goods, thereby addressing supply chain thinking and showing options to remain within planetary boundaries from the perspective of consumers and companies. It provides a strong communication tool for policy-makers and citizens.

The presentation is organized by means of the following sections:

• Water footprint (WF) assessment.

• Sustainability assessment.

• One indicator to be used with others.

• Relevant scenarios.

• Conclusions.

Water footprint (WF) assessment

Introduction

Two different approaches to conduct a WF assessment exist in parallel (see Figure S1 in the supplemental data online). The volumetric approach as described inThe Water Footprint Assessment Manual (Hoekstra, Chapagain, Aldaya, & Mekonnen, 2011) was first developed and published in 2011. The Life Cycle Assessment (LCA) communitystarted later with the development of a methodology in parallel, and published in 2014 its procedure in the ISO 14,046 document (ISO, 2014). The different stages of both methodologies show that both consist of an inventory and impact assessment stage.

The Water Footprint Assessment Manual was developed within the framework of integrated water resources management (IWRM), the ISO 14,046 was not. The latter provides an assessment and reporting standard related to the WF of products, processes and organizations based on LCA. It focuses on product LCAs and environmental impact, while the Water Footprint Network (WFN) standard offers a broader framework in which WFs can be studied with a different focus (product, producer, consumer or geographical) and from different perspectives (environmental sustainability, social equity, resource efficiency or water risk) (Hoekstra 2017). As the present special issue is situated within the context of IWRM, only the WFN approach is discussed here in detail.

Quantification of WF volumes for agriculture

For the quantification of the WF of the EU (the ‘inventory’ or ‘water accounting’ phase shown in Figure S1 in the supplemental data online), which refers to a geographical WF (the EU), the following definitions are important:

• WF of production (WF_prod): the sum of the direct and indirect water use of domestic freshwater resources of a geographical region.

• WF of consumption (WF_cons): the total volume of freshwater used to produce the goods consumed by inhabitants of a geographical region. It is the sum of direct and indirect water use of domestic and foreign water resources through domestic consumption. WF_cons equals WF_prod plus virtual water (VW) imports (VW_i) but minus virtual water exports (VW_e).

• Consumptive water use: WF amounts relate to consumptive water use (the difference between abstraction/withdrawal and return flow). In addition, these amounts also include the water incorporated into a product along the supply chain.

• Blue water: the liquid water in rivers, lakes, aquifers and reservoirs.

• Green water: the soil water held in the unsaturated zone, formed by precipitation and available to plants (Rockström et al., 2009). Irrigated agriculture receives blue water (from irrigation) as well as green water (from precipitation), while rainfed agriculture receives only green water. The inclusion of green water in IWRM is a necessity and now recommended by most authors (Gerten et al., 2013;Hoekstra, 2016;Jalava, Kummu, Porkka, Siebert, & Varis, 2014;Karimi, Bastiaanssen, & Molden, 2013;Porkka, Gerten, Schaphoff, Siebert, & Kummu, 2016;Ran, Lannerstad, Herrero, Van Middelaar, & De Boer, 2016;Rockström et al., 2014;Schyns, Hoekstra, & Booij, 2015;van Eekelen et al., 2015;Vanham, 2012).

• Grey water: the grey WF component is an indicator of the degree of water pollution (Hoekstra et al., 2011). It is defined as the volume of water needed to dilute a certain amount of pollution such that it meets ambient water quality standards (Hoekstra et al., 2011). The WFN’s comprehensive guideline document on accounting the grey WF (Franke, Boyacioglu, & Hoekstra, 2013) states that it isdetermined by the pollutant that is most critical (i.e., requires the most water for dilution).

Many authors (e.g., Hoff et al., 2014;Thaler, Zessner, Bertran De Lis, Kreuzinger, & Fehringer, 2012;Vanham & Bidoglio, 2013) regard the grey WF component critically for various reasons:

• The water quantity it represents is not associated with the actual physical water volume of return flows. Therefore, it represents an amount of water that physically cannot be compared/added to blue and green WF components. The latter are actual physical volumes (water flows) within a hydrological water cycle/balance; the grey WF component is not.

• The water quantity is very dependent on data availability and the chosen (available) water quality standard (Thaler et al., 2012). In the past, the grey WF was generally computed based on nitrogen leaching (Hoekstra & Mekonnen, 2012;Mekonnen & Hoekstra, 2015), thereby discarding other water pollutants. Recently, efforts have been made to include other elements, for example, phosphorous (Mekonnen, Lutter, & Martinez, 2016b;Senta, Terzic, & Ahel, 2013) and other chemicals. A recent assessment of the WF of Austria (Thaler et al., 2013) results, for example, in much higher grey WF amounts as compared with a previous assessment (Vanham, 2013b), as the authors included phosphorus in addition to nitrogen. Data availability on pollutants to be included (Franke et al., 2013) is thus a restricting factor.

• When the WF is used in combination with other footprint indicators, the so-called footprint family (Galli et al., 2012;Gephart et al., 2016;Leach et al., 2016), the grey WF could be regarded as double counting. As an example, Vanham, Bouraoui, Leip, Grizzetti, and Bidoglio (2015), who quantified the water and nitrogen footprint of the EU’s consumer food waste, chose not to include the grey WF because the nitrogen (N) footprint accounts for N pollution in receiving water bodies.

Although water quality as an issue is very important, we choose not to use the grey WF component, especially in an assessment combined with other footprints. Other scholars include this component in WF assessments.

A quantification of the WF_prod, WF_cons and VW flows for the EU was presented by Vanham and Bidoglio (2013). Figure S2 (in the supplemental data online) shows that the WF_prod for agricultural products adds up to 487 km³/yr, of which crops constitute 426 km³/yr (369 km³/yr green and km³/yr blue water) and livestock 61 km³/yr (of which 55 km³/yr green and 6 km³/yr blue water). Green water consumption for crop production is spread all over the EU, whereas irrigated blue water consumption is concentrated around the Mediterranean.

The highest livestock water consumption is concentrated in Western Europe.

Figure S3 (in the supplemental data online) shows a VW balance for agricultural products for the EU consisting of WF_prod, WF_cons, VW_i and VW_e. The WF_cons is larger than the WF_prod, which means that the EU is a net VW importer for agricultural products. This has several reasons:

• The EU is for some products not self-sufficient (although it is for many products).

• Overconsumption in the EU of water-intensive products (e.g., meat, more than 50% of cereals production in the EU is for feed) (Vanham & Bidoglio, 2013;Vanham, Mekonnen, & Hoekstra, 2013b).

• The production of agricultural products is very water efficient in the EU as compared with the countries from which it imports. Domestic water productivity depends on production methods (irrigated versus rainfed, conservation agriculture, nutrient application etc.), higher yield, and agroclimate conditions (soil, climate etc.) (Vanham & Bidoglio, 2013).

The main agricultural products that account for the largest VW imports include wheat and soybeans from the Americas, cotton from Asia and cocoa and coffee (see Figure S4 in the supplemental data online).

The main agricultural products that account for the largest VW exports from the EU include cereals to Northern Africa, Turkey, Switzerland, China and Japan, as well as meat and wine to the United States, Russia and Japan (see Figure S5 in the supplemental data online).

The status of a region as a net VW importer or exporter says nothing about the sustainability of water use within that region or the regions it imports VW from and/or exports VW to. For that, a WF sustainability assessment needs to be made.

Other important components/sectors to be included in a geographical WF assessment

Although the focus of this paper is on the WF of agriculture, it should be noted that in geographical WF assessments other sectors also account for a WF.

Domestic and industrial water uses are generally included in geographical WF assessments. However, within the water–energy–food–ecosystem (WEFE) nexus context (see Figure S6 in the supplemental data online), other sectors/components should also be included (see Figure S7 online). This is discussed in detail by Vanham (2016). The inclusion of these other components is not common praxis. This is recognized in recent research (e.g., Schyns, Booij, & Hoekstra, 2017). Other scholars refer to the water–energy–food (WEF) nexus (Taniguchi, Endo, Gurdak, & Swarzenski, 2017) or the food–energy–water (FEW) nexus (Chini, Konar, & Stillwell, 2017;Scanlon et al., 2017).

Sustainability assessment

The SDGs for water, energy and food security

In order to provide the Sustainable Development Goals (SDGs) for water, food and energy security in a nexus setting (Vanham, 2016) to a growing and urbanizing global population (UN, 2014), within global planetary boundaries with limited (water) resources availability (Rockstrom et al., 2009), solutions need to come from both the production and consumption sides (Foley et al., 2011;Godfray et al., 2010).

Production-side solutions include (Foley et al., 2011;Godfray et al., 2010):

• The sustainable intensification of agriculture. Increasing water productivity (expressed in, e.g., kg/l, kg/m³, ton/m³,, the inverse of WF_prod) by closing yield gaps and integrated land and water management on existing agricultural lands (rainfed and irrigated) is key to this development. Often, the increase in water productivity (decrease in WF_prod) is referred to as ‘more crop per drop’. In the wider c...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Citation Information
• Notes on Contributors
• Acknowledgments
• Introduction: Virtual water: its implications on agriculture and trade
• 1 The water footprint of the EU: quantification, sustainability and relevance
• 2 The exposure of a fresh fruit and vegetable supply chain to global water-related risks
• 3 Advising Morocco: adopting recommendations of a water footprint assessment would increase risk and impair food security for the country and its farmers
• 4 Future crop yields and water productivity changes for Nebraska rainfed and irrigated crops
• 5 Can Sub-Saharan Africa feed itself? The role of irrigation development in the region’s drylands for food security
• 6 Sustainability of aquifers supporting irrigated agriculture: a case study of the High Plains aquifer in Kansas
• 7 Irrigation variability and climate change affect derived distributions of simulated water recharge and nitrate leaching
• 8 The water footprint challenge for water resources management in Chilean arid zones
• 9 The effect of diet changes and food loss reduction in reducing the water footprint of an average American
• 10 Water footprint for Korean rice products and virtual water trade in a water-energy-food nexus
• 11 Water footprint of beef production on Texas High Plains pasture
• 12 Tradeoffs in the water-energy-food nexus in the urbanizing Asia-Pacific region
• Index