Quantifying Virtual Water Flows in the 12 Continental Countries of SADC

2016 ◽  
pp. 9-43
Author(s):  
David Phillips ◽  
Stephen Boyall
Keyword(s):  
Virtual Water ◽  
Water Flows

Estimation of the virtual water trade between two Spanish regions: Castilla-la Mancha and Murcia

2010 ◽  
Vol 10 (5) ◽  
pp. 831-840 ◽  
Author(s):  
Ángel De Miguel ◽  
Eloy García ◽  
Irene De Buestamante
Keyword(s):  
Water Flow ◽  
Food Processing ◽  
Virtual Water ◽  
Water Transfer ◽  
Water Efficiency ◽  
International Context ◽  
Water Flows ◽  
Spanish Regions ◽  
La Mancha ◽  
Virtual Water Flow

Virtual water is defined as the water needed to produce a product. We can use virtual water flow calculations to estimate the water efficiency of a country, as well as its economic dependence on water resources. Former studies on this area have focused on quantifying the virtual water flows between countries, in an international context. In this study we reduce the action framework to regions within a country, determining the virtual water balance between two Spanish regions: Castilla-La Mancha and Murcia. In 2004, Castilla-La Mancha exported to Murcia 2,453,442 tons of commercial products, from which 1,191,628 tons were agricultural goods. In terms of virtual water, it means 1,365 hm3, including food-processing, and industrial products. It is necessary to add 350 hm3 to the result, because of the water transfer (Tajo-Segura transfer) between the rivers basins of these regions, so the final virtual water number, in 2004, was 1,715 hm3. The other way round, Murcia exported in 2004 2,069,000 tons of products, from which 490,351 tons were agricultural goods. That supposes 712 hm3 of virtual water. Virtual water flow is unbalanced and displaced towards Murcia with a difference of 1,003 hm3.

scholarly journals Evaluating Cryospheric Water Withdrawal and Virtual Water Flows in Tarim River Basin of China: An Input–Output Analysis

2021 ◽  
Vol 13 (14) ◽  
pp. 7589
Author(s):  
Yang Yang ◽  
Shiwei Liu ◽  
Cunde Xiao ◽  
Cuiyang Feng ◽  
Chenyu Li
Keyword(s):  
Water Resources ◽  
River Basin ◽  
Socioeconomic Development ◽  
Virtual Water ◽  
Water Withdrawal ◽  
Tarim River ◽  
Tarim River Basin ◽  
Input Output ◽  
Output Analysis ◽  
Water Flows

In Tarim River Basin (TRB), the retreat of glacier and snow cover reduction due to climate warming threatens the regional economy of downstream basins that critically depends on meltwater. However, the quantitative evaluation of its impact on multiple sectors of the socioeconomic system is incomplete. Based on compiled regional input–output table of the year 2012, this study developed a method to analyze the relationships between economic activities and related meltwater withdrawal, as well as sectoral transfer. The results show that the direct meltwater withdrawal intensity (DMWI) of agriculture was much higher than other sectors, reaching 2348.02 m3/10,000 CNY. Except for A01 (agriculture) and A02 (mining and washing of coal), the embodied meltwater withdrawal (EMW) driven by the final demand of other sectors was greater than direct meltwater withdrawal, and all sectors required inflows of virtual water (72.45 × 108 m3, accounting for 29% of total supply from cryospheric water resources) for their production processes in 2012. For sectors with high DMWI, improving water-use efficiency is an effective way to reduce water withdrawal. To some extent, the unbalanced supply of cryospheric water resources due to geographical segregation can be regulated by virtual water flows from water-saving to water-intensive sectors. Such decisions can affect the balance between socioeconomic development and environment conservation for long-term sustainability.

Exploring solutions to alleviate the regional water stress from virtual water flows in China

2021 ◽  
pp. 148971
Author(s):  
Feng Wang ◽  
Beiming Cai ◽  
Xi Hu ◽  
Yu Liu ◽  
Wei Zhang
Keyword(s):  
Water Stress ◽  
Virtual Water ◽  
Water Flows ◽  
Regional Water

scholarly journals Assessment of regional trade and virtual water flows in China

2007 ◽  
Vol 61 (1) ◽  
pp. 159-170 ◽  
Author(s):  
Dabo Guan ◽  
Klaus Hubacek
Keyword(s):  
Virtual Water ◽  
Regional Trade ◽  
Water Flows

A step forward toward the high-resolution assessment of virtual water flows at the company’s scale

2021 ◽  
Author(s):  
Elena De Petrillo ◽  
Marta Tuninetti ◽  
Francesco Laio
Keyword(s):  
Water Management ◽  
High Resolution ◽  
Water Resources ◽  
Virtual Water ◽  
The State ◽  
Green Water ◽  
Blue Water ◽  
Food Trade ◽  
Water Flows ◽  
Final Consumer

<p>Through the international trade of agricultural goods, water resources that are physically used in the country of production are virtually transferred to the country of consumption. Food trade leads to a global redistribution of freshwater resources, thus shaping distant interdependencies among countries. Recent studies have shown how agricultural trade drives an outsourcing of environmental impacts pertaining to depletion and pollution of freshwater resources, and eutrophication of river bodies in distant producer countries. What is less clear is how the final consumer – being an individual, a company, or a community- impacts the water resources of producer countries at a subnational scale. Indeed, the variability of sub-national water footprint (WF in m<sup>3</sup>/tonne) due to climate, soil properties, irrigation practices, and fertilizer inputs is generally lost in trade analyses, as most trade data are only available at the country scale. The latest version of the Spatially Explicit Information on Production to Consumption Systems model  (SEI-PCS) by Trase provides detailed data on single trade flows (in tonne) along the crop supply chain: from local municipalities- to exporter companies- to importer companies – to the final consumer countries. These data allow us to capitalize on the high-resolution data of agricultural WF available in the literature, in order to quantify the sub-national virtual water flows behind food trade. As a first step, we assess the detailed soybean trade between Brazil and Italy. This assessment is relevant for water management because the global soybean flow reaching Italy may be traced back to 374 municipalities with heterogeneous agricultural practises and water use efficiency. Results show that the largest flow of virtual water from a Brazilian municipality to Italy -3.52e+07 m<sup>3</sup> (3% of the total export flow)- comes from Sorriso in the State of Mato Grosso. Conversely, the highest flow of blue water -1.56e+05 m<sup>3</sup>- comes from Jaguarão, in the State of Rio Grande do Sul, located in the Brazilian Pampa. Further, the analysis at the company scale reveals that as many as 37 exporting companies can be identified exchanging to Italy;  Bianchini S.A is the largest virtual water trader (1.88 e+08 m<sup>3</sup> of green water and 3,92 e+06 m<sup>3</sup> of blue water), followed by COFCO (1,06 e+08 m<sup>3</sup> of green water and 6.62 m<sup>3</sup> of blue water)  and Cargill ( 6.96 e+07 m<sup>3</sup> of green water and 2.80 e+02 m<sup>3</sup> of blue water). By building the bipartite network of importing companies and municipalities originating the fluxes we are able to efficiently disaggregate the supply chains , providing novel tools to build sustainable water management strategies.</p>

scholarly journals (Virtual) Water Flows Uphill toward Money

2016 ◽  
Vol 50 (22) ◽  
pp. 12320-12330 ◽  
Author(s):  
Ranran Wang ◽  
Edgar Hertwich ◽  
Julie B. Zimmerman
Keyword(s):  
Virtual Water ◽  
Water Flows

scholarly journals Water saving through international trade of agricultural products

2006 ◽  
Vol 10 (3) ◽  
pp. 455-468 ◽  
Author(s):  
A. K. Chapagain ◽  
A. Y. Hoekstra ◽  
H. H. G. Savenije
Keyword(s):  
Water Resources ◽  
Water Use ◽  
Virtual Water ◽  
Water Saving ◽  
Agricultural Products ◽  
Green Water ◽  
Blue Water ◽  
Water Flows ◽  
Global Water ◽  
National Water

Abstract. Many nations save domestic water resources by importing water-intensive products and exporting commodities that are less water intensive. National water saving through the import of a product can imply saving water at a global level if the flow is from sites with high to sites with low water productivity. The paper analyses the consequences of international virtual water flows on the global and national water budgets. The assessment shows that the total amount of water that would have been required in the importing countries if all imported agricultural products would have been produced domestically is 1605 Gm3/yr. These products are however being produced with only 1253 Gm3/yr in the exporting countries, saving global water resources by 352 Gm3/yr. This saving is 28 per cent of the international virtual water flows related to the trade of agricultural products and 6 per cent of the global water use in agriculture. National policy makers are however not interested in global water savings but in the status of national water resources. Egypt imports wheat and in doing so saves 3.6 Gm3/yr of its national water resources. Water use for producing export commodities can be beneficial, as for instance in Cote d'Ivoire, Ghana and Brazil, where the use of green water resources (mainly through rain-fed agriculture) for the production of stimulant crops for export has a positive economic impact on the national economy. However, export of 28 Gm3/yr of national water from Thailand related to rice export is at the cost of additional pressure on its blue water resources. Importing a product which has a relatively high ratio of green to blue virtual water content saves global blue water resources that generally have a higher opportunity cost than green water.

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