Effect of Variation of Water-Use Efficiency on Structure of Virtual Water Trade - Analysis Based on Input–Output Model

2015 ◽  
Vol 29 (8) ◽  
pp. 2947-2965 ◽  
Author(s):  
Guangyao Deng ◽  
Liujuan Wang ◽  
Yanan Song
Water Policy ◽  
2014 ◽  
Vol 17 (4) ◽  
pp. 649-663 ◽  
Author(s):  
Rashid Hassan ◽  
Djiby Racine Thiam

This paper employs an economy-wide framework to evaluate impacts of water and trade policy reforms in South Africa (SA) on virtual water flows. To pursue this analysis, the study derives net virtual water trade flows between SA and its partners to assess implications of recent trade agreements within the South African Development Community compared to economic cooperation with other major trading blocks (e.g. European Union, Asia, and Brazil, Russia, India and China (BRIC)). Recent trends in actual trade confirm model predictions that liberalization of water allocation would switch water from field crops to horticulture and promote growth in non-agricultural exports. The results suggest that it is necessary to introduce policies that enhance likely outcomes of liberalization promoting higher water use efficiency within irrigation agriculture such as increased adoption of more efficient irrigation methods (sprinkler, drip, etc.) as water becomes more expensive under wider open competition. Moreover, investment in higher water use efficiency and improved competitiveness of dryland agriculture therefore represent the sound economic options for strengthening the capacity to achieve food security objectives as the country strives to lower net water exports. Finally, careful coordination of trade and water policy reforms is another necessary challenge for SA's strive to manage a water stressed economy.


2016 ◽  
Vol 02 (02) ◽  
pp. 1650016
Author(s):  
Xueting Zhao ◽  
Randall W. Jackson

The success of China’s economic development has brought increasing pressures on its water resources, motivating it to better understand water use characteristics and how scarce water resources are transferred among regions. Virtual water is a term used to refer to the volume of freshwater consumed for producing traded goods and services. It reflects the actual human consumption of water resources and therefore is important for water resources management. The goal of this paper is to evaluate the current inter-regional virtual water trade (VWT) structure and to assess the implications of these trade patterns for water use and water conservation strategies in China. Based on the most recently available multi-regional input–output (MRIO) data, we have developed an extended inter-regional input–output (IRIO) model for eight economic regions in China to account for virtual water flows. The findings show that water use efficiency has increased over the years, but it is still unbalanced among the regions. The total amount of VWT has increased, and the major source of the trade is domestic inter-regional trade, especially intermediate products trade. Moreover, the main direction of virtual water transfer is from water-poor inland regions to water-rich regions, which is unfavorable for water resource allocation and efficiency. Therefore, in addition to enhancing water use efficiency and encouraging water-saving production alternatives, we suggest that China’s government should also adopt a market-based water pricing system.


2013 ◽  
Vol 10 (1) ◽  
pp. 67-101 ◽  
Author(s):  
M. Konar ◽  
Z. Hussein ◽  
N. Hanasaki ◽  
D. L. Mauzerall ◽  
I. Rodriguez-Iturbe

Abstract. The international trade of food commodities links water and food systems, with important implications for both water and food security. The embodied water resources associated with food trade are referred to as "virtual water trade". We present the first study of the impact of climate change on global virtual water trade flows and associated savings for the year 2030. In order to project virtual water trade under climate change, it is essential to obtain projections of both bilateral crop trade and the water-use efficiency of crops in each country of production. We use the Global Trade Analysis Project (GTAP) to estimate bilateral crop trade flows under changes in agricultural productivity. We use the H08 global hydrologic model to estimate the water-use efficiency of each crop in each country of production and to transform crop flows into virtual water flows. We find that the total volume of virtual water trade is likely to go down under climate change. However, the staple food trade is projected to save more water across most climate impact scenarios, largely because the wheat trade re-organizes into a more water-efficient structure. These findings indicate that trade may be an adaptation measure to climate change with ramifications for policy.


Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 748
Author(s):  
Ming Li ◽  
Qingsong Tian ◽  
Yan Yu ◽  
Yueyan Xu ◽  
Chongguang Li

The sustainable and efficient use of water resources has gained wide social concern, and the key point is to investigate the virtual water trade of the water-scarcity region and optimize water resources allocation. In this paper, we apply a multi-regional input-output model to analyze patterns and the spillover risks of the interprovincial virtual water trade in the Yellow River Economic Belt, China. The results show that: (1) The agriculture and supply sector as well as electricity and hot water production own the largest total water use coefficient, being high-risk water use sectors in the Yellow River Economic Belt. These two sectors also play a major role in the inflow and outflow of virtual water; (2) The overall situation of the Yellow River Economic Belt is virtual water inflow, but the pattern of virtual water trade between eastern and western provinces is quite different. Shandong, Henan, Shaanxi, and Inner Mongolia belong to the virtual water net inflow area, while the virtual water net outflow regions are concentrated in Shanxi, Gansu, Xinjiang, Ningxia, and Qinghai; (3) Due to higher water resource stress, Shandong and Shanxi suffer a higher cumulative risk through virtual water trade. Also, Shandong, Henan, and Inner Mongolia have a higher spillover risk to other provinces in the Yellow River Economic Belt.


2009 ◽  
Vol 13 (10) ◽  
pp. 1967-1977 ◽  
Author(s):  
J. M. Dabrowski ◽  
E. Masekoameng ◽  
P. J. Ashton

Abstract. The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently, increased attention has focussed on partitioning the virtual water content of crops into green and blue water (derived from rainfall and irrigation, respectively) as the latter has higher opportunity costs associated with its use and therefore impacts directly on scarcity. Maize is the most important crop traded within the SADC region. South Africa is the largest producer and exporter of maize, with the majority of its exports destined for other SADC countries. In comparison to other SADC countries, South Africa produces maize relatively efficiently, with a low virtual water content and a high green (868 m3 t−1) to blue (117 m3 t−1) water ratio. The blue water content is however higher than for maize produced in all other SADC countries, with the exception of Namibia (211 m3 t−1). Current trade patterns therefore result in a net expenditure of blue water (66×106 m3), almost all of which is exported by South Africa (65×106 m3). South Africa is one of the most water scarce countries in the region and analysis of virtual water flows indicates that current SADC maize trading patterns are influenced by national productivity as opposed to water scarcity. The virtual water content of maize was estimated for each of South Africa's nineteen Water Management Area's (WMA) and used as a proxy to represent water use efficiency for maize production. The virtual water content varied widely across all of the WMAs, ranging from 360 m3 t−1 in the Ustutu Mhlatuze to 1000 m3 t−1 in the Limpopo. A comparison of the virtual water content and production of maize (expressed as a percentage of the total national production) identified those WMAs where maize production is highly water inefficient (e.g. Lower Orange and Limpopo WMAs). Results suggest that, while a national estimate of the virtual water content of a crop may indicate a relatively efficient use of water, an analysis of the virtual water content at smaller scales can reveal inefficient use of water for the same crop. Therefore, analysis of the virtual water content of crops and trading of agricultural products at different spatial scales (i.e. regional, national and WMA) could be an important consideration within the context of water allocation, water use efficiency and alleviation of water scarcity.


2017 ◽  
Vol 35 (1) ◽  
pp. 275-280
Author(s):  
Hossein Yousefi ◽  
Ali Mohammadi ◽  
Mitra Mirzaaghabeik ◽  
Younes Noorollahi

AbstractShortage 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.


2008 ◽  
Vol 5 (5) ◽  
pp. 2727-2757 ◽  
Author(s):  
J. M. Dabrowski ◽  
E. Masekoameng ◽  
P. J. Ashton

Abstract. The concept of virtual water encourages a country to view agricultural crops in terms of the amount of water required to produce those crops, with a view to implementing trading policies that promote the saving of scarce water resources. Recently, increased attention has focussed on partitioning the virtual water content of crops into green and blue water (derived from rainfall and irrigation, respectively) as the latter has higher opportunity costs associated with its use and therefore impacts directly on scarcity. Maize is the most important crop traded within the SADC region. South Africa is the largest producer and exporter of maize, with the majority of its exports destined for other SADC countries. In comparison to other SADC countries, South Africa produces maize relatively efficiently, with a low virtual water content and a high green (868 m3 tonne−1) to blue (117 m3 tonne−1) water ratio. The blue water content is however higher than for maize produced in all other SADC countries, with the exception of Namibia (211 m3 tonne−1). Current trade patterns therefore result in a net expenditure of blue water (66×106 m3), almost all of which is exported by South Africa (65×106 m3). South Africa is one of the most water scarce countries in the region and analysis of virtual water flows indicates that current SADC maize trading patterns are influenced by national productivity as opposed to water scarcity. The virtual water content of maize was estimated for each of South Africa's nineteen Water Management Area's (WMA) and used as a proxy to represent water use efficiency for maize production. The virtual water content varied widely across all of the WMAs, ranging from 360 m3 tonne-1 in the Ustutu Mhlatuze to 1000 m3 tonne−1 in the Limpopo. A comparison of the virtual water content and production of maize (expressed as a percentage of the total national production) identified those WMAs where maize production is highly water inefficient (e.g. Lower Orange and Limpopo WMAs). Results suggest that, while a national estimate of the virtual water content of a crop may indicate a relatively efficient use of water, an analysis of the virtual water content at smaller scales can reveal inefficient use of water for the same crop. Therefore, analysis of the virtual water content of crops and trading of agricultural products at different spatial scales (i.e. regional, national and WMA) could be an important consideration within the context of water allocation, water use efficiency and alleviation of water scarcity.


2019 ◽  
Vol 222 ◽  
pp. 354-366 ◽  
Author(s):  
Donglin Wang ◽  
Hao Feng ◽  
Yi Li ◽  
Tibin Zhang ◽  
Miles Dyck ◽  
...  

2018 ◽  
Vol 19 (2) ◽  
pp. 635-643 ◽  
Author(s):  
Huiping Huang ◽  
Jiangfeng Wang ◽  
Yuping Han ◽  
Lei Wang ◽  
Xinsheng Li

Abstract Many areas around the world are faced with water scarcity and virtual water can provide ways to resolve the problem. This paper presents a comprehensive water system based on a system dynamics model to assess how water regulations from the viewpoint of virtual water affect the regional water stress index in the Haihe River Basin, China. The results show that green water absorption, blue water consumption, virtual water flow, and water use efficiency play important roles in the water resources system. Water stress can be relieved by improving the infiltration coefficient, irrigation efficiency, industrial water use efficiency, and virtual water import.


2006 ◽  
Vol 10 (3) ◽  
pp. 443-454 ◽  
Author(s):  
H. Yang ◽  
L. Wang ◽  
K. C. Abbaspour ◽  
A. J. B. Zehnder

Abstract. Amid an increasing water scarcity in many parts of the world, virtual water trade as both a policy instrument and practical means to balance the local, national and global water budget has received much attention in recent years. Building upon the knowledge of virtual water accounting in the literature, this study assesses the efficiency of water use embodied in the international food trade from the perspectives of exporting and importing countries and at the global and country levels. The investigation reveals that the virtual water flows primarily from countries of high crop water productivity to countries of low crop water productivity, generating a global saving in water use. Meanwhile, the total virtual water trade is dominated by green virtual water, which constitutes a low opportunity cost of water use as opposed to blue virtual water. A sensitivity analysis, however, suggests high uncertainties in the virtual water accounting and the estimation of the scale of water saving. The study also raises awareness of the limited effect of water scarcity on the global virtual water trade and the negative implications of the global water saving for the water use efficiency and food security in importing countries and the environment in exporting countries. The analysis shows the complexity in evaluating the efficiency gains in the international virtual water trade. The findings of the study, nevertheless, call for a greater emphasis on rainfed agriculture to improve the global food security and environmental sustainability.


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