scholarly journals Water for maize for pigs for pork: an analysis of inter-provincial trade in China

Author(s):  
La Zhuo ◽  
Yilin Liu ◽  
Hong Yang ◽  
Arjen Y Hoekstra ◽  
Wenfeng Liu ◽  
...  

<p>Trade in commodities implies trade in virtual water (VW), which refers to the water that was used to produce the traded goods. Various studies have quantified international or inter-provincial virtual water (VW) flows related to the trade in crops and animal products. Until date, however, no effort has been undertaken to understand how the water embodied in traded feed crops (trade stage TS1) will be transferred further because of trade in animal products (trade stage TS2). This is the first study showing this mechanism, in a case study in China for maize (the major pig feed) and pork (the dominant meat), considering the period 2000-2013. We estimate the annual green and blue water footprints in maize production and then quantify the inter-provincial VW flows related to trade in maize (TS1) and trade in maize embodied in pork (TS2). Results show that in TS1, maize-related VW flowed from the water-scarce North to the water-rich South, with an increase of 40% over the study period (from 43 to 61 billion m<sup>3 </sup>y<sup>-1</sup>). In TS2, about 10% of the water embodied in maize exports from North to South China returns in the form of pork, with an increase in the absolute amount of 25% (from 4.8 to 6.1 billion m<sup>3 </sup>y<sup>-1</sup>). Considering blue VW flows specifically, we find that North-to-South blue VW flows decreased by 5% in TS1, while South-to-North blue VW flows increased by 23% in TS2.</p><p> </p><p>References:</p><p>Zhuo, L. et al. (2019) Water for maize for pigs for pork: An analysis of inter-provincial trade in China. Water Research 166, 115074, doi:https://doi.org/10.1016/j.watres.2019.115074.</p><p> </p>

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.


2014 ◽  
Vol 18 (2) ◽  
pp. 447-461 ◽  
Author(s):  
M. Kummu ◽  
D. Gerten ◽  
J. Heinke ◽  
M. Konzmann ◽  
O. Varis

Abstract. Interannual climatic and hydrologic variability has been substantial during the past decades in many regions. While climate variability and its impacts on precipitation and soil moisture have been studied intensively, less is known on subsequent implications for global food production. In this paper we quantify effects of hydroclimatic variability on global "green" and "blue" water availability and demand in global agriculture, and thus complement former studies that have focused merely on long-term averages. Moreover, we assess some options to overcome chronic or sporadic water scarcity. The analysis is based on historical climate forcing data sets over the period 1977–2006, while demography, diet composition and land use are fixed to reference conditions (year 2000). In doing so, we isolate the effect of interannual hydroclimatic variability from other factors that drive food production. We analyse the potential of food production units (FPUs) to produce a reference diet for their inhabitants (3000 kcal cap−1 day−1, with 80% vegetal food and 20% animal products). We applied the LPJmL vegetation and hydrology model to calculate the variation in green-blue water availability and the water requirements to produce that very diet. An FPU was considered water scarce if its water availability was not sufficient to produce the diet (i.e. assuming food self-sufficiency to estimate dependency on trade from elsewhere). We found that 24% of the world's population lives in chronically water-scarce FPUs (i.e. water is scarce every year), while an additional 19% live under occasional water scarcity (water is scarce in some years). Among these 2.6 billion people altogether, 55% would have to rely on international trade to reach the reference diet, while for 24% domestic trade would be enough. For the remaining 21% of the population exposed to some degree of water scarcity, local food storage and/or intermittent trade would be enough to secure the reference diet over the occasional dry years.


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.


Author(s):  
Eckart Woertz

West Asia is one of the most water-scarce regions of the world and one of its foremost importers of virtual water despite sustained efforts at self-sufficiency, especially in cereal production. Technology-oriented policy solutions eye a reorientation of agriculture towards fruit and vegetables that are less water-intensive than cereals and provide more value added per water unit consumed. Turkey is a role model here; the country has an agricultural trade surplus and ranks among the top ten agricultural economies globally in value terms. Yet technology-oriented policy prescriptions overlook the sociopolitical ‘problemsheds’ that emerge (along with new agro-lobbies) and agriculture as the main water consumer has to compete with other economic sectors and sprawling urbanization. This article looks at the different categories of countries and their specific challenges.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fatemeh Karandish ◽  
Hamideh Nouri ◽  
Marcela Brugnach

AbstractEnding hunger and ensuring food security are among targets of 2030’s SDGs. While food trade and the embedded (virtual) water (VW) may improve food availability and accessibility for more people all year round, the sustainability and efficiency of food and VW trade needs to be revisited. In this research, we assess the sustainability and efficiency of food and VW trades under two food security scenarios for Iran, a country suffering from an escalating water crisis. These scenarios are (1) Individual Crop Food Security (ICFS), which restricts calorie fulfillment from individual crops and (2) Crop Category Food Security (CCFS), which promotes “eating local” by suggesting food substitution within the crop category. To this end, we simulate the water footprint and VW trades of 27 major crops, within 8 crop categories, in 30 provinces of Iran (2005–2015). We investigate the impacts of these two scenarios on (a) provincial food security (FSp) and exports; (b) sustainable and efficient blue water consumption, and (c) blue VW export. We then test the correlation between agro-economic and socio-environmental indicators and provincial food security. Our results show that most provinces were threatened by unsustainable and inefficient blue water consumption for crop production, particularly in the summertime. This water mismanagement results in 14.41 and 8.45 billion m3 y−1 unsustainable and inefficient blue VW exports under ICFS. “Eating local” improves the FSp value by up to 210% which lessens the unsustainable and inefficient blue VW export from hotspots. As illustrated in the graphical abstract, the FSp value strongly correlates with different agro-economic and socio-environmental indicators, but in different ways. Our findings promote “eating local” besides improving agro-economic and socio-environmental conditions to take transformative steps toward eradicating food insecurity not only in Iran but also in other countries facing water limitations.


Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1769
Author(s):  
Maria Macarena Arrien ◽  
Maite M. Aldaya ◽  
Corina Iris Rodriguez

Agriculture is the largest fresh water consuming sector, and maize is the most produced and consumed crop worldwide. The water footprint (WF) methodology quantifies and evaluates the water volumes consumed and polluted by a given crop, as well as its impacts. In this work, we quantified for the first time the green WF (soil water from precipitation that is evapotranspired) and the green virtual water exports of maize from Buenos Aires province, Argentina, during 2016–2017, due to the relevance of this region in the world maize trade. Furthermore, at local level, we quantified the green, blue (evapotranspired irrigation), and grey (volume of water needed to assimilate a pollution load) WF of maize in a pilot basin. The green WF of maize in the province of Buenos Aires ranged between 170 and 730 m3/ton, with the highest values in the south following a pattern of yields. The contribution of this province in terms of green virtual water to the international maize trade reached 2213 hm3/year, allowing some water-scarce nations to ensure water and water-dependent food security and avoid further environmental impacts related to water. At the Napaleofú basin scale, the total WF of rainfed maize was 358 m3/ton (89% green and 11% grey) and 388 m3/ton (58% green, 25% blue, and 17% grey) for the irrigated crop, showing that there is not only a green WF behind the exported maize, but also a Nitrogen-related grey WF.


Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 459
Author(s):  
Ignacio Cazcarro ◽  
Albert E. Steenge

This article originates from the theoretical and empirical characterization of factors in the World Trade Model (WTM). It first illustrates the usefulness of this type of model for water research to address policy questions related to virtual water trade, water constraints and water scarcity. It also illustrates the importance of certain key decisions regarding the heterogeneity of water and its relation to the technologies being employed and the prices obtained. With regard to WTM, the global economic input–output model in which multiple technologies can produce a “homogeneous output”, it was recently shown that two different mechanisms should be distinguished by which multiple technologies can arise, i.e., from “technology-specific” or from “shared” factors, which implies a mechanism-specific set of prices, quantities and rents. We discuss and extend these characterizations, notably in relation to the real-world characterization of water as a factor (for which we use the terms technology specific, fully shared and “mixed”). We propose that the presence of these separate mechanisms results in the models being sensitive to relatively small variations in specific numerical values. To address this sensitivity, we suggest a specific role for specific (sub)models or key choices to counter unrealistic model outcomes. To support our proposal we present a selection of simulations for aggregated world regions, and show how key results concerning quantities, prices and rents can be subject to considerable change depending on the precise definitions of resource endowments and the technology-specificity of the factors. For instance, depending on the adopted water heterogeneity level, outcomes can vary from relatively low-cost solutions to higher cost ones and can even reach infeasibility. In the main model discussed here (WTM) factor prices are exogenous, which also contributes to the overall numerical sensitivity of the model. All this affects to a large extent our interpretation of the water challenges, which preferably need to be assessed in integrated frameworks, to account for the main socioeconomic variables, technologies and resources.


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