Virtual water has been proposed as a mechanism with potential to reduce the effects of water scarcity on food security. To evaluate the role of virtual water in reducing the effect of water scarcity on food security, all components of the available water resource in agricultural areas must be quantified to provide a basis for evaluating food imports driven by water scarcity. We refer to this situation as ‘agri-compatible connections’ among water scarcity, virtual water, and food security. To date, this has not been captured in the literature on water scarcity, virtual water flows and food security. The lack of agri-compatibility has rendered the virtual water concept seemingly inconsistent with trade theories and water-food security policy needs. We propose two requirements for achieving agri-compatible connections: (i) the limit of crop production imposed by water scarcity should be captured by quantifying all components of the water available to satisfy specific crop water requirement in the importing economy, and (ii) food import should satisfy ‘water-dependent food security’ need, which is the actual or potential food security gap created by insufficient available water from all sources for crop production (all other things being equal). Further, we propose that agri-compatible water scarcity should capture three key elements: (i) a reflection of aridity or drought potential, (ii) quantification of all the components of water resource available to a given crop at a given locality and time, and (iii) use of crop- and catchment-specific water scarcity factors to evaluate the effect of crop production and virtual water on water scarcity. In this paper, we show the conceptual outlines for the proposed agri-compatible connections. Achieving agri-compatible connections among water scarcity, virtual water and food security will enhance the analysis and understanding of the role of virtual water for food security in the importing economy and water scarcity in the exporting economy. We suggest that achieving agri-compatibility will improve the use of virtual water as a mechanism to reduce existing and future pressures on global food security

The agricultural community has a challenge of increasing food production by more than 70% to meet demand from the global population increase by the mid-21st century. Sustainable food production involves the sustained availability of resources, such as water and energy, to agriculture. The key challenges to sustainable food production are population increase, increasing demands for food, climate change, and climate variability, decreasing per capita land and water resources. To discuss more details on (a) the challenges for sustainable food production and (b) mitigation options available, a special issue on “Water Management for Sustainable Food Production” was assembled. The special issue focused on issues such as irrigation using brackish water, virtual water trade, allocation of water resources, consequences of excess precipitation on crop yields, strategies to increase water productivity, rainwater harvesting, irrigation water management, deficit irrigation, and fertilization, environmental and socio-economic impacts, and irrigation water quality. Articles covered several water-related issues across the U.S., Asia, Middle-East, Africa, and Pakistan for sustainable food production. The articles in the special issue highlight the substantial impacts on agricultural production, water availability, and water quality in the face of increasing demands for food and energy.

The agricultural community has a challenge of increasing food production by more than 70% to meet demand from the global population increase by the mid-21st century. Sustainable food production involves the sustained availability of resources, such as water and energy, to agriculture. The key challenges to sustainable food production are population increase, increasing demands for food, climate change, and climate variability, decreasing per capita land and water resources. To discuss more details on (a) the challenges for sustainable food production and (b) mitigation options available, a special issue on “Water Management for Sustainable Food Production” was assembled. The special issue focused on issues such as irrigation using brackish water, virtual water trade, allocation of water resources, consequences of excess precipitation on crop yields, strategies to increase water productivity, rainwater harvesting, irrigation water management, deficit irrigation, and fertilization, environmental and socio-economic impacts, and irrigation water quality. Articles covered several water-related issues across the U.S., Asia, Middle-East, Africa, and Pakistan for sustainable food production. The articles in the special issue highlight the substantial impacts on agricultural production, water availability, and water quality in the face of increasing demands for food and energy.

Food aid is a critical component of the global food system, particularly when emergency situations arise. For the first time, we evaluate the water footprint of food aid. To do this, we draw on food aid data from theWorld Food Programme and virtual water content estimates from WaterStat. We find that the total water footprint of food aid was 10 km3 in 2005, which represents approximately 0.5% of the water footprint of food trade and 2.0% of the water footprint of land grabbing (i.e., water appropriation associated with large agricultural land deals). The United States is by far the largest food aid donor and contributes 82% of the water footprint of food aid. The countries that receive the most water embodied in aid are Ethiopia, Sudan, North Korea, Bangladesh and Afghanistan. Notably, we find that there is significant overlap between countries that receive food aid and those that have their land grabbed. Multivariate regression results indicate that donor water footprints are driven by political and environmental variables, whereas recipient water footprints are driven by land grabbing and food indicators.

Cities are complex and evolving systems with various factors playing key roles, e.g., population increase, the migration of population, the availability of resources, and the flexibility of policies. Consumers’ socioeconomic status is also an important aspect that needs to be studied in the context of a self-reliant urban city in its resource consumption. In this regard, the association between water–food and socio-economic attributes was analyzed based on the consumer-centric approach for the Hyderabad Metro Development Authority (HMDA) region, India. In this study, the embedded water content in food consumption was estimated and analyzed for nine food groups and twelve economic classes of the HMDA region. The middle economic classes were found to correspond to ~80% of embedded water content in the HMDA region, followed by the upper and lower economic classes. Except for cereals, per capita, the water consumption of all food groups increased with the spending power of the economic class. The green, blue, and grey consumption water footprints (WFs) suggested that much of the water that is being consumed in the HMDA region is precipitation-driven, followed by surface and groundwater resources. Limited water resources, water resource variability, climate change consequences including future climate projections, uncertainty in data, WF estimates, and region’s future growth imply a detailed study in drafting policies to become a self-reliant region.

Cities are complex and evolving systems with various factors playing key roles, e.g., population increase, the migration of population, the availability of resources, and the flexibility of policies. Consumers’ socioeconomic status is also an important aspect that needs to be studied in the context of a self-reliant urban city in its resource consumption. In this regard, the association between water–food and socio-economic attributes was analyzed based on the consumer-centric approach for the Hyderabad Metro Development Authority (HMDA) region, India. In this study, the embedded water content in food consumption was estimated and analyzed for nine food groups and twelve economic classes of the HMDA region. The middle economic classes were found to correspond to ~80% of embedded water content in the HMDA region, followed by the upper and lower economic classes. Except for cereals, per capita, the water consumption of all food groups increased with the spending power of the economic class. The green, blue, and grey consumption water footprints (WFs) suggested that much of the water that is being consumed in the HMDA region is precipitation-driven, followed by surface and groundwater resources. Limited water resources, water resource variability, climate change consequences including future climate projections, uncertainty in data, WF estimates, and region’s future growth imply a detailed study in drafting policies to become a self-reliant region.

We present a network model of interstate food trade and report comprehensive estimates of embodied irrigation energy and greenhouse gas (GHG) emissions in virtual water trade for the United States (U.S.). We consider trade of 29 food commodities including 14 grains and livestock products between 51 states. A total of 643 million tons of food with a corresponding 322 billion m³ of virtual water, 584 billion MJ of embodied irrigation energy, and 42 billion kg CO₂-equivalent GHG emissions were traded across the U.S. in 2012. The estimated embodied GHG emissions in irrigation water are similar to CO₂ emissions from the U.S. cement industry, highlighting the importance of reducing environmental impacts of irrigation. While animal-based commodities represented 12% of food trade, they accounted for 38% of the embodied energy and GHG emissions from virtual irrigation water transfers due to the high irrigation embodied energy and emissions intensity of animal-based products. From a network perspective, the food trade network is a robust, well-connected network with the majority of states participating in food trade. When the magnitude of embodied energy and GHG emissions associated with virtual water are considered, a few key states emerge controlling high throughput in the network.

Water, energy, and food security are of critical concern as rising population growth and rapid urbanization place greater pressure on our natural resources. The trade of ‘virtual water’ through agricultural products and its appropriation through foreign direct investment (FDI) in food production have emerged as potential strategies for water-scarce countries seeking food security. In Saudi Arabia, where domestic agricultural enterprise remains a state priority despite extreme water scarcity, a shift to overseas food production to meet domestic demand could have significant implications for water and energy use as well as local labor markets. This study evaluates the growing internationalization of food production in water-scarce countries using the case of Saudi Arabia as a microcosm to illustrate the tradeoffs in resource consumption associated with crop selection and farming practices. This analysis indicates that the implications of different types of large-scale agribusiness must be more explicitly accounted for in government policy given the non-renewable nature of groundwater and energy. This work also quantifies the increase in the import of virtual water through conventional trade, which has significant potential to minimize groundwater pumping for food production in arid environments. A brief, complementary assessment of the growing role of FDI shows that further analysis is needed to ascertain the long-term resource impacts of direct investment in overseas enterprise and to minimize potentially negative impacts on water access and rural livelihoods in target nations. Active engagement of local communities and/or more holistic investment in infrastructure or improving agricultural productivity could also help avoid the potential for conflict and contribute towards long-term sustainability.

One possible approach for addressing water and food insecurity involves food production, trade, and water used elsewhere. In this study, we introduce a water footprint for Korean rice products and focus on the impacts of localized cultivation and water supply systems on the water footprint. In addition, we discuss several studies on the application of water footprint and virtual water trade in water and food management in Korea. Finally, we suggest the role of water footprint and virtual water trade in sustainable resource management through a water-energy-food nexus approach.

Poorer countries often face a severe trade-off: the need to improve socio-economic conditions is hard to balance with the maintenance of key ecological processes. As a case study, we select Colombia, a Latin American country with almost 10% of its inhabitants living in extreme poverty. We elaborate a water–food–labour (WFL) nexus grounded on a sub-national Environmentally Extended Input–Output (EEIO) analysis to assess the virtual water trade (VWT) and virtual informal labour (VIL) flows across administrative departments and economic sectors related to domestic trade. The main results are the following: high cross-departmental resource interdependence both in terms of VWT and VIL, rich departments highly depend on the resources of their neighbouring trading partners, extreme poverty conditions shown by economically isolated departments, and considerable income inequality in the food production sectors. Moreover, departments that are net exporters of virtual water suffer from water stress that might be exacerbated by future high rainfall variability due to climate change. These results suggest that strategies to attain sustainable development goals (SDGs) must deal with the biophysical constraints and the economic and political feasibility of the proposed solutions. In this vein, we argue that a holistic framework, grounded on quantitative analyses, is necessary to support informed policy decisions for the simultaneous achievement of multiple (possibly contrasting) goals. Moreover, severe spatial imbalances call for local policy responses coordinated at the national level.