Rapid urban growth in sub-Saharan Africa challenges food supply of cities. As food and other organic matter are transported from production areas to consumption points, water, which has been used for their production, is transported virtually. This study aimed at determining the magnitude and sources of virtual water flows in food trade of two West African cities, in order to better assess food provisioning risks and water resource use and planning. To this end, flows of unprocessed food from local, regional, national and international sources were systematically recorded at all roads leading to Tamale, Ghana and Ouagadougou, Burkina Faso. The survey was conducted within two years covering the peak (November - December) and lean season (March - April), respectively, for six days in a row. Virtual water flows were computed by multiplying the flow quantities (t yr-1) by their respective virtual water contents (m3 t-1). Results showed that virtual water of all food commodities imported to Tamale and Ouagadougou were 514 and 2105 million m3 yr-1 respectively, out of which 68% and 40% were re-exported to other regions of the country. The data also showed major seasonal variation in virtual water flows across the year. Reflecting their dominating role in local diets, cereals contributed most to the total virtual water inflows in both cities. Southern Ghana is the major net virtual water importer from Tamale through cereals, legumes, vegetables, and livestock. The Northern Region of Ghana, on the other hand, is a net exporter of virtual water in all food groups apart from fruits. In Ouagadougou, large flows of virtual water were imported in cereals, specifically rice from Asian countries, via Ivory Coast.

Rapid urban growth in sub-Saharan Africa challenges food supply of cities. As food and other organic matter are transported from production areas to consumption points, water, which has been used for their production, is transported virtually. This study aimed at determining the magnitude and sources of virtual water flows in food trade of two West African cities, in order to better assess food provisioning risks and water resource use and planning. To this end, flows of unprocessed food from local, regional, national and international sources were systematically recorded at all roads leading to Tamale, Ghana and Ouagadougou, Burkina Faso. The survey was conducted within two years covering the peak (November - December) and lean season (March - April), respectively, for six days in a row. Virtual water flows were computed by multiplying the flow quantities (t yr⁻¹) by their respective virtual water contents (m³ t⁻¹). Results showed that virtual water of all food commodities imported to Tamale and Ouagadougou were 514 and 2105 million m³ yr⁻¹ respectively, out of which 68% and 40% were re-exported to other regions of the country. The data also showed major seasonal variation in virtual water flows across the year. Reflecting their dominating role in local diets, cereals contributed most to the total virtual water inflows in both cities. Southern Ghana is the major net virtual water importer from Tamale through cereals, legumes, vegetables, and livestock. The Northern Region of Ghana, on the other hand, is a net exporter of virtual water in all food groups apart from fruits. In Ouagadougou, large flows of virtual water were imported in cereals, specifically rice from Asian countries, via Ivory Coast.

Rapid urban growth in sub-Saharan Africa challenges food supply of cities. As food and other organic matter are transported from production areas to consumption points, water, which has been used for their production, is transported virtually. This study aimed at determining the magnitude and sources of virtual water flows in food trade of two West African cities, in order to better assess food provisioning risks and water resource use and planning. To this end, flows of unprocessed food from local, regional, national and international sources were systematically recorded at all roads leading to Tamale, Ghana and Ouagadougou, Burkina Faso. The survey was conducted within two years covering the peak (November - December) and lean season (March - April), respectively, for six days in a row. Virtual water flows were computed by multiplying the flow quantities (t yr-1) by their respective virtual water contents (m3 t-1). Results showed that virtual water of all food commodities imported to Tamale and Ouagadougou were 514 and 2105 million m3 yr-1 respectively, out of which 68% and 40% were re-exported to other regions of the country. The data also showed major seasonal variation in virtual water flows across the year. Reflecting their dominating role in local diets, cereals contributed most to the total virtual water inflows in both cities. Southern Ghana is the major net virtual water importer from Tamale through cereals, legumes, vegetables, and livestock. The Northern Region of Ghana, on the other hand, is a net exporter of virtual water in all food groups apart from fruits. In Ouagadougou, large flows of virtual water were imported in cereals, specifically rice from Asian countries, via Ivory Coast.

Sustainable food systems are high on the political and research agendas. One of the three pillars of sustainability is environmental sustainability. We argue that, when defining related policies, such as policies under the European Green Deal, both environmental pressures and impacts carry important and complementary information and should be used in combination. Although the environmental focus of a sustainable food system is to have a positive or neutral impact on the natural environment, addressing pressures is necessary to achieve this goal. We show this by means of the pressure water use (or water footprint) and its related impact water stress, by means of different arguments: 1) Water use and water stress are only weakly correlated; 2) water use can be evaluated towards a benchmark, addressing resource efficiency; 3) water use is used for resource allocation assessments within or between economic sectors; 4) water amounts are needed to set fair share amounts for citizens, regions, countries or on a global level 5) the pressure water use requires less data, whereas water stress assessments have more uncertainty and 6) both provide strong communication tools to citizens, including for food packaging labelling. As a result, we present a water quantity sustainability scheme, that addresses both water use and water stress, and can be used in support of food system policies, including food package labeling. | JRC.D.2 - Water and Marine Resources

Sustainable food systems are high on the political and research agendas. One of the three pillars of sustainability is environmental sustainability. We argue that, when defining related policies, such as policies under the European Green Deal, both environmental pressures and impacts carry important and complementary information and should be used in combination. Although the environmental focus of a sustainable food system is to have a positive or neutral impact on the natural environment, addressing pressures is necessary to achieve this goal. We show this by means of the pressure water use (or water footprint) and its related impact water stress, by means of different arguments: 1) Water use and water stress are only weakly correlated; 2) water use can be evaluated towards a benchmark, addressing resource efficiency; 3) water use is used for resource allocation assessments within or between economic sectors; 4) water amounts are needed to set fair share amounts for citizens, regions, countries or on a global level 5) the pressure water use requires less data, whereas water stress assessments have more uncertainty and 6) both provide strong communication tools to citizens, including for food packaging labelling. As a result, we present a water quantity sustainability scheme, that addresses both water use and water stress, and can be used in support of food system policies, including food package labelling.

Policymaking in the water−energy−food nexus is characterized by complex ecological, social, and economic interdependencies. Nexus research assumes these interactions to be overseen in the respective resource governance resulting in sectoral perspectives contributing to unsustainable outcomes. In Germany, the political priority given to the formation of an internationally competitive livestock sector by means of intensification, specialization and regional concentration has exerted sustained pressure on water and soil resources. The expansion of bioenergy plants promoted by the renewable energy act has exacerbated the situation. Despite the persistency of the ecological challenges, German policymakers only reacted when the European Commission referred Germany to the European Court of Justice. Current policy efforts to tackle the ecological problems are now provoking disruptions in the agrarian sector in regions with high nitrate concentrations in water resources. By combining the social-ecological systems framework with hypotheses derived from nexus research, we explore the interactions between food, water and energy systems and aim at understanding the unsustainable outcomes. We argue that the non-consideration of the complex interdependencies between the agricultural, the water and the energy system in policymaking and the divergence of policy goals constitute a major cause of unsustainable governance.

Policymaking in the water&ndash:energy&ndash:food nexus is characterized by complex ecological, social, and economic interdependencies. Nexus research assumes these interactions to be overseen in the respective resource governance resulting in sectoral perspectives contributing to unsustainable outcomes. In Germany, the political priority given to the formation of an internationally competitive livestock sector by means of intensification, specialization and regional concentration has exerted sustained pressure on water and soil resources. The expansion of bioenergy plants promoted by the renewable energy act has exacerbated the situation. Despite the persistency of the ecological challenges, German policymakers only reacted when the European Commission referred Germany to the European Court of Justice. Current policy efforts to tackle the ecological problems are now provoking disruptions in the agrarian sector in regions with high nitrate concentrations in water resources. By combining the social-ecological systems framework with hypotheses derived from nexus research, we explore the interactions between food, water and energy systems and aim at understanding the unsustainable outcomes. We argue that the non-consideration of the complex interdependencies between the agricultural, the water and the energy system in policymaking and the divergence of policy goals constitute a major cause of unsustainable governance.

Policymaking in the water–energy–food nexus is characterized by complex ecological, social, and economic interdependencies. Nexus research assumes these interactions to be overseen in the respective resource governance resulting in sectoral perspectives contributing to unsustainable outcomes. In Germany, the political priority given to the formation of an internationally competitive livestock sector by means of intensification, specialization and regional concentration has exerted sustained pressure on water and soil resources. The expansion of bioenergy plants promoted by the renewable energy act has exacerbated the situation. Despite the persistency of the ecological challenges, German policymakers only reacted when the European Commission referred Germany to the European Court of Justice. Current policy efforts to tackle the ecological problems are now provoking disruptions in the agrarian sector in regions with high nitrate concentrations in water resources. By combining the social-ecological systems framework with hypotheses derived from nexus research, we explore the interactions between food, water and energy systems and aim at understanding the unsustainable outcomes. We argue that the non-consideration of the complex interdependencies between the agricultural, the water and the energy system in policymaking and the divergence of policy goals constitute a major cause of unsustainable governance.