Assessment of wheat's water footprint and virtual water trade: a case study for Turkey

Background Many countries are experiencing significant water scarcity and related problems due to limited availability, uneven distribution of water resources and high demand. Therefore, increasing water use efficiency and better management of existing resources have become substantially important. The agricultural sector is responsible for around 80% of global freshwater withdrawal. Wheat is one of the most important crops having large volumes of virtual water (VW) which is defined as the hidden water embedded in the products. Methods Water footprint (WF) is an indicator showing the total volume of freshwater consumption of a product or process. Blue water concept is defined as the amount of exploited surface and groundwater resources. Green water represents the total volume of rainwater allocated by the product. WF methodology brings a new approach to inter-regional water use and management by quantifying the amount of direct and indirect water use and tracing the hidden links between production, consumption and trade. The main objective of this study is to analyze Turkey's national blue and green WF of wheat production, consumption and virtual water trade between 2008 and 2019. Detailed province-based quantification of wheat's water exploitation is provided using spatial interpolation method. Results Total consumptive WF of wheat production and consumption of Turkey is calculated as 39.3 and 48.1 Gm(3)/year, respectively. The average blue and green VW contents of wheat production through Turkey are assessed to be 1161 and 748 m(3)/ton, respectively. The water footprint parameters of each province are calculated and discussed using climatic and agricultural data. VW transfer of Turkey's international wheat trade is also analyzed. Total national water saving is calculated as 7.8 Gm(3)/year which is mostly imported from Russia. Global VW deficit due to international wheat trade is calculated to be 1.76 Gm(3)/year. Conclusion Despite its high contribution to global wheat production, increasing population and strong wheat-based diet, quantitative, comparative and up-to-date analyses of the blue and green WF and the VW transfer of wheat production in Turkey are not available. This study contributes to the national and international water management and planning studies to increase the water allocation efficiency of agricultural products.