Water resources management of large hydrological basins in semi-arid regions: Spatial and temporal variability of water footprint of the Upper Euphrates River basin.

The existing water accounts for large-scale, semi-arid and transboundary river basins are usually lack of sufficient spatial-temporal elements of water use, a prerequisite for identifying potential water savings and for sustainable management of scarce water resources. This study aims to demonstrate value of water footprint (WF) accounting framework for such river basins with the case study of the Upper Euphrates River basin which is not only used as major food and energy production resource in Turkey but also a focal point for international conflict, diplomacy and dialogue in Middle East. The methodology is based on Water Footprint Assessment Manual which is published by Water Footprint Network. The study maps spatial-temporal variations of sectoral water use in the study area for the agriculture, domestic water supply and industry for the period of 2008-2019. The water footprint of the Upper Euphrates River basin is calculated as 27.4 Gm, most of which is related to the agricultural activities. The downstream and lower plains of the study area exhibited a considerably high blue and grey agricultural WF, reaching 2397 and 349 mm, respectively. Several crops have substantially large WFs in the region such as cotton, wheat, pistachio, and barley. The analysis given in this study revealed importance of spatial-temporal disaggregated information in water accounting for sustainable management of water resources. These accounts can provide insights that were not available to the decision makers before, such as water saving opportunities, potential water efficiency and productivity benchmarks, strategic planning for various climatic conditions etc. These are the major values that water footprint accounting can introduce in water management in a large scale, semi-arid transboundary river basins.