ViWA identifies global hotspots of agricultural water use efficiency

Virtual Water Values (ViWA) monitors global water use efficiency and develops instruments to efficiently use water resources in agriculture. The project uses an agro-hydrological simulation model and extends a general-equilibrium economic model of agricultural trade with virtual water data. Thus current water use efficiency, crop yields and virtual water flows of traded agricultural goods are simulated. The project further identifies global hot- and coldspots of water use, which serve for an analysis of trade-offs between commercial water use and ecosystem service protection.

ViWA aims at reducing the water footprint of food production through the development of innovative instruments for managing water resources in agriculture more efficient and sustainable and therewith providing, once fully developed, deeper insights into the global water-food nexus.

The project particularly (1) develops a new real time monitoring and modelling systems for global agricultural water use efficiency based on satellite remote-sensing data (COPERNICUS Sentinel satellite data streams), (2) simulates current water use efficiency, yields and virtual water flows of traded agricultural goods, thus creating impact scenarios of agricultural water use efficiency on global agricultural trade. This is achieved through coupling a computable general-equilibrium economic model of agricultural trade (DART-WATER) with a biophysical hydro-agro model (PROMET) in order to determine trade options in favour of sustainable water use. (3) ViWA carries out a sustainability assessment of global and regional agricultural water use, developing unsustainable water use indicators, which can be monitored continuously. Based on this work ViWA will identify global actual and potential hot- and coldspots of water use efficiency and sustainable or unsustainable use of water in agriculture to further investigate trade-offs between water use for commercial purposes and the protection of ecosystems services.

The projects methodology will be applied in two case study basins, the Danube and Zambezi river basins, in order to demonstrate the regional applicability. For the two basins the complete water cycle will be simulated, water allocation conflicts (with regard to crop yields, irrigation, ecological water demands, and domestic and industrial water consumption) will be analysed and the effects of improved water use efficiency will be investigated.

In the Danube basin, ViWA uses spatial analyses to extend the computable general-equilibrium economic model to explicitly include water. Water demand for irrigation and power production, the sustainability of water use and crop yields towards green and blue water is considered. The sustainability assessment determines the degree of sustainability of water use of different crops. First water use efficiency results for maize show hotspots of water loss in rainfed and irrigated maize cultivation. With that, ViWA offers a comprehensive spatial picture of water demands for irrigation in the Danube river basin and points to future potential conflicts.

In the near future, activities within ViWA will focus, among other activities, on analysing trade-offs of irrigation vs power production in the Danube, applying the approach in the Zambezi river basin and on fully developing the computable general-equilibrium economic model to include virtual water flows that are coupled with the hydro-agro model. The data stream of more than 15.000 sentinel images, which have been analysed globally is integrated into PROMET to fully implement the novel global agricultural water use efficiency monitoring system.

Find out more on ViWA here.