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The spatial mismatch between energy resources and water resources has been widely concerned. Electricity trade drives virtual water flows from electricity production sides to consumption sides, which can aggravate or alleviate regional water scarcity. Investigating the historical evolution of virtual water transmission and its impacts on water scarcity benefits the sustainable development of energy and water. To reduce data uncertainties, in this study, we built provincial water intensity of electricity generation inventory considering the impacts of factors such as electricity generation types, cooling technologies and generator units. Besides, to investigate how the direction and quantity of virtual water flows aggravate or alleviate the regional water scarcity, the impact assessment model was built, and the impact assessment index was defined. The results showed that the water consumption of electricity generation and interprovincial virtual water transfer increased by 2.61 times and 5.12 times during 2005–2015, respectively. Changes in the amount of electricity generation and the electricity transmission structure were the two main drivers of increases in virtual water flows, contributing to a total increase of 85.28%. A large amount of virtual water was transferred from the southwest and the northwest to the eastern coastal areas. There were many "positive flows" from the southwest to Jiangsu-Zhejiang-Shanghai, while "negative flows" were concentrated in Xinjiang-Henan, Gansu-Qinghai and Gan-Shaanxi. The nodes with the largest impact assessment index value were Hubei, Sichuan and Shanghai, while the lowest were Gansu, Xinjiang and Qinghai. This study can provide a basis for optimizing the electricity generation mix and electricity transmission structure, alleviating the growing tension between energy and water, and realizing the sustainable development of water resources. • The provincial water intensity for electricity generation inventory is built. • The amount of virtual water flows increased 5.12 times from 2005 to 2014. • The virtual outflows of the southwestern regions alleviated national water scarcity. [ABSTRACT FROM AUTHOR]

Along with electricity transmission, virtual water is transferred from electricity generation provinces to load hubs, reallocating spatial water resources and impacting regional water scarcity. To assess whether virtual water in electricity transmission mitigated or aggravated national water scarcity, a rationality assessment model was proposed from energy-water nexus perspective. The interprovincial virtual water flows were calculated based on provincial water intensity and electricity transmission considering the provincial electricity generation mix. The flow rationality index and node rationality index were proposed and defined to evaluate the net benefit of virtual water flows and provinces, respectively, according to the interprovincial differences in water stress index. The results show that: 1) a large amount of virtual water was transferred from the northwest and southwest provinces to the southeast provinces and Beijing-Tianjin-Hebei region; 2) the flow with the highest flow rationality index is Inner Mongolia-to-Hebei (29.8), while the lowest one is Shanxi-to-Hubei (−102.5); 3) the node with the highest node rationality index is Hebei (32.0), while the lowest one is Shanxi (−104.7). By quantifying the impacts of electricity transmission on provincial and national water stress, this study aims to provide guidance for national virtual water strategy by electricity transmission to mitigate national water scarcity. • Virtual water transfers embodied in China's interprovincial electricity trade is calculated in 2014. • A rationality assessment model is proposed to evaluate whether the water transfers positively or negatively impacts overall water scarcity for a region. • Based rationality assessment model, the rationality index for flows and provinces is analyzed. [ABSTRACT FROM AUTHOR]