Virtual water transfer through physical power transmission and its driving factors in China during 2006–2022: A bottom-up approach

Large volumes of water are utilized for power generation and transmitted across regions through power transmission networks in the form of virtual water. However, existing research on virtual water flows faces significant limitations, primarily stemming from three critical constraints: the reliance on monetized power transmission data, the coarse spatial resolution of power production, and the discontinuity of study periods. This study analyzes virtual water flows across provinces via power transmission from 2006 to 2022, adopting a bottom-up approach with an inventory of over 7900 power plants and a dataset on physical power transmission. The findings reveal that water consumption for power production in China increased from 13 Gm3 to 26 Gm3. Virtual water transfer via power transmission grew significantly, from 1.5 Gm3 (11.8 % of total water consumption for power production) in 2006 to 7.2 Gm3 (27.5 % of total water consumption for power production) in 2022. Over the study period, a decoupling trend was observed between virtual water flows and power transmission volumes. The expansion of power production was the primary driver of increased virtual water, while the decline in virtual water intensity of power transfer-out helped reduce overall virtual water flows. These findings underscore the significant water impacts associated with power production and transmission, highlighting the need for enhanced collaboration between power-transfer-out and power-transfer-in regions.