Revealing the potential geographic convergence of global water scarcity risk and virtual water trade inequality: A three-module integrated analytical approach

• Three-dimensional water scarcity risks for 123 countries are assessed. • Blue water footprint embodied in global supply network is tracked. • International unequal exchange of virtual water is quantified. • Geographic convergence of global water scarcity and virtual water inequality is identified. • Virtual water trade regulation is potential policy design to alleviate global water scarcity. Unequal virtual water transfer may aggravate local water scarcity risk. However, the quantitative confirmation of a clear geographic convergence between virtual water transfer and water scarcity risk remains undetermined. We present an analytical framework that reveals the spatial matching between global water scarcity risk and virtual water trade inequality. This framework integrates a three-dimensional water scarcity risk assessment, hybrid input-output analysis, pollution trade term construction, and geographic convergence identification. The framework is applied to 123 countries for long-term validation from 1991 to 2021. We show that despite global improvements in water efficiency and security, countries exceeding the maximum water vulnerability threshold have increased by 50 %. South Asia is the largest net exporter of virtual water. Central Asia exhibits the most pronounced virtual water trade inequality. To achieve the same economic growth, Central Asia needs to pay several times the local water consumption costs of developed regions (15.9 − 83.6 times, 2021). In the past 30 years, the average geographic convergence index exceeded 0.8. Countries facing severe water scarcity also exhibit pronounced inequalities in virtual water trade, indicating that a significant geographic convergence relationship exists. Effectively responding to this unsustainable relationship necessitates balancing both domestic resource risk management and global virtual water trade regulation.