Mapping the virtual water trade in water-scarce basin: an environmentally extended input-output analysis in the Yellow River Basin of China

China's Yellow River, the nation's second-longest, grapples with severe water scarcity, impeding the high-quality development of its basin. Our study meticulously examines the intricate virtual water trade network inside and outside the basin, providing essential insights to combat its acute water scarcity. We calculated water consumption coefficients for seven pivotal sectors across diverse Chinese provinces, forming the foundational data for quantifying virtual water trade both inside and outside the basin. Utilizing the 2015 Multi-Regional Input-Output Table, we assessed the Yellow River Basin's reliance on external water resources. Despite enduring chronic water scarcity, the basin annually exports a substantial 27.2 billion m3 of virtual water, equivalent to half of its yearly runoff. This outflow predominantly flows to the economically advanced eastern coastal region, with Agriculture and Manufacturing sectors dominating. Significantly, an irrational industrial layout leads to a substantial transfer of virtual water from economically disadvantaged areas to more affluent regions, exacerbating water scarcity in the basin's less privileged areas. Our study yields critical insights for mitigating water shortages in the Yellow River Basin and provides a transferrable framework for regions worldwide grappling with analogous challenges.