Interactive national virtual water-energy nexus networks

Across the globe, many regions import virtual resources to support their development. Although many researchers have studied transfers of a single virtual resource, interactions across two types of virtual resource transfer networks - energy and water, for example - have rarely been explored simultaneously. To address these knowledge gaps, we constructed and analyzed interprovincial virtual water and energy transfer networks, using China (the largest energy consumer and is undergoing severe water scarcity) as a demonstration. The results unexpectedly showed that more than 40% of provinces gained one kind of resource (either water or energy) through trade at the expense of losing the other kind of internal resource (energy or water), and 20% of provinces suffered a double loss of both water and energy. The remaining provinces gained both water and energy. Surprisingly, approximately 40% of transferred water/energy was from relatively water/energy-scarce provinces to water/energy-abundant provinces, further deepening resource inequality. Moreover, 33.3% and 26.7% of the provinces relied more on cross-border trade than on internal resources to support their water and energy consumption, respectively. Furthermore, in terms of total trade volume, 83.3% and 73.3% of provinces depended more on distant provinces via trade than adjacent ones to support their water and energy consumption, respectively. Overall, virtual water-energy networks tended to enhance each other. Trade largely shaped the nexus relationship between water and energy consumption in provinces. Our study suggests that there is an urgent need to assess multiple virtual resource networks simultaneously in other countries to uncover unintended consequences and to develop cross-sectoral and holistic policies to achieve global sustainability and human well-being.