Research on virtual water and the water footprint is mainly focused on agriculture and industry, and less so on the service sector. The trade in products generates virtual water flow, as does the flow of people. The flow of international tourists will inevitably lead to the transfer and exchange of water resources embedded in the virtual form. This study takes China's inbound tourism flow as the research object, from the perspective of the water footprint, in order to explore virtual water "exports" to the world. Based on kernel density estimation and ArcGIS spatial analysis, spatial-temporal evolution and structural difference were investigated. Virtual water "exports" showed an increasing trend. The kernel density estimation curves basically exhibited a "single peak" feature which indicated that virtual water "exports" from tourism were not significantly polarized in China. In terms of spatial evolution, this varied greatly at the provincial and regional level and Guangdong was always in the high value area. The south displayed greater values than the north, but this difference in provinces narrowed over the years. The water footprint of food was the largest, more specifically, the green component of this water footprint. Promoting a reasonable diet, reducing food waste, improving agricultural production technology, reducing the frequency of changing hotel supplies, and encouraging the use of new energy helped to reduce the water footprint. Virtual water trade in the service sector provides a new idea for helping to mitigate the global water crisis, in addition to virtual water flow for agricultural products.
Keywords: China inbound tourism; spatial-temporal evolution; structural difference; tourism water footprint; virtual water export; water resource management.