全球农作物虚拟水贸易可持续动态变化 postprint

Abstract: Incorporating agricultural irrigation water into the global trade chain and determining its sustainability is vital for ensuring water and food security. However, the issue of sustainability in the virtual water footprint of crop trade has received limited attention, due to the conflict between economic benefits and water resource utilization. Thus, based on the crop production and trade matrix data from the Food and Agriculture Organization, this study conducted physical trade flow and spatial correlation analyses as well as multiscale geographically weighted regression to systematically analyze the spatiotemporal distribution, the spatial correlation characteristics, and the driving factors of net exported virtual water sustainability in global crop trade from 2000 to 2019. Based on the findings, the sustainable and unsustainable net exported virtual water volumes in global crop trade (especially cotton) exhibited a fluctuating upward trend (approximately 0.20 Gm3 per year) over the past two decades. However, due to agricultural technological advancements, the proportion of unsustainable virtual water in the total virtual water trade volume decreased from 42.31% to 41.40%. Although the spatial analysis revealed considerable spatial clustering of unsustainable net exported virtual water volumes between 2000 and 2009, as shown by global and local Moran’s I statistics, this clustering trend weakened and became more dispersed over the past decade. Moreover, the increase in net exported virtual water was mainly driven by changes in cultivated land area, with agricultural value-added having a significant negative impact on virtual water in trade. Overall, these results highlight the importance of implementing stringent food security policies in order to facilitate the sustainable development of the global virtual water trade in crops and to further reduce the proportion of unsustainable water use.