The college of Environment and Planning, Henan University, Kaifeng, 475004, China.
Key Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions (Henan University), Ministry of Education, Kaifeng, 475004, China.
Environ Sci Technol. 2020 May 5;54(9):5365-5375. doi: 10.1021/acs.est.0c00256. Epub 2020 Apr 15.
Interregional trade can potentially extend the management of scarce resources beyond a region's territory along supply chains. Here we combined the multiregional input-output model with structural decomposition analysis to reveal the distant connections of agricultural land and water use as well as the drivers behind their variations in China. Our results show that trade-embodied agricultural land use increase by 2.3-fold and 2.5-fold for virtual agricultural water use flows from 2002 to 2012. The water-starved northern China with abundant agricultural land is the main exporter of virtual (also called trade-embodied) agricultural land and water. Moreover, the role of the virtual water use importers and exporters were determined by the availability of land, rather than water resources. Based on scenario analysis, we found that if agricultural water use efficiency of north China reached the world's top-level but agricultural land use efficiency remained unchanged, the virtual water flows would be reduced by 32% and only water resources, not agricultural land, would be able to sustain future economic development. Our findings may provide significant information for potential solutions to China's regional water shortage from a land-water nexus perspective.
区域间贸易可以沿着供应链将稀缺资源的管理从一个地区的范围扩展到其他地区。在这里，我们结合多区域投入产出模型和结构分解分析，揭示了中国农业土地和水利用的远距离联系及其变化的驱动因素。我们的研究结果表明，从 2002 年到 2012 年，贸易隐含的农业土地利用增加了 2.3 倍，虚拟农业用水量增加了 2.5 倍。水资源短缺的北方地区拥有丰富的农业土地，是虚拟（也称为贸易隐含）农业土地和水资源的主要出口地。此外，虚拟水使用的进口国和出口国的作用取决于土地的可用性，而不是水资源。基于情景分析，我们发现，如果中国北方的农业用水效率达到世界最高水平，但农业土地利用效率保持不变，虚拟水流量将减少 32%，只有水资源而不是农业土地能够支撑未来的经济发展。我们的研究结果可能为从土地-水联系的角度解决中国区域性水资源短缺问题提供重要信息。
