Increased Grain Crop Production Intensifies the Water Crisis in Northern China.

Growing crop production increases agricultural water consumption (AWC), but whether these two factors are matched in northern and southern China in the past two decades remains controversial. Here we used a remote sensing‐based water‐carbon coupling model combined with satellite observations to quantify the crop production, AWC, and water deficit changes in China over 2003–2018. We show that in northern China, crop production and AWC significantly (p < 0.05) increased, mainly due to planting area expansion, and the increasing rates were 2.6 and 6.2 times greater than those in southern China. The increasing irrigation demand in northern China greatly reduced the availability of stored terrestrial water and could not be met by the agricultural water supply in the next two decades. Our results show that the conflict between the limited agricultural water supply and the increasing irrigation demand cannot be resolved by the South‐to‐North Water Diversion Project, and better management in water resources and crop production is needed to achieve the United Nations Sustainable Development Goals. Plain Language Summary: Water is essential to agricultural production. Increasing water consumption in water supply limited areas may result in a water crisis and threaten sustainable food security, especially in China, the most populated agricultural country in the world. There are continuous arguments regarding the matches between agricultural water consumption and supply in China for the past decades and for the future. Satellite‐based observation is an advanced technique to detect the real crop growth characteristics in large scales. Here we used a satellite‐driven water‐carbon coupling model to show the conflicts between the agricultural production and water resources in northern and southern China. We found that expansion in arable land areas increased irrigation water demand in northern China during 2003–2018 and has intensively reduced the available terrestrial water resources in agricultural areas. The additional water supplied by China's largest water transfer project has limited capability to mitigate the agricultural water crisis problems in northern regions in the near future, calling for improved agricultural water management measures to ensure food‐water security in a changing environment. Key Points: The crop production‐water resource conflicts between northern and southern China intensified during 2003–2018Crop water consumption and demand increased faster in north China than in south China due to crop production expansionChina's largest water transfer project has limited capacity to ease water crisis in next two decades, calling for improved water governance [ABSTRACT FROM AUTHOR]