Dynamic law of virtual water equilibrium for foodstuff production and consumption in China

In order to optimize spatial allocation of water resources, spatial distribution dynamics of virtual water for foodstuff production, consumption and their equilibrium in China for 1998~2007 were analyzed. The analysis shows that North China outputs increasing virtual water for foodstuff production from 3 019.1×10⁸ m³ in 1998 to 3 197.5×10⁸ m³ in 2007. On the other hand, South China shows the opposite trend where virtual water for foodstuff production declines from 3 207.5×10⁸ m³ in 1998 to 2 801.4×10⁸ m³ in 2007. There is 4.43% growth of virtual water consumption for foodstuff from 1998 to 2006 in China. The north has 7.70% growth of virtual water consumption for foodstuff while the south has only 1.84% growth. Virtual water equilibrium for foodstuff production and consumption is negative in China. However, the south and the north have different trends. The south has an increasing negative equilibrium trend whereas the opposite is the case for the north. The North-South Water Diversion of virtual water in China has an increasing significant implication for foodstuff production and consumption. The northeast is a typical virtual water output region whereas Huang-Huai-Hai, North China, Southeast and South China are typical virtual water input regions. From the perspective of water resources, the study shows that foodstuff production and consumption pattern in China has some problems that requires proper adjustment.