关键词: 虚拟水, 粮食作物, 东北三省, 时间变化

Abstract: The authors investigated the temporal and spatial patterns of the virtual water content (/kg) and total virtual water requirements for rice, wheat, maize and soybeans in Liaoning Province, Jilin Province and Heilongjiang Province in Northeastern China from 1988 to 2008. The results show that soybeans had the highest water demand per kilogram, followed by wheat, rice and maize. Spatial variations were evident. Per kilogram rice consumes more water in Heilongjiang, while wheat in Jilin, maize and soybeans in Liaoning. In Heilongjiang, rice, wheat and soybeans had the highest total virtual water needs, 8.60×10⁹, 3.98×10⁹ and 1.22×10¹⁰m³, respectively. Whereas the largest total virtual water for maize (1.08×10¹⁰m³) appeared in Jilin Province. During the studied period, water demands per kilogram of soybeans and wheat fluctuated, while for rice and maize the demands were stable. As to total virtual water demand, it increased for maize and rice, whereas decreased significantly for wheat. These findings provide insights on the water demand of the four crops, and thus are meaningful for decision-makers.

Key words: virtual water, selected agricultural products, Northeastern China, temporal variation