Calculation of the Virtual Resources Flows Condensed in Grain in Gansu Province

Increasing shortage of water and land resources is an uncontroversial fact with population growth and economic development in Gansu Province.How to alleviate the pressure of water and land resources is a major issue faced by decision-makers.Based on the concept of virtual water and virtual land,in this paper a matrix of virtual resources flows condensed in grain and an outline of virtual resources trade are developed through the grain supply and demand at different consumption levels in Gansu Province in 2005 and the next decades.The result shows that the ultimate output of grain in Gansu Province in 2005 could satisfy a per capita grain consumption of 300 kg only.In order to achieve the ample and well-off grain consumptions,it needs to import grain of 6.80×105~1.97×106 t from other provinces or foreign countries.It is predicted that the inter-regional virtual flows of water and land resources condensed in grain will be 4.23×109~6.74×109 m3 and 6.00×105~9.44×105 hm2 respectively by 2020.In a long-term,the trend of virtual resources flows from the Hexi Corridor to the ecological regions in the central and southern parts of Gansu Province will not be significantly changed.The virtual resources trade provides a new choice for guaranteeing the food security and alleviating the shortage of resources in Gansu Province.