Abstract:

Water is scarce in China Rapid economic and societal development， as well as the dense population， cause severe pressure on local water resources This paper aimed to provide a new thought of adjusting the agricultural structure by calculating the virtual water in Chongqing This paper used the CROPWAT model and CLIMWAT database recommended by FAO to investigate the temporal patterns of the virtual water content and total virtual water requirements for rice， wheat， maize， groundnut and vegetables in Chongqing from 2001 to 2010， and gave a suggestion about the adjustment of the crop planting structure in Chongqing The results showed that the groundnut had the highest water demand per kilogram， vegetable had the lowest Rice had the highest total virtual water needs， which was closed to 40×108m3， while the groundnut need the lowest total virtual water During the studied period， water demands per kilogram of vegetable stayed stable The variation trend of most products were coincident， which appeared the trend of decline before or after 2006The gross virtual water of groundnut stayed a low level， whereas the total needs of vegetable increased， while the needs of wheat was dramatic decline In terms of the perunit virtual water content， it is appropriate to plant rice， maize and vegetables in Chongqing However， wheat is not inappropriate to plant in Chongqing The agricultural structure can be changed and increase the virtual water trade to exploit water properly