基于粮食作物的广州市虚拟水贸易研究

Research on Virtual Water Trade Based on Grain Crops in Guangzhou City

采用联合国粮农组织推荐的作物需水量计算方法,研究了广州市1999—2019年粮食作物的虚拟水含量及其贸易量变化,结果表明:(1)广州市粮食作物以稻谷和大豆为主,研究时段内二者播种面积和总产量分别占全部粮食作物的81%和84%,粮食贸易长期处于逆差,进出口结构比较稳定但相对单一;(2)广州市早稻、晚稻、大豆的年平均需水量分别为496 mm、608 mm和293 mm,1999—2019年粮食作物生产消耗的虚拟水总量逐渐减少,占同期农业用水量的比例平均为59%并呈下降趋势;(3)广州市1999—2019年基于粮食贸易的虚拟水输入量累计达到6.8×10^(10)m^(3),主要来自北美洲和拉丁美洲,而虚拟水输出主要流向亚洲和非洲。

Based on the calculation method of crop water requirements recommended by the Food and Agriculture Organization of the United Nations,this paper studied the changes of virtual water content and trade volume of grain crops in Guangzhou from 1999 to 2019.The results show that:(1)Rice and soybean are the major grain crops in Guangzhou.During the study period,the sown area and total yield of them ac⁃counted for 81%and 84%of all grain crops,respectively.The grain trade has been in deficit for a long time,and the import and export struc⁃ture is stable but relatively single.(2)The mean annual water requirement of early rice,late rice and soybean in Guangzhou was 496 mm,608 mm and 293 mm,respectively.The total virtual water of major grain crops decreased gradually from 1999 to 2019,and accounted for ap⁃proximately 59%of agricultural water consumption in the same period and showed a decreasing trend.(3)From 1999 to 2019,the accumulat⁃ed volume of virtual water input based on grain trade in Guangzhou reached 6.8×1010 m3,mainly from North America and Latin America,while the virtual water output mainly flowed to Asia and Africa.