利用2000—2003年县级统计数据,揭示21世纪初我国粮食供需的空间格局。我国粮食供需平衡以东西分异规律为主,其次是南北分异。地势第二级阶梯以东,主要余粮区分布最广,北方明显多于南方;胡焕庸线以西,常年缺粮区为主;两线之间,潜在缺粮区居多。东北地区、华北平原生产全国近70%的余粮。长江中下游以南地区既是我国温饱水平缺粮总数最多的地区,也是第三大余粮生产区。地势第二级阶梯上的农牧交错带,温饱水平缺粮总量列第二位,是我国粮食安全最脆弱的地区。上述地区主要位于环境变化敏感地带,粮食安全自然风险最大。因此,加强环境变化对粮食供需平衡的影响研究,对深入认识我国粮食供需平衡的稳定性具有重要的现实意义和理论价值。

Based on county-level statistic data in 2000-2003,this article reveals new regional distribution and difference of supply-demand of grain in China in the early 21st century.According to per capita grain available,four types of grain supply-demand are given in this study.Regional pattern of grain supply-demand in China shows a dominant rule of east-west differentiation,and then the rule of south-north differentiation.At present,the main grain-surplus regions are most extensively distributed to the east borderline of the second ladder of topography in China,being about 1/4 of the whole country.At nearly the same quantity,the food-shortage regions in average year are mostly distributed in the region west to the sideline of population geography from Heihe city in Heilongjiang province to Tengchong city in Yunnan province,namely Huhuanyong sideline in China.The potential food-shortage regions are located between the above two geographic boundaries,which have the largest numbers of the four types of grain supply-demand regions,about 1/3 of the whole country.According to the above regional pattern of grain supply-demand,this article divided the whole country into six regions to analyze regional difference in grain production with some key indices.Northeast China and North China Plain produced nearly 70% of the surplus grains of the whole country,and the southern region of the middle and lower reaches of the Yangtze River ranks the third.Northeast China has the least number of food-shortage regions,and supplied about 40% of the surplus grains in China.The southern region of the middle and lower reaches of the Yangtze River has the greatest number of food-shortage regions in China,followed by the interlock area of farming and pasturing in the region east to the borderline of the second ladder of topography.This region is also the most fragile region in food security in China,where the level of grain production and economic development is very low.Most of the above areas are located on the regions sensitive to environmental changes,which have the highest natural risk of grain production.It is necessary to improve human acclimatization and strengthen the studies on impact of environmental changes on China's food security.