【摘要】 人口增长、耕地减少及全球变化引起的粮食供需变化不稳定,是区域粮食安全生产必须要考虑的问题之一。运用1981～2008年天水市人口、耕地面积、粮食产量及夏、秋粮生产季节气候因子变化资料,借助数理统计分析方法,分析了该地近30年人口、耕地面积、粮食供需及耕地安全等特征。结果表明:自20世纪80年代以来,天水市人口以4.09×104人/年的速度增长,耕地面积以766.5hm2/年的速度减少。粮食总产组成结构变化较大,20世纪80年代-90年代中期,粮食总产主要由夏粮构成,20世纪90年中期以后,粮食总产主要由秋粮构成。自1981年以来粮食总产以1.41×104t/年的速度上升,自给程度逐年改善,在2001～2005年人均平均粮食占用水平下,2004年以后粮食自给指数全部为正,在小康水平下,粮食自给程度仍然较低。20世纪80年代以来,农村人均耕地面积以0.001hm2/年的速度下降,粮食单产以37kg/hm2/年的速度增加。1981～2008年人均耕地减少了0.039hm2/人,最小人均耕地面积降低了0.252hm2/人,耕地压力呈缓解之势,耕地压力指数接近1。预计2015年粮食自给程度将有所提高,最小人均耕地面积将有所减少,耕地压力指数仍基本维持现在水平。经营好现有耕地,提高单位面积的产品输出量,是减轻耕地压力主要途径。更多还原

【Abstract】 The regional grain production safety was seriously affected by instability of grain supply and demand which was caused by population increasing,cultivated land decreasing and global changing.Based on the data of population,area of cultivated land,quantity of grain supply and demand and the variations of climatic factors during period of summer and autumn crop production,their variation characteristics were analyzed with the statistic methods in 1981-2008 in Tianshui.The results showed that the population was increasing with the speed of 40 900 person every year and cultivated land decreasing with speed of 766.5 ha every year from 1981.The structure of total grain had been changed in which total grain mainly contained summer grain in 1980’s and now mainly contained autumn grain.It also showed that the total grain had been increasing by the speed of 14 100 ton every year since 1981 and the level of self-support had been improved a lot.The index of self-support showed positive since 2004 under the level of average value of 2001-2005 of consumption per capita but there was still insufficiency of supply-demand under well off level.It indicated that land area per capita had decreased with ratio of 0.001 ha every year and per unit yield increased at ratio of 37kg/ha every year since 1981.The land area per capita had decreased by 0.039 ha and minimum area per capita deceased by 0.252 ha since 1981.The press index of cultivated land nearly reached 1 and pressure of cultivated land decreased.It was forecasted that the degree of grain self-support would be improved,the minimum area per capita would be decreased and the press index of cultivated land would remain as same as now by 2015.To manage the existing land carefully and increase the per unit area yield is the main approaches to reducing the press of cultivated land.更多还原