贵州省50年来耕地资源数量变化特征及其与粮食产量的关系研究

贵州省耕地资源不足、人口增长速度快、粮食短缺、生态环境脆弱等问题，成为区域可持续发展的重要障碍．利用贵州省近50年的统计数据，分析耕地面积的变化过程及其驱动因子，并对耕地和粮食数量变化的相关关系作了初步研究．贵州耕地面积变化经历了快速增加-缓慢减少-快速减少-平稳减少=缓慢增加5个过程，驱动因子可归结为经济建设、农业发展、交通建设及人口压力4个方面；用耕地面积和粮食总产量的变化率进行的耕地和粮食的相关分析显示：1969年以前两的变化呈同向波动，粮食增产主要来源于耕地面积的增加；1969年以后基本呈反向变化，在大部分年份，耕地减少的同时粮食实现增产，单产的提高是增产的主要途径．

Relationship between the Arable Land Change and the Grain Production in Guizhou Province during the Past 50 Years

In general, national food security is based on grain self-sufficiency. Cultivated land plays an important role in influencing the grain self-sufficient capability. The food problem becomes greater and greater due to continuous population growth and the demand for food increase because of the improvement of living conditions in China. The conflict between population and land is acute because the precious arable land will be partly transformed for non-agricultural use during the process of economic development. This article tracks some of the major factors of driving forces on land decrease and the relationship between changes of arable land and grain production that are better supported by case study evidence of Guizhou province. Based on the analysis of the statistics data of arable land from 1949 to 1999 of Guizhou province, the research results show that the changes of arable land area experienced five stages including increase gently decrease, rapid decrease, gently decrease and gently increase. 1965-1970 experienced the largest decrease of arable land and 30 000 hm~2 land was lost per year and 150 000 hm~2 in total. The principal component analyzing results support the conclusion that the decrease in arable land is mainly due to the driving of economic growth, agricultural development, transportation construction and population pressure. The correlation based on the variability of grain production and arable land has been analyzed. The research has revealed that from 1949 to 1969 the change directions were almost the same: the grain production increased when land number rised, while the grain production reduced when land number decreased. But after that, from 1969-1999, the grain production almost kept going up even when the number of arable land went down because of the high output of the grain production per hm~2.