根据甘肃省1985—2005年的气候资料和同时期主要作物播种面积等统计资料,利用快速聚类分析方法分析了气候变暖背景下甘肃省主要作物的种植格局和种植界限演变情况。结果表明:过去20 a里特别是进入20世纪90年代,在河西地区,玉米和棉花播种范围扩张趋势明显,种植面积比重显著增加,春小麦种植面积比重快速降低,种植范围大幅向祁连山浅山区退缩,种植结构的这种调整使玉米和棉花逐渐取代小麦成为河西主要作物,并最终导致该区主要作物种植格局从以小麦为主转变为以玉米和棉花为主;在中部地区,春小麦面积逐年缩小,冬小麦和杂粮种植扩张,玉米的种植比例逐年上升,马铃薯种植逐渐形成规模,形成了以小麦和玉米为主的种植格局;在东南部地区,春小麦和冬小麦面积逐年缩小,玉米、冬油菜和其他喜温的经济作物种植比例逐年上升。相关分析表明,上述作物种植格局的变化与气候变暖带来的积温增加及积温带北移东扩密切相关。

Global warming during the 20th century, especially the impacts of the global warming in the past two decades has been paid much attention worldwide. A case study is made in this paper on the relationship between change of main crops structure and global warming in Gansu Province of Northwest China based on the statistical data of agriculture and ground based climate data during 1985 to 2005. The results showed that in the past 20 years, especially in 1990s, in Hexi Corridor corn and cotton sown area expanded obviously, the proportion of cotton and corn sown area increased significanly, but the proportion of the spring wheat dropped rapidly and retreat extensively to the Qilian shallow mountain region, corn and cotton gradually replaced the wheat in Hexi Corridor and became the main crops. In the central region, the sown area of spring wheat reduced year by year, and winter wheat planting area expanded, the proportion of maize increased year by year also, potato planting scale increased gradually; in the southeastern region, winter wheat and spring wheat planting area decreased year after year, but corn, winter oilseed rape and other cash crops increased year by year. Under global warming, it is proved that temperature change has influenced human society to a certain extent and people began to adapt to the new environment by transferring the land use patterns.