极干旱区气候变暖与种植业结构变化趋势分析——以敦煌市为例

利用敦煌国家基准气候站1971~2008年地面气象观测资料,采用温度距平时间序列及线性趋势拟合等方法,对敦煌年平均气温、平均最高气温、平均最低气温和≥10℃积温的变化趋势进行了分析。结果表明,年平均气温,平均最高气温,平均最低气温均呈波动上升趋势,递增率分别为0.46、0.38℃/10a和0.60℃/10a。≥10℃积温呈明显的增加趋势。同时利用敦煌市统计局提供的农作物种植面积资料,对其时间演变序列进行分析,得出自1998年以来,由于受社会需求增加和气候变暖等因素的影响,粮、棉、蔬菜等农作物的种植结构发生了根本性变化。20世纪90年代以前,敦煌农作物种植面积的布局顺序为粮、棉、蔬菜;进入21世纪以后,农作物种植面积的布局顺序改变为棉、蔬菜、粮。由此可见:社会需求增加和气候变暖对极干旱区农作物种植结构的变化有重大影响。

Analysis on climate warming in extreme arid area and the variation trend of crop planting structure——Taking Dunhuang in Gansu Province as an example

Based on the surface observation data of Dunhuang which is national basic station from 1971 to 2008, using temperature anomaly time series and linear trend fitting, the variation trend of the annual mean temperature, the annual mean maximum temperature, the annual mean minimum temperature, and the accumulated temperature ≥10℃ is analyzed. The results show that the three former present a wavelike rising trends, their increasing rates are 0.46℃/10a, 0.38℃/10a and 0.6℃/10a respectively, while the accumulated temperature ≥10℃ shows a significant rising trend. Using crop acreage data from Dunhuang Municipal Statistical Bureau, the temporal evolution sequence is analyzed. Influenced by social demand increase and climate warming, the grain, cotton and vegetable planting structures take basic changes, and a inflection point about grain, cotton planting area happened since 1998. The sequential placement of the crop planting structure is grain, cotton and vegetable before 1990s, while it becomes cotton, vegetable and grain since 21st century. So, social demand increase and climate warming change to the crop planting structure in the extreme arid regions obviously.