冬季气候变暖对山西省冬小麦可种植区的影响

基于山西省境内较为均匀分布的70 个地面气象观测站1970-2012 年冬季逐日气温资料，采用线性倾向估计法分析了负积温、最冷月平均气温和年极端最低气温的变化特征，采用累积距平法确定其突变点，以突变点为界分为前后2 个时间段，依据前后时间段等值线的变化分析冬季气候变暖对山西省冬小麦可种植区的影响。结果表明：山西省负积温呈现显著减少趋势（通过了α=0.01 的显著检验），最冷月平均气温和年极端最低气温呈现不显著升高趋势；突变后，负积温平均减少了103.4℃，最冷月平均气温和年极端最低气温分别升高了0.8℃和0.7℃；在3 个指标中，决定山西省冬小麦能否种植的关键因子是负积温和年极端最低气温，最冷月平均气温的影响较小；冬季气候变暖后，平均状况下，冬小麦可种植区域面积扩大了约2.9×10⁶ hm²，扩大52%，80%保证率下，冬小麦种植面积扩大了约2.3×10⁶ hm²，扩大79%。

Influence of climate warming in winter on the winter wheat cultivable area in Shanxi Province

Based on the daily mean temperature data of 70 meteorological stations in Shanxi Province from 1970 to 2012, the negative accumulated temperature in winter, average monthly temperature in January and extreme minimum temperature were computed and their changing trends were analyzed in this paper using linear trend estimation method, and their abrupt change points were observed by means of accumulated variance method and contours of the negative accumulated temperature in winter, average monthly temperature in January and extreme minimum temperature were compared respectively after being divided into two groups according to the abrupt change points. The results showed that the negative accumulated temperature in winter showed a remarkable decrease, and the average monthly temperature in January and extreme minimum temperature did not increase significantly. Changes were found between the two groups, the negative accumulated temperature decreased by 103.4℃, and the average monthly temperature in January and extreme minimum temperature rose by 0.7℃and 0.9℃, respectively. The negative accumulated temperature and extreme minimum temperature played a key role, which are the thresholds that the winter wheat Province could be planted or not. Under climatic warming, the winter wheat cultivable area and the reliable planting area expanded by 2.9×10⁶ hm² (increased by 52%) and 2.3×10⁶ hm² (rose by 79%), respectively.