1970-2012年山西省负积温变化特征及其影响

为了揭示山西省负积温的变化规律，科学合理利用冬季气候资源，在山西省境内选择70个地面气象观测站作为代表站，利用代表站1970-2012年冬季逐日气温资料统计负积温，分析负积温的变化趋势及其突变特征。结果表明：近43a来，山西省平均负积温和日平均气温0℃以下持续日数均呈现显著减少趋势，分别通过了 和 的显著检验，突变点分别出现在1987年和1995年；突变后，全省平均负积温减少了103.4℃，日平均气温0℃以下持续日数减少了约10天；代表站负积温的气候倾向率为-8～-78℃/10a，全省各地一致为减少趋势，约80%的代表站通过了 的显著检验，日平均气温0℃以下持续日数的气候倾向率为-7.9～0.1d/10a，只有一个站为增加趋势，但均未通过显著性检验。山西省从1980年代后期开始，发生暖冬年的频次明显增加。负积温减少有利于山西省冬小麦种植面积的扩大，可种植北界北移0.2个纬度，可种植区域增加3.0×106hm2，增加52%，但同时会增加病虫害的越冬几率，对山西省农业的影响利弊并存。

Variation of negative accumulated temperature and its effect from 1970 to 2012 in Shanxi Province

In this paper, 70 representative meteorological stations were selected over Shanxi province, the absolute value of negative accumulated temperature was computed and its changing trend was analyzed by means of Modern climate statistical methods. The results showed that during the recent 43a,the descending trend of the absolute value of annual negative accumulated temperature and days of daily average temperature<0℃ was significantly，their abrupt change happened in 1987 and 1995 respectively, too. They were relatively low after 1986 and 1995 with a decreasing by 103.4℃ and 10d on average respectively，even warm winter mainly occurred. As a result, the winter wheat cultivable area expanded, in the mean time, it reduced the mortality rate of winter sickness egg (cocoon) and increased its survival quantity, so it is easy to cause plant diseases, increases the preventing and controlling difficult. There are both advantages and disadvantages of change negative accumulated temperature to winter wheat in Shanxi province.