陕西省近48年5℃界限积温变化特征分析

Change of the Accumulated Temperature above 5℃ Critical Temperature in Shaanxi during Past 48 years

在气候变化背景下,农业热量资源发生变化,因此研究陕西省热量资源的时空变化具有重要的意义。分析陕西1961-2008年平均气温稳定通过5℃的初日、终日、初终间隔时间、积温的年际变化、年代际变化,结果发现,陕西省及各区域日平均气温稳定通过5℃的积温变化均呈增加的趋势,全省范围内每10 a增加57.92℃.d;各区域的初终日间隔时间变化均呈增加趋势;初日呈提前趋势;终日变化趋势不一致;积温年际稳定性降低,年代际波动增加,冷暖交替频率加快,可能抵消热量资源增加带来的益处。

Climate warming was increasingly significant in recent decades,affecting agro-climatic resources.It not only had obvious affected the growth and distribution of crops,but also had influenced agricultural policy and breeding.Therefore,it had important significance that analyzing the spatial and temporal change of ≥5 ℃accumulated temperature in Shaanxi.By using systemic observation data of 82 meteorological stations in Shaanxi from 1961 to 2008,meteorological data,involving the beginning day,ending day,duration and accumulated temperature of the daily temperature above 5 ℃ stably,were analyzed.The results showed that accumulated temperature of Shaanxi and all regions had an increasing trend,which increased 57.92 ℃ per decade in Shaanxi.Zhen＇an had the highest value with 177.6 ℃ per decade.Duration of all regions had an increase tendency.The beginning day was delayed.The ending day changed differently： it＇s delayed in the central Shaanxi plain,the north Shaanxi,the north Weibei dry land,Yijun,Taibai,Hua mountain,Xunyi and Zhen＇ an;it＇s moved up the north and west of the south Shaanxi and Shangluo.The duration days became longer in all regions.