天水地区近50年气温与降水变化特征

Changes on Temperature and Precipitation Characteristics in Tianshui of Gansu Province during the Past 50 Years

根据1961-2006年天水7个站每月温度和降水资料,分析了近50a天水温度和降水的突变事实。在此基础上给出了气候变暖前后气温、降水的概率分布,比较了变暖前后时段天水气温、降水空间分布的差异。结果表明:1)20世纪90年代初期天水气温、降水发生了明显突变,进入温度显著增暖和降水偏少时段;2)增暖后天水气温和降水的概率分布发生了明显变化,气温偏冷的概率显著减小,偏暖的概率显著增大;降水偏少的概率明显增多,偏多的概率明显减少;3)气候变暖后天水地区和各气候分区气温上升幅度均较显著;降水距平百分率渭北区下降幅度相对突出。进而,讨论了温度增加和降水减少对该地区农业生产的影响。

Based on monthly mean temperature and precipitation data from seven stations in Tianshui during 1961-2006 by using Mann-Kendall statistic test, the abrupt change of temperature and precipitation was analyzed. The probability distributions of the temperature and precipitation before the warming （1961-1993） and after the warming （1994-2006） were given and the spatial differences in temperature and precipitation between the two climatic periods were also compared. The results show that： 1） temperature and precipitation has had the remarkable abrupt decrease in the early 1990s in Tianshui, entering a time interval of temperature obvious increase and precipitation decrease; 2） after the warming the probability of temperature tending to be cold has obviously reduced, the probability of temperature warming increased and probability of scarce precipitation has obviously increased, many probabilities obviously reduced; 3） the temperature increase rate is remarkable in Tianshui and the precipitation anomalous percentage decline rate is relatively prominent in the north of Weihe River. Then the influence of temperature increase and precipitation decrease on agricultural production in Tianshui is discussed.