基于甘肃省及周边地区46个气象站点的气温和降水年值、月值数据,对数据进行均一化检验和订正后,采用气候倾向率法、Mann-Kendall非参数检验法对甘肃近50 a气候变化时空特征进行了分析.结果表明:甘肃省平均气温、平均最低气温、平均最高气温、极端最高气温、极端最低气温均升温明显,其中以最低气温升温最为显著.气温的季节变化空间差异较大,空间上四季最低气温和极端最低气温升温最显著,春、冬季平均最低气温升温最显著;夏、秋季极端最低气温升温最为显著.降水变化的区域差异大,降水气候倾向率最小值达-22.2 mm·(10a)^-1,最大值14.1 mm·(10a)^-1,乌鞘岭以东表现为减少趋势,以西增加.河西地区气温突变时间为1986年,早于河东气温突变时间(1993年).甘肃气候变化时空差异明显,乌鞘岭是近50 a甘肃气候转型分异的一条重要分界线.
As a consequence of global warming and water cycle enhancing,the climate change becomes most notable in Northwest China. Gansu Province is a significant ecological barrier in Northwest China. In this paper,daily temperature and precipitation data were collected from 46 meteorological stations in Gansu Province and surrounding areas. The spatial and temporal changes of climate were analyzed by means of linear trend,MannKendall test after detecting data homogenization over Gansu Province for nearly 50 years. The results show that(1)average temperature,minimum temperature,maximum temperature,extreme maximum temperature,extreme minimum temperature were increasing significantly,especially,the minimum temperature rising was the most significant. Seasonal variation of air temperature was quite different from place to place. Seasonal minimum temperature and extreme minimum temperature risings were the most significant. Especially,spring and winter average minimum temperatures had increased outstandingly. In summer and autumn,the extreme minimum temperature rising was the most significant;(2)variation of precipitation in Gansu Province had regional difference,precipitation in east of Wushaoling had a decreasing trend and in west of Wushaoling had a increasing trend;the minimum precipitation tendency rate was over- 22.2 mm·(10a)^-1 and the maximum one was 14.1mm·(10a)^-1;(3)there was an abrupt change of air temperatures around 1986 in Hexi Region,earlier than that in Hedong Region(around 1993). According to the above analyses,spatial and temporal differences of climate change in Gansu Provinces were distinct and the Wushaoling has been a clear dividing line of the climate shift in the recent 50 years.