甘肃临夏地区近43a来的气候特征

Climate Change of Linxia of Gansu Province in Recent 43 Years

采用临夏地区临夏市、康乐、和政、广河、永靖和东乡6个站点1968～2010年的气温、降水等资料,采用线性倾向估计法、Mann-Kendall突变检验法,分析了临夏地区43 a来气温、降水量分布特点和变化趋势及气温的突变性。结果表明,近43 a来临夏地区年平均气温呈上升趋势,突变出现在1990年代中期,1990年代中期以前增温缓慢,以后增温明显加快。冬季和夏季变暖的趋势远大于秋季,春季气温变化幅度较小,临夏地区气温以中部和北部增温幅度最大;降水变化整体持平略减少趋势,但有明显起伏的特征。主要表现为:1960年代末至1970年代末期,降水量交替升降变化幅度较大,整体表现为增加趋势,年降水量极大(小)、次大(小)值均出现在这一时期,大涝大旱现象明显。1980年代至1990年代末期,降水量变化较平稳,整体表现为正常略偏少,之后降水整体呈增加趋势,出现增湿现象,2000年代中期后逐渐呈减少趋势。4季降水量夏季表现为略减少趋势,其他季节持平,基本无变化。

The variation trends of precipitation and temperature were analyzed based on observational data from the six stations of Linxia area during 1968 - 2010 by means of linear trend method and Mann - Kendall test. The results show that the average temperature presented increasing trend in recent 43 years, and the break point was in the middle of the 1990s. The warming trend in winter and summer was more greater than that in autumn and little change occurred in spring, and the increasing extent of temperature was most at the middie and the north part of Linxia area. The precipitation had little change but there was obvious fluctuation in recent 43 years, and more change occurred in the 1970s and the maximum（ sub -maximum） and minimum（ subminimum） of precipitation also occurred during this period. From the 1980s to the end of 1990s, the whole tendency of rainfall presented slight decrease trend, and then it increased untill to the year 2005. The seasonal change of precipitation was slight decrease in summer and almost unchanged in other seasons in recent years.