近50年开都河流域下游降水和气温变化特征分析

Variation features of precipitation and air temperature in lower reaches of Kaidu River Basin of Xinjiang during recent 50 years

采用开都河流域下游焉耆县、和静县、和硕县三个气象站1960—2009年气温和降水观测资料,以线性趋势函数,M-K突变检验等方法,分析开都河流域下游气温和降水的年际变化、季节变化特征。研究结果表明:(1)焉耆县、和静县与和硕县的年平均气温呈上升趋势,年平均气温线性拟合增长率分别为0.366℃.10a-1、0.256℃.10a-1、0.033℃.10a-1。(2)和硕县月平均最低气温呈现下降趋势,而焉耆县与和静县平均最高气温、最低气温均呈上升趋势;从季节年际变化来看,三个县四季气温均有增加趋势,冬季增温明显,秋季平均气温的年际变化幅度与年平均气温的年际变化幅度相似。(3)三个县年降水量距平值呈下降-上升-下降特征,降水量有微弱增多趋势。(4)和静县与和硕县两站气温异常,焉耆县降水异常,气温突变均出现在20世纪90年代,而且突变发生较频繁。

Through the data of air temperature and precipitation from 1960 to 2009 at the three stations of Yanqi,Hejing,and Heshuo County,and using methods of linear fitting and Mann-Kendall test,seasonal and annual changes of air temperature and precipitation in lower reaches of Kaidu River Basin were characterized in this study.The results indicated that：（1） Annual average temperature of these three counties showed an escalating trend.The linear fitting growth rates of these three counties are 0.366℃·10a-1,0.256℃·10a-1 and 0.033℃·10a-1.（2） Mean maximum temperature and the mean minimum temperature of Yanqi and Hejing County showed an ascending trend,while monthly mean minimum temperature in Heshuo county showed a decreasing trend.As for as seasonal and annual temperature alternations are concerned,seasonal temperature of all these three counties showed an increasing trend.Temperature increase in winter is significant.The inter-annual alternation extent of fall average temperature is at same range of inter-annual alternation of annual average temperature.（3） Annual precipitation anomalies of three counties appeared down-up-down trend.（4） Lapse rate was abnormal in three counties,and precipitation rate was abnormal in Yanqi county.Abrupt atmospheric temperature change occurred frequently and all of them ocurred in the 1990s.