1961～2015年格尔木市汛期极端降水事件变化特征

THE VARIATION CHARACTERISTICS OF EXTREME PRECIPITATION EVENTS IN THE FLOOD SEASON IN GEERMU CITY FROM 1961 TO 2015

为了研究格尔木市汛期极端强降水事件在全球气候变暖背景下的变化特征,利用格尔木市1961~2015年汛期(5~9月)逐日降水资料,采用百分位值法定义了极端强降水事件的阈值,然后统计出逐年极端强降水事件的降水量、频数、强度和1日最大降水量,运用线性倾向估计法、Mann-Kendall检验、R/S方法分析极端强降水事件的变化特征以及对未来趋势的预测。结果表明,极端降水频数呈微弱的下降趋势,极端降水量、极端降水强度和1日最大降水量均呈上升趋势,极端降水事件各指标波动幅度较大;各指标均无突变发生;格尔木市汛期极端降水频数(极端降水量)主要集中在6~7月,而5月、8~9月发生极端降水事件的概率较小;极端降水频数时间序列具有反持续性,极端降水量、极端降水强度和1日最大降水量具有持续性。

To study the geermu flood season strong extreme precipitation events under the background of global climate warming change characteristics,use of geermu from 1961 to 2015 in flood season（ from may to September） daily rainfall data,the percentile value method is used to define the threshold value of extreme heavy precipitation event,then the statistics of annual extreme heavy precipitation event of rainfall,frequency,intensity and 1,maximum precipitation,using linear tendency estimate method,Mann-Kendall test,R/S method analyzing the change of the extreme heavy precipitation event characteristics and prediction of future trends. The result indicates that the extreme precipitation frequency weak decline,extreme precipitation and extreme precipitation intensity maximum precipitation are on the rise,and 1,extreme precipitation events each index volatility is larger; No mutation occurred in all indexes; The extreme precipitation frequency（ extreme precipitation） in the flood season in the city of guermu is mainly concentrated in June to July,while the probability of extreme precipitation events in May,August and September is relatively small. The time series of extreme precipitation frequency has the antipersistence,the extreme precipitation,the extreme precipitation intensity and the maximum precipitation of the first day is continuous.