额尔齐斯河流域降水变化特征

Variation characteristics of precipitation over Irtysh River Basin

选择额尔齐斯河流域4个气象水文测站（斋桑泊、塞米巴拉金斯克、鄂木斯克和塔帕）近70a（1936—2005年）的降水系列资料,采用5a滑动平均法、Mann-Kendall法、复Morlet小波分析法和R/S分析法分析这4个气象水文测站的降水变化特征。结果表明：这4个气象水文测站的年降水量呈现不同程度的上升趋势,其中鄂木斯克和塔帕存在显著的上升趋势;4个气象水文测站的年降水存在11~13a时间尺度的交替,表现出明显的周期特征,其次7~9a以及4a左右时间尺度的周期性也相对比较明显;Hurst值表明未来斋桑泊气象水文测站年降水量总体上将呈减少趋势,但反持续程度很弱,其余3个气象水文测站的降水量仍将呈上升趋势。

With the precipitation data from four hydrological and meteorological stations （Zaysan, Semipalatinsk, Omsk, and Thapa） in the Irtysh River Basin from 1936 to 2005, the five-year moving average method, the Mann-Kendall method, the Morlet wavelet analysis method, and the R/S analysis method were used to analyze the variation characteristics of precipitation at these stations. The results show that the annual precipitation had an increasing trend at the four stations, and a significant upward trend at the Omsk and Thapa stations had; the annual precipitation series had significant periodic variation and three evident characteristic time scales of annual precipitation variation with periods of 4a, 7 - 9a, and 11 -13a, and the characteristic time scale of 11 - 13a was a dominant period; and,basedon the Hurst values, precipitation at the Omsk Station will have a downward trend at some time in the future, while the precipitation at the other three stations will still have an upward trend.