三江源区径流演变规律分析

通过线性回归、滑动平均、Mann-Kendall检验、累积距平、滑动t检验和Morlet小波分析等方法分析了三江源区1956—2012年的年径流量演变规律。结果表明: 57 a来直门达、吉迈和香达站的年径流量呈上升趋势,唐乃亥站的年径流量呈下降趋势,直门达站的年径流量通过显著性检验;直门达和吉迈站均在2004年发生显著性均值突变,其余站点突变不显著;三江源区年径流量均存在6~8 a和23 a左右的主周期,以23 a左右时间尺度上的信号最强,周期相位变化均存在3个偏多期和2个偏少期。研究结果可为我国中下游的水资源保护与管理提供参考依据。

Variation Characteristics of Runoff Time Series in the Source Region of Three Rivers

The runoff time series during 1956-2012 in the source region of Three Rivers (the Yangtze River,the Yellow River,and the Lancang River) are analyzed by using linear regression,moving average,Mann-Kendall test,accumulative anomaly,moving t test and Morlet wavelet analysis method.Results indicate that:1) during the past 57 years,the annual runoff at Zhimenda station,Jimai station and Xiangda station presented upward trend,among which the runoff trend at Zhimenda station was significant,whereas at Tangnaihai station the annual runoff presented a downward trend;2) abrupt change occurred in 2004 at Zhimenda station and Jimai station rather than the other stations;3) annual runoff in the source region of Three Rivers had main oscillation cycles in common of 6-8 years and 23 years,of which the interval of 23 years experienced the most significant fluctuation.There were three more-than-normal periods and two less-than-normal periods.The research results provide reference for the protection and management of water resources in the middle and lower reaches.