长江源区径流变化及其影响因素探讨

Change and Influencing Factors of Runoff in Source Region ofYangtze River

长江源区对气候变化的响应较为敏感,其河川径流也随之产生了明显的变化。根据长江源区直门达水文站及长江源区5个气象站1960—2022年实测水文气象资料,分析长江源区年径流和季节性径流变化规律。利用相关分析、交叉小波变换及主成分分析法,分析径流变化与主要气象要素之间的关联性。研究结果表明,近63 a来直门达站年径流呈现显著上升的趋势,尤其是近20 a径流大幅度增加。1960—2000年期间,长江源区各季节性径流变化趋势较为平稳。2000—2022年期间,各季节性径流均呈现出增加的态势并延续至今。对直门达站径流影响最为密切的气象要素主要为降水、气温、相对湿度等。

The source region of Yangtze River is highly sensitive to climate change,leading to significant alterations in river runoff.According to hydro-meteorological data from Zhimenda hydrological station and five meteorological stations in the source region of Yangtze River spanning 1960 to 2022,we investigated the changes in annual and seasonal runoff in the source region of Yangtze River.Utilizing correlation analysis,cross-wavelet transform,and principal component analysis,we further examined the relationship between runoff fluctuations and key meteorological factors.Findings indicated a notable upward trend in annual runoff at Zhimenda station throughout 1960 to 2022,with a particularly substantial increase of runoff in the past two decades.The seasonal runoff trend in the source region remained relatively stable from 1960 to 2000,but exhibited an increasing trend from 2000 to 2022,persisting to the present day.Precipitation,temperature,and relative humidity emerged as the primary meteorological factors exerting the most significant influences on the runoff at Zhimenda station.