摘要
为从更精细的角度分析长江上游主汛期典型涝年的降雨特征及气候成因,将长江上游分为5个关键区,利用长江上游1961~2021年282个雨量站逐日降雨资料,通过Morlet小波分析等方法分析长江上游及5个关键区主汛期降雨特征并找出长江上游典型涝年进行分类,最后对不同型降雨典型涝年的水汽输送及气候成因进行了探讨。研究表明:(1)长江上游与金沙江、长江上游干流降雨量的年际波动总体较为一致,异常涝年的出现时间也较为一致,嘉陵江、岷沱江流域年际波动的阶段性突变较为明显,乌江流域的年际波动则较为平稳;长江上游及5个关键区降雨量周期变化较为一致,均存在3 a左右的振荡周期。(2)长江上游典型涝年5个关键区降雨可分为3类,分别为关键区一致多型、关键区四多一少型及关键区三多两少型。(3)长江上游主汛期不同型降雨的水汽输送来源存在一定差异,关键区一致多型及关键区四多一少型水汽输送主要来自西太平洋及孟加拉湾,而关键区三多两少型水汽输送主要来自西太平洋及南海。(4)青藏高原积雪偏多有利于长江上游降水量偏多;关键区一致多型一般发生于暖海温向冷海温转折变化的年份,而关键区四多一少型及关键区三多两少型一般发生在冬季海温偏冷的年份。
To analyze the rainfall characteristics and climatic causes of typical flood years during the main flood season in the upper reaches of the Changjiang River from a more detailed perspective,this study divided the upper reaches of the Changjiang River into five key areas.Then using the daily rainfall data from 282 rainfall stations in the upper reaches of the Changjiang River from 1961 to 2021,we analyzed the rainfall characteristics of the main flood season in the upper reaches of the Changjiang River and the five key areas by Morlet wavelet analysis,and classified the typical flooding years.Finally we explored the water vapor transport and the climatic causes of the typical flooding years with different types of rainfall.The results showed that:①The interannual fluctuations of rainfall in the upper reaches of the Changjiang River,Jinsha River and the upper main stream of the Changjiang River were consistent on the whole,and the occurrence time of abnormal wet years was consistent.The rainfall cycles in the upper reaches of the Changjiang River and the five key regions were consistent,with a three-year oscillation cycle.②The rainfall in the five key areas of the upper reaches of the Changjiang River in typical wet years could be divided into three categories:uniform polytype in the key area,four-over-one-under type in the key area,and three-over-two-under type in the key area.③There were differences in the water vapor transport sources of different rainfall types in the upper reaches of the Changjiang River during the main flood season.The water vapor transport of uniform polytype and four-over-one-under type in the key area were mainly from the Western Pacific and the Bay of Bengal,while the water vapor transport of three-over-two-under type in the key area was mainly from the Western Pacific and the South China Sea.④More snow cover on the Qinghai-Tibet Plateau is conducive to more precipitation in the upper reaches of the Changjiang River.The uniform polytype in the key area generally occurred in the years when the warm sea temperature changed to the cold sea temperature.The four-over-one-under type and three-over-two-under type in the key area generally occurred in the years when the winter sea temperature was cold.
作者
邢雯慧
王飞龙
邱辉
时玉龙
XING Wenhui;WANG Feilong;QIU Hui;SHI Yulong(Bureau of Hydrology,Changjiang Water Resources Commission,Wuhan 430010,China;China Three Gorges Corporation,Yichang 443100,China)
出处
《人民长江》
北大核心
2024年第1期91-96,共6页
Yangtze River
基金
国家重点研发计划项目(2022YFC3002701)
中国长江三峡集团有限公司科研项目(0799245)。
关键词
降雨特征
气候成因
典型涝年
水汽输送
长江上游
rainfall characteristics
climatic causes
typical flooding years
water vapor transport
upper reaches of Changjiang River
