首先利用Morlet小波对汉江流域降水进行多时间尺度分析,然后分析主要周期下汉江流域降水与74个环流因子的相关性。结果表明:近50年,汉江流域降水有4,7和18年的主要周期,其中以18年的主要周期最为突出,降水呈现偏少的趋势,同时降水量与西太平洋副高面积指数、冷空气、东太平洋副高北界、北半球极涡中心位置等14个环流因子具有非常强的正相关,而与东亚槽位置、太平洋区极涡强度指数、亚洲区极涡强度指数有非常强的负相关。研究成果将为今后提高汉江流域降水预报水平和有效开展汉江流域及长江中下游防汛抗旱工作提供科学依据。
First, this paper uses Morlet wavelet to the multiple time scales analysis of the Hanjiang River Basin precipitation and then to the correlation analysis of the Hanjiang River Basin precipitation and 74 circulation factors. The results show that: the precipitation has the main cycle with 4-year, 7-year and 18-year in the HanjiangRiver Basin for nearly 50 years, in which the 18-year time scale is most prominent and the precipitation decreases ; the Hanjiang River Basin precipitation respectively has a closely positive correlation with 14 circulation factors such as the western Pacific subtropical high area index, the cold air, the northern boundary of the eastern Pacific subtropical high and the northern pdar vortex center position. The Hanjiang River Basin precipitation respectively has a closely negative correlation with East Asia slot position, the Pacific polar vortex index and Asia polar vortex intensity index. This study provides scientific basis for improving the level of the Hanjiang River Basin precipitation forecast and effective development of downstream flood control and drought relief work in the Hanjiang River Basin and the Yangtze River.