四川省年夜雨时间演变特征

Time Variation Characteristics of Annual Nighttime Rainfall in Sichuan Province

摘要: 利用1961~2021年共61年四川省126个地面气象站逐日降水观测数据，采用集合经验模态分解(Ensemble Empirical Mode Decomposition，以下简称EEMD分解)及小波分析(wavelet analysis)等方法对四川省年夜雨的时间演变特征进行了详细研究。结果表明：(1) 四川省年夜雨的小波分析四川省五个区域年夜雨具有多尺度的周期变化特征，并集中在2~7年和14~16年的显著周期，在20年的大周期上差异较大。(2) 四川省年夜雨EEMD分解显示，成都平原具有3.5、9.3、26.0、48.7的变化周期；川南山地具有3.4、9.1、29.5、48.7的变化周期；川东南丘陵具有3.7、9.8、22.5、52.3的变化周期；川西高原具有7.4、12.8、19.5、57.4的变化周期；川东北丘陵具有4.4、12.2、23.4、55.4的变化周期。

Abstract: Using daily precipitation observation data from 126 ground meteorological stations in Sichuan Province from 1961 to 2021 (a total of 61 years), this study conducted a detailed investigation into the spatiotemporal variation characteristics of nighttime rain in Sichuan Province by employing methods such as Ensemble Empirical Mode Decomposition (EEMD), and wavelet analysis. The results indicate: (1) The wavelet analysis of Sichuan’s New Year’s Eve rainfall reveals that the five regions exhibit multi-scale periodic variation characteristics, concentrated in significant cycles of 2~7 years and 14~16 years, while showing greater divergence in the 20-year long-term cycle. (2) The EEMD decomposition of Sichuan’s New Year’s Eve rainfall indicates that the Chengdu Plain has variation cycles of 3.5, 9.3, 26.0, and 48.7 years; the Southern Sichuan Mountains exhibit cycles of 3.4, 9.1, 29.5, and 48.7 years; the Southeastern Sichuan Hills show cycles of 3.7, 9.8, 22.5, and 52.3 years; the Western Sichuan Plateau has cycles of 7.4, 12.8, 19.5, and 57.4 years; and the Northeastern Sichuan Hills display cycles of 4.4, 12.2, 23.4, and 55.4 years.