基于两种高时空分辨率的 1951- 2015 年日降雨序列数据, 选择 11 个极端降雨指数, 采用 Mann-Kendall( M- K) 检验法和极点对称模态分解法, 分析了广西极端降雨事件的多尺度非线性时空演变特征。结果表明: 1951 - 2015 年广西 11 个极端降雨指数除连续湿润日 CWD、中雨日数 R10总体呈现下降趋势外, 其余 9 个指数均呈现较显著的增强趋势; 广西连续干日指数 CDD 高值区位于桂东和桂西, 其余指数均呈现出从桂东北及南部向桂西南、桂西北递减的空间分布特征; 各极端降雨指数显示, 广西极端降雨演变多在 2008- 2010 年发生显著的突变; 广西极端降雨演变存在 2. 85~ 3. 34 a 和 5. 34~ 9. 19 a 的年际准周期, 存在 10. 09~ 17. 11 a 和 22. 35~ 35. 62 a 的年代际准周期, 其多重周期的波动振荡主要以极端降雨的年际变化贡献为主。

Based on two kinds of high spatial and temporal resolution daily rainfall time series data from 1951 to 2015, 11 extreme rainfall indices are selected to comprehensively characterize the multi-scale non-linear spatial and temporal evolution o f extreme rainfall events in Guangxiusing Mann-Kendall ( M2K ) test and pole symmetric mode decomposition. The results show that: except for continuo us wetday s ( CWD) and moderate rainy days ( R10 ) , the other 9 extreme rainfall indices showed a downward trend, and the rest of the other 9 indices showed a significant increasing trend from 1951 to 2015 in Guang xi, the high-value area of the CDD ( continuo us dry-day ) index in Guangxi is located in western and eastern Guangxi, while the other indexes show the decreasing spatial distribution characteristics from northeast and south to southwest and northwest Guang xi, various extreme rainfall indices show that the evolution o f extreme rainfall in Guang xi occurs mainly in the vicinity of 2008 to 2010, there are 2.85 - 3.34 a and 5.34 - 9.19 a interdecadal quasi-cycles in the evolution of extreme rainfall in Guang x i, and 10 .09 - 17.11 a and 22. 35 - 35.62 a interdecadal quasi-cycles, respectively, and the fluctuation of multiple cycles is mainly due to the contribution of the interannual variation of extreme rainfall.

国家自然科学基金( 51609041; 41901132) ; 广西教育厅科研项目( 2018KY0027) ; 广西大学“ 大学生创新创业训练计划”国家级项目( 201810593030)