青岛市降雨侵蚀力与ENSO的相关研究

The Related Research Between Qingdao Rainfall Erosivity and ENSO

基于青岛气象台站1961-2010年50年逐月降水资料,计算青岛市降雨侵蚀力。利用Mann-Kendall非参数检验法和累积距平等方法,对青岛市年降雨侵蚀力的变化趋势进行分析。运用连续小波变换(CWT)、交叉小波变化(XWT)和小波相干谱(WTC)分析降雨侵蚀力与ENSO相关指数的周期及其之间的相关关系。结果表明:青岛市年降雨侵蚀力呈下降趋势,变化倾向率为5. 3 MJ·mm/(hm^2·h·a^2),特别是20世纪80年代以来,降雨侵蚀力下降较为显著;分月看,降雨侵蚀力8月最大,为1190. 1 MJ·mm/(hm^2·h·a),12月最小,仅13. 1 MJ·mm/(hm^2·h·a),月际差异明显。累积距平得出,年降雨侵蚀力与ENSO相关指数的突变点位置基本一致,但变化趋势存在差异。青岛市年降雨侵蚀力存在4~5 a的变化周期,与ENSO相关指数呈现出相似的震荡特征;侵蚀力与ENSO相关指数存在显著相关性,在高能量区,降雨侵蚀力和SOI、SST距平值和MEI共振周期是一致的,但分布的时间段不同,且位相变化相反;在低能量区,降雨侵蚀力与SOI有0~0. 5 a呈同位相的共振周期,与SST距平值有4. 5~5 a和5~5. 5a呈负位相的共振周期,与MEI存在0~1 a的共振周期。

Based on the monthly precipitation data of Qingdao meteorological stations from 1961-2010,calculate the Qingdao rainfall erosivity.Using the Mann-Kendall nonparametric test and cumulative departure method,the change trend of annual rainfall erosivity of Qingdao is analyzed.Using continuous wavelet transform(CWT),cross wavelet change(XWT)and wavelet coherence spectrum(the WTC),comprehensive study the cycle of rainfall erosivity and ENSO and the relationship between them.The results indicated that the annual rainfall erosivity decreased by 5.3 MJ·mm/(hm^2·h·a^2)per year,especially since the 1980 s,the rainfall erosivity has decreased significantly.The monthly view,rainfall erosivity is biggest in August,minimum in December,month difference is obvious.Cumulative anomaly obtained,rainfall erosivity associated with ENSO index in mutation point location,but changing trend is different.Qingdao rainfall erosivity had 4-5 year oscillation circles,which was similar to the pattern of the ENSO.Rainfall erosivity associated with ENSO index exists significant correlation,the high energy area,rainfall erosivity,SOI,SST and MEI resonance cycle is consistent,but distribution not at the same time,and different phase change.In the low energy area,rainfall erosivity and SOI had 0-0.5 year positive phase of resonant cycle,4.5-5 year and 5-5.5 year negative phase of the resonance cycle with the SST,and 0-1 year resonance cycle with the MEI index.