李斐斐, 姚素香. 基于EOF分析的江苏省沿江7市梅雨量变化特征[J]. 云南大学学报(自然科学版), 2015, 37(2): 250-258. doi: 10.7540/j.ynu.20140510
引用本文: 李斐斐, 姚素香. 基于EOF分析的江苏省沿江7市梅雨量变化特征[J]. 云南大学学报(自然科学版), 2015, 37(2): 250-258. doi: 10.7540/j.ynu.20140510
LI Fei-fei, YAO Su-xiang. Variation characteristics analysis of the Meiyu rainfall in seven Jiangsu riverside cities based on EOF analysis[J]. Journal of Yunnan University: Natural Sciences Edition, 2015, 37(2): 250-258. DOI: 10.7540/j.ynu.20140510
Citation: LI Fei-fei, YAO Su-xiang. Variation characteristics analysis of the Meiyu rainfall in seven Jiangsu riverside cities based on EOF analysis[J]. Journal of Yunnan University: Natural Sciences Edition, 2015, 37(2): 250-258. DOI: 10.7540/j.ynu.20140510

基于EOF分析的江苏省沿江7市梅雨量变化特征

Variation characteristics analysis of the Meiyu rainfall in seven Jiangsu riverside cities based on EOF analysis

  • 摘要: 使用江苏省沿江7市(南京、苏州、无锡、常州、镇江、扬州、南通)梅雨期具有典型代表性的梅雨量序列,1954—2013年共60 a资料,通过EOF分解法计算出特征向量分布、时间系数序列,并根据特征向量方差贡献,确定出梅雨季东旱西涝或东涝西旱的基本空间分布型,同时结合分解出的时间系数,分析出江苏省沿江地区梅雨季降水量的长期趋势及年代际变化具有明显的区域特征.20世纪80年代末以前地区梅雨季降水量表现为东涝西旱,而20世纪90年代以后则表现为东旱西涝.进入20世纪80年代以来,南京、无锡、常州、镇江的梅雨季节降水量异常明显,其余各地区整体上变化不明显.同时,辅助以Morlet小波分析方法,通过小波能量密度研究了第1主分量时间系数的年际及年代际振荡随时间的演变及其方差贡献率.结果表明,江苏省沿江地区的梅雨量存在一个显著3~4 a的年际振荡周期和13~14 a的年代际振荡周期,1975到1980年,3~4 a振荡对年际振荡贡献较大,而13~14 a尺度振荡对年代际振荡的方差贡献则主要集中在20世纪70年代以后.

     

    Abstract: Based on the most representative rainfall data during the plum rainy season from 1954 to 2013 in seven Jiangsu riverside cities (Nanjing,Suzhou,Wuxi,Changzhou,Zhenjiang,Yangzhou,Nantong),weve calculated the distribution of feature factors and time sequence using EOF decomposition model.Weve also got the plum rainy seasons main spatial distribution patterns based on the variance contribution of the feature factors.In addition,in the light of the time factor,weve found the distinct regional characteristics with the long-term trend of the precipitation during the plum rainy season and decade change.Weve noticed that during the plum rainy season,before the late 1980 s,the east was water-logging while the west was drought,but after 1990 s,the situation is reverse.Since 1980 s,the rainfall during the plum rainy season in Nanjing,Wuxi,Changzhong and Zhenjiang has a significant change,but there is no obvious change in other areas.In addition,the time-dependent evolution and variance contribution of Meiyu intensity series have been investigated using wavelet energy density technique.The results show that there are significant decade oscillation periods,which last 3—4 years and 13—14 years.The oscillation of the period from the year 1975 to 1980 contributed more to the decade oscillation,and the contribution to the variance of the period of 13—14 years exerted influence on the years after 1970 s.

     

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