中文摘要：

基于中国东部55站点1600~2012年旱涝等级序列及集合经验模分解（EEMD）等方法,分析了中国东部旱涝年代际到百年尺度的变率分布特征及其与太平洋年代际振荡（PDO）指数的关系.结果表明：400多年来该区域最主要的旱涝分布型是一致型,即同期大多数站点同旱或同涝,变率中心位于黄河中下游;其次为南北反相型,该型近百年来有加强趋势,最典型案例即20世纪70年代后期至21世纪初频繁出现的南涝北旱异常分布,400多年来历史上类似事件很少见.在多年代际尺度上,基于多种代用PDO指数序列的集合平均PDO序列与华北一带旱涝变率有显著的正相关关系,即PDO暖位相对应华北偏旱,而PDO冷位相对应偏涝.结果拓展了多年来主要基于近代气象记录获得的PDO影响中国旱涝气候变化的认识,更完善地诠释了我国夏季风区旱涝气候多年代际演变规律.

英文摘要：

We analyzed dryness/wetness indices at 55 sites across eastern China （east of 105°E） for the period AD 1600-2012 using the Ensemble Empirical Mode Decomposition （EEMD） method to investigate decadal-to-centennial timescale variations of dry/wet patterns in this region and their relationship with the Pacific Decadal Oscillation （PDO）. Empirical Orthogonal Function （EOF） analysis shows that the most important regional dry/wet pattern is a monopole （consistently dry or wet throughout eastern China）, with a center of variability in northern China. The southern-flood-northern-drought （SFND） pattern represents a secondary type of variability for the historical period; however, this tended to intensify and has become the dominant pattern over the 20th century. Multidecadal SFND events, such as that prevailing from the late 1970s to the early 21st century, have rarely occurred during the last 413 years. Multi-decadal dry/wet variations in northern China exhibit positive correlation with an ensemble mean PDO index of various reconstructed indices throughout this historical period.