利用史料和文献建立了太湖流域公元960～1992年的逐年干湿等级序列,对此序列进行了周期分析和突变分析。分析表明,本区近千年来的历史干湿气候变化是一种复合振动,其主周期是准100年,另外还有多个周期,这些周期与天体活动密切相关。统计还发现1247～1263年附近由干变湿和1618～1635年附近由湿变干的两次非局地性气候突变事件。其中,14、15世纪是太湖流域近千年来最湿润的时期,它可能是东亚地区大范围气候变湿波动的体现。

The present study collected historic climatic records since 960 A.D. from the Taihu drainage basin. A dry/wet series, i.e. a five-grade index of severe flood (1), flood (2), normal (3), drought (4), and severe drought (5) from 960 A.D. to 1992 A.D. was reconstructed and χ²-test was used to examine the evenly distribution of the series. Power spectrum analysis was made for the present 1033-year dry/wet grade series with different lagging of 280, 200, and 150. Process of "Red Noise" was applied to make the significance test (α=0.05). Moving t-test was applied to detect the abrupt climate changes of the study area. The 11-year and 30-year moving average curves and their 6-degree polynomial regression curves are also presented to help the detection of climate jump. Spectral analysis reveals that the change of drought-wet climate in the study area was a superposed phenomenon with the major period of ～100-year, and other notable periods of 36-year, 26-27-year, 11-year, 22-year, 15-year, 19-year, 2-3-year, 8-year, and 5-6-year. Compared with those of celestial activity and climate change collected by previous work, these periods are supposed to be closely related to the celestial activities that control the planetary wind system and East Asia monsoon circulation. The moving t test detected two large-scale abrupt changes, i.e., 1247-1263 A.D. and 1618-1635 A.D. The climate between these two abrupt changes was relative humid. Before 1247 A.D. and after 1635 A.D. it was relative dry. The 14th to 15th centuries was the wettest episode during the last 1000 years in the study area. This getting-humid event occurred widely in East Asia.