根据郑州 1955- 2015 年逐月降水数据, 结合长、短周期旱涝急转指数、线性倾向估计及 M ann2Kendall 突变检 验等数学模型, 对郑州年降水特征以及 6 月- 9 月份旱涝急转演变规律进行研究。结果表明: 郑州的年降水量总体 以- 71 87 mm/ ( 10a) 的速率下降; 郑州地区的长周期旱涝急转指数( LDFAI) 趋势变化不明显, 但 LDFAI 强度呈阶 段性变化特征, 存在 2 个偏强期和 2 个偏弱期, 其中 LDFAI 强度大于 1 占 371 7% , 旱涝急转比较频繁; 各相邻月之 间的短周期旱涝急转指数 SDFAI 曲线振荡最频繁的是 6 月- 7 月, 7 月- 8 月次之, 8 月- 9 月指数变化平缓。总体 来说, LDFAI 的涝转旱的强度比旱转涝强, 长、短周期旱涝急转现象均呈现减弱趋势。

Based on the mo nt hly precipit at ion dat a of Zheng zhou meteor olog ical statio n fr om 1955 to 2015, using lo ng2and sho rt2 cy cle droug ht2f loo d abrupt alter nat ion index, Linear Tendency Estimation, Mann2Kendall test and other mathematical models, we analy zed the annual precipitation and the evolut ion of dr ought2floo d during June to September in Zheng zho u. T he r esults wer e as follow s: T he annual precipitation significantly decreased at a rate of - 71 87 mm/ ( 10a) . T he chang e t rend of the LDFAI in Zheng zhou w as not o bv io us, but the intensit y of LDFAI ex hibited periodic changes, including t wo str ong and tw o w eak peri2 o ds. The intensity of LDFAI g reater than 1 accounted for 371 7% in the r ecent 61 years, w hich meant droug ht2f loo d abrupt alter2 natio n o ccurred f requent ly. The sho rt2cy cle dro ug ht2flo od abrupt alt ernation index bet ween adjacent months had t he most f re2 quent fluctuation from June t o July , the second most from July to Aug ust , and it lev eled off from August to September. In g ener2 al, the intensity of lo ng2cycle flo od2 to2droug ht tr ansit ion w as g ener ally st rong er t han t hat of dr ought2to2flo od tr ansit ion. Bo th long2and sho rt2cy cle dr ought2floo d abrupt alter nat ion phenomena showed a trend o f decline

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