辽阳地区1951-2015年夏季旱涝急转特征分析

Analysis on Characteristics of Rapid Conversion of Drought and Flood in Liaoyang Area from 1951 to 2015

根据1951-2015年辽阳地区逐日降水数据,结合LDFAI和SDFAI指数、线性回归方程、M-K突变检验等数学方法,对辽阳地区汛期(6-9月)降水特征及其旱涝急转变化规律进行分析。结果表明:辽阳地区降水集中在汛期,占比72.3%,有-2.0mm/a下降趋势,通过了置信度99%的M-K检验;辽阳地区长周期旱涝急转频繁,频率为2.71a/次,趋势变化不明显;短周期旱涝急转指数曲线中8月-9月变化最为频繁和剧烈,6月-7月次之;长、短周期旱涝急转指数没有明显的相关关系。总体来看,辽阳地区旱涝急转现象由旱转涝趋向于涝转旱为主导,强度呈现微弱的减弱趋势。

In this paper,the author,According to daily precipitation data of Liaoyang Area from 1951 to 2015,analyzed the characteristics of precipitation in flood season(June to September)in Liaoyang Area and the law of rapid conversion of drought and flood,through by some mathematical methods,such as LDFAI and SDFAI factors,linear regression equation and M-K mutation test.The results show that the precipitation in Liaoyang Area are concentrated in flood period,accounting for 72.3%,with a downward trend of-2.0 mm/a,and the results being passed the m-k test with 99%confidence.Besides,in Liaoyang Area,the frequency of long-term rapid conversion of drought and flood is 2.71 a/time,and the trend change is not obvious.In addition,in the short-period ones index curve,the conversion is the most frequent and severe from August to September,followed by the data from June to July.Moreover,there is no significant correlation between the index of rapid conversion of drought and flood in short and long period.In general,the phenomenon of rapid conversion of drought and flood in Liaoyang Area is dominated by the trend of the conversion from drought to flood to flood to drought,and the intensity shows a weak weakening trend.