近60年山西省极端降水时空变化特征

Tempo-spatial Variation Characteristics of Extreme Precipitation in Shanxi Province in Recent 60 Years

气候变化背景下,极端降水事件发生频率与强度的增加直接影响区域生态安全,分析极端降水时空变化特征对于区域风险评估具有重要意义。基于山西省1960—2019年22个气象站点的逐日降水数据,选取12个极端降水指数,采用线性趋势分析、Mann-Kendall趋势检验与突变分析、Morlet小波分析和反距离权重插值等方法,对山西省近60年极端降水的时空变化特征进行研究。结果表明:(1)山西省整体呈干旱化趋势,降雨日数(R1MM)下降趋势显著;(2)部分极端降水指数在20世纪70年代前后发生突变,突变后呈显著下降趋势;(3)极端降水变化存在约17年的主要周期,部分极端降水指数还存在7~8,4~5年的周期变化;(4)山西省西南部整体呈干旱化趋势,西北部极端降水事件趋于增加。研究结果将为山西省极端降水事件的响应对策实施提供依据。

Under the background of climate change,the increase of the frequency and intensity of extreme precipitation events directly affects regional ecological security.Analyzing the tempo-spatial variation characteristics of extreme precipitation is of great significance for regional risk assessment.Based on the daily precipitation data of 22 meteorological stations in Shanxi Province from 1960 to 2019,12 extreme precipitation indices were selected,the tempo-spatial variation characteristics of extreme precipitation in Shanxi Province during past 60 years were studied by using the methods of linear trend analysis,Mann-Kendall trend test,mutation analysis,Morlet wavelet analysis and Inverse Distance Weighted(IDW)interpolation.The results showed that:(1)A trend of drought was detected in Shanxi Province,and the number of rainfall days(R1MM)exhibited a significant downward trend.(2)Some extreme precipitation indices experienced a mutation around the 1970s,meanwhile,a significantly downward trend was detected after the mutation.(3)The variation of extreme precipitation had the main cycle of about 17 years,some indices had periodic changes around 7~8 years or 4~5 years.(4)The southwestern part of Shanxi Province showed a trend of drought,while the extreme precipitation events in northwestern part showed an increasing trend.The results of this study provided references for the implementation of countermeasures in response to extreme precipitation events in Shanxi Province.