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    辽宁地区夏季不同历时极端降水时空变化特征

    Spatial and temporal characteristics of summer precipitation extremes in Liaoning province

    • 摘要: 利用1981-2015年辽宁省54个气象站降水观测资料,采用气候趋势系数、Morlet小波分析和Mann-Kendall突变分析等气候统计方法,分析了辽宁省夏季不同历时极端降水的时空变化特征。结果表明:1981-2015年夏季辽宁省西南部沿海、渤海北部沿海、黄海北部沿岸地区及大连市区为极端降水阈值大值区,辽宁省西部地区和东部山区极端降水阈值较小,极端降水强度的空间分布特征与极端降水的阈值相似。辽宁省夏季不同历时极端降水发生频次的分布特征基本相同,时间长期变化趋势不明显,主要表现为年际变化,存在3 a、5 a和8 a的变化周期,东部山区极端降水发生频次较多,环渤海沿岸和朝阳地区极端降水发生频次较少。近35 a夏季辽宁省24 h、12 h、6 h、3 h和1 h降水量极值的空间分布极不均匀,最大值与最小值分别差1.2、1.6、1.6、2.4倍和1.8倍。极端湿期长度最大值出现在新宾地区,为11.3 d;极端干期长度最大值出现在大石桥地区,为24.3 d。

       

      Abstract: Based on the precipitation data from 54 meteorological stations in Liaoning province from 1981 to 2015,the spatial and temporal characteristics of summer precipitation extremes were analyzed using climatic trend coefficient,Morlet wavelet analysis and Mann-Kendall sudden change analysis and other climatic statistical methods.The results show that the larger values of the threshold of summer precipitation extremes occur in the coastal areas in the southwestern part of Liaoning province,the northern parts of the Bohai Sea and the Yellow Sea and in Dalian urban district.The smaller values occur in the western and eastern mountain areas of Liaoning province.The spatial distribution characteristics of extreme precipitation intensity are similar to those of the precipitation threshold.Basically,the distribution characteristics of extreme precipitation frequencies for different precipitation durations are same.There is not a clear trend in the long-term change of it.It mainly shows an inter-annual variation,with 3,5 and 8 years' change periods.The frequency of extreme precipitation is higher in the eastern mountain areas and lower in the coastal area of the Bohai and Chaoyang city.The spatial distribution of precipitation amount extremes within 24 h,12 h,6 h,3 h and 1 h in summer is particularly uneven,and the corresponding ratios of the maximum to minimum of extreme values are 1.2,1.6,1.6,2.4 and 1.8,respectively.The maximum length of extreme wet period occurs in Xinbin area and lasts about 11.3 days,and that of extreme dry period occurs in the Dashiqiao area and is persistent 24.3 days.

       

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