近40年华南前汛期极端降水时空演变特征

Temporal and Spatial Variations of Extreme Precipitation in the Pre-flood Period of South China in Recent 40 Years

利用国家气象信息中心提供的华南89个代表站1969～2008年逐日降水资料,研究了近40年我国华南前汛期(4～6月)极端降水时空演变特征,主要结论是:(1)华南前汛期降水强度、强降水量和暴雨日数的空间分布与总降水量的空间分布基本一致;(2)极端降水指数随时间的变化对华南整个区域前汛期总降水量的变化有很好的指示意义,特别是强降水量、强降水频率和暴雨日数;90年代以来华南前汛期总降水量的显著增加与强降水量、强降水频率以及暴雨日数显著增加密切相关,且极端强降水量异常程度明显增强。

Daily precipitation data of the 89 representative stations from 1969 to 2008,provided by the National Meteorological Information Center,are used to investigate the spatial and temporal variable characteristics of extreme precipitation for the pre-flood season （April-June） in South China,the main conclusions are： （1） The spatial distribution of the precipitation intensity,heavy precipitation amount,and rainstorm days are basically in agreement with the distribution of the total precipitation in South China during the pre-flood season; （2） the temporal variation of extreme precipitation indices are of good indicating significance to the area-averaged total precipitation,a significant increase in area-averaged total precipitation is closely related to that of heavy precipitation amount,its frequency and rainstorm days since the 1990s for the pre-flood season in South China; the anomalies of extremely heavy precipitation are significantly enhanced since the 1990s.