1960—2018年佛冈县前汛期极端降水的变化特征

利用1960—2018年佛冈县国家观测站4—6月的逐日降水量资料,对前汛期极端降水进行年际和年代际变化分析,结果表明:近59年佛冈县前汛期极端降水量、强度和日数均呈弱的下降趋势。近59年佛冈县前汛期共出现30次连续性极端降水,最长持续时间为3d。前汛期极端降水强度和日数分别在1988和1969年发生减少突变,极端降水量未发生突变。前汛期极端降水量、强度和日数均存在5~8年的年际周期振荡,年代际周期变化则存在差异。

On the Variation Characteristics of Extreme Rains During April-June Raining Season in Fogang County From 1960 to 2018

Using the data of daily rain amount from a national observation station in Fogang during the April-June raining season from 1960 to 2018,this paper studies the interannual and interdecadal variations of extreme rain during the raining season.The result is shown as follows.For the April-June raining season in the 59 years studied,the rain amount,intensity and number of rain days of the extreme rain all show a slightly declining trend.There are all together 30 persistently extreme rains during the period of interest,with the longest one lasting for 3 d.Their intensity and the number of rain days had abrupt decreases in 1988 and 1969,respectively while the rain amount did not.All of the three oscillate at an interannual period of 5 to 8 years though their interdecadal periodic variations differ.