怀集县暴雨的时空分布特征

On the Spatiotemporal Distribution Characteristics of Heavy Rain in Huaiji County

采用1957—2022年怀集国家基本气象站逐日降水资料、2013—2022年25个区域气象观测站逐日降水资料,运用统计分析、Morlet小波等方法,分析怀集暴雨的时空分布特征。结果表明:近66年怀集县暴雨日数减少趋势不显著,暴雨强度增强趋势也不显著。暴雨主要出现在4—8月;总暴雨日数的月际变化呈单峰型分布,峰值出现在5月。暴雨日数存在准24、4、6和12年的周期震荡,其中准24年周期为第1主周期,目前处于暴雨日数偏少期;暴雨日数呈现“南北多、中部少、北部明显多于南部”的分布特点;暴雨强度呈现“北强南弱”的分布特点;北部地区的暴雨日数和暴雨强度都明显多(强)于其他地区。

The data of daily rainfall from a national basic meteorological station in Huaiji from 1957 to 2022 and daily precipitation from 25 regional meteorological observation stations from 2013 to 2022 were used to study the spatiotemporal distribution characteristics of heavy rain in the county,together with the methods of statistical analysis and Morlet wavelet.The result is shown as follows.For the 66 years studied,both the decreasing trend of the numbers of heavy rain days and the increasing trend of heavy rain intensity were insignificant.Heavy rains mainly occurred from April to August.Monthly variations of total numbers of heavy rain days were unimodal with the peak in May.The numbers of heavy rain days were periodic at quasi⁃24-,4-,6-,and 12-years,with the quasi⁃24 year period being the first primary period.At present,the number of heavy rain days is relatively small.The number of heavy rain days was more in both the south and north than in the middle part of the county,with the northern part much more than the southern.The heavy rain intensity was larger in the north than in the south.Heavy rain occurred much more and the inten⁃sity was much larger in the north than in any other parts of the county.