On the Spatiotemporal Distribution Characteristics of Heavy Rain in Huaiji County
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.
climatologynumber of heavy rain daysheavy rain intensityspatiotemporal distributionHuaiji county