Analysis of the spatiotemporal characteristics of nighttime precipitation and heavy rainfall frequency in Guangxi over the past 60 years
Using daily precipitation data from 91 stations in Guangxi from 1962 to 2022 at 08:00-20:00 and 20:00-08:00,trend analysis and Mann-Kendall were used to analyze the spatiotemporal distribution characteristics of nighttime precipitation and nighttime rainstorm frequency in Guangxi over the past 60 years from the perspectives of precipitation amount and frequency.The results show that:(1)The daily variation of precipitation in Guangxi is significant,with significant spatial differences in nighttime rainfall rates,which is mainly manifested as decreasing from northwest to southeast,with mountainous areas significantly higher than plains.(2)Over nearly 60 years,the annual average number of nightime rainfallstorm days at each station in Guangxi in the past 60 years ranges from 3.7 d to 13.6 d.Northwestern Guangxi experienced stronger nighttime precipitation generally,with the maximum nighttime precipitation in most areas of Guangxi ranging from 200～250 mm.(3)Statistics show significant increases in rainfallstorm days and the amount of nighttime rainfal in the past 60 years.The probability of occurrence of extreme rainstorms is growing,with April-September being the peak season of nighttime rainstorms in Guangxi,and the most nighttime rainstorms occurring in June.(4)Among Guangxi's 14 prefecture-level cities,Hechi has the highest rate of nocturnal rainfall,and Fangchenggang has the highest amount of nocturnal rainfall and the highest contribution to rainstorms.The intensity of nighttime precipitation in Guangxi is high,and the phenomenon of nighttime rainstorm increases significantly,especially in mountainous areas where the risk of nighttime rainstorms is extremely high.Meteorological departments at all levels need to further improve the monitoring,warning of nighttime rainstorms in mountainous areas as well as their service capabilities.
万方数据
维普
