韶关汛期不同持续时间的降水特征分析

Analysis of Precipitation Characteristics of Different Duration in the Rainy Season of Shaoguan

基于2008—2021年韶关8个国家站的逐时降水数据,分析了韶关汛期不同持续时间降水的特征,结果表明:韶关汛期降水的平均持续时间为3.9 h,持续2~6 h降水事件的累计降水量较大,随着持续时间的增长,累计降水量逐渐减少,降水频次迅速减小,持续时间大于10 h降水事件的降水强度较大。短时降水事件主要始发于午后到傍晚,降水量峰值出现在14:00—20:00;持续性降水事件主要始发于夜间到清晨,降水量的峰值出现在清晨;不同持续时间的降水事件均较少始发于08:00—12:00,且该时段降水量较少。短时降水午后到傍晚的降水量峰值是降水频次和降水强度共同作用下形成,清晨的次峰值主要取决于降水频次;持续性降水的降水频次在各个时次相差不大,其降水量日变化主要来自于降水强度的贡献。前汛期(4—6月)持续性降水和短时降水各占一定的比例,持续性降水略多;后汛期(7—9月)以短时降水为主。

Based on the hourly precipitation data from eight national stations in Shaoguan in 2008-2021,this paper analyzed the characteristics of precipitation in the city for different duration of the rainy season.The results are shown as follows.The average duration of precipitation was 3.9 h and precipitation events persisting for 2-6 h had larger cumulative amount.With the growth of the duration,cumulative precipitation decreased gradually while precipitation frequency decreased rapidly.Precipitation events lasting for more than 10 h had larger precipitation intensity.Short-term precipitation events mainly started from afternoon to evening,and peak precipitation occurred from 14:00 to 20:00.Persistent precipitation events mainly started from night to early morning and peak precipitation occurred in early morning.It is less likely for precipitation events,regardless of the duration,to start from 08:00 to 12:00,and the precipitation in this period had smaller amount.For short-term precipitation from afternoon to evening,the peak was formed by the joint action of precipitation frequency and intensity,and the secondary peak in the morning mainly depended on the precipitation frequency.The frequency of persistent precipitation did not differ much at each time,and the daily change of precipitation mainly came from the contribution of precipitation intensity.Persistent precipitation and short-term precipitation for the annually first rainy season(April-June)accounted for a certain proportion,with persistent precipitation being slightly more.The annually second rainy season(July-September)was mainly of short-term precipitation.