气候变化背景下济南短历时暴雨强度及雨型特征

Intensity and rain pattern characteristics of short-duration rainstorm in Jinan under climate change

城市暴雨强度和暴雨雨型的确定是科学合理规划和设计城市排水系统的基础。根据济南国家基本气象站1961—2017年分钟降水数据,采用概率分布模型、芝加哥法及同频率法,研究济南1961—1990年、1971—2000年、1981—2010年、1991—2017年等4个不同年代下短历时暴雨强度和雨型变化特征。结果表明:济南短历时强降水自20世纪80年代开始增强,特别是20世纪90年代以来增大的趋势较明显;短历时和长历时强降水都主要集中在降水过程的前半程且有推后的趋势时段。建议每隔10年或当暴雨强度变化率超过5%时,对当地暴雨强度公式进行修订。

The determination of urban rainstorm intensity and rainstorm pattern serves as the basis for scientific planning and rational design of urban drainage systems.Based on the detailed precipitation data from Jinan National Basic Weather Station for 1961—2017,this paper studied the characteristics of short-duration rainstorm intensity and rain pattern change in four different periods using probability distribution model,Chicago method,and co-frequency method:1961—1990,1971—2000,1981—2010,and 1991—2017.The results showed that Jinan's short-duration rainstorm had been increasing intensity since the 1980s,and this is especially obvious since the 1990s.The short-duration and long-duration strong precipitation were all mainly concentrated in the first half of the precipitation process and had a tendency to postpone.This paper suggests that the local rainstorm intensity formula should be revised every 10 years or when the change rate of the rainstorm intensity exceeds 5%.