湖南短时强降水事件气候特征

Climatic Characteristics of Short-duration Rainstorm Events in Hunan Province

基于湖南省97个地面气象观测站1981-2010年自记降水资料,运用数理统计方法,开展湖南短时强降水事件气候特征分析,结果表明:①湖南省1 h、3 h、12 h强降水事件出现频率夏季高于春季、春季高于秋季,夏季白天短时强降水事件出现频率高于夜间、春季夜间高于白天、秋季白天夜间差异不明显;②湖南省1 h、3 h、12 h强降水事件频率变化趋势以不显著增加为主,其中12 h强降水事件增多趋势较1 h、3 h显著,湘西北地区夜间增幅最大,湘东南地区白天增幅最大;春季强降水事件增幅最明显的地区是湘西北地区,夏季强降水事件频率增幅最明显的是湘东南地区;③1 h、3 h、12 h强降水事件开始时间出现在不同时间段的频率变化呈现为双峰型,1 h、3 h强降水事件以05-08时出现频率最高,12 h以11-14时出现频率最大。

Based on the 1981-2010 self-recording precipitation data at 97 stations of Hunan province,the Climatic characteristics of short-duration rainstorm events in Hunan Province are analyzed by mathematical statistics method.The results show that： ① The frequency of short-duration（1 hour,3 hours and 12 hours） rainstorm events in summer is higher than those in spring,and in spring higher than in autumn in Hunan Province.The frequency of daytime is higher than nighttime in summer,and exact opposite in spring and little different in autumn.② The change trend of frequency of short-duration（1 hour,3 hours and 12 hours） rainstorm events are increased,which 12 hours more significant increasing than others.The biggest increase trend of night and spring is in the Northwestern,and of day and summer in the Southeast.③ The frequency of short-duration（1 hour,3 hours and 12 hours） rainstorm events beginning time shows bimodal,1 hour,3 hours often start at 5：00-8：00,and 12 hours at 11：00-14：00.