Analysis of the Characteristics of Short-Term Extreme Precipitation in China in the Last 30 Years
Because of the limitations of observational data,only very few studies have investigated the characteristics and thresholds of short-term extreme precipitation below the daily scale in the past.Based on the hourly precipitation data during 1991-2021 from 2464 stations in China,which is newly developed by China Meteorological Administration,this paper analyzes the frequency characteristics of the 1-h and 3-h precipitation in China,uses the percentile method to count the 1-h and 3-h extreme precipitation thresholds,and explores the climatic characteristics of short-term extreme precipitations in China.The analysis results show that the hourly precipitation frequency is relatively high(up to 12%)at some stations in Sichuan,Guizhou,Hunan,Jiangxi,Fujian,and Zhejiang provinces and is generally low(less than 3%)at most stations in Northwest China.From 1991 to 2021,the frequency of 1-h and 3-h extreme precipitation shows a decreasing trend.Among the stations,64.7%demonstrate linear trends for the 3-h extreme precipitation frequency,which is in phase with that of the 1-h extreme precipitation frequency.The spatial characteristics of extreme precipitation and the extreme precipitation threshold in China are obvious.The extreme precipitation threshold of the 1-h precipitation shows large spatial characteristics in Southeast China and small in Northwest China.Compared with other regions in China,Guangdong,Guangxi,and Hainan have larger thresholds.The historical average extreme value for the 1-h precipitation in Hainan,Guangdong,Guangxi,and Jiangsu provinces exceeds 80 mm h-1,with Hainan province exhibiting the highest average extreme value,reaching 102.7 mmh-1.