Seasonal differences of variation characteristics of extreme precipitation events over China in the last 50 years.

By using the 1958—2007 daily rainfall data of 419 stations in China,the basic characteristics of seasonal extreme precipitation events over sub-region in China during the last 50 years are investigated.Results show that:(1)Evident zonal distribution and significant seasonal differences are found in the spatial distribution of the climatological extreme precipitation events.The frequency of extreme precipitation events in the south of the Yangtze River is higher in spring and winter.Howerver,the frequency is higher over Southwest China but lower in the east of Northwest China,in annual,summer and autumn cases.(2)The longterm trend of annul extreme precipitation events is similar to that in summer.An increasing trend is also found in North China and Northeast China,but decreasing trends in other regions.(3)The frequencies of extreme precipitation events in different seasons exhibit significant interannual and interdecadal variabilities.The polynomial fitting curves of the time series of annual extreme precipitation events are consistent with that of the summer in most cases,and the variability of extreme precipitation events in other seasons shows great diversity as well as evident seasonal difference.