Characteristic of Extreme Precipitation Events Change in Central North China in Recent 45 Years

Using daily precipitation data of 41 meteorological stations in Central North China from 1961 to 2005 and the extreme precipitation indices developed by WMO/CCL and CLIVAR,the temporal and spatial characteristics of extreme precipitation events change was analyzed.Results show that the annual average maximum daily precipitation presented a decreasing trend in central North China,but the average heavy and extreme rainfall days changed indistinctively;the days and intensity of heavy rainfall increased obviously in the middle and late 1990s';there was a significant drop in rainfall days,especially in the south and southeast region,but no significant change in rainfall intensity.These imply that the proportion of the extreme precipitation events in the total rainfall days increased,and the proportion of extreme precipitation amount in the total annual precipitation might increase also in the period 1961-2005 in the research region.