Variation Characteristics of Extreme Precipitation During Meiyu Flood Period over YangtzeHuaihe Basin in Recent 53 Years
Based on the 53 a (1961-2013) daily precipitation data in Meiyu flood period over YangtzeHuaihe Basin, the threshold of extreme precipitation for each station is defined by percentile method, and the spatial and temporal distribution and mutation features are analyzed. The results show that the 95% thresholds of extreme precipitation are more than 50 mm, and their high value centers are mainly located from eastern Hubei to southern Anhui. The average intensity distribution of extreme precipitation is similar to the distribution of thresholds. Both the extreme precipitation and extreme rainfall days present decreasing features from southern Anhui to its surrounding areas, while the former accounts for about 1/4 to 1/3 of total Meiyu precipitation. In addition, stations of extreme precipitation for each pentad show single peak type with the maximum centered in the 5th pentad of June to the 2nd pentad of July. The extreme precipitation, extreme rainfall days and the extreme precipitation perecntage of the total precipitation in Meiyu period have obvious interannual variability with ascending trends, and the mutations of the extreme precipitation and rainfall stations occur in 1980.