Spatio-temporal characteristics of extreme precipitation in East China from 1961 to 2015

Using daily precipitation data from 344 meteorological stations, the temporal and spatial variations and trends of precipitation extremes were analyzed, and the frequency distribution of extreme precipitation and the differences between urban and rural stations were also investigated over East China during 1961-2015. Ten extreme precipitation indices from R-language Climate Index (RClimDex) were selected and the change characteristics were examined using the methods of trend analysis, Mann-Kendall (M-K) test, and spatial analysis module of ArcGIS 10.2.1. Results indicated that almost all of the regional precipitation indices related to the frequency or intensity of precipitation extremes had increasing trends in the past 55 years, with the indices of Rx1day, Rx5day, R95p, R99P, SDII and R25mm increasing significantly. Spatially, the distribution of precipitation extremes had obvious regional differences. The increase of PRCPTOT, SDII, R95p, R20mm and R25mm were observed mainly in the southern and middle parts of East China, though most of the trends were statistically insignificant. For CWD, a decreasing trend was dominant over almost all study area. There were also prominent differences of precipitation extremes between urban and suburban stations. Urbanization had generally accelerated the increasing rate for heavy precipitation days, extreme precipitation amount and precipitation intensity in East China. More detailed studies are needed to fully understand the changes in extreme precipitation and its relationship with other factors, including urbanization.