Abstract: Using 1960-2009 daily precipitation data of 89 stations, the spatio-temporal distribution of extreme rainstorm events in Hunan Province in recent 50 years is analysed by linear regression, abrupt change analysis and wavelet analysis. The results showed that the intensity and frequency of rainstorm events increased in the last 60 years. Extreme rainstorm events showed a wave-increase: low in the 1960s and 1980s whereas high in the 1970s and 1990s. A abrupt change (from dry to wet) can be observed from the late 1980s to early 1990s. In addition, the extreme rainstorms also occurred in cycles of 2-year, 5-year, 7-year, and 21-years. Generally, the numbers of rainstorms and the associated precipitation of May to August are significantly higher than the average. Precipitation of the western Hunan shows a decreasing trend, while that of the northern and central Hunan is increasing. The eastern and southern Hunan may become much drier. Extreme rainstorm shows a increasing trend, while that of the southwestern, northwestern and central Hunan shows a decreasing trend.

Key words: extreme rainstorm events, Hunan Province, regional difference, spatio-temporal characteristics