Abstract: Based on the precipitation data at 24 weather stations from 1960 to 2011 in Donting Lake area, the annual precipitation variation was analyzed by methods of a climatic trend rate, a Mann-Kendall test and a wavelet analysis. Annual SPI (standard precipitation index) was calculated by methods of an EOF (empirical orthogonal function) and a REOF (rotated empirical orthogonal function), and the temporal and spatial distributions of drought and flood were discussed. The results show that the annual precipitation increases from south to north on spatial scale in Dongting Lake area, while its trend is not significant on temporal scale. An abrupt change of annual precipitation appears in 1963. There are 6 years, 9 years, and 16-17 years precipitation oscillation cycles in Dongting Lake area. Drought and flood are frequent and extreme weather events are in increasing trends in the study area. The annual precipitation has good consistency on spatial scale, i.e. general drought or flood. But there are also cases in which it is drought in the south and flood in the north and vice verse. There are the south, northwest and middle areas of abnormal climate regions for annual precipitation in Dongting Lake area.

Key words: font-family: "Times New Roman", mso-font-kerning: 1.0pt, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA, Oscillation period')">mso-fareast-font-family: 宋体">Oscillation period, Abrupt change, Drought and flood