Spatial distribution characteristics of drought disasters in Hunan Province of China from 1644 to 1911 based on EOF and REOF methods

Under the background of climate warming, drought disasters occur frequently in China, especially in the Central China. In this study, drought disaster grade sequences from 14 representative stations were chosen from 268 years of drought disaster historical data for the Hunan Province of China collected during the Qing Dynasty (1644–1911). The empirical orthogonal function (EOF) and rotated empirical orthogonal function (REOF) methods were used to conduct a spatial characteristics analysis of these drought disasters. The results are as follows. (1) There was an inconsistency between the frequency and intensity of the drought disasters. (2) The spatial distribution of the first four EOF loads for the drought disasters showed regional consistency; however, there was a difference in the anti-phase changes in the east–west, south–north, and central directions. (3) The features of the drought disaster distribution in the Hunan Province during the Qing Dynasty are evident, and according to the high values (absolute value ≥ 0.6) for the first six EOF rotational loads, the study area can be divided into the following sections: northeast Xiang (Section I), west Xiang (Section II), southeast Xiang (Section III), middle Xiang (Section IV), north Xiang (Section V), and southwest Xiang (Section VI). The study of drought disasters in Qing Dynasty is of great significance and reference value for disaster prevention, disaster reduction and climate prediction.