Abstract:Based on the daily temperature and precipitation data at 78 stations of Anhui Province during 1961-2008, this paper adopts a cumulative frequency method to correct the threshold of five drought indexes, and then uses the corrected indexes to analyze the drought features of the interannual variability, seasonal evolution and spatial distribution etc. in Anhui Province. The results show that the changing trends of the sum of drought days calculated in terms of drought process are basically consistent; the years with many drought days are in accordance with the typical drought years in history of Anhui Province; the seasonal changes of Z and SPI indexes are not obvious, but those of Pa, MI and CI indexes are not only obvious but also consistent; the drought in autumn ranks first, in summer second and in winter and spring least; the spatial distributions of Z and SPI indexes are not obvious, but those of Pa, MI and CI indexes are consistent and in zonal patterns; the frequency of drought descends from north to south. As to the drought monitoring in Anhui Province, the CI index is the optimum among the five drought indexes.