| Based on the meteorological data such as daily temperature, precipitation, wind speed and relative humidity from 1981 to 2012 at 96 meteorological stations in Shaanxi Province, three daily dynamic drought-monitoring indexes, including percentage of precipitation anomalies (Pa), standardized precipitation index (SPI) and relative moisture index (MI), were calculated for each station. By dividing the whole province geographically into north, central and south Shaanxi, and dividing the seasons into spring (March to May), summer (June to August), autumn (September to November) and winter (December to January), the corresponding drought occurrence frequency of different drought-monitoring indices was calculated and compared with the historical record of actual drought events, so as to analyze the applicability of these drought-monitoring indexes in Shaanxi Province. The result showed that: (1) in summer, the drought occurrence frequency obtained by MI was the highest while that obtained by Pa was the lowest, but in winter, the drought occurrence frequency obtained by MI was the lowest while that obtained by Pa was the highest; (2) Pa was relatively suitable for spring and winter while MI was relatively suitable for summer and autumn; (3) since Shaanxi was prone to strong precipitation in summer but long-term lack of precipitation in autumn and winter, SPI was not suitable for summer, autumn and winter in Shaanxi Province. |