Spatial and temporal variation of drought in Sichuan Province, China based on SPEI analysis

Drought variation is of great significance to agricultural production and social stability. Meteorological data during 1965-2019 in Sichuan Province was used. Drought variation was explored based on standardised precipitation evapotranspiration index (SPEI), drought frequency, and drought station ratio. The results showed that SPEI totally increased over time. Moderate drought was most severe, occurring in February-April. Mild drought was prevalent in January, November, and December. SPEI decreased from northeast to southwest. From southeast to northwest, the SPEI tendency rate increased gradually. Average drought frequency was 31.86%. Mild, moderate, severe, and extreme drought frequency was 14.89%, 10.86%, 4.34%, and 1.77%, respectively. Drought station ratio decreased over time. There were 20, 16, 9, and 2 events of local, partial regional, regional, and panregional drought, respectively. The results of this study provide a reference for drought prevention in Sichuan Province.