Application of a standardized precipitation index for mapping drought severity in an arid climate region, southeastern Iran

Drought is a recurring climate phenomenon causing many environmental and agricultural problems among others. To limit drought consequences, it is essential to monitor drought and implement efficient control measures. The aim of this study is to investigate the application of the Standardized Precipitation Index (SPI) for the 1-, 3-, 6-, 12-, 24-, and 48-month timescales for mapping the drought severity as an effective water management tool in an arid climate region. Calculations of the SPI were performed using historic records of monthly precipitation data of 50 stations over the Sistan and Baluchistan province, southeast of Iran. The majority of the SPI variants showed a moderate to strong spatial correlation with a spherical structure. In 1997, having a higher amount of rainfall, all areas across the province were in a wet or normal condition. In the years with a low rainfall amount (e.g., 2012), the western and southeastern parts of the province have been affected by different degrees of drought especially at the moderate timescales 6 and 12 months. The generated SPI maps identified the most vulnerable regions to drought over the province where government investments should be prioritized for an improved resiliency of the water management infrastructures and for designing a strategic crop management plan with less irrigation water demands.