Comparison the Suitability of SPI, PNI and DI Drought Index in Kahurestan Watershed (Hormozgan Province/South of Iran)

Abstract

Drought is a climatic anomaly, characterized by shortage (lack) of rainfall, high evaporation and unsuitable distribution of rainfall. This study investigated and compared the Standardized  Precipitation Index (SPI),Percent Normal Precipitation Index(PNPI) and Deciles Index (DI) indices for drought monitoring in Kahurestan watershed in Hormozgan province in south of Iran. In this study, rainfall data of five stations including Kahurestan ,Tedrouye, Dezhgan, Ghalat  and Shahgeyb were selected from 1985 to 2010 (26 years). The SPI, PNPI and DI are compared in different stations. Then, Assessment of the suitability of drought index was performed with rainfall minimal symmetry test in the study area. Results shows that PNI index due to determine the frequency of droughts and also, accurate showing of drought years with different severities, it is categorized in the first place and DI and SPI are categorized in next place, respectively.

Keywords: Drought, Standardized Precipitation Index (SPI), Percent Normal Precipitation Index (PNPI), Deciles Index (DI), Kahurestan, Hormozgan, Iran