Numerical comparison of RAI and PNPI meteorological indices in order to assess and quantify the drought situation in Khuzestan province

Number and frequency of drought are more than other natural disasters that have influenced human societies in recent decades. Drought is a kind of natural disaster which is formed and extended smoothly and in a crawling way in comparison with natural hazards like heavy precipitations and floodwaters. There are different and numerous indicators for quantitative expression of drought. Percentage Indicators of normal precipitation (PNPI) and precipitation abnormality (RAI) status and continuation of drought in 8 stations of Abadan, Ahvaz, Bandar-e Mahshahr, Bostan, Masjed Soleyman, Omidieh, Ramhormoz and Safi Abad in Khuzestan province during the statistical period (1990-2014) have been considered in this research. Results represented that based on PNPI indicator, the most severe drought happened during period 1990-2014 in Bandar- e Mahshahr station with the amount of 20.39 in 2010. Also, the most severe wet period happened in Ahvaz station with the amount of 216.33 in 1997, based on PNPI indicator. Also, based on RAI indicator, the most severe drought happened in Bandar- e Mahshahr with the amount of 6.26 in 2010 during the period 1990-2014. Based on RAI indicator, the most amount of wet period occurred in Ahvaz station with the amount of 8.6 in 1997.