Comparison of SIAP, PN and RAI Index for Surveying of Droughts in Khouzestan Province Emphasizing The Abadan and Dezful Stations

With regards to natural disasters that have occurred in the past decades which have affected human beings¡ the number and Frequency of drought phenomenon has proven to be the worst by far. In order to convert and consider the drought phenomenon in a quantitative manner, various indices are available. The following research uses and studies SIAP (Standard Index Annual precipitation), PN (Percent of Normal) and RAI (Rainfall Anomaly Index) in 2 synoptic stations in Abadan and Dezful with in a statistical period of 45 years (1961-2005).Results obtained reveals that drought frequency and duration with various degrees was shown greater in Abadan than Dezful. According to the SIAP and RAI indices intensive drought frequency in Dezful more than Abadan and only in PN index intensive drought frequency in Abadan station more than Dezful. also in three mentioned indices the most intensive drought in 1964 occurred at Dezful station and in 1964¡1973 and 2005 at Abadan station.