Drought Condition Assessment of Kermanshah Province using StreamflowDrought Index (SDI)
In the midst of extreme events, the drought is occurring gradually and taking its effects during the longer time. Among the drought monitoring methods, Nalbanti proposed SDI method based on the analysis of drought characteristics based upon the volume of the cumulative river. Being easy is of this method’s advantages. This method has been used to analyze the drought characteristics of many countries such as the United States, India, Iran, Iraq, and Greece. The mean of average annual precipitation is 437 mm in Kermanshah province which has been increased in recent years during the humid season and has been decreased during the dry season, for climate changes and temperature increase. The difference in river volume between the humid and dry seasons has led to the drought. This research aims to investigate the continuity and severity of hydrological drought via using Streamflow Drought Index (SDI) based on the 3, 6, 12, 18 and 24-month periods in this province. Daily Dubai data was used from 10 hydrometric stations for a 31-year period (1981-2011) in order to achieve this goal. The result of the river flow index showed that wet years began in 1363 and continued until 1998 at the stations of Totshami, Shah Gozar, Arangharb, Doab, Polchehr, Khers Abad, DuabMerk, and Ghorbaghestan. And the drought began since 1998 at the stations of Totashi, Arangharb, Plochehr, Khers Abad, DuabMerk and Ghorbaghistan and continued till the recent years (2011).