Studying drought indices in Kurdistan province and comparing with trend of dry farming wheat

Droughts are the clear signs of disorder and changes in parameters of meteorology such as rain and temperature which are observed in most parts of tropical and semitropical regions of the world within years. Aspect of climatology all parts of the world exposure dearth and drought and due to geographical situation and climatic. Conditions of Iran, drought has been one of the main threats for its people and civilizations during history.Kurdistan province is considered most rain full areas and isranked in high in dry farming specially wheat in the country.But within years dearth and droughts have been occurred in these provinces and provided damages for farmers.In this research drought in Kurdistan province was studied and indices in farming year range in comparing dry farming wheat were evaluated. For this reason, 3 drought indices such as SPI, PN and standard deviation of rain for a 25 year period in were used in the next stage the trend of wheat dry farming in both provinces during a 25 year period and the results of drought, indices were combined. According to results of ANOVA based on 3 methods to determined drought in province, indices SPI with the highest correlation coefficient with trend of dry farming wheat and the best significant level as the best drought indices was selected in comparing with PN method. Also three droughts occurred in both provinces which during 2007-2008 its degree was high intense and during years 1998-99 and 1999-2000 their degrees were in intense and medium.