Evaluation of the Wheat Agricultural Drought Return Period in the Province of Fars Using RDI Index

Subject Areas : Subjects

H. زندی لک ¹ (دانش آموخته‌ی کارشناسی ارشد آبیاری و زهکشی، دانشگاه آزاد اسلامی، واحد مرودشت)
H. فولادمند ² (دانشیار گروه آبیاری و زهکشی، دانشگاه آزاد اسلامی، واحد مرودشت)
F. بوستانی ³ (استادیار دانشگاه آزاد اسلامی، واحد علوم و تحقیقات فارس)

Received: 2014-10-01 Accepted : 2014-10-01 Published : 2014-11-22

Keywords: Agricultural drought, evapotranspiration, Province of Fars, Reconnaissance Drought Index (RDI), return period,

Abstract :

Drought is a natural phenomenon with high frequency in arid and semi-arid regions of Iran, especially in the Province of Fars. Monitoring and evaluation of drought is a basic need for agriculture and water resources management to reduce its adverse effects. Reconnaissance drought index (RDI) is one of the agricultural drought indices used to categorize drought intensity. In this study, agricultural drought return period for wheat for the Province of Fars was assessed based on RDI. Twelve synoptic weather stations, with the minimum of 10 years data were selected for this purpose. Evapotranspiration was calculated based on the Penman-Monteith method, and the drought intensityof normalized and standardized RDI for each year was calculated. The results showed that the most severe drought in the Province of Fars occurred in the 2007-2008 hydrological year. After classifying the wheat drought intensity, the results indicated that the normal drought was the most prevalent in all of the selected stations. Also, zoning maps of wheat drought with the return periods of 2, 5, 10, 25 and 50 years were prepared for the Province of Fars. The results showed that the wheat agricultural drought for the Province of Fars is normal in the return periods of 2 and 5 years; however, it was different for the frequency of 10, 25 and 50 years.