Assessment of drought hazard impact on wheat cultivation using standardized precipitation index in Iran

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ORIGINAL PAPER

Assessment of drought hazard impact on wheat cultivation using standardized precipitation index in Iran Mohammad Reza Mansouri Daneshvar & Ali Bagherzadeh & Mahmood Khosravi

Received: 8 June 2012 / Accepted: 16 September 2012 # Saudi Society for Geosciences 2012

Abstract The assessment of drought hazard impacts on wheat cultivation as a strategic crop in Iran is essential for making mitigation plans to reduce the impact of drought. Standardized precipitation index has gained importance in recent years as a potential drought indicator and is being used more frequently for assessment of drought hazard in many countries. In the present study, the calculated standardized precipitation index for 48 stations dataset in the 30-year time scale fulfilled 30 statistical matrices. The drought hazard index map was produced by sum overlaying the spatial representations of 30 statistical matrices and categorized into four levels of low, moderate, high, and very high, which demonstrated probability of drought occurrences of 10–20 %, 20–30 %, 30–40 %, and 40–50 %, respectively. Finally, after the general division of zonal statistics in

M. R. Mansouri Daneshvar Department of Physical Geography and Climatology, University of Sistan and Baluchestan, Zahedan, Iran M. R. Mansouri Daneshvar (*) Department of Geography, Mashhad Branch, Islamic Azad University, Mashhad, Iran e-mail: [email protected] A. Bagherzadeh Department of Agriculture, Mashhad Branch, Islamic Azad University, Mashhad, Iran e-mail: [email protected] M. Khosravi Department of Physical Geography and Climatology, University of Sistan and Baluchestan, Zahedan, Iran e-mail: [email protected]

drought hazard index map of Iran, major drought hazard zones were geographically classified into five zones. The statistical analysis showed a significant correlation (R2 0 0.701 to 0.648) between drought occurrences and wheat cultivation including surface area and total production for these drought hazard zones. Keywords Drought hazard index (DHI) . Standard precipitation index (SPI) . Wheat cultivation . Geographical information system (GIS)

Introduction Drought is a very important and complex phenomenon that significantly impacts agriculture in various territories and especially in arid and semi-arid regions. Drought events are usually explained by drought indicators, as variables that identify drought characteristics, i.e., the magnitude, duration, severity, and spatial extent. In addition, over the years, several indices have been proposed to detect and monitor droughts. Drought indices are used to investigate occurrence and extent of drought events. Many metrological drought indices have been developed, including Palmer Drought Severity Index (Palmer 1965), the Drought Severity Index (Phillips and McGregor 1998), and the Standardized Precipitation Index (SPI) (McKee et al. 1993). One of the well-known meteorological drought indices is the SPI, which is based on the long-term precipitation record for a desired period. The SPI is fitted to a