Zahra Rahmati - Master of Natural Resources- desertification, Ilam University
Haji Karimi - Associate Professor and faculty member at College of Agriculture, Ilam University
Marzban Faramarzi - Assistant Professor and faculty member at College of Agriculture, Ilam University
Abdolali Karamshahi - Assistant Professor and faculty member at College of Agriculture, Ilam University

Mehran plain is one of the largest plains of Ilam Province. This plain is located in Iran s western border. Drought is a natural phenomenon that often starts with raining shortage and may affect rivers, soil moisture, groundwater, ecosystems and people’s life. The purpose of this study is to monitor different indicators of drought and determine the most appropriate indicator to monitor drought in Mehran plain. Therefore, we have collected precipitation data during the years 1972-2013 and entered them into the DIP software. After calculating the Standardized Precipitation Index (SPI), Z Score index (ZSI), percent of normal (PN), Chinese Z index (CZI), deciles index (DI) and modified Chinese Z index (MCZI), the results related to each index calculation were transferred to an Excel environment via DIP software. We used the hypothesis called Assay in order to determine the most appropriate index for monitoring drought in the studied region. The results indicated that DI, SPI and CZI indices in the first stage and ZSI and PNI in second stage are appropriate indices to evaluate drought in Mehran plain. Also it became clear that MCZI is an appropriate index to monitor drought in Mehran plain.

Mehran Plain, drought indices, DIP software.