Drought Monitoring of Arjan-Parishan Plain (Study Area of Parishan Lake of Fars Province)

Drought is a phenomenon that has impacted on human life style throughout the history. In recent decades due to global warming and human interferences on natural ecosystems، drought frequency، duration and intensify has increased. In addition to agricultural and water resources degradations، drought impacts economic and social sectors of human societies. The aim of this study is to evaluate the Arjan- Parishan Plain drought phenomenon (study area of Parishan Lake) during a 37-year period، and to examine the impact of drought on lake’s water level. Drought monitoring of 5 stations around the Lake was conducted using 6 drought indices of SPI، CZI، MCZI، ZSI، PN and DI in three time scales of short-term (3 months)، middle-term (12 months) and longterm (48 months). The overall trends of SPI، CZI، MCZI and ZSI were almost similar، and no significant difference was observed between them. The results of monitored droughts by SPI، CZI، MCZI and ZSI in all stations for short term scale showed that severe drought occurrences had less frequencies and durations، while the mild and moderate drought occurrences had more frequencies and durations. By increase of time scale، severe drought occurrences reduced، while its duration increased. The indices of PN and DI، especially in short time scales، reflected quick and intensified changes in humidity.