پایش وضعیت اقلیمی استان تهران با استفاده از شاخص‌های ارزیابی خشکسالی

Monitoring system is a prerequisite for drought-response schemes, which time has a crucial role to play in its functionality and performance. One of the important issues in drought studies and monitoring is using of indicators which they can assess the severity, duration and magnitude of drought in one region. In this study, information of eight synoptic stations of Tehran province in order to monitor drought status during 18 years period (1996-2014) is used. In this regard, by using meteorological drought methods such as percent of normal precipitation (PNPI), standardized method index (Z), deciles index (DI) and SIAP indicator was analyzed. Also minimum amount of precipitation method was used to select appropriate indicators. Results revealed that most stations except Firoozkooh, at the same time that other stations fitted to minimum amount of rainfall, drought and severe drought was under normal condition too. The most severe drought in the months of June, July, August and September occurred and in most cases can not be used to determine the unique identifier. Most Z (wet 1.54) was for Abali station in March and the most severe drought (-1.62) has been allocated to Firoozkooh station in September. Zoning also showed the severity of the drought in southern regions is more than other regions.