بررسي آماري خشكسالي استان اصفهان

The Statistical Study of Isfahan Province Drought

Isfahan Province is located in the arid zone of centeral Iran; so the fluctuation of rainfall is very high in these areas. Meteorological Drought occurs when precipitation is below a threshold level and an important area of the region is affected, and occurEnce of this phenomenon has three main characteristics:Frequency,duration and extent. In this article, by comparison of different statistical indicies, index of drought(percent of long term mean rainfall) has been used, features of drought occurence in a 32 years period( 1972-2004) for 14 synoptic stations of province has been analyzed. The intensity of drought determined, and for selection of the best distribution X-square test and correlation have been used.On the basis of selected distribution, the forecasting of drought for return periods of 10, 20, 50 and 100 years accounted. The results of this study indicated that drought is one of the main features of the province, and there is a high negative fluctuation in rainfall amounts.