Drought in Gorgan Synoptic Station. Estimation and Analysing

Subject Areas : Urban and Regional Planning Studies

Hossein  Mohammadi ¹ (دانشیار گروه آموزشی جغرافیای طبیعی، دانشکدۀ جغرافیا، دانشگاه تهران)
Mohsen  Soltani ² (دانشجویان کارشناسی ارشد اقلیم شناسی، دانشکده جغرافیا، دانشگاه تهران)
Ali  Hanafi ³ (دانشجویان کارشناسی ارشد اقلیمشناسی، دانشکده جغرافیا، دانشگاه تهران)

Received: 2007-04-03 Accepted : 2007-09-16 Published : 2008-02-20

Keywords: drought, deciles, precipitation analysing, standard distribution, percentage normal,

Abstract :

Drought is the most important kinds of natural hazards and it is a secret and slow phenomena which results from climate processes. The intensity and frequency of it depends on geographical position. it occurs due to decrease of raining rate once at several years. In order to study of Gorgan station droughts we used from Meteorological organization data for a period (1976-2005).After primary investigation, drought was analysed by using of standard distribution, Percentage Normal and Deciles, so that it was extracted the weak and intermediate droughts and its trend on station. Results showed that 85-95 decades were the driest decade in statistical duration and according to used indexes, the year of 1990 had the severest drought value.