Spatio-Temporal Analysis of Drought Vulnerability using the Standardized Precipitation Index (Case study: Semnan Province, Iran)

Document Type: Research Paper

Authors

1 Associate Professor, International Desert Research Center, University of Tehran, Tehran, Iran

2 Ph.D. Student, Faculty of Natural Resources, University of Tehran, Karaj, Iran

3 Assistant Professor, International Desert Research Center, University of Tehran, Tehran, Iran

4 MSc. Graduate, Faculty of Natural Resources, University of Tehran, Karaj, Iran

Abstract

This study was conducted to identify drought event and its emerging regions in Markazi desert, Iran with focus on
Semnan province in a 30 years statistical period. In this research, 61 stations having adequate data selected and used
after extracting annual statistic from monthly and daily data. Standardized precipitation index values for each station
were calculated and classified. The Results have shown that there was drought condition in 17 studied stations. Also
among 44 stations with no drought condition, there was one humid year in 20 cases. Khareh sarlazor station has the
first position of drought and humid condition among other stations, with 10 drought years and 5 humid years. The
number of common years with normal condition is 3 years and the most extensive drought in 1999 has occurred in 10
dry stations and 1 very dry station. The existence of common trend of variation using study of correlation among
stations has resulted in determination of 7 groups which these results can be useful according to temporal distance of
one or two years in appearing drought in the same group of stations.

Keywords