Spatio-temporal Characteristics of Droughts and Drought Trends in Qazvin Province of Iran

A study has been carried out to characterize the spatial patterns of droughts with different time scales as well as their trends in Qazvin province of Iran where droughts are recurrent phenomena. Thirty-five years (1971-2004) monthly rainfall data recorded at twenty rainfall stations are used for the study. Standardized precipitation index is used for the reconstruction of drought events from rainfall data in order to characterize the spatial and temporal distributions of droughts. A non-parametric trend test known as Mann-Kendall test is used to analysis the changes in rainfall and drought events. The results show that the north especially northwest part of the provinces most prone to droughts with different time spans and severities. Trend analysis shows significant changes in rainfall and droughts only in few stations sporadically distributed over the study area. It is expected that the study will be helpful in drought mitigation and adaptation planning in the area.

GIS, Iran, standardized precipitation index, spatio-temporal pattern, trend analysis