Regional Hydrological Drought Monitoring Using Empirical Orthogonal Functions (EOF-SDI)

Having Drought quantification is a decision-making approach for water resources planners and managers. Calculating a drought index in the measured grid-points of a given region is as the pre-requisite for regionalization process of drought by these methods. The aim of this study is the regional analysis of the streamflow drought using the multivariate technique of principal components analysis (PCA). To this end, the streamflow drought Index (SDI) was calculated in the seven hydrometric stations of Sefid-Rud basin, Iran for the period 1984-2013 in different time scale using PCA technique summarizing the SDI series of all stations into a new series so called the Multivariate Streamflow Drought Index (MSDI). Results showed a relatively high correlations between the SDI series of the stations for a given time scales. MSDI’s series at multiple time scales follow all stations SDI fluctuations and appropriately monitor droughts occurred in the region especially in long dry periods.

Keywords:

Hydrological Drought , PCA , Streamflow , Regional Analysis , Iran