Evaluation of Spatial-Temporal Variability of Drought Events in Iran Using Palmer Drought Severity Index and Its Principal Factors (through 1951-2005)

Copyright © 2013 Mojtaba Zoljoodi, Ali Didevarasl. This is an open access article distributed under the Creative Commons Attribu-tion License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Intensity and variability of droughts are considered in Iran during the period 1951 to 2005. Four variables are consid-ered: the Palmer Drought Severity Index (PDSI), the soil moisture, the temperature and the precipitation (products used for the analysis are downloaded from the NCAR website). Link with the climatic index La Nina is also considered (NOAA downloadable products is used). The analysis is based on basic statistical approaches (correlation, linear re-gressions and Principal Component Analysis). The analysis shows that PDSI is highly correlated to the soil moisture and poorly correlated to the other variables—although the temperature in the warm season shows high correlation to the PDSI and that a severe drought was experienced during 1999-2002 in the country