Relationship of Drought and Teleconnection Patterns; Case Study of Qara-Qom Basin

Abstract

Aims & Backgrounds: Drought is a natural feature of an area and in every region that occurs, it leads to economic, social and environmental losses. In this research, the Teleconnection patterns in drought occurrence in Qara-Qom basin has been investigated. Methodology: In this regard, precipitation data of 30 rain gauge and synoptic stations as well as data on 32 numerical indexes of teleconnection from NOAA site during the 1987-2013 period were obtained. Initially, the standardized precipitation index data in the 9 to 48-month scale were classified by Factor Analysis and stations with similar behavior were identified in the study area. Then, the relationship between the average drought index of each area with each of the Teleconnection patterns was evaluated simultaneously and with a delay of 6 and 9 months through the correlation statistical method. Findings: The effects of Teleconnection patterns on drought vary in different zones. The Multivariate ENSO Index, Pacific Decadal Oscillation, Southern Oscillation Index, Nino 3/4, 3 has the most significant correlation with the standardized precipitation index scales. Also, the correlation with 6-month delayed drought index indicated that four factors (total basin), drought index with nino 4 indexes, 3/4 and 3, multivariate ENSO, Madden Julian oscillation in regions 20, 70, 80, 100 degrees East direct relationship, and With East Pacific- North Pacific index, the southern oscillation and Madden Julian in the regions of 160 ° East, 120 ° and 40 ° West has a significant negative relationship. Four factors (total basin stations): The 9-month delayed drought index showed a significant negative correlation with the East Pacific- North Pacific index, southern oscillation and Mandden Julian fluctuations in the regions 120 and 40 degrees west, and with the Nino 3 indicator, the multivariate ENSO And the fluctuations of Madden Julian in the regions of 70, 80 and 100 degrees east has a significant direct relationship. Conclusion: The results of correlation analysis showed that there is a significant relationship between Teleconnection patterns and droughts in Qara-Qom basin.