The effect of several climatic signals on rainfall features using factor analysis and multivariate regression methods (Case of Hamadan province, Iran)

In this study, the effects of 16 selected climatic signals on several rainfall features including maximum and the frequency of one, two, three-days rainfall and the total monthly amount in Hamadan province, Iran was evaluated using the factor analysis and multivariate regression methods. Rainfall data of raingauges, synoptic and climatology stations during the period of 1977-2013 were collected. The statistical periods of 1977-2002, and 2003-2013 were selected as the calibration and validation periods, respectively. The results showed the most significant effect of climatic signals in October, November, December, February, April and May. In autumn, among the study signals, the effect of climatic signals MEI, NINO4, NINO3.4, NINO3, NINO1 + 2 and ONI on selected rainfall features were more significant than others. Also, the findings revealed that maximum rainfall of 1, 2, 3 days, and the frequency of 1 and 2 rainy days, have the highest correlation with MEI, NINO4, NINO3.4, NINO3, NINO1 + 2 and ONI, climatic signals.