%0 Journal Article %T Impacts of Large-Scale Climate Signals on Seasonal Rainfall in the Maharlu - Bakhtegan Watershed %J Journal of Range and Watershed Managment %I University of Tehran %Z 5044-2008 %A choubin, bahram %A KHalighi Sigaroodi, SHahram %A Malekian, Arash %D 2016 %\ 05/21/2016 %V 69 %N 1 %P 51-63 %! Impacts of Large-Scale Climate Signals on Seasonal Rainfall in the Maharlu - Bakhtegan Watershed %K Seasonal Rainfall %K Principal component analysis %K Maharlu - Bakhtegan watershed %K Large-scale climate signals %K Cross- correlation %R 10.22059/jrwm.2016.61733 %X Predicting climate trends, especially forecasting rainfall, provides managers of different fields withsuitable tools so that considering these predictions; they can devise future-state policies. At thisstudy, after selecting the most effective climate indices applying PCA method, the effects of largescaleclimate signals in seasonal rainfall of basin Maharlu - Bakhtegan were investigated bothsimultaneously and by delay through statistical methods (Pearson correlation and cross-correlationcoefficient) and by applying stepwise regression model, regression equation for forecasting rainfallwas offered. The results showed that in cross-correlation between the time series of SPI (dependentvariable) at time (t) and climate signals (independent variable) at time (t-k), only SOI indexconcurrently has a significant relationship with rainfall, whereas, most of indices turned significantwith standardized precipitation index with different lag times. In season to season study of thesignals with the standard precipitation index using Pearson's correlation coefficient it was found thatclimate signals of spring and summer are not significantly correlated with SPI. Representationcoefficients (R2) and standardized regression effect (Beta) in stepwise regression model showed thatsimultaneous and with season to season delays signals (for example: SPI index of autumn with fourprevious seasons indexes) at method Pearson correlation have higher relationship with seasonalstandardized precipitation index than the cross-correlation in time (t-k), (which signals of allseasons given is delay together with than SPI of all seasons) show. %U https://jrwm.ut.ac.ir/article_61733_13aa7dc302492d19f90b4eb3f2474892.pdf