Title Assimilation of PSO and SVR into an improved ARIMA model for monthly precipitation forecasting Type of Research Article Keywords Improved ARIMA, Monthly, SVR, IARIMA-C-PSO, RPD Abstract Assimilation of PSO and SVR into an improved ARIMA model for monthly precipitation forecasting Researchers Laleh Parviz (First Researcher)، Mansour Ghorbanpour (Second Researcher)