Abstract
In this study, we aimed to investigate the hydrological performance of three gridded precipitation products-CHIRPS, RFE, and TRMM3B42V7-in monthly streamflow forecasting. After statistical evaluation, two monthly streamflow forecasting models-support vector machine (SVM) and artificial neural network (ANN)-were developed using the monthly temporal resolution data derived from these products. The hydrological performance of the developed forecasting models was then evaluated using several statistical indices, including NSE, MAE, RMSE, and R-2. The performance measures confirmed that the CHIRPS product has superior performance compared to RFE 2.0 and TRMM data, and it could provide reliable rainfall estimates for use as input in forecasting models. Likewise, the results of the forecasting models confirmed that the ANN and SVM both achieved acceptable levels of accuracy for forecasting streamflow; however, the ANN model was superior (R-2 = 0.898-0.735) to the SVM (R-2 = 0.742-0.635) in both the training and testing periods.