Seasonal Streamflow Forecast in the Tocantins River Basin, Brazil: An Evaluation of ECMWF-SEAS5 with Multiple Conceptual Hydrological Models

The assessment of seasonal streamflow forecasting is essential for appropriate water resource management. A suitable system requires the evaluation both numerical weather prediction (NWP) and hydrological models to represent atmospheric processes conditions in a specific region. In this paper, we evaluated ECMWF-SEAS5 precipitation product with four forecasts performed at hydropower plants Legal Amazon adopted included GR4J, HYMOD, HBV, SMAP, which were calibrated on daily scale period from 2014 2019 validated 2005 2013. obtained 2017 by considering simulation comprising an ensemble 51 members forecasts, starting first day every month up 7 months ahead. For each forecast, corresponding monthly time series was estimated. post-processing procedure based adjustment autoregressive model residuals applied correct bias forecasts. Hence, calibration validation period, results show that HBV provides better plant, presenting NSE NSElog values greater than 0.8 0.9, respectively, during stage. However, SMAP achieves performance 0.5 raw addition, correction displayed significant improvement all models, specifically representation dry periods, significantly reducing variability residuals.