Seasonal streamflow forecasting in South America’s largest rivers
Ingrid Petry, Fernando Mainardi Fan, Vinícius Alencar Siqueira, Walter Collishonn, Rodrigo Cauduro Dias de Paiva, Erik Quedi, Cléber Henrique de Araújo Gama, Reinaldo Silveira, Camila S. Freitas, Cássia Silmara Aver Paranhos
Abstract
South America large basins (>5000 km²) This work represents a first assessment of seasonal streamflow forecasts in South America based on a continental-scale application of a large scale hydrologic-hydrodynamic model and ECMWF's seasonal forecasting system precipitation forecasts (SEAS5-SSF) with bias correction. Seasonal streamflow forecasts were evaluated against a reference model run. Forecast skill was estimated relative to the Ensemble Streamflow Prediction (ESP) method. We observed that bias correction was essential to obtain positive skill of SEAS5-SSF over ESP, which remained a hard to beat benchmark, especially in regions with high seasonality, and highly dependent on initial conditions. SEAS5-SSF skill was found to be dependent on initialization month, basin and lead time. Rivers where the skill is higher were Amazon, Araguaia, Tocantins and Paraná.